scholarly journals Properties of wood from 7-year-old Cedrela odorata trees of two different populations growing in agroforestry systems with Theobroma cacao

2018 ◽  
Vol 24 (1) ◽  
Author(s):  
Priscilla Rigg-Aguilar ◽  
Róger Moya Roque
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Theobroma Cacao ◽  
Morphological Characteristics ◽  
Agroforestry Systems ◽  
Modulus Of Rupture ◽  
Tension Stress ◽  
Cedrela Odorata ◽  
Green Density ◽  
Two Populations

This study evaluated the properties of juvenile wood from 7-year-old Cedrela odorata trees in two populations with the same provenance and planted in an agroforestry system with Theobroma cacao (cacao). The morphological characteristics (diameter at breast height; heartwood, sapwood, bark, and pith percentages; and eccentricity of pith), physical properties (shrinkage, green moisture content, green density, and specific gravity) and mechanical properties (modulus of rupture (MOR) and modulus of elasticity (MOE) in bending, compression stress, Janka hardness, tension stress and shear stress) were determined between two populations. The variation of the physical properties and morphological characteristics at different tree heights was also evaluated. The results showed that there were differences in both populations in terms of bark, pith, volumetric shrinkage, green moisture content, green density, MOR and MOE in bending, longitudinal compression and perpendicular tension. The results showed that population 2 presents better characteristics of growth and quality of wood for structural and furniture uses; hence, this population planted in agroforestry systems has good plantation conditions and wood quality.

scholarly journals Biomass decomposition dynamic in agroforestry systems with Theobroma cacao L. in Rionegro, Santander (Colombia)

2017 ◽  
Vol 35 (2) ◽  
pp. 182-189 ◽  
Author(s):  
Jairo Rojas M. ◽  
Victor Caicedo ◽  
Yeirme Jaimes
Keyword(s):  
Theobroma Cacao ◽  
Plant Material ◽  
Nutrient Release ◽  
Magnesium Content ◽  
Agroforestry System ◽  
Agroforestry Systems ◽  
Leaf Biomass ◽  
Cedrela Odorata ◽  
Material Decomposition ◽  
Biomass Decomposition

The study was carried out in an agroforestry system (AFS) with cacao trees already established in La Suiza Research Center, Corpoica, located in Rionegro, Santander (Colombia). The objective was to evaluate biomass input and nutrient release rate of the species that comprise the AFS (Gmelina arbórea, Gliricidia sepium, Cedrela odorata, Theobroma cacao). The plant material decomposition process of the species was monitored with decomposition bags after 8, 15, 23, 84 and 113 days, evaluating remnant weight and nitrogen, phosphorous, potassium, calcium and magnesium content. Results showed significant differences in plant material decomposition of the species considered. The largest weight loss was found in G. arborea (87.55%) and the lowest in C. odorata (40.01%). The highest nutrient release value was found in G. arborea followed by G. sepium, and the lowest in T. cacao and C. odorata.Therefore, depending on the species that comprise the AFS there is a differential leaf biomass decomposition dynamic and hence, of the nutrient input to the soil. Of the species evaluated the highest input of new organic matter to the soil in this AFS comes from G. arborea. Altogether, the litter generated by the species evaluated contributed with 10% of the nutrients required for a cacao harvest.

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.

scholarly journals Evaluation of Acacia Mangium in Structural Size at Green Condition

2011 ◽  
Vol 2 (2) ◽  
pp. 17-22 ◽  
Author(s):  
Gaddafi Ismaili ◽  
Badorul Hisham Abu Bakar ◽  
Khairul Khuzaimah Abdul Rahim
Keyword(s):  
Tensile Strength ◽  
Moisture Content ◽  
Mechanical Strength ◽  
Physical Properties ◽  
Basic Density ◽  
Acacia Mangium ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Structural Size ◽  
Green Condition

Acacia mangium is one of the most popular choices in the reforestation and rehabilitation of abandoned shifting cultivation areas dated back to the 70’s. This paper looks into the evaluation of mechanical strength and physical properties in structural size at green condition for Acacia mangium. The mechanical strength properties tests were referred to the modulus of rupture, modulus of elasticity and tensile strength. Meanwhile, physical properties determination referred to basic density and moisture content. At green condition, Acacia mangium had been identified under the strength group SG6. It was found that strength value of modulus of rupture was higher than the tensile strength value with 44% stronger in bending compared to in tension. At the structural size, the mean value for moisture content and basic density at green condition were reported with 73.03% and 0.54g/cm3 respectively.

Modelling agroforestry systems of cacao (Theobroma cacao) with laurel (Cordia alliodora) or poro (Erythrina poeppigiana) in Costa Rica

1990 ◽  
Vol 12 (3) ◽  
pp. 229-249 ◽  
Author(s):  
J. Beer ◽  
A. Bonnemann ◽  
W. Chavez ◽  
H. W. Fassbender ◽  
A. C. Imbach ◽  
...  
Keyword(s):  
Costa Rica ◽  
Theobroma Cacao ◽  
Agroforestry Systems ◽  
Cordia Alliodora ◽  
Erythrina Poeppigiana

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.

Influence of Moisture Content in some Mechanical Properties of Two Brazilian Tropical Wood Species

2014 ◽  
Vol 1025-1026 ◽  
pp. 42-45 ◽  
Author(s):  
Luiz A. Melgaço N. Branco ◽  
Eduardo Chahud ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Rosane A.G. Battistelle ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Moisture Content ◽  
Analysis Of Variance ◽  
Wood Species ◽  
Modulus Of Elasticity ◽  
Modulus Of Rupture ◽  
Tropical Wood ◽  
Fiber Saturation ◽  
Brazilian Standard

This study aimed, with the aid of analysis of variance (ANOVA), to investigate and quantify the influence of moisture ranging between 12% and over 30% (fiber saturation) on the mechanical properties: strength and modulus of elasticity in compression and in tension parallel to grain; modulus of rupture and modulus of elasticity in static bending; shear strength parallel to grain considering wood species Ipê (Tabebuia sp) and Angelim Araroba (Vataireopsis araroba). Tests were performed according to the assumptions and calculating methods Brazilian standard ABNT NBR 7190, Anexx B, totalizing 400 tests. Results of ANOVA revealed a significant reduction (16% on average) for mechanical properties wood due to the increase in moisture content from 12% to over 30% (fiber saturation). The same behavior also occurred when assembly containing the two species was considered.

Measuring the Thermo-Technical Parameters of Autoclaved Aerated Concrete

2016 ◽  
Vol 824 ◽  
pp. 100-107 ◽  
Author(s):  
Alena Struhárová
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Physical Properties ◽  
Bulk Density ◽  
Capillary Absorption ◽  
Measuring Device ◽  
Technical Parameters ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Technical Properties

Bulk density and moisture content are factors that significantly affect the physical properties of autoclaved aerated concrete (AAC) including thermal conductivity and other thermo-technical characteristics. This article shows the results of measurements of compressive strength, capillary absorption, water absorption and porosity of AAC (ash on fluidized fly ash) at different bulk density and also the results of thermal conductivity of AAC at different bulk density and variable moisture content of the material. The thermo-technical properties were measured using the Isomet 2104, a portable measuring device. Acquired results demonstrate dependence of physical properties including thermal conductivity of AAC on bulk density and moisture content. The reliability and accuracy of the method of measuring was also shown.

Selected Properties of Parallel Strand Lumber Made from Southern Pine and Yellow-Poplar

Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Y. Liu ◽  
A.W.C. Lee
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Specific Gravity ◽  
Moisture Content ◽  
Dimensional Stability ◽  
Modulus Of Rupture ◽  
Southern Pine ◽  
Yellow Poplar ◽  
Average Modulus ◽  
Parallel Strand Lumber

Summary This study was conducted to explore basic physical and mechanical properties of parallel strand lumber (PSL) made exclusively from southern pine and yellow-poplar, respectively, and to examine their relationships using statistical analysis. Small specimens were prepared from commercial southern pine PSL and yellow-poplar PSL billets and tested for specific gravity, moisture content, dimensional stability, bending properties, shear strength and compressive strength. Results indicate average specific gravity of southern pine PSL is higher than that of yellow-poplar PSL, while their average moisture content and dimensional stability are very similar. Southern pine PSL has higher average modulus of elasticity but lower average modulus of rupture than yellow-poplar PSL. While average longitudinal shear strength does not exhibit differences between southern pine PSL and yellow-poplar PSL, average compressive strength of southern pine PSL is higher than that of yellow-poplar PSL. There are positive correlations among modulus of elasticity, modulus of rupture and specific gravity. PSL improves some properties of solid wood from which PSL is made.

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