Alexandre Florian da Costa

Essential Oil of Piper xylosteoides (Kunth) Steud. from Federal District, Brazil

Abstract The essential oil from Piper xylosteoides leaves from Federal District was isolated by hydrodistillation and analyzed by a combination of gas chromatography and gas chromatography/mass spectrometry. Piper xylosteoides oil was found to contain a high oil yield (1.8% on dry weight basis). The oil obtained was characterized by being rich in myrcene (31%) and γ-terpinene (26%).

Resistência natural de seis espécies de madeiras da região amazônica a fungos apodrecedores, em ensaios de laboratório.

This study evaluated the natural resistance of six Amazonian wood species: Aspidosperma desmanthum (Araracanga) , Parinari excelsa (Parinari) , Mouriri callocarpa (Mirauba) , Marmaroxylon racemosum (Angelim-rajado) , Peltogyne paniculata (Roxinho) e Astronium sp. (Muiracatiara) against Pycnoporus sanguineous , a white rot fungus, and Gloeophyllum trabeum , a brown rot fungus. Testing was performed based on the American Society for Testing and Materials - Standard Method for Accelerated Laboratory Test of Natural Decay Resistance of Woods - ASTM D2017/81(86). Results showed that all tested wood species were classified as very resistant to both decay fungi, except the wood of Aspidosperma desmanthum , which demonstrated to be very resistant to Pycnoporus sanguineous and resistant to Gloeophyllum trabeum . The wood of Peltogyne paniculata showed the best performance against Pycnoporus sanguineous , whereas the wood of Astronium sp. presented the best results when submitted to Gloeophyllum trabeum attack.

Dureza Rockwell da madeira de três espécies amazônicas submetidas a ensaios de apodrecimento acelerado

This study aimed to evaluate the use of Rockwell hardness in the characterization of the biodeterioration of Simarouba amara (marupa), Cariniana micrantha (jequitiba) e Dipteryx odorata (cumaru) woods, which were submitted to decay fungi Trametes versicolor (white rot) and Gloeophyllum trabeum (brown rot). For this purpose, specimens of each Amazon species were submitted to decay fungi, according to ASTM D2017 (2005). The characterization of the Rockwell hardness was performed weekly until the fourth week, and then every two weeks until the twentieth week. Additionally, it was determined the mass loss, according to criteria established by ASTM D2017 (2005). The results indicated that the Rockwell hardness can be used as a primary tool in the characterization of the biodeterioration of wood, being sensitive in predicting the early stages. Among the Amazon woods, cumaru wood showed a greater natural resistance to decay fungi. With respect to decay fungi, brown rot more intensely attacked the three Amazon woods.

Monitoramento da biodeterioração da madeira de três espécies amazônicas pela técnica da colorimetria

This work aimed to evaluate the use of colorimetry in the characterization of biodeterioration marupa, jequitiba and cumaru wood, submitted to white and brown rot. For this purpose, specimens of each Amazonian species were submitted to accelerated decay tests, according to American Society for Testing and Materials - ASTM D2017, during 20 weeks. With a colorimeter, the colorimetric parameters L* (lightness), a* (green-red coordinate), b* (blue-yellow coordinate) and total color change (ΔE) were determined weekly until the fourth week, and then every two weeks until the twentieth week. Additionally, it was determined the mass loss. The results indicated that the colorimetry was effective in monitoring of biodeterioration of wood, as well as to differentiate white and brown rot. The best predictions of natural resistance to white and brown rot were obtained with the parameters b* and L*, respectively. We also emphasizes the use of ΔE to estimate the biodeterioration of wood, because of their significant correlations with weight loss.

Caracterização do ataque de fungos apodrecedores de madeiras através da colorimetria e da espectroscopia de infravermelho

Wood samples of marupa ( Simarouba amara ) and andiroba ( Carapa guianenis ) were submitted to Trametes versicolor (white rot) and Gloeophylum trabeum (brown rot) fungi attack. Colorimetry was used to determine the color of the wood before and after wood decaying fungi. To evaluate the changes in chemical compounds levels in the wood samples, the diffuse reflectance medium infrared spectroscopy was used. Both wood were non resistant against white rot fungus, while with brown rot attack andiroba was resistant and marupa was not. After Gloeophyllum trabeum attack both woods changed to a darken color, and after Trametes versicolor attack andiroba changed to a lighter color and marupa darkened slightly, The analysis showed a reduction in the peak intensity of cellulose, hemicellulose and lignin, for both species, after Trametes versicolor attack and a reduction in the peak intensity of cellulose after Gloeophyllum trabeum attack.

INFLUÊNCIA DAS DIMENSÕES DOS CORPOS DE PROVA E DA VELOCIDADE DE ENSAIO NA RESISTÊNCIA À FLEXÃO ESTÁTICA DE TRÊS ESPÉCIES DE MADEIRAS TROPICAIS

O presente trabalho teve como objetivo verificar a influencia da combinacao de tres velocidades de ensaios e de cinco dimensoes de corpos de prova na determinacao da resistencia a flexao estatica de tres especies de madeiras de florestas naturais tropicais. Pretende-se fornecer subsidios para implementacao de uma metodologia de ensaios que possibilite otimizar seus custos sem perda de precisao, qualidade e variabilidade nos resultados, considerando a inexistencia de uma norma brasileira especifica para caracterizacao fisico-mecânica de especies de madeira. As referencias de dimensoes e velocidades foram selecionadas com base na Comision Panamericana de Normas Tecnicas (COPANT 555/73). As normas COPANT estabelecem procedimentos para determinacao das propriedades fisicas e mecânicas de especies de madeiras com pequenos corpos de prova isentos de defeitos. Tradicionalmente, ensaios para pequenas variacoes de velocidades e dimensoes nos corpos de prova foram pouco abordados, possivelmente pela falta de interesse em alterar metodologias ja consagradas. A metodologia utilizada envolveu ensaios de flexao estatica com teor de umidade a 12%, cinco dimensoes de corpos de prova e tres velocidades de ensaios. Foram caracterizadas as especies: cumaru (Dipterix odorata), jequitiba (Allantoma lineata) e quaruba (Vochyisia guianensis). Os resultados mostraram que a resistencia a flexao e significativamente aumentada com a reducao da dimensao do corpo de prova, mas nao e influenciada pela velocidade de teste para todas as especies estudadas. Concluindo, para se manter a compatibilidade com os resultados de caracterizacao ja publicados utilizando-se essa norma nao e recomendado alterar o tamanho do corpo de prova atual, mas a velocidade de teste podera ser aumentada dentro dos limites estudados.

Estimativa do consumo residencial de lenha em uma pequena comunidade rural do município de São João D’Aliança, GO.

This work was carried out in Engenho, Sao Joao D’Alianca-GO, Brazil. The consumption was estimated by weighing the biomass used by families during a normal day, for cooking. The socio economic characteristics of the community were obtained with questionnaire. Firewood consumption was defined as 10.54 kg/house/day or 3,847 kg/house/year, with a personal consumption of 2.53 kg/person/day. The basic density was 0.61 g/cm 3 and the heat of combustion was 12,131 J/kg. The energy consumption estimated in 137.04 J/house/day or 46,680.34 J/house/year.

Natural resistance of eight Brazilian wood species from the region Caatinga determined by an accelerated laboratory decay test against four fungi

Abstract Natural resistance of eight wood species from Caatinga, an exclusive Brazilian biome, was evaluated according to [ASTM Standard (2005) D 2017-05. Standard test method of accelerated laboratory test of natural decay resistance of woods.]. Samples were exposed to white rot (WR) and brown rot (BR) fungi, namely to Trametes versicolor (WR), Pycnoporus sanguineus (WR), Gloeophyllum trabeum (BR) and Gloeophyllum striatum (BR). Weight loss, specific gravity and extractive content of each wood species were evaluated. Diptychandra aurantiaca, Pterodon abruptus and Terminalia fagifolia were classified as “highly resistant”, while T. fagifolia was “resistant” to T. versicolor only. Machaerium acutifolium was resistant to all fungi. Aspidosperma multiflorum was resistant to WR fungi and Combretum glaucocarpum to a BR fungus. The species Pityrocarpa moniliformis and Swartzia psilonema were moderately resistant.

RELAÇÃO ENTRE O TEOR DE UMIDADE E A CONSTANTE DIELÉTRICA DE ESPÉCIES DE MADEIRA DA AMAZÔNIA DURANTE O PROCESSO DE SECAGEM1

The objective of this study was to determine the relation between dielectric constant and the humidity of six species of wood, by the construction of a capacitor. The material used was non commercialized Amazonian wood, but with high abundance and domination in the National Forest of Tapajos - State of Para, such as: Albizia duckeana (fava-parica), Brosimum sp. (amapa-doce), Chamaecrista scleroxylon (pau-santo), Qualea dinizii (mandioqueira-rosa), Trattinnickia burserifolia(amescla) and Swartzia laurifolia (gombeira). The samples used to determinate the dielectric constant were made with the dimensions of: 4.5 x 4.5 x 1 cm, defined by preliminary tests made at Forestry Products Laboratory (LPF). The values of capacitance were collected by the construction of a capacitor using a digital multimeter, copper wires, and aluminum plates; and the values were collected eight times with intervals of one hour, during the drying process, starting at saturated mass to constant mass. Therefore, with the collected data the regression curves were established between humidity values and the dielectric constant of wood, which showed a strong correlation between the two variables, showing the direct and proportional influence of the humidity over the dielectric constant. Due to the inexistence of direct relation between specific mass and dielectric constant of the studied species, we suggest new studies to explain the relation between those characteristics.

Análise da Influência do Tratamento Preservativo na Cor e Rugosidade de Superfícies de Madeiras Tropicais

Although the chemical treatments increase wood durability, there are side effects due to the use of some products, such as the change of its original color and in its surface. The present work aimed to evaluate the surface of three tropical wood species impregnated with CCA preservative using colorimetric and roughness techniques. We used three tropical wood species representing groups of low, medium and high density. The color of the wood samples changed significantly, darkening with reduction of red and yellow pigments and a tending to surface`s greening. Regarding roughness, all samples showed an increase in the arithmetic mean roughness (Ra) and the mean maximum height (Rz), increasing surface roughness.