scholarly journals Basic physical properties of spruce wood (Picea abies Karst) from plantations

2007 ◽  
pp. 97-110
Author(s):  
Borislav Soskic ◽  
Zoran Govedar ◽  
Nebojsa Todorovic ◽  
Danijela Petrovic
Keyword(s):  
Physical Properties ◽  
Growth Ring ◽  
Fibre Saturation Point ◽  
Surface Anisotropy ◽  
Saturation Point ◽  
Average Value ◽  
Breast Height ◽  
Spruce Wood ◽  
Volume Porosity ◽  
Ring Diameter

The basic physical properties of spruce wood from plantations in the surroundings of Banja Luka were researched. The dependence of growth ring diameter and wood density, density, volume porosity, shrinkage, fibre saturation point and absorption of moisture were analysed on three trees average age about 16 years. The data for breast height and for all specimens from breast height to 9.3 m were statistically processed. The research and analysis of the basic physical properties of plantation-grown spruce wood shows that the effect of growth ring diameter on the density is negative and that the dependence is logarithmic, which confirms the previous results. Average value of wood density is lower than the usual value reported in references. Average value of radial shrinkage is 3.90%, and tangential 8.10%. This research confirms the linear dependence between the nominal density and volumetric shrinkage of spruce wood and that density has a negative effect on the coefficient of surface anisotropy. At breast height, average value of the coefficient of surface anisotropy is 2.16, volume porosity 72%, and fibre saturation point 32.6%. Average rate of absorption is 3.42% per day, for the first 7 days, and 0.12% per day for the last 30 days. The study results were compared to the results reported by other authors.

Physical properties of earlywood and latewood of Pinus radiata D. Don: Anisotropic shrinkage, equilibrium moisture content and fibre saturation point

Holzforschung ◽  
2005 ◽  
Vol 59 (6) ◽  
pp. 654-661 ◽  
Author(s):  
Shusheng Pang ◽  
Alfred Herritsch
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Pinus Radiata ◽  
Growth Ring ◽  
Fibre Saturation Point ◽  
Longitudinal Shrinkage ◽  
Saturation Point ◽  
Breast Height ◽  
Second Growth ◽  
Tangential Shrinkage

Abstract Anisotropic shrinkage (tangential and longitudinal), equilibrium moisture content (EMC) and fibre saturation point (FSP) were measured for separated earlywood (EW) and latewood (LW) of a 0.75-m-long log of 20-year old Pinus radiata that was cut at breast height from a selected tree in the forest of Central North Island, New Zealand. The experimental results have shown that at 12% moisture content (MC), tangential shrinkage was 3.23% for EW and 3.90% for LW, with an overall average of 3.56%. Longitudinal shrinkage was 0.23% for EW and 0.21% for LW with an overall average of 0.22%. Shrinkage for the oven dry (OD) state showed similar trends to those at 12% MC in terms of the differences between EW and LW. The tangential and longitudinal shrinkage varied significantly along the radius from pith to bark. The EW tangential shrinkage increased from pith to the seventh growth ring and then remained relatively constant until the last ring adjacent to the bark. The LW tangential shrinkage also increased from the pith outwards until the seventh growth ring, but beyond that was more variable than the EW shrinkage. Both EW and LW showed similar longitudinal shrinkage, with the highest values in the second growth ring, from which the shrinkage decreased exponentially towards the bark. LW had a slightly higher EMC than EW at a relative humidity (RH) below 80%, but the trend was reversed for RH above 80%. The EMC differences between EW and LW were less than 0.6%. The overall average FSP for Pinus radiata was 29.1%, with actual values varying from 25% to 32.8%. The earlywood FSP (28.9%) was slightly lower than that of the latewood (29.4%).

scholarly journals A study of water exchange in wood by means of 2D NMR relaxation correlation and exchange

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Julia Cox ◽  
Peter J. McDonald ◽  
Barry A. Gardiner
Keyword(s):  
Water Exchange ◽  
Nmr Relaxation ◽  
2D Nmr ◽  
Fibre Saturation Point ◽  
Two Dimensional ◽  
Saturation Point ◽  
One Dimensional ◽  
H Nmr ◽  
Spruce Wood ◽  
Content Range

Abstract Two-dimensional T 1-T 2 1H NMR relaxation correlation spectra and T 2-T 2 relaxation exchange spectra for samples of spruce wood across the full moisture content range from 0% to >100% are presented. The T 1-T 2 spectra unambiguously identify water in different environments within the wood that overlap in the corresponding and more traditional one-dimensional T 1 or T 2 experiment. The T 2-T 2 spectra unambiguously reveal the presence of water exchange between the lumen and cell wall above the fibre saturation point in sapwood. An estimate is made of the exchange rate: 1/30 to 1/3 ms-1.

Influence of Age on Selected Anatomical Properties of Populus Clones

IAWA Journal ◽  
1994 ◽  
Vol 15 (3) ◽  
pp. 311-321 ◽  
Author(s):  
Ilona Peszlen
Keyword(s):  
Growth Ring ◽  
Hybrid Poplar ◽  
Populus Euramericana ◽  
Breast Height ◽  
Image Analyser ◽  
Anatomical Properties ◽  
Effect Of Age

Anatomieal properties of three Euramerican hybrid poplar [Populus × euramericana (Dode) Guinier] clones, the Italian 'I-214' and the Hungarian 'Kopecky' and 'Koltay', were investigated. Six trees from each clone were sampled from plantations (aged 15 and 10 years) at two sites in Hungary. Disks were removed at breast height from each tree to study the effect of age on variation of anatomical properties. Along the eastern radius, vesscl and fibre parameters were measured for each growth ring using an image analyser.

scholarly journals MECHANICAL STRENGTH OF COAL: METHODS OF DETERMINATION AND FACTORS OF INFLUENCE (REVIEW)

2021 ◽  
Vol 6 ◽  
pp. 4-17
Author(s):  
V.V Koval ◽  
D.V. Miroshnichenko ◽  
O.V. Bogoyavlenska
Keyword(s):  
Mechanical Strength ◽  
Physical Properties ◽  
Physical And Mechanical Properties ◽  
Mechanical Tests ◽  
Point Of View ◽  
Statistical Characteristics ◽  
Measuring Instruments ◽  
Industrial Processing ◽  
Average Value ◽  
Advantages And Disadvantages

The article substantiates the importance and problems of determining of such an indicator of the quality of solid fossil fuels, as mechanical strength. The strength of coal depends on a large number of factors (viscosity, brittleness, properties of structural bonds, etc.), the change of which is impossible to take into account. Therefore, the strength of coal in the sample, piece, pack and formation must be represented by some integral index, which inevitably fluctuates around a certain average value and can be determined only approximately. The evaluation of the strength properties of coal should be carried out on the basis of mass tests using statistical methods that allow to calculate the average value and coefficient of variation. Since the strength dispersion is mainly due to the natural inhomogeneity of the coal, the excessive accuracy of the measuring instruments has almost no effect on the statistical characteristics. Laboratory methods of mechanical tests of mine samples, in comparison with full-scale, as a rule, are very accessible and, at qualitative performance of tests, are highly reliable. The properties of coal as an object of enrichment and use are largely related to its physical properties. The physical properties of coal and mineral impurities significantly affect the formation of the main parameters that characterize the particle size distribution and fractional composition, it`s changes during the mining, transportation and enrichment processes. The basic physical and mechanical properties of solid fuels from the point of view of their industrial processing have been listed, the review has been made of the most widespread methods of study of coals mechanical durability and the equipment used for these purposes. The main advantages and disadvantages have been summarized of these methods, as well as their relationship. The factors have been Indicated tinfluencing the mechanical strength of coal. The expediency of using existing methods from the point of view of informativeness for thesphere of its application has been estimated. The methods common in the coal processing industry are considered in more detail. Keywords: coal, solid fuel mining, mechanical strength, determination methods, influencing factors, grinding strength, crushing index. Corresponding author V.V. Koval, e-mail: [email protected]

scholarly journals EFFECT OF VARIATIONS OF BETA VULGARIS EXTRACTS ON MASKING THE BITTER TASTE OF MOMORDICA CHARANTIA EXTRACT SYRUP

2018 ◽  
Vol 10 (1) ◽  
pp. 159
Author(s):  
Sutriyo . ◽  
Raditya Iswandana ◽  
Elisa Nur Widiya
Keyword(s):  
Specific Gravity ◽  
Physical Properties ◽  
Beta Vulgaris ◽  
Sodium Benzoate ◽  
Bitter Taste ◽  
Momordica Charantia ◽  
The Other ◽  
Bitter Melon ◽  
Average Value

Objective: This study aimed to obtain a formula with an optimal sweetener concentration of beet extract that can cover the bitter taste of bitter melonand confer optimal physical properties on the syrup.Methods: The syrups were prepared by mixing bitter melon extract, sucrose, beet extract, sorbitol, sodium benzoate, strawberry essence, anddemineralized water. The control formula and formulas 1, 2, and 3 contained beet extract at concentrations of 0% and 10%, 15%, and 20%, respectively.All formulas were evaluated to determine their physical properties, stability, and bitterness. The bitterness was tested on 30 respondents, with databeing analyzed using Wilcoxon’s test on SPSS software.Results and Conclusion: Formula 3 with 20% beet extract was identified as the best formula for masking bitter taste because it had a significantlybetter average value than the other formulas (p<0.05) and the highest bitterless taste percentage (86.67%), with physical properties of a brownishblackcolor, odor of mixture of strawberry and dominant beet, a sweet and dominant beet taste, pH 5.46, and specific gravity of 1.228 g/mL.

scholarly journals Fibre Saturation Point of Wood

Nature ◽  
1935 ◽  
Vol 135 (3414) ◽  
pp. 545-545 ◽  
Author(s):  
WILFRED W. BARKAS
Keyword(s):  
Fibre Saturation Point ◽  
Saturation Point

HEAT AND MASS TRANSFER DURING SAPWOOD DRYING ABOVE THE FIBRE SATURATION POINT

2000 ◽  
Vol 18 (8) ◽  
pp. 1647-1664 ◽  
Author(s):  
P. Wiberg ◽  
S.M.B. Sehlstedt-P ◽  
T.J. Morén
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Fibre Saturation Point ◽  
Saturation Point
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