Análise do desempenho físico-mecânico de painéis compensados de Pinus sp. produzidos com adesivos aquosos a base de poliacetato de vinila e de homopolímero vinílico

This study aimed to evaluate the physico-mechanical performance of three PVA adhesive formulations according to the Brazilian standards for plywood testing and to evaluate the results with those presented in the technical literature and specified in normative documents. The study presents the production process of the panels, the obtaining of samples and, finally, the implementation of physico-mechanical characterization tests based on plywood Brazilian standards. For the panels production it was used a gramature of 120 g / m² and applied a pressure of 15 bars and two temperature combinations and pressing time for each adhesive. The commercial adhesives used were PVA 1810, PVA 1060 and Vinyltec 239. The physical tests conducted were thickness swelling, density, moisture content and water absorption. The mechanical tests were static flexion, for the determination of elasticity modulus (MOE) and rupture modulus (MOR), and shear in the glue line. Among the three formulations studied none showed good performance in the presence of water. However, other trials in the adhesive showed better results and closer to the commercially equivalent used, in the case the urea-formaldehyde, was the PVA 1810, that can be applied in non-structural uses and in environments without the presence of moisture

Concentração de tensões em peças e componentes estruturais - uma abordagem através do método dos elementos finitos

Any failure process that may occur in a part probably is located where the stress exceeded the level of resistance. When a part or component has a sharp change in geometry, such as slots, holes, grooves, bumps or other irregularities, there is an increased concentration of stress at a specific location of the part. The objective of this study is to determine the maximum stresses in structural parts and components using the equations of elasticity theory in conjunction with the stress concentration factor experiment and compare them with results obtained by finite element method

Preparação e caracterização da casca de banana prata particulada para aplicação com reforço em compósito de matriz de PEAD

The waste, exaggerated and incorrect disposal of biomass are common practices in modern times where everything is disposable. However the growing concern with the nature and the environment compel man to give nobler destinations for these products through sustainability and recycling of waste. Banana peel is a residual biomass, which is not consumed. It generates tons of waste per week in São Paulo city. This trash is disposed in dumps and landfills, which could be reduced by using it as reinforcement in natural composites. The high density polyethylene (HDPE) is a polymer derived from the ethylene polymerization and is easily recycled. Which makes it a sustainable material. In the present work characteristics of the natural composite composed with banana peel and high-density polyethylene were studied. It was noted that removing the lignin present in the banana peel, the fiber introduces a significant improvement in thermal resistance. The preparation of composite was made with a ratio of 5% and 10% of reinforcement in comparison with polymeric matrix mass. Composites were thermally, mechanically and microscopically characterized. The addition of fiber in the polymer increased the mechanical strength of the composite. The fiber surface treatment with distilled water removed the amorphous material present in the fibers, improving significantly thermal stability and increasing crystallinity of the celullose. The addition of 5% fiber in mass to the polymer increased significantly the tensile strength and elasticity modulus for the composite. With 10% of fiber addiction there were also an improvement when compared with pure HDPE, but when compared with 5% composite the mechanical properties are slightly lower. This may be due to the fiber particle size, which are small and eventually become a hub of tension ... (Complete abstract click electronic access below)

Síntese e caracterização de hidrogéis de amido retrogradado e goma gelana utilizados como matriz em sistemas de liberação cólon específica de fármacos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da adição de CGTase e β-ciclodextrina na qualidade e taxa de envelhecimento de pães

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

Colágeno: caracteristicas químicas e propriedades funcionais

Many types of food contain ingredients or bioactive compounds that provide health benefits. The collagen is a fibrous protein found in the connective tissue of the body, and it plays a part in the tissues resistance and elasticity. Due to their functional characteristics, this protein has been added into foods in order to achieve therapeutic effects. This paper aimed at showing how the collagen formation occurs, and the beneficial effects of this compound in the organism as well as its characteristics, properties and applications in food.

Confecção e avaliação de chapas de madeira aglomerada com aproveitamento de resíduos de marcenaria industrial

Pós-graduação em Engenharia Civil - FEIS

Estudo da influência da adição de resíduos de óleo em concretos para aplicação em pavimentos

Pós-graduação em Engenharia Civil - FEIS

Estabilidade do fator de von Willebrand e fator VIII no crioprecipitado canino em diferentes protocolos de armazenamento

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

Concreto com adição de cinza de bagaço de cana-de-açúcar

Pós-graduação em Engenharia Civil - FEIS

Residues of different gel formulations on dentinal walls: a SEM/EDS analysis

The aim of this study was to evaluate the presence of residues of sodium hypo-chlorite gel, chlorhexidine gel, and EDTA gel on dentina l walls after canal preparat ion throughchemical SEM- elemental chemical microanal ys is (EDS) analysis. Forty-eight single-rootedteeth were selected. They had their crowns sectioned and were instrumented with a reciprocat-ing system. The canals were irrigated with 5 mL of saline solution during root canal preparation.After instrumentation, the root canals were irrigated with 3 mL 17% EDTA followed by 1 min ofultrasonic passive activation (33 20 sec) to remove the smear layer, and then irrigated with3 mL of saline solution. The specimens were randomized into three groups (n 5 12) accord ing tothe chemical substance that filled the root canal for 30 min: GI: 5.5% sodium hypochlorite gel;GII: 2% chlorhexidine gel; GIII: 24% EDTA gel; Negative c ontrol group: no substance was used.Then, the root canals were irrigated with 6 mL of saline solution followed by 1 min of ultrasonicpassive activation (33 20 sec). After ultrasonic activation , the canals were irrigated with 2 mLsaline. The roots were sect ioned, and the perce ntage of each chemical element present in thesamples was analyzed through chemi cal SEM-EDS microanalysis. All expe rimental groupsshowed a significantly higher percentage of chemical elements (Na and/or Cl) than the controlgroup (P < 0.03). This in vitro study has shown that, regardless of chemical solutions used evenafter the final irrigation protocol, chemical residues of d ifferent substances remained attached tothe r oot c anal wa lls. Microsc. Res. Tech. 78:495–49 9, 2015.

Regulação da temperatura corporal em diferentes estados térmicos: ênfase na anapirexia

Temperature is certainly one of the major factors that affect biochemical and physiological processes. So, the investigation of how animals regulate body temperature (Tb) and respond to changes in ambient temperature is indispensable. There are five thermal states defined up to date that include euthermy, hypo and hyperthermia (forced fall and increase of Tb, respectively), fever and anapyrexia (regulated increase and fall of Tb, respectively). In this review, we present some classic and recent data about thermoregulatory mechanisms involved in those thermal states with special attention directed to anapyrexia, a phenomenon that has attracted the interest of researchers due to its potential therapeutic benefits.

Ultrassonografia de glândulas genitais acessórias em carneiros da raça Dorper: caracterização e correlações reprodutivas

Pós-graduação em Medicina Veterinária - FCAV