Relations between the colorimetric values and densities of sapwood

Nishino, Yoshihiko; Janin, G.; Yainada, Yuji; Kitano, Daisuke

doi:10.1007/bf00766215

Cited by 27 publications

(21 citation statements)

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“…According to Burger and Richter (1991), radial section has a more shining surface due to effect of horizontal bands of rays. Nishino et al (2000) stated that color differences between radial and tangential sections can be ascribed to anatomical characteristics like arrangement of cells, large rays and spiral grain.…”

Section: Resultsmentioning

confidence: 99%

THERMAL MODIFICATION OF Eucalyptus grandis WOOD: VARIATION OF COLORIMETRIC PARAMETERS

Cademartori

Schneid

Gatto

et al. 2013

Maderas, Cienc. tecnol.

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The color modifications in Eucalyptus grandis thermally modified wood were investigated. One hundred eighty specimens (10 x 10 x 200 mm) were prepared and thermally modified in an electric kiln for 4 and 8 h at 180-240ºC. The color parameters (L*, a*, b*, C*, h* and ΔE) were determined by the CIE-L*a*b* method on radial and tangential sections of untreated and treated wood. The results indicated the darkening of specimens in the radial and tangential sections. Both sections showed variation of L* between 73 and 30, a* between 9 and 5 and b* between 20 and 8. The thermally modified wood at 180 and 200ºC showed similar patterns, equally at 220 and 240ºC. The time of exposure indicated significance just in treatment at 200ºC.

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Section: Resultsmentioning

confidence: 99%

THERMAL MODIFICATION OF Eucalyptus grandis WOOD: VARIATION OF COLORIMETRIC PARAMETERS

Cademartori

Schneid

Gatto

et al. 2013

Maderas, Cienc. tecnol.

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“…Si se considera que las manchas MM (las más comúnmente halladas en este clon, con altos valores de a*), se presentan duras y firmes, de consistencia vidriosa al astillarlas y sin signos evidentes de pérdida de resistencia en el tejido, no sorprende que las mismas provoquen un aumento de la densidad en las rodajas, según sea la superficie que involucran. Varios autores corroboran esta relación positiva entre el peso específico de la madera y el color rojizo: Nishino et al (2000) analizaron las relaciones entre color y densidad en 26 latifoliadas japonesas y encontraron incrementos en a* a medida que la madera es más densa. Unsal et al (2003) estudiaron la madera de Eucalyptus camaldulensis y concluyeron que la disminución de densidad causada por un tratamiento térmico fue acompañada por menores valores de a*, b* y L*.…”

Section: -Relaciones Entre Propiedades óPticas Y Composición Químicaunclassified

“…En la madera sana de sauce americano, la densidad aumenta a medida que su color tiende al amarillo (Tabla 3a), coincidiendo con las observaciones efectuadas en madera normal de otras latifoliadas (Nishino et al, 2000;Unsal et al, 2003;Sotelo Montes et al, 2008). A medida que la madera de MMc y ZO es más rojiza (mayor a*), el número de vasos con tílides disminuye.…”

Section: -Relaciones Entre Propiedades óPticas Y Composición Químicaunclassified

Wood characterization of Salix. 2: Relationships between optical and other wood properties

Villegas

Área

2009

For. syst.

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ResumenSe analizaron posibles relaciones entre algunas características de la madera de sauces (Salix) y se determinó su influencia sobre las propiedades ópticas de la madera.En los dos sauces estudiados, la presencia de manchas en la madera ocasionó disminuciones de blancura, L* y b*, acentuándose a medida que aumenta la superficie deteriorada y un incremento en el contenido de tilosis.La madera más blanca presentó los mayores valores de L*, siendo también más amarilla y menos roja, exceptuando la zona oscurecida en sauce americano y las manchas castañas y azul en sauce híbrido, donde los parámetros a* y b* correlacionaron positivamente.La presencia de deterioro en la madera se relacionó con disminuciones de densidad en ambos clones, exceptuando la mancha castaño oscuro de sauce americano, que provocó aumentos de densidad en las rodajas que la presentan.Las manchas de la madera afectaron su composición química. En sauce americano la madera más oscura presentó más lignina insoluble y total. En el híbrido, los extractivos en agua caliente y en alcohol-benceno se relacionaron con la mancha azulada y con los solubles en NaOH, medida utilizada generalmente como indicadora del grado de deterioro de la madera. Abstract Wood characterization of Salix. 2: Relationships between optical and other wood propertiesThe objective of this study was to establish relationships between some characteristics of the wood of Salix and their possible influence on its optical properties.In both willow clones, the presence of stains caused the decrease of brightness, L*, and b*. This effect was intensified in the more deteriorated areas. Tyloses increased with the presence of such stains.The whiter wood showed the highest values of L *, being more yellow and less red, except for the "dark zone" in the American willow, and the "brown stains" and the "blue stain" in the hybrid willow, in which the parameters a * and b * correlated positively.The presence of defects in the wood was related to the decrease of density in both clones, except for the "dark-brown stain" in the American willow, which caused the increase of disks density when present.The content of insoluble and total lignin correlated negatively with brightness and L* in American willow, and with basic density in the hybrid. In the last clone, the extractives in hot water and alcohol-benzene, correlated with the alkalisoluble substances content (frequently used as a measure of decay degree), and also played an important role in determining the tendency to blue color in the stains of the wood.

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“…Além disso, a utilização de técnicas de colorimetria tem demonstrado utilidade para a classificação de madeiras com propriedades físicas e mecânicas semelhantes, diferindo amostras provenientes de diferentes plantios, o que favorece a obtenção de lotes com propriedades mais homogêneas e previsíveis (Nishino et al, 2000;Moya & Marín, 2011).…”

Section: Introductionunclassified

Caracterização colorimétrica dos lenhos juvenil e adulto de quatro espécies de eucalipto

Delucis

Gatto

Stangerlin

et al. 2015

Agraria

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Relations between the colorimetric values and densities of sapwood

Cited by 27 publications

References 1 publication

THERMAL MODIFICATION OF Eucalyptus grandis WOOD: VARIATION OF COLORIMETRIC PARAMETERS

THERMAL MODIFICATION OF Eucalyptus grandis WOOD: VARIATION OF COLORIMETRIC PARAMETERS

Wood characterization of Salix. 2: Relationships between optical and other wood properties

Caracterização colorimétrica dos lenhos juvenil e adulto de quatro espécies de eucalipto

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