Data/hora: 22/09/2024 17:09:14

Biblioteca(s): 	Embrapa Instrumentação.	
Data corrente: 	03/07/2003	
Data da última atualização: 	17/03/2016	
Autoria: 	MACEDO, A.; VAZ, C. M. P.; PEREIRA, J. C. D.; NAIME, J. M.; CRUVINEL, P. E.; CRESTANA, S.	
Afiliação: 	Embrapa Instrumentação Agropecuária, São Carlos, SP.	
Título: 	Wood density determination by X-and gamma-ray tomography.	
Ano de publicação: 	2002	
Fonte/Imprenta: 	Holzforschung, Berlin, v. 56, p. 535-540, 2002.	
Idioma: 	Inglês	
Conteúdo: 	Wood density measurements is related to several factors that influence wood quality. In this paper, a CT image calibration procedure which allows image quantification in terms of dry bulk density is presented for three different X-and gamma-ray energies (28.3, and 59.5, and 662.0 keV). The mass attenuation coefficients measured for a set of eight wood species did not vary significantly, allowing a single calibration for determination of bulk density of air-dried wood samples at each energy. The equation for bulk density calibration obtained was validated using a second set of twelve wood species. Comparison of bulk density determined by CT images, using the calibration procedure proposed, with values obtained by gravimetric methods, presneted a very good linear correlation coefficient (R2=0.94). The main advantage of CT imaging over conventional techniques for wood bulk density determination is that it allows detection and quantification of heterogeneities and internal defects. At the sub-millimetric spatial resolution level, it is possible to identify morphological and structural aspects of wood samples.	
Palavras-Chave: 	Conteúdo; Densidade; Imagem tomográfica; Mass attenuation coefficient; Tomografia computadorizada; Wood water content.	
Thesagro: 	Água; Madeira.	
Thesaurus Nal: 	computed tomography; wood density.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Instrumentação (CNPDIA)	
Exemplares: 	CNPDIA - (7678-1) - UPC - SP - -- - PROCI-02.00072 -  - 2002.00072 - DIS