A Comparative Study on Wood Properties of Teaks from Different Geographical Provenances

2012 ◽  
Vol 430-432 ◽  
pp. 508-511
Author(s):  
Peng Xiang Peng ◽  
Kai Fu Li ◽  
Kun Nan Liang ◽  
Kai Meng Xu

In order to understand the effects of geographical provenances of teak on wood properties and improve the quality of afforestation in china, research was carried on wood properties of eight provenances of teak at age 27 in Ledong Country, Hainan Island. The slices revealed that the constructional characteristics from different geographical provenances of teak were very similar. But the effect of geographical provenance on teak wood properties was highly significant. The relationship results for properties of teak showed that properties of most wood species had the obvious relation with basic density, which can be used to guide the selection of the teak provenance in the early planting to improve the quality of teak.

2018 ◽  
Vol 48 (6) ◽  
pp. 621-628
Author(s):  
Raquel Gonçalves ◽  
Rafael Gustavo Mansini Lorensani ◽  
Esther Merlo ◽  
Oscar Santaclara ◽  
Manuel Touza ◽  
...  

Early selection of trees allows acceleration of genetic improvement, as well as processes related to forest management, to improve the quality of the wood produced; however, to reach this objective, it is necessary to know which parameters can be used as predictors of a tree’s aged condition. The objective of this research was to study parameters that are measurable in nursery seedlings and that could be used in prediction models of basic density (BDt), modulus of elasticity (EMt), and strength (fmt) of wood from trees. The tests were performed in 240 seedlings (3 and 6 months old) and in 52 trees (72 months old) from seven genetic units of two species: three Eucalyptus clones and four Pinus pinaster progenies. In the seedlings, measurements of longitudinal velocity of ultrasonic waves (VLs), basic density (BDs), height (Hs), diameter (Ds), strength (fts), and modulus of elasticity (Ets) in tension parallel to the grain were obtained. The EMt and fmt can be predicted by parameters obtained in seedlings of the same genetic unit. Thus, the use of these parameters, in association with others already used in selection programs, may increase the positive results of the early selection, with economic gains and time reductions in forest management.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Bárbara Luísa Corradi Pereira ◽  
Aylson Costa Oliveira ◽  
Ana Márcia Macedo Ladeira Carvalho ◽  
Angélica de Cássia Oliveira Carneiro ◽  
Larissa Carvalho Santos ◽  
...  

Considering the wide variety of species and clones ofEucalyptuscultivated in Brazil, it is necessary to search for new information on wood properties, so that the selection of genetically superior material may be successful. The present study aimed to determine the properties of wood and charcoal from different clones ofEucalyptusspp. Six clones at the age of 7.5 years were evaluated and the samples were from a clonal, located in the city of Lassance, Minas Gerais, Brazil. Basic density, chemical composition, and higher heating value were determined. Carbonizations in a laboratory kiln were done and the levels of volatile matter, ash, and fixed carbon, higher heating value, and bulk density of the charcoal produced were determined. Evaluated genetic materials showed differences in their properties. According to research results, several properties of wood should be considered together for the selection of clones for charcoal production. However, basic density and chemical composition of wood, especially high contents of lignin and low contents of extractives, are the properties that had more influence on charcoal yield and its quality. Concerning charcoal production for steelmaking, clone 6 stood out and, conversely, clone 4 showed inferior properties to those of others.


1975 ◽  
Vol 5 (3) ◽  
pp. 424-432 ◽  
Author(s):  
J. E. Nicholson ◽  
W. E. Hillis ◽  
N. Ditchburne

The relationship between level of longitudinal growth strain and stress, modulus of elasticity, basic density, volumetric shrinkage, fiber classification, and stem form was investigated with 10 Eucalyptusregnans regrowth trees. Close relationships were observed. It is suggested that variations in these properties within trees are closely controlled, possibly to enable optimum positioning of the tree crown in relation to its immediate environment. The concept of fiber structure varying as a response to environment is supported by the observed variation in wood properties within and between trees of this species. The often-reported association between eccentric radial growth and reaction wood was not substantiated in this study.The data indicate that if economically justifiable, it would be possible to segregate trees that are likely to contain material that is hard to season.


2017 ◽  
Vol 3 (1) ◽  
pp. 1-5
Author(s):  
Futoshi Ishiguri ◽  
Kazuko Makino ◽  
Imam Wahyudi ◽  
Jun Tanabe ◽  
Yuya Takashima ◽  
...  

The present study clarified the relationship between the growth and wood properties of 54-year-old Agathis sp. trees planted in Indonesia. Stem diameter, pilodyn penetration, and stress-wave velocity (SWV) were measured for all trees (35 trees) in a plot (30  30 m) located almost at the center of a stand. Based on the mean stem diameter, 10 standard trees in a plot were selected for measuring the basic density (BD) and compressive strength parallel to grain (CS). Core samples (5 mm in diameter) were collected from the 10 selected trees to determine BD and CS. The mean stem diameter, pilodyn penetration and SWV in the plot were 40.2  11.3 cm, 23.4  2.1 cm, and 3.85  0.43 km/s, respectively. No  significant correlation coefficeint (r = -0.327, no significance at 5% level) was obtained between stem diameter and SWV. The mean BD and CS in the 10 trees were 0.42  0.03 g/cm3  and 28.1  2.7 MPa, respectively. A significant positive  correlation was observed between BD and CS. Analysis of variance (ANOVA) revealed a significant difference between BD and CS values of the 10 trees, indicating that wood properties may differ among trees with the same standard growth in a stand. From these results, we concluded that wood quality improvement in this species could be achieved by selecting  trees with high density and strength in tree breeding programs.


2010 ◽  
Vol 145 ◽  
pp. 449-452
Author(s):  
Jian Jun Hao ◽  
Qing Xue Huang ◽  
Xue Liang Zhang

Based on straightening principle of profile straightening equipment, the relationship between process parameters and quality of profile straightening is studied, which can provide basis for optimization and selection of process parameters.


Metabolomics ◽  
2021 ◽  
Vol 17 (9) ◽  
Author(s):  
Naser Davarzani ◽  
Carmen Diez-Simon ◽  
Justus L. Großmann ◽  
Doris M. Jacobs ◽  
Rudi van Doorn ◽  
...  

Abstract Introduction The relationship between the chemical composition of food products and their sensory profile is a complex association confronting many challenges. However, new untargeted methodologies are helping correlate metabolites with sensory characteristics in a simpler manner. Nevertheless, in the pilot phase of a project, where only a small set of products are used to explore the relationships, choices have to be made about the most appropriate untargeted metabolomics methodology. Objective To provide a framework for selecting a metabolite-sensory methodology based on: the quality of measurements, the relevance of the detected metabolites in terms of distinguishing between products or in terms of whether they can be related to the sensory attributes of the products. Methods In this paper we introduce a systematic approach to explore all these different aspects driving the choice for the most appropriate metabolomics method. Results As an example we have used a tomato soup project where the choice between two sampling methods (SPME and SBSE) had to be made. The results are not always consistently pointing to the same method as being the best. SPME was able to detect metabolites with a better precision, SBSE seemed to be able to provide a better distinction between the soups. Conclusion The three levels of comparison provide information on how the methods could perform in a follow up study and will help the researcher to make a final selection for the most appropriate method based on their strengths and weaknesses.


Holzforschung ◽  
2020 ◽  
Vol 74 (12) ◽  
pp. 1089-1097
Author(s):  
José Clailson Franco Coelho ◽  
Graziela Baptista Vidaurre ◽  
João Gabriel Missia da Silva ◽  
Maria Naruna Felix de Almeida ◽  
Ramon Ferreira Oliveira ◽  
...  

AbstractThe relationship between grain angle and wood properties has not been focus of researches in wood industry. The aim of this study was to establish grain angle variations in commercial Eucalyptus logs and their effects on physical-mechanical wood properties. Wood maximum angular deviation (MAD) was correlated with density, volumetric shrinkage, compressive strength parallel to grain, flexural strength and stiffness as determined by bending and acoustic methods in wood of seven Eucalyptus grandis × Eucalyptus urophylla clones at 13 years old. The relationship between MAD at pith-bark and base-top positions and its effect on the physical and mechanical properties were evaluated. Amplitude of MAD values was small for the seven clones, and the mean was 6.2°. The grain deviation decreased by only 8% in base-top direction, and the correlations among MAD and three logs heights were small and negative (r = −0.13). MAD values presented an increasing trend of 33% in pith-bark direction, with a small positive correlation (r = 0.42). Basic density (BD) presented a significant correlation with the MAD (r = 26). There was no significant correlation between the MAD and volumetric shrinkage, mechanical properties and modulus of elasticity dynamic (determined by stress wave timer, ultrasound or transverse vibration).


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