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Wyniki wyszukiwania dla: WOOD PROPERTIES
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The influence of drying parameters on wood properties
PublikacjaThe influence of drying conditions on wood properties is presented. The classical approach was used to determine energetic effects (cutting forces and cutting power) of wood sawing process on the basis of the wood specific cutting resistance, material constant. Before mashining wood material (soft and hard) was dryied at various conditions using air at 25oC, air-steam meaxture at 80oC and steam at 110oC.
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The influence of drying parameters on wood properties
PublikacjaResults of influence of gas-steam mixture drying process on wood mechanical properties are presented. Wood species, namely pine (Pinus sylvestris L.) and beech (Fagus silvatica L.) from the northern part of Pomerania region in Poland, were subject of steam kiln-drying process in a laboratory kiln specially arranged for that reason.
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SAWING PROCESS AS A NEW ALTERNATIVE WAY OF DETERMINING SOME WOOD PROPERTIES
PublikacjaCutting forces (power) could be considered from a point of view of modern fracture mechanics. The developed cutting model, derived from fracture mechanics, includes work of separation (fracture toughness) in addition to plasticity and friction, and also dullness of the cutting edge described by the cutting edge radius. Moreover, forecasting of the shear plane angle for the cutting models, broaden possibilities of energetic effects...
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Dynamics of cutting power during sawing with circular saw blades as an effect of wood properties changes in the cross section
PublikacjaIn the paper the effect of the method calculation upon the cutting power is presented. In computations were used models in which fracture toughness was incorporated. The comparison concerned models as follows: FM-CM – classic model in which the sum of all uncut chip thicknesses of the simultaneously teeth engaged represented the mean uncut chip thickness, FM-FDM – full dynamical model in which besides variable uncut chip thickness...
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Influence of steam drying process on wood mechanical properties
PublikacjaResults of influence of gas-steam mixture drying process on mechanical properties of material are presented. Wood species, namely oak (Quercus L.), beech (Fagus L.), pine (Pinus L.) and spruce (Picea K.) from the northern part of Pomerania region in Poland, were subject of air-steam mixture drying process in a laboratory kiln especially arranged for that reason. Measurements of the global coefficient of elasticity and bending strength...
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Validation of polyurethane-wood composites properties
Dane BadawczeThis study focuses on the development of the PU-WC manufacturing method, the determination of properties of this type of composite, and the indication of its potential application. The mechanical properties of PU-WC were characterized by flexural tests. To determine the thermal properties, dynamic mechanical analysis (DMA) and thermogravimetric analysis...
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Investigation of Wood Flour Size, Aspect Ratios, and Injection Molding Temperature on Mechanical Properties of Wood Flour/Polyethylene Composites
PublikacjaIn the present research, wood flour reinforced polyethylene polymer composites with a coupling agent were prepared by injection molding. The effects of wood flour size, aspect ratios, and mold injection temperature on the composites’ mechanical properties were investigated. For the preparation of the polymer composites, five different formulations were created. The mechanical properties including tensile strength and the modulus,...
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Methodology for determination of the selected mechanical properties of wood based on cutting tests
PublikacjaFrom kiln-dried spruce wood (with steam) as well as in natural conditions were randomly selected 8 samples. After determining the average dimensions, moisture content and density of the samples they have been cut on the frame sawing machine PRW15M for measurement of cutting power. Based on those results from a linear rela-tionship of cutting power versus feed per toot mechanical properties of wood such as facture toughness and...
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AN ALTERNATIVE WAY OF DETERMINING MECHANICAL PROPERTIES OF WOOD BY MEASURING CUTTING FORCES
PublikacjaThe cutting force is an energetic effect of splitting material, and might be therefore considered from a point of view of modern fracture mechanics. The dedicated mathematical model developed for description of the wood cutting has been developed here on the base of fracture theory, and includes work of separation (fracture toughness) in addition to the material plasticity and friction. The effect of the cutting edge dullness is...
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Mechanical Properties and Strength Reliability of Impregnated Wood after High Temperature Conditions
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Selected mechanical properties of steam kiln-dried wood determined on the basis of cutting power
PublikacjaW artykule przedstawiono wyniki wiązkości oraz naprężeń granicznych przy ścinaniu drewna suszonego z użyciem pary wodnej na podstawie zmierzonych wartości mocy skrawania. Badaniom poddawano próbki dębowe oraz sosnowe pochodzące z północnych regionów Pomorza. Wykazano, że przyspieszone suszenie drewna z użyciem pary wywołuje obniżenie badanych właściwości mechanicznych, które wyznaczano z wykorzystaniem współczesnej mechaniki pękania.
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The Effect of Openings’ Size and Location on Selected Dynamical Properties of Typical Wood Frame Walls
PublikacjaThe wooden frame constructions are now popular in many developed countries of the world. Many of these locations where such buildings are constructed are exposed to seismic and other shocks which are generated by human activities. This paper discusses the effect of the size and location of openings in the wooden frame walls under dynamic loadings. Natural frequencies of such frames with and without openings have been determined....
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The influence of high temperature wood drying conditions using air-steam mixture on its properties
PublikacjaThe results of properties change of beech wood after drying process are presented. The wood taken to experiments was from northern part of Pomeranian region in Poland. Before the main high temperature drying process using air-steam mixture, wood was initially dried in an open air conditions. The high temperature drying process was conducted at temperature 120oC, humidity 48%, flow rate of drying medium 2.5m/s and atmospheric pressure....
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The change of mechanical properties of selected wood species after drying process under various conditions
PublikacjaThe result of mechanical properties change of selected wood species after drying process under various parameters are presented. The global elasticity modulus and bending strength for steam dried, air-steam mixture dried and air dried samples as reference were measured. It allowed to reveal the effect of wood stream, air-steam mixture and their temperature on mechanical properties of wood. It has been recognized that steam and...
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Impact of high temperature drying process on beech wood containing tension wood
PublikacjaThe technology of high temperature drying has a great inuence on dimensional and selected physical changes in tension wood. Article is focused on the measurement properties such as moisture content, color changes and longitudinal warping. The quality of beech wood is determined based on structure and properties of wood, frequency of defects in wood material. The tension wood is considered as an important wood defect causing negative...
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Polyurethane-wood composites (PU-WC) as a method of wood waste management
PublikacjaIn recent years, due to the progressive environmental degradation and increase of environmental awareness, the sustainability of production systems in wood processing, the wood industry, and wood waste management is a crucial issue for European industry and society. Consequently, the problem of generating wood-like waste and the associated risks has become an increasingly noticeable challenge for science. Although various methods...
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Synthesis and characterization of biopolyols through biomass liquefaction of wood shavings and their application in the preparation of polyurethane wood composites
PublikacjaThe sustainability of production systems in wood processing, wood industry, and wooden waste disposal is an important issue for European industry and society. Proper development of products based on renewable wood resources gives an opportunity to provide materials with long-term environmental, social, and economic sustainability. This study aims to establish a new way of forestry and agricultural waste materials utilization by...
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The selected effects of high temperature air-steam mixture wood drying
PublikacjaThe results of properties change of beech wood after drying process are presented. The wood taken to experiments was from northern part of Pomeranian region in Poland. Before the main high temperature drying process using air-steam mixture, wood was initially dried in an open air conditions. The high temperature drying process was conducted at temperature 120oC, humidity 48%, flow rate of drying medium 2.5m/s and atmospheric pressure....
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A novel approach in wood waste utilization for manufacturing of catalyst-free polyurethane-wood composites (PU-WC)
PublikacjaIn recent decades, due to the increase in environmental awareness and noticeable environmental degradation, the area of wood waste management has attracted increasing attention. The purpose of this study is to develop a new type of highly filled polyurethane wood-composite (PU-WC) by the utilization of large amount of wood wastes without addition of a catalyst. Although wood-plastic composites (WPCs) are widely known, there is...
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High temperature drying of beech with content of tension wood
PublikacjaThe presented artcle is focused on comparison of tension and normal wood of beech (Fagus sylvatica L.) in a high-temperature drying process. Samples of 26 mm thickness were selected from sapwood zone with different angle of growth rings. The article evaluated properties of tension and normal wood before and after drying process. Properties which are monitored were moisture, moisture gradients, covering tests, colour changes and...
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Kazimierz Orłowski prof. dr hab. inż.
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The Influence of Drying Temperature on Color Change of Hornbeam and Maple Wood Used as Surface and Inner Layers of Wood Composites
PublikacjaThe thermal treatment of wood changes its structure due to the degradation of wood polymers (cellulose, hemicellulose and lignin), so the physical properties of wood are either improved or degraded. Color changes apply not only to natural wood, but also to such wood composites for which some amount of glue is used in their construction (e.g., plywood, blockboard or laminboard). This article is focused on the analysis of hornbeam...
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Small wood waste fired combined heat and power plant. Possible use of wood biomass for the generation of electric and heat energy as an alternative to fossil fuels
PublikacjaThis article discusses the possibility of burning wood biomass instead of fossil fuels in boilers. It describes the properties of wood biomass, including the variation of its calorific value depending on the moisture content of wood. The article proposes several variants of a combined heat and power plant (CHP) system burning wood biomass for the generation of electric and heat energy, using the energy contained in exhaust gases...
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Analyses of Shear Angle in Orthogonal Cutting of Pine Wood
PublikacjaThe determination of energy effects for wood machining processes, such as cutting power and cutting forces, is very useful in designing of manufacture process of wooden products. A more accurate prediction of cutting forces requires a correct determination of the shear angle value, which can be determined using various models. In this article, shear angle values for an orthogonal linear cutting process of pine wood are determined. The...
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Is It Right To Predict Cutting Forces On The Basis Of Wood Density?
PublikacjaSeveral properties of wood can be correlated to wood density. It is widely accepted that the cutting power requirements are following this general assumption. Therefore, according to classic literature sources available for determination of the cutting power for both band- and circular- sawing machines, the cutting power requirements (and/or cutting forces) are computed as a function of the wood specific gravity SG. It was shown...
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Recent advances in compatibilization strategies of wood-polymer composites by isocyanates
PublikacjaWood-polymer composites technologies are gaining more and more attention in the scientific community, positively affecting the increase in their industrial applications, for example, automotive, building, 3D printing, etc. Many research works are focused on the improvement in matrix–lignocellulosic filler interactions to produce highly filled composites with satisfying performance properties. In this field of research, using isocyanates...
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Activated Carbon Produced by Pyrolysis of Waste Wood and Straw for PotentialWastewater Adsorption
PublikacjaPyrolysis of straw pellets and wood strips was performed in a fixed bed reactor. The chars, solid products of thermal degradation, were used as potential materials for activated carbon production. Chemical and physical activation processes were used to compare properties of the products. The chemical activation agent KOH was chosen and the physical activation was conducted with steam and carbon dioxide as oxidising gases. The eect...
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Particulate Matter Production of Small Heat Source Depending on the Bark Content in Wood Pellets
PublikacjaWood pellets as biofuel are more and more used in small heat sources in Europe. Standard wood pellets are produced from wood sawdust without bark. The paper deals about the impact of bark in wood pellets on their properties and combustion process. Special attention in this work is paid to production of particulate matter during combustion of wood pellets depending on bark content. There were experimentally produced spruce wood...
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Effect of the Drying Method of Pine and Beech Wood on Fracture Toughness and Shear Yield Stress
PublikacjaThe modern wood converting processes consists of several stages and material drying belongs to the most influencing future performances of products. The procedure of drying wood is usually realized between subsequent sawing operations, affecting significantly cutting conditions and general properties of material. An alternative methodology for determination of mechanical properties (fracture toughness and shear yield stress) based...
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The impact of drying and steaming processes on surface color changes of tension ad normal beech wood
PublikacjaThe aim of the article is to present the influence of high temperature to selected properties of beech wood (Fagus sylvatica L.). The properties such as moisture content, color changes and longitudinal warping were analyzed. The quality of beech wood is determined based on structure and properties of wood, frequency of defects in wood material. The tension wood is considered as an important wood defect causing negative alterations...
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Influence of high temperature air-steam mixture application on time wood drying process
PublikacjaThe results of influence gas-steam mixture drying process on time wood drying process are presented. Wood species, namely oak (Quercus L.), beech (Fagus L.), pine (Pinus L.) and spruce (Picea K.) from the northern part of Pomerania region in Poland, were subject of air-steam mixture drying process. Main focus of those tests was to shorten the time of drying process and afterward to check properties of wood.
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Experimental and Numerical Investigation of Tensile and Flexural Behavior of Nanoclay Wood-Plastic Composite
PublikacjaIn this study, the effect of wood powder and nanoclay particle content on composites’ mechanical behavior made with polyethylene matrix has been investigated. The wood flour as a reinforcer made of wood powder was at levels of 30, 40, and 50 wt.%, and additional reinforcement with nanoclay at 0, 1, 3, and 5 wt.%. Furthermore, to make a composite matrix, high-density polyethylene was used at levels of 70, 60, and 50% by weight....
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Liquefaction of alder wood as the source of renewable and sustainable polyols for preparation of polyurethane resins
PublikacjaLiquefaction of wood-based biomass gives different polyol properties depending on the reagents used. In this article, alder wood sawdust was liquefied with glycerol and poly(ethylene glycol) solvents. Liquefaction reactions were carried out at temperatures of 120, 150 and 170 °C. The obtained bio-polyols were analyzed in order to establish the process efficiency, hydroxyl number, acid value, viscosity and structural characteristics...
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By-Products from Food Industry as a Promising Alternative for the Conventional Fillers for Wood–Polymer Composites
PublikacjaThe present paper describes the application of two types of food-industry by-products, brewers’ spent grain (BSG), and coffee silverskin (ŁK) as promising alternatives for the conventional beech wood flour (WF) for wood–polymer composites. The main goal was to investigate the impact of partial and complete WF substitution by BSG and ŁK on the processing, structure, physicochemical, mechanical, and thermal properties of resulting...
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Modeling of wood frame structures with different insulation materials under damaging dynamic loading
PublikacjaWood frame buildings are very popular in regions that are exposed to different dynamic excitations, such as damaging earthquakes. Their seismic resistance is really important in order to prevent structural damages and human losses. This paper presents the results of advanced numerical investigation carried out using the FEM. Based on the models of wall panels, the numerical model of real structure of the wood frame building has...
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The Effect of Wood Provenance and Density on Cutting Forces While Sawing Scots Pine (Pinus sylvestris L.)
PublikacjaSeveral properties of wood including the cutting power requirements can be correlated to wood density. Therefore, according to the literature, the cutting power requirements (and/or cutting forces) could be computed as a function of the wood specific gravity. This research shows that such an approach, based solely on specific gravity, may be considered a rather rough and imperfect estimate of cutting power. Samples of Scots pine...
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Wood Moisture-Content Measurement Accuracy of Impregnated and Nonimpregnated Wood
PublikacjaThe influence of the impregnation process of pine wood (Pinus sylvestris L.) samples on the electrical resistance changes and the moisture-content measurement accuracy is presented in this paper. In this study, the resistances of impregnated and nonimpregnated green pine timber harvested from northern Poland were compared. An impregnation method based on a vacuum-pressure chamber was used. Copper salts were applied as the impregnated...
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High Temperature Drying Process of Beech Wood (Fagus sylvatica L.) with Different Zones of Sapwood and Red False Heartwood
PublikacjaThis study examined the changes in the properties of beech wood (Fagus sylvatica L.) after intense drying. Beech wood with false red heartwood was selected as the test specimen. The test samples had dimensions of 50 mm thickness, 180 mm width, and 350 mm length. The specimens were divided into two groups, false red heartwood and sapwood. These specimens were selected with different angles of the growth rings (radial and tangential)....
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Effect of applied standard wood machining fluid on colour and chemical composition of the machined wood surface
PublikacjaAppropriate monitoring of wood machining processes is a key issue to ensure the expected quality of the processed wood, expected efficiency and minimize energy consumption of production processes. A new trend is the design of environmentally friendly machining fluids. In this paper, as a preliminary study in this field, the effect of applied standard wood machining fluid on changes in the colour and chemical composition of the...
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Influence of Wood Moisture on Strength and Elastic Modulus for Pine and Fir Wood Subjected to 4-point Bending Tests
PublikacjaThe main purpose of this research paper was to determine the influence of the wood moisture on the strength and elastic modulus of pine and fir wood specimens subjected to the 4-point bending tests. Six bending tests for each wood species and for two different moisture level have been performed. Then, the advanced statistical analysis of the results has been carried out. On the basis of the obtained results, it has been noted that...
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On-line measurement of wood surface smoothness
PublikacjaThe latest progress in the field of optics and microelectronics resulted in development of new generation vision systems capable of scanning surface topography with very high sampling frequencies. The blue color of illuminating light as well as novel systems for controlling ultra-thin laser line thickness allows measurement of the porous surface of wood with a triangulation method. Three alternative sensors were tested here in...
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Distinctive properties of Scots pine (Pinus sylvestris L.) originating from the Carpathian and Great Poland-Pomeranian of Nature and Forest Land
PublikacjaIn this paper values of properties of Scots pine, the fracture toughness and of shear yield stress in the shear zone are presented. Samples of Scotch pine (Pinus sylvestris L.) wood of two provenances from Poland were tested. These properties were determined from the values of cutting power obtained experimentally on the saw frame PRW-15M. The values of fracture toughness and shear yield stress based on the Atkins model for cutting...
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Productivity of wood cutting process
PublikacjaW artykule przedstawiono analizę przykładowej linii przecinania drewna. Produktywność linii oceniono na podstawie stopnia wykorzystania przecinarki i faktycznej prędkości przecinania.
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Smoothing of wood surface by burnishing
PublikacjaW artykule zaprezentowano rozwój bezwiórowych metod obróbki wykańczającej drewna. Przedstawiono wpływ nagniatania ślizgowego na chropowatość powierzchni drewna. Badania przeprowadzono na próbkach wykonanych z drzewa sosnowego toczonych i nagniatanych ślizgowo. Nagniatanie ślizgowe przeprowadzono z wykorzystaniem nagniataka elastycznego o elemencie ślizgowym wykonanym z Karbonado. Wyniki odniesiono do głównych parametrów nagniatania...
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Influence of Thermal Decomposition of Wood and Wood-Based Materials on the State of the Atmospheric Air. Emissions of Toxic Compounds and Greenhouse Gases
PublikacjaThis paper presents the energy characteristics of wood and wood-based materials in the form of commercially available pellets, furniture board (MDF) and OSB. Toxicometric indices were determined for gaseous destructs arising from thermal decomposition and combustion of the materials studied. The paper proves that combustion conditions are crucial in terms of toxic destructive emissions. It has been shown that the combustion of...
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The effect of beech wood (Fagus sylvatica L.) steaming process on the colour change versus depth of tested wood layer
PublikacjaThe results of experimental research on the colour changes of beech wood at different depths of the tested layer are presented. Beech wood (Fagus sylvatica L.) dried in a conventional kiln was tested. Half of the wood samples were steamed prior to the drying process. Colour changes were measured at various depths after the face milling process was used to remove the material to expose to the deeper surface. The colour changes were...
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Economical wood sawing with circular saw blades
PublikacjaMaterial- and energy-saving belong to the basic requirements which are imposed on the contemporary manufacturing processes. Since realization of those processes gives measurable profits not only economical but also ecological. In case of wood sawing with circular saw blades material- and energy-savings are dependent on total overall set of teeth (theoretical kerf) and teeth position accuracy in relation to the workpiece. Hence,...
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Gas-steam mixture wood drying
PublikacjaBadania skuteczności suszenia wysokotemperaturowego suszenia drewna w komorze suszarniczej - wstępne wyniki.
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Timber - material of the future. Examples of small wooden architecture structures.
PublikacjaThe aim of this article is to present various types of wood-based products, classified as engineered timber, while specifying the implications of their structural properties for their forms. Timber is used as a construction material due to its fire resistance, good structural characteristics and insulating properties. The advent of new technologies of wood processing and wood-based materials production has converted timber into...
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The effect of the annual growth and the late wood share upon density of the Polish pine wood as a function of its origin
PublikacjaW artykule przedstawiono zróżnicowanie gęstości polskiego drewna sosnowego (Pinus sylvestris L.) w zależności od udziału drewna późnego w przyroście rocznym z uwzględnieniem krainy pochodzenia drewna. Wspomniane zróżnicowanie jest w istotne statystycznie w skali globalnej oraz dla większości miejsc pochodzenia. Pomiar gęstości wykonano przy użyciu metody stereometrycznej. Metoda ta polegała na określeniu objętości pryzmy poprzez...