Experimental Investigation of Water Soaked Wood at Uniaxial and Biaxial States of Stress

1995 ◽  
Vol 48 (10) ◽  
pp. 684-688 ◽  
Author(s):  
M. Kowal ◽  
S. J. Kowalski
Keyword(s):  
Experimental Investigation ◽  
Stress State ◽  
Moisture Content ◽  
Radial Direction ◽  
Tangential Direction ◽  
Biaxial Stress ◽  
Growth Rings ◽  
Significant Difference ◽  
Free Swelling

It is possible to observe a significant difference in swelling strains of unstressed and stressed water soaked wood. This paper points out that the swelling strains depend not only on the magnitude of stress in wood but also on the kind of stress state. Our main aim is to investigate the relation between various states of stress and the swelling strains in water soaked wood. Three different states of stress are studied: tension in the radial direction, compression in the tangential direction with respect to the growth rings, and both these stresses acting together (biaxial stress). Some weighty conclusions follow from the investigations. The main one is that, although the mechanical strains alone are negligibly small compared to the free swelling strains, the coupled mechanical-swelling strains, being a function of the stress state and the moisture content, have a great significance in total strains of water soaked wood.

scholarly journals Physical properties of sessile oak (quercus petraea l) used by the wood industry in Kosovo

2020 ◽  
Vol 2 (7) ◽  
pp. 278-285
Author(s):  
Rrahim Sejdiu ◽  
Florit Hoxha ◽  
Bujar Jashari ◽  
Lulzim Idrizi
Keyword(s):  
Specific Gravity ◽  
Moisture Content ◽  
Physical Properties ◽  
Radial Direction ◽  
Tangential Direction ◽  
Quercus Petraea ◽  
Sessile Oak ◽  
Content Ratio ◽  
Wet Condition ◽  
Shrinkage Coefficient

The paper shows some physical properties of sessile oak obtained in Kosovo regions. In the study are shown: wood shrinkage, specific gravity, shrinkage coefficient for 1% change of moisture content, ratio of shrinkage in tangential and radial direction etc. The amount of volumetric shrinkage of sessile oak is 15.95%, heartwood part has an average shrinkage 15.41% in The shrinkage of sapwood part is 17.56%. Specific gravity at: wet condition: (1.013gr/cm3); 12% (0.853gr/cm3) and 0% (0.826gr/cm3) of moisture content. Specific gravity of heartwood at: wet condition (1.05gr/cm3); 12% (0.88gr/cm3); 0% (0.85gr/cm3). The specific gravity of sapwood at: wet condition (0.91gr/cm3); 12% (0.77gr/cm3); 0% (0.748gr/cm3). The ratio of average shrinkage between tangential and radial cutting direction is 1.71%. This ratio was significantly higher in sapwood than heartwood. Coefficient of shrinkage (changing 1% of moisture content) in the radial direction is 0.00196, and 0.00323 in tangential direction.  

Influence of Moisture Sorption on Swelling of Mahogany (Swietenia macrophylla King) Wood

Holzforschung ◽  
2001 ◽  
Vol 55 (6) ◽  
pp. 590-594 ◽  
Author(s):  
R. Arévalo ◽  
R.E. Hernández
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Radial Direction ◽  
Moisture Sorption ◽  
Tangential Direction ◽  
Order Effects ◽  
Swelling Ratio ◽  
Swietenia Macrophylla ◽  
Dimensional Changes ◽  
Moisture Conditions

Summary Samples of mahogany wood (Swietenia macrophylla King) from Peru were used for moisture sorption tests associated with swelling tests at 25°C. Seven adsorption and five desorption moisture conditions were investigated to study the differences in swelling between adsorption and desorption curves at a given equilibrium moisture content. The results demonstrated that dimensional changes in the tangential direction and in volume were greater for desorption than for adsorption. The presence of these second order effects of moisture sorption in mahogany wood were not detected in the radial direction. Finally, the tangential/radial swelling ratio of this wood was lower in both states of sorption, and was lower in adsorption than in the desorption state.

Properties of Gliricidia Wood (Gliricidia sepium) lntercropped with Cocoa (Theobroma cocoa) in Malaysia

2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader
Keyword(s):  
Cell Wall ◽  
Specific Gravity ◽  
Moisture Content ◽  
Wall Thickness ◽  
Age Groups ◽  
Gliricidia Sepium ◽  
Cell Wall Thickness ◽  
Tree Age ◽  
Lumen Diameter ◽  
Significant Difference

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.

scholarly journals Experimental investigation of vertical and horizontal reinforcement geotextiles in forest road pavement

2018 ◽  
Vol 64 (No. 7) ◽  
pp. 296-302 ◽  
Author(s):  
Dini Morteza ◽  
Nikooy Mehrdad ◽  
Naskovets Michael Trofimovich ◽  
Ghomi Alireza
Keyword(s):  
Experimental Investigation ◽  
The Other ◽  
Data Logging ◽  
Truck Traffic ◽  
Horizontal Structure ◽  
Forest Road ◽  
Vehicle Traffic ◽  
Road Pavement ◽  
Significant Difference ◽  
Experimental Survey

In this research, the results of an experimental survey on the measurement of vertical stresses are presented. Four treatments were used in this study such as combination of geotextile vertical and horizontal structure with dimensions of 5 × 5 and 10 × 10 cm, horizontal geotextile and the treatment without geotextile. Five sensors were installed in different hole locations and the lead of the truck traffic was transmitted by cables to data logging and recording devices to measure the pressure from vehicle traffic on the simulated pavement layer. Mean comparison of the treatments showed that the geotextile with vertical and horizontal structure and dimensions of 5 × 5 cm exerted the lowest pressure on the lower layers compared with the other treatments and there was a significant difference between the value of this treatment and the other treatments and that this treatment could significantly reduce the pressure of truck traffic on the forest road.

Cell grouping and primary wall generations in the cambial zone, xylem, and phloem in Pinus

1968 ◽  
Vol 16 (2) ◽  
pp. 177 ◽  
Author(s):  
A Mahmood
Keyword(s):  
Cell Division ◽  
Mother Cell ◽  
Secondary Wall ◽  
Radial Direction ◽  
Cell Plate ◽  
Tangential Direction ◽  
Primary Wall ◽  
Photographic Evidence ◽  
Secondary Wall Deposition ◽  
Cambial Zone

The use of the term cambium, or equivalent terms, in modern literature is discussed. The term cambial zone adopted in this paper includes the cambial initial and the dividing and enlarging cells. The tissue mother cell produced at each division of the initial produces a group of four cells in xylem or two cells in phloem. Theoretical constructs have been made for xylem and phloem production by associating the concepts that xylem and phloem are produced in alternate series of initial divisions and that a new primary wall is deposited around each daughter protoplast at each cell division. Correlations are derived from the theoretical constructs for the thickness of primary wall layers lying in the tangential direction and of those lying in the radial direction at progressive histological levels. Deductions from theoretical constructs are made when the initial is producing xylem, when it changes its polarity from xylem to phloem production, and when the reverse change occurs. Most of the theoretical deductions are supported by photographic evidence. The chief point of this study is the demonstration of generations (multiplicity) of primary parental walls. The term intercellular material proposed in this paper includes the cell plate plus any remnants of ancestral primary walls between the current primary walls surrounding the adjacent protoplasts. This term is still applicable to cells where secondary wall deposition is taking place or has been completed.

Study on the Best Reinforcement Arrangement of Thick-Walled Cylinder

2011 ◽  
Vol 94-96 ◽  
pp. 2009-2014
Author(s):  
Yun Qian Xu ◽  
Ai Zhong Lu ◽  
Ning Zhang ◽  
Pan Cui
Keyword(s):  
Stress State ◽  
Bearing Capacity ◽  
Functionally Graded Material ◽  
Radial Direction ◽  
Plain Concrete ◽  
Functionally Graded ◽  
Reinforcement Ratio ◽  
Uniform Load ◽  
Graded Material ◽  
Walled Cylinder

In order to improve the ultimate bearing capacity, In this paper, the theory of functionally graded material is introduced. This paper simulate thick-walled cylinder with functionally graded characteristics through the analysis of using different reinforced ways along the radial direction. The author analyzes the stress state of the thick-walled cylinder with plain concrete and three different reinforced ways under the radical uniform load. Comparisons and evaluations are provided based on ANSYS results. The paper provide a reasonable reinforced way that is a larger reinforcement ratio near the outer and a smaller reinforcement ratio near the inner and is different with the traditional way. But the worst reinforcement arrangement is that a larger reinforcement ratio near the inner and a smaller reinforcement ratio near the outer. The conclusion shows that the principle that larger reinforcement ratio should be adopted where the tangential stress is larger is not suitable to the thick-walled cylinder.

Parameters Affecting Milling Qualities of Undefatted Soybeans (Glycine max, L. Merill) (2): Selected Physical Properties

2005 ◽  
Vol 1 (5) ◽  
Author(s):  
Abdul Ganiy O. Raji ◽  
John Alaba Victor Famurewa
Keyword(s):  
Moisture Content ◽  
Protein Content ◽  
Soybean Protein ◽  
Soy Flour ◽  
International Institute ◽  
Attrition Mill ◽  
Protein Retention ◽  
Significant Difference ◽  
Glycine Max L ◽  
Flour Yield

Soybean protein is highly rich in the essential amino acid needed by human body. In the developing countries, its use will be more generally acceptable when converted to flour like wheat. This work focused on establishing the optimum conditions of some physical characteristics of soybean for high quality and acceptable soy flour. The characteristics studied for soybean samples subjected to heat treatment of boiling and oven drying were the effect moisture content (MC) and the hull thickness on the quality of the flours. Ten samples of Tax 1485 at different moisture levels ranging from 20.6% to 8.6% and five varieties (Tax 1440-1E, Tax 1740, Tax 1485, Tax 1456 and Tax 1448-2E) obtained from International Institute for Tropical Agriculture (IITA), having different hull thicknesses were used. Soybean with mixed varieties commonly found in the open markets was also used to compare the effects of MC on the studied parameters. Flours obtained from the samples milled in an attrition mill were subjected to proximate, sieve and organoleptic evaluations. The hull thickness was found to have no correlation with protein retention, acceptability and flour yield, but moisture content has a very significant effect on the qualities. Between moisture content of 20.6% and 8.6%, protein and acceptability reduced from 40.0% to 27.7% and 4.3 to 2.2 respectively while yield increased from 0.9% to 5.8%. Though protein was reducing with reduced MC, there was no significant difference (p<0.05) in protein retention between MC of 20.6% and 10.1% but it became significant at 9.4%. There was no significant difference in acceptability from 13.6% to 8.6% MC and between 8.9% and 11.0% MC for flour yield. Both Tax 1485 and mixed varieties followed the same trend only that they have different absolute values. The mixed varieties however had no significant difference in protein content between 19.8% and 10.2% MC. These results, therefore established that to obtain acceptable soyflour of high flour yield and protein content, moisture content of soybean after processing should be about 10% (dry basis).

scholarly journals Physico-chemical properties, probiotic stability and sensory characteristics of Lactobacillus plantarum S20 – supplemented passion fruit (Passiflora edulis f. flavicarpa Deg.) juice powder

Food Research ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 320-326
Author(s):  
Reifrey, A. Lascano ◽  
M.G.L.D. Gan ◽  
A.S.L. Sulabo ◽  
D.M.O. Santiago ◽  
L.B. Ancheta ◽  
...  
Keyword(s):  
Moisture Content ◽  
Lactobacillus Plantarum ◽  
Spray Drying ◽  
Fruit Juice ◽  
Chemical Properties ◽  
Passion Fruit ◽  
Soluble Solids ◽  
Passiflora Edulis ◽  
Physico Chemical ◽  
Significant Difference

The study aimed to develop a non-dairy-based probiotic-supplemented product using an underutilized crop in the Philippines such as the yellow passion fruit (Passiflora edulis f. flavicarpa Deg.). The physico-chemical properties (moisture content, water activity, pH, and total soluble solids), probiotics stability at different storage temperatures (4°C, 25°C, and 37°C), and the sensory characteristics of Lactobacillus plantarum S20-supplemented passion fruit juice powder was evaluated. Passion fruit juice powder and L. plantarum S20 were first prepared using low-temperature spray drying utilizing maltodextrin as a carrier, with yield as 42.97% and 21.17%, respectively. Spray drying of probiotics culture also resulted in 42.68% log survivability. The formulated juice powder had a final moisture content of 1.729±0.38% and water activity of 0.398±0.0051, and with recommended dilution with water, had a final pH and total soluble solids of 3.40±0.10 and 12.00±0.00° Brix, respectively. Results also showed that storage of the formulated juice powder at 4°C yielded the highest probiotic stability, maintaining a viable log count of 4.27 per g, while storage at 37°C showed no microbial growth. Sensory evaluation of probioticsupplemented passion fruit juice against a non-probiotic-supplemented one revealed significant difference in terms of color, sweetness, and sourness, while no significant difference was observed in terms of aroma, mouthfeel, and general acceptability.

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