scholarly journals Basic and Grade Stress for Some Timber in Sarawak

2011 ◽  
Vol 2 (2) ◽  
pp. 35-38
Author(s):  
Gaddafi Ismaili ◽  
Badorul Hisham Abu Bakar ◽  
Khairul Khuzaimah Abdul Rahim
Keyword(s):  
Exotic Species ◽  
Modulus Of Elasticity ◽  
Acacia Mangium ◽  
Wood Properties ◽  
Strength Properties ◽  
Indigenous Species ◽  
Medium Density ◽  
Compression Stress ◽  
Strength Group ◽  
Fast Growing Species

Strength properties’ tests are conducted in the small clear sample. This paper aim to acquire the basic and grade stresses of some fast growing species thus identifies its strength group. Thus, the information of wood properties from different species and condition are acquired from strength property's test. The required information namely, bending parallel to the grain, compression stress parallel to grain, shear parallel to grain and modulus of elasticity. The condition of the trees which is referred to green and air-dry condition. Three different species which are referred to exotic species of Acacia mangium and indigenous species of Aras. The results from the study indicated that, Acacia mangium classified under the strength group SG5, whilst Aras was classified under the strength group SG7. The timber is of medium density Light Hardwood ranging from 0.37-0.52g/cm3 air-dry condition.

scholarly journals Strength Classification of Aras as Fast-Growing Indigenous Species Timber in Sarawak

2014 ◽  
Vol 695 ◽  
pp. 617-621
Author(s):  
Gaddafi Ismaili ◽  
Khairul Khuzaimah Abdul Rahim ◽  
Alik Duju ◽  
Iskanda Openg ◽  
Zurina Ismaili
Keyword(s):  
Modulus Of Elasticity ◽  
Acacia Mangium ◽  
Strength Properties ◽  
Indigenous Species ◽  
Medium Density ◽  
Compression Stress ◽  
Strength Group ◽  
Fast Growing ◽  
Dry Conditions

Strength properties’ tests are conducted in the form of small clear sample. This paper aimed to acquire the strength group of fast-growing indigenous species of Aras and exotic species of Acacia mangium. Thus, the information of strength properties of species is acquired from strength property's test at green and air-dry conditions. The required information namely, bending parallel to grain, compression stress parallel to grain, shear parallel to grain and modulus of elasticity. The ultimate stresses obtained from strength properties of the species is to be converted into basic and grade stresses to determine the strength group of the species based on MS 544: Part 2 (2001). The results from the study indicated that, Acacia mangium classified under strength group SG5, whilst Aras was classified under strength group SG7. The timber is classified as medium density of Light Hardwood ranging from 0.37-0.52 g/cm3 at air-dry condition.

scholarly journals The Behavior of Strength Properties from Three Different Tree Boles of Aras in Sarawak

2011 ◽  
Vol 2 (2) ◽  
pp. 48-52
Author(s):  
Gaddafi Ismaili ◽  
Badorul Hisham Abu Bakar ◽  
Khairul Khuzaimah Abdul Rahim
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Compressive Stress ◽  
Modulus Of Elasticity ◽  
Basic Density ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Compression Stress ◽  
Mean Values ◽  
Green Condition

 Aras had been selected and tested in small clear specimens. Sampling of test specimens are made from three sections of the tree bole namely from bottom, middle, and top parts. This paper looks into the information of strength properties from three sections of sampled. The strength properties test required are the modulus of rupture, modulus of elasticity and compression stress parallel to grain. Meanwhile, the physical properties' test referred to moisture content and basic density. The testing conducted in two different conditions of the trees, which were referred to green and air-dry condition. It was found that the average mean values for modulus of rupture, modulus of elasticity and compressive stress parallel to grain tested at green condition were 47.52N/mm2, 6358.56N/mm2 and 22.42N/mm2 respectively meanwhile at air-dry condition were 70.49N/mm2, 8217.64N/mm2 and 34.07N/mm2 respectively. Meanwhile, the average mean values for moisture content at green condition were 83.34% whilst at the air-dry condition were 12.33%. Basic density remains unchanged from both conditions.

Medium Density Particleboard with Addition of Impregnated Paper

2014 ◽  
Vol 1025-1026 ◽  
pp. 543-546
Author(s):  
Juliana Cortez Barbosa ◽  
Anderson Luiz da Silva Michelon ◽  
Elen Aparecida Martines Morales ◽  
Cristiane Inácio de Campos ◽  
André Luis Christoforo ◽  
...  
Keyword(s):  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Mechanical Tests ◽  
Modulus Of Rupture ◽  
Medium Density ◽  
Test Results ◽  
Thickness Swelling ◽  
Adhesion Test ◽  
Layer Medium ◽  
Determine Moisture Content

The aim of this research was to produce three-layer Medium Density Particleboard (MDP), with the addition of impregnated paper, in the inner layer, in proportions of 1; 5 and 20%. In this study, MDP was composed with particles of small size in outer layers, and larger particles in internal layer. After panel manufacturing, physical and mechanical tests based on Brazilian Code ABNT NBR 14.810 were carried out to determine moisture content; density; thickness swelling; water absorption; modulus of rupture (MOR) and modulus of elasticity (MOE) in static bending and internal adhesion. Test results were compared to commercial panels, produced with 100% Eucalyptus, considering the requirements specified by Brazilian Code. Properties presented values close to normative specifications, indicating positively the possibility of production of MDP using addition of waste paper impregnated.

Genetic relationships between wood quality traits and diameter growth of juvenile core wood in Sitka spruce

2013 ◽  
Vol 43 (1) ◽  
pp. 1-6 ◽  
Author(s):  
S.G. Kennedy ◽  
A.D. Cameron ◽  
S.J. Lee
Keyword(s):  
Growth Rate ◽  
Genetic Correlation ◽  
Modulus Of Elasticity ◽  
Genetic Relationships ◽  
Wood Quality ◽  
Wood Properties ◽  
Sitka Spruce ◽  
Acoustic Velocity ◽  
Picea Sitchensis ◽  
Good Growth

The trend towards shorter rotations in planted conifer stands has resulted in a reduction in the proportion of mature wood relative to juvenile core wood, raising concerns that the mechanical performance of sawn battens will be affected. The potential to improve the wood quality of the juvenile core of Sitka spruce (Picea sitchensis (Bong.) Carrière) without compromising growth rate was investigated. Rapid and inexpensive indirect methods of assessing wood properties on standing trees using a Pilodyn gun and acoustic velocity were compared with direct measurements made on wood samples cut from the juvenile core. Strong genetic correlations were observed between Pilodyn gun values and direct measures of density (–0.76) and between the square of acoustic velocity and modulus of elasticity (0.73). The genetic correlation between the square of acoustic velocity and microfibril angle was also strong (–0.84). These results suggest that indirect assessments of wood properties within juvenile core wood are sufficiently reliable for these techniques to be used in the Sitka spruce breeding programme. Although a strong negative genetic correlation between diameter at breast height and density was noted (–0.79), sufficient variation exists within the breeding population to select families with both good growth rate and high modulus of elasticity wood.

scholarly journals Sixteen properties of Eucalyptus Tereticornis wood for structural uses

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Marta Cristina de Jesus Albuquerque Nogueira ◽  
Victor Almeida de Araujo ◽  
Juliano Souza Vasconcelos ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr
Keyword(s):  
Mechanical Properties ◽  
Decision Making ◽  
Shear Stress ◽  
Modulus Of Elasticity ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Eucalyptus Tereticornis ◽  
Moisture Contents ◽  
Through Diffusion ◽  
Standard Documents

Forest Red Gum eucalypt provides a versatile wood and is converted into different purposes. However, such wood is somewhat limited in structural ends, which highlights the need to exploit this gap through diffusion of mechanical properties of such timber. Obtained results should assist engineers and architects in decision-making for its best building application. This paper studied two physical and fourteen mechanical properties evaluation of Eucalyptus tereticornis at two different moisture contents, following the prescriptions of Brazilian (ABNT NBR 7190: 1997) and North American (ASTM D-143-14: 2014) standard documents. Thus, 1091 repeats were carried out for all properties. By a moisture reduction from 30% to 12%, the bulk density and eleven strength properties statistically showed changes such as modulus of rupture (static bending, parallel and perpendicular compressions), modulus of elasticity (perpendicular compression and static bending), shear stress, tangential cleavage, and parallel and perpendicular hardnesses. Then, the Eucalyptus tereticornis timber could be better usable if is further applied for structural construction uses.

Technological Properties of Wood from Trees in Polluted Regions

IAWA Journal ◽  
1986 ◽  
Vol 7 (4) ◽  
pp. 389-397 ◽  
Author(s):  
A. Frühwald
Keyword(s):  
Moisture Content ◽  
Wood Quality ◽  
Wood Properties ◽  
Biological Indicators ◽  
Strength Properties ◽  
West Germany ◽  
Technological Properties ◽  
Growth Rings ◽  
Physical Chemical ◽  
Faster Development

Wood quality from about 230 healthy and diseased fir, spruce, pine and beech trees from various locations in West Germany was tested. In general results are satisfactory for mechanical wood properties, but some physical, chemical and biological indicators lead to the conclusion that logs from heavily diseased trees may be attacked a !ittle earlier and faster by microorganisms during storage. Width of growth rings is reduced in severely damaged softwood trees on most locations whereas beech shows no significant reduction. Declining health of the trees had no or little influence on wood density; the modulus of elasticity and strength were at normal levels and independent of tree damage. Width and moisture content of sapwood were reduced little in pines but more in spruce and fir. A tendency to a more intensely developed irregular brown heartwood in severeIy damaged beech trees could not be proved until now. Storage of spruce in a log yard for four months has shown a slightly faster development of discoloration caused by fungi in diseased trees whereas after seven months wood from healthy trees was more discoloured. After storage strength properties are not or only slightly reduced, but no difference was found between trees assigned to the various health classes. After two years of storage under sprinkling water, pine logs from healthy and diseased trees show no difference in discoloration.

Barrier plants in South Africa

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 635-639 ◽  
Author(s):  
L. Henderson
Keyword(s):  
South Africa ◽  
Exotic Species ◽  
Potential Barrier ◽  
Literature Survey ◽  
Indigenous Species ◽  
Different Types

It is stated that there is a need both to extend the range of barrier plants available in South Africa, and to replace some much-used exotic species that have become invasive. A literature survey and computerized herbarium search revealed that of the 428 plants recorded as having been used as barriers 62% are exotics. Of these. 26% are naturalized or invasive in one or other part of South Africa. Ideal characteristics for different types of barrier plants have been defined and used as a guide in selecting a range of potential barrier plants from the indigenous species available. Lists of recognized barrier plants are given including some species revealed as a result of the present investigation.

Influence of the Method of Polymerization of Composite Material for Teeth Crown Fillings on its Strength Properties

2015 ◽  
Vol 240 ◽  
pp. 168-173
Author(s):  
Grzegorz Milewski ◽  
Tomasz Majewski
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Composite Material ◽  
Modulus Of Elasticity ◽  
Strength Properties ◽  
Dental Practice ◽  
Polymerization Shrinkage ◽  
Filling Materials

Polymerization shrinkage of composite filling materials still becomes one of the most important features which decreases strength properties of reconstructed teeth crowns. From among various methods to reduce that disadvantageous phenomenon which are used in a dental practice sandwich filling processing of crown cavity seems to be the most effective one. The paper presents the results of the strength examination of the influence of the different ways of layered polymerization processing on the mechanical properties of modern hybrid micro composite material with regards to the following quantities: compressive strength, strain to fracture, modulus of elasticity and work to fracture.

Genotypic variation in the basic density, dynamic modulus of elasticity and tracheid traits of Pinus elliottii in three progeny trials in southern China

Holzforschung ◽  
2019 ◽  
Vol 74 (1) ◽  
pp. 1-9
Author(s):  
Meng Lai ◽  
Leiming Dong ◽  
Chunhui Leng ◽  
Lu Zhang ◽  
Min Yi
Keyword(s):  
Genetic Correlation ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Southern China ◽  
Wood Quality ◽  
Basic Density ◽  
Pinus Elliottii ◽  
Wood Properties ◽  
Correlated Response ◽  
Dynamic Modulus Of Elasticity

AbstractA firm understanding of the genetic relationships among wood properties is a prerequisite for breeding for higher wood quality in Pinus elliottii families. To examine and deal with such relationships, increment cores were sampled at breast height from 1260 trees in 42 open-pollinated families in three 27-year-old Slash pine progeny trials in southern China, and genetic variation, genotype-by-environment (G × E) interaction, genetic correlation and correlated response were investigated. The basic density (BD), dynamic modulus of elasticity (MOED) and tracheid traits were found to be under moderate to strong genetic control for the three locations combined, with individual narrow-sense and family mean heritability ranging from 0.28 to 0.44 and 0.52 to 0.69, respectively. Type B genetic correlation estimates indicated that the G × E interaction had a small-level influence on wood properties. Strong genetic correlations (rg) were found between BD and MOED at the three sites (rg = 0.46–0.85), and BD or MOED showed moderate to strong correlations with most tracheid traits at specific localities. In tree breeding programs, one possible strategy would be to improve pulpwood quality and the strength of structural wood through selection for different wood quality traits.

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