Tectona grandis L. f. (teak) is highly valued in the international market, but its volume and properties vary depending on its genetic material and planting site. Evaluating these factors is crucial ...for promoting new plantations. Therefore, this study aimed to assess the impact of genetic material (clones TG1 and TG3 and seminal material) and planting site (Nova Maringá and Água Boa, Mato Grosso, Brazil) on morphological parameters (heartwood, sapwood, bark, pith proportions, and pith eccentricity), physical properties (shrinkage and air-dry density), and mechanical properties (static bending strength—fm, compressive strength—fc0, Janka hardness—fH90, and shear strength—fv0). For this purpose, we sampled five trees aged 13 years per genetic material from commercial plantations. In Nova Maringá, trees exhibited, on average, 56.07% heartwood, while in Água Boa, this value was less than 50%. Seminal material showed the lowest percentage of heartwood (49.2%). The pith percentage was significantly greater in Água Boa than in Nova Maringá, regardless of the genetic material. We observed the highest standard deviation (5.61) in pith eccentricity for the seminal material. Both the planting site and genetic material influenced the air-dry density (~12% moisture content), which ranged from 0.535 to 0.618 g·cm−3. Trees grown in Nova Maringá produced wood with higher dimensional stability than those from Água Boa, exhibiting a 14% lower radial shrinkage and a 6% lower volumetric variation. In Nova Maringá, the wood from the seminal material exhibited greater resistance. On the other hand, in Água Boa, that material showed lower resistance (fv0, fm, and fc0), or there was no significant difference (fH90) compared to the clonal materials. When comparing the clonal materials (TG1 and TG3) at each planting site, they demonstrated similar mechanical properties. The variability in physical and mechanical properties among different genetic materials and planting locations highlights the need to select appropriate teak genetic materials for each region. We concluded that more productive teak clones can be selected without compromising the physical and mechanical properties of the wood.
Teakwood from fast-growth plantations is commercialized at increasingly younger ages for economic reasons. However, wood features are influenced by the age of the tree. This study examined how age ...affects heartwood proportion, color parameters, chemical composition, and natural teakwood durability. Trees with 5, 10, 15, and 20 years of fast-growth at commercial plantations located in Mato Grosso, Brazil were evaluated. The base diameter of the trees ranged from 13.1 (5 years) to 28.3 cm (20 years), and the heartwood percentage increased from 16.3 to 60.0%, respectively. The color parameters in the CIELab system indicated that wood became darker and more saturated, and the predominance of yellow color decreased compared with red as age advanced. The total extractive content ranged between 7.4 (5 years) and 9.6% (15 years), without a clear trend of age affecting the extractive content. The extractives from five-year-old wood were mainly composed of tectoquinone (43.3%), phthalic acid (19.1%), and 1,3-indandione (9.2%), while those from 20-year-old wood were mainly composed of tectoquinone (60.7%), lapachol (13.8%), and phthalic acid (9.7%). Teakwood can be classified as resistant (5 years) to very resistant (20 years) after being submitted to an accelerated decay test.
ABSTRACT The objectives of the present work were to determine the properties of wood and charcoal from Eucalyptus clones and assess impacts of charcoal features on the CO2 gasification reactivity and ...to compare with coke reactivity. Gasification reactivity was performed using charcoal particles in a furnace setup at 820 °C, under CO2 atmosphere. The results show that there is wood variability among evaluated clones and strong correlations between wood and charcoal properties. All charcoals had higher reactivity in comparison to coke. The decrease in porosity and increase in apparent density in Eucalyptus wood led to a slight decrease of CO2 gasification reactivity. In addition, strong positive correlation between charcoal reactivity and potassium concentration (K) was found.
Drying is an indispensable process for the industrial use of wood because it results in greater stability, durability, quality, and value of the final product. However, pre-established programs for ...tropical species have been poorly evaluated. The objective of this study was to formulate and evaluate drying programs for tropical species. The woods of Astronium lecointei (muiracatiara), Dinizia excelsa (faveira-ferro) and Hymenolobium heterocarpum (angelim-pedra) were used. The anatomical characteristics and physical properties of these species were evaluated. The drying programs for each wood were elaborated based on the drying potential to estimate the initial and final temperatures. The programs were executed in a laboratory oven with forced air circulation and afterward, the drying rates and defects were evaluated. The highest values of basic density were observed for faveira-ferro (0.92 g cm
-
³) followed by muiracatiara (0.70 g cm
-
³), and angelim-pedra (0.59 g cm
-
³). As for the volumetric shrinkage, the values were increased in the following order: angelim-pedra (9.87%), faveira-ferro (12.70%), and muiracatiara (14.23%). The anisotropy coefficient of the three wood evaluated was less than 1.5. The density and vessel diameter influenced the drying rate of the woods. The application of the drying programs in this work resulted in a high rate of top and surface cracking, which can compromise the use of wood for more demanding purposes. The woods were classified as first-class because the warping did not exceed the allowed limits.
The research on Amazon wood waste focuses on the species’ individual characteristics, not considering the conditions usually found in the industries, such as variations in the storage method and the ...waste’s condition after exposure to the environment. Accordingly, the objective of this paper was to analyze the management of waste generated by wood industries located in Mato Grosso, Brazil, and to determine the physical and chemical properties of the stocked particulate waste for energy-generation purposes. Twenty-four industries located in eight cities were investigated regarding the generation, management, and trade of wood waste, and samples of the particulate waste were collected for characterization. Each of the evaluated industries processed an average of 857.92 m
2
of wood logs per month, and 51.13% of this volume was waste. The species
Erisma uncinatum
and
Qualea
spp. stood out due to their greater processing volumes. The types of waste found were of firewood (in 100% of the industries), sawdust (87.5%), wood shavings (16.5%), and wood chips (12.5%). The main destinations of the traded waste were: intermediate buyers (30%), bioenergy plants (22%), cold rooms (18%), and grain dryers (16%). The humidity and bulk density of sawdust and wood chips were, respectively, over 41% and 236 kg m
−3
. The ash content of 76.7% of the waste was under 2.0%. If the 24 evaluated industries performed the thermochemical conversion of their wood waste, it would be possible to supply electricity to approximately 63 houses with average consumption of 162 kWh/month. The effective management of the waste will result in its commercial appreciation and increase its energy potential.
Intrinsic water-use efficiency (
i
WUE
, the ratio between net photosynthetic rate and stomatal conductance to water vapor) is assumed to be insensitive to leaf-to-air vapor pressure deficit (
VPD
l
...) for some plant species. This assumption has led many researchers to accept that
i
WUE
may be more useful for evaluating plants for drought-resistance than instantaneous water-use efficiency (
WUE
, the ratio between net photosynthetic rate and transpiration rate), since the latter is known to depend on
VPD
l
. However, the assumption that
i
WUE
does not depend on
VPD
l
may not be always correct because the stomatal aperture (ostiole area,
A
o
) and the resulting stomatal conductance (
gs
w
) has been shown to respond to
VPD
l
in some plant species. In this study, we present experimental data on leaf gas exchange and anatomical evaluations in three wild (non-commercial) and one commercial
Phaseolus vulgaris
L. cultivars, as well as a bibliographic review of the topic supporting that sensitivity of stomata to
VPD
l
is species-specific. These results provide important implications for the interpretation of
i
WUE
as a useful parameter to screen bean cultivars for identifying drought resistance forms.
QUALITY OF TROPICAL HARDWOOD FLOORS Costa, Ana Carolina Silva; Oliveira, Aylson Costa; Pereira, Bárbara Luísa Corradi ...
Revista árvore,
01/2021, Volume:
45
Journal Article
Peer reviewed
Open access
ABSTRACT This study aimed to determine the basic density of the wood and to simulate the performance of flooring produced with wood from five tropical species: Dipteryx odorata (Cumaru), Handroanthus ...spp. (Ipê), Hymenaea Courbaril (Jatobá), Astronium Lecointei (Muiracatiara), and Bowdichia virgilioides (Sucupira-Preta). Falling steel sphere, static and dynamic friction, indentation caused by loads applied in small areas, rolling load, and abrasiveness impact tests were simulated. The results were subjected to analysis of variance and Tukey’s test at 5% significance, and Pearson’s correlation was performed between the basic density and the indexes of each flooring. The basic density of the wood flooring made from the evaluated species ranged from 0.735 to 0.958 g.cm-3. D. odorata, Handroanthus spp. and H. courbaril woods were classified as heavy, while those of A. Lecointei and B. Virgilioides as moderately heavy. It was possible to indicate D. odorata, Handroanthus spp., H. courbaril, and B. Virgilioides flooring for environments with intense traffic where there is dragging or falling objects such as industries and companies. The A. Lecointei flooring can be used in residential environments with light traffic, where the loads exerted are low. There was a correlation between the basic wood density and the flooring use simulation tests.
RESUMO O objetivo deste estudo foi determinar a densidade básica da madeira e simular o comportamento em uso de pisos maciços produzidos com madeiras de cinco espécies tropicais: Dipteryx odorata (cumaru), Handroanthus spp. (ipê), Hymenaea courbaril (jatobá), Astronium lecointei (muiracatiara) e Bowdichia virgilioides (sucupira-preta). Nos testes de simulação foram realizados os ensaios de impacto da esfera de aço cadente, de atrito estático e dinâmico, de endentação causada por cargas aplicadas em pequenas áreas, de carga rolante e de abrasividade. Os resultados foram submetidos à análise de variância e ao teste de Tukey, a 5% de significância, e realizou-se a correlação de Pearson entre a densidade básica e os índices de cada ensaio de simulação de pisos. A densidade básica dos pisos de madeira das espécies avaliadas variou de 0,735 a 0,958 g·cm-3, sendo as madeiras de D. odorata, Handroanthus spp. e H. courbaril classificadas como pesadas e as de A. lecointei e B. virgilioides como moderadamente pesadas. Foi possível indicar os pisos de D. odorata, Handroanthus spp., H. courbaril e B. virgilioides para ambientes com tráfego intenso, onde há o arraste ou a queda de objetos, como indústrias e empresas. Já o piso de A. lecointei pode ser utilizado em ambientes residenciais, com tráfego leve, onde as cargas exercidas sejam baixas. Houve correlação entre a densidade básica da madeira e os ensaios de simulação dos pisos em uso.
The study was developed in Nova Maringá - MT. The objectives of this work were to evaluate the sawn timber yield, the use of wood residues and the quantification of products for the species Qualea ...paraensis (cambará) and Erisma uncinatum (cedrinho) in three diametric classes: Class A - 40.0 to 49.9 cm; Class B - 50.0 to 59.9 cm; Class C - 60.0 to 69.9 cm. Four replicates per class were evaluated, totaling 12 logs per species of varied lengths. The sawn timber yield did not show a statistical difference between diametric classes for both species. Average yield for Qualea paraensis was equal to 43.97% and for Erisma uncinatum, 42.05%. The residues use increased the total yield in 4.40% and 6.52% for Qualea paraensis and Erisma uncinatum, respectively. For Erisma uncinatum, the sawed products with the highest production were the board in the primary unfolding and the short board in the residues use. As for Qualea paraensis, there was more production of rafters and short battens in the same processes.
TORREFIED BRIQUETTES OF SUGAR CANE BAGASSE AND EUCALYPTUS Costa, Emylle Veloso Santos; Pereira, Matheus Perdigão de Castro Freitas; Silva, Carlos Miguel Simões da ...
Revista árvore,
01/2019, Volume:
43, Issue:
1
Journal Article
Peer reviewed
Open access
ABSTRACT Torrefaction and briquetting are two techniques that improve the quality of the biomass and facilitate direct use as fuel. The objective was to evaluate the effect of torrefaction ...temperature on the properties of the compound briquettes made from sugar cane bagasse and Eucalyptus sawdust. After sample preparation and particle analyses, briquettes were produced with the mixture of the two biomasses, a total of five compositions (0, 25, 50, 75 and 100%) at 120 °C and pressure of 1500 PSI. Subsequently, the briquettes were torrefied at temperatures of 180, 220 and 260 °C, for a period of 15 minutes. According to the results, both biomasses of Eucalyptus sawdust and sugar cane bagasse showed potential for the production of briquettes. The torrefaction reduced hygroscopicity and increased the calorific value of compound briquettes. The ideal composition for the production of briquettes is 100% Eucalyptus. The composition of 50% Eucalyptus + 50% sugar cane bagasse is also a great option, as some bagasse parameters were excellent. 260 °C was the best temperature to promote energy savings.
RESUMO A torrefação e a briquetagem são duas técnicas que melhoram a qualidade da biomassa e facilitam seu uso direto como combustível. O objetivo do trabalho foi avaliar o efeito da temperatura de torrefação nas propriedades dos briquetes compostos produzidos com bagaço de cana-de-açúcar e serragem de eucalipto. Após o preparo das amostras e análises das partículas, produziram-se briquetes com a mistura das duas biomassas, totalizando cinco composições (0, 25, 50, 75 e 100%), na temperatura de 120°C e pressão de 1500 PSI. Posteriormente, realizou-se a torrefação dos briquetes nas temperaturas de 180, 220 e 260°, por um período de 15 minutos. De acordo com os resultados, tanto as biomassas de serragem de eucalipto como a de bagaço de cana apresentaram potencial para produção de briquetes. A torrefação reduziu a higroscopicidade e aumentou o poder calorífico dos briquetes compostos. A composição ideal para a produção de briquetes é a de 100% eucalipto. A composição de 50% eucalipto + 50% bagaço de cana também é uma ótima opção, já que alguns parâmetros do bagaço se sobressaíram. A temperatura de 260°C foi a que promoveu melhores ganhos energéticos.
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