This study investigated the variations in tracheid length of Pseudotsuga menziesii (Mirb.) Franco from three sites in Croatia in relation to cambium age, within- and between-site differences, and ...growth rate. Tracheids are the main structural element in P. menziesii wood, varying in length following different patterns that should be precisely determined. After the maceration procedure, earlywood tracheid length (EWTL), latewood tracheid length (LWTL), annual growth ring tracheid length (RTL), earlywood ring width (EWW), latewood ring width (LWW), and annual ring width (ARW) were measured in selected annual growth rings. The significant effect of annual growth rings and zone interaction for EWTL and LWTL, as well as of annual growth rings, trees, and sites for RTL, was determined. The results conclude on the differences between the trends in EWTL and LWTL from pith toward the bark. In addition, the correlation analysis between the tracheid length and different growth patterns was investigated, and very weak or no association between the variables was detected. This research contributes to better understanding the degree of wood uniformity of P. menziesii from the technological perspective, as well as the variability factor in the optimization of forest management with favoring overall wood quality.
The interpretation and presentation of research on the physical and mechanical properties of wood in the radial direction is important for the estimation of technological properties in primary wood ...processing. It is common practice to define the boundary between the juvenile and mature wood zone of tree growth because of the differences in wood properties in these two zones. The juvenile and mature wood zones can be determined statistically based on the significance of the difference in the properties in a particular zone. This paper presents the insufficiency in the statistical determination of the boundary between juvenile and adult wood. Such limitations detract from the potential value and technological exploitation of wood as raw material. Statistical tests yielded zones that were too wide for the transition of juvenile wood to mature wood. Representations of the distribution of properties in the radial direction also complement the knowledge for assessing the technological properties based on the researched use of the presentation of polynomials of the second degree and the display of the Tukey HSD test in the form of comparison tables. The graphical representations by groups of the tested annual rings of fir wood also help to assess the technological properties.
The aim of this research is to measure the energy consumption and compare the cutting performance of three types of battery-powered chainsaws (Stihl MSA 200, Stihl MSA 220, and Stihl MSA 300). Tested ...chainsaws were powered by two different battery packs (Stihl AP 300 S and Stihl AP 500 S) with different energy capacity and output current when cutting two wooden beams, European beech (Fagus sylvatica L.) and black locust (Robinia pseudoacacia L.) with different densities and moisture content. Energy consumption was measured using a multimeter built-in battery charger housing, and consumed energy was noted in watt-hours. Each individual cut was recorded with an action camera at 60 frames per second, and the duration of the cuts recorded in centiseconds was observed on the obtained recordings. Results show significant differences in energy consumption and cutting duration between individual chainsaw/battery combinations. Energy consumption ranged from 2.45 to 4.50 Wh per cut for beech (Stihl MSA300E_AP500S and Stihl MSA220_AP300S, respectively) and from 3.10 to 5.00 Wh per cut for black locust (Stihl MSA300M_AP500S and Stihl MSA220_AP500S, respectively). Duration of the cut ranged from 3.48 to 9.24 s per cut for beech (Stihl MSA300M/H_AP500S and Stihl MSA220_AP300S, respectively) and from 3.74 to 9.35 s per cut for the black locust (Stihl MSA300M_AP500S and Stihl MSA220_AP300S, respectively). In general, it can be concluded that more powerful chainsaw/battery combinations (Stihl MSA300_AP500S) consumed less energy per cut and had better cutting performance (shorter cut). In that regard, more powerful chainsaws had greater cutting efficiency, i.e., more cuts on one charge (battery) but shorter cutting time on one charge. The effect of tree species (fresh-sawed beech/air-dried black locust) on energy consumption and cutting performance is absent on the most powerful chainsaw/battery combinations. Today, lithium-ion batteries still have 70 times less energy density than petrol. However, if there is a significant increase in the energy density of the batteries in the coming times, battery chainsaws will most certainly displace petrol chainsaws from use in the future.
The modification of wood and its surface is one of the challenges that is being perfected with the aim of transitioning to sustainable management. This study investigated the dynamic mechanical and ...thermal behaviour of unmodified and styrene modified fir wood (
Mill.). Styrene monomer was chosen and impregnated into the porous structure of fir wood by reversible addition-fragmentation chain transfer (RAFT) polymerisation. Attenuated total reflection Fourier-transform infrared spectroscopy (FTIR-ATR), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA) were employed to characterise the chemical structure, viscoelastic properties, and thermal stability of unmodified and modified (surface-modified) wood. All tests have to be regarded as being preliminary due to the small number of specimens. Fourier transform infrared analysis showed evidence of the phenyl group from styrene at 700 cm
. DMA results showed that the modified wood caused an increase in the glass transition temperature relative to the unmodified wood. In addition, modification with styrene improves thermal stability, as revealed by thermogravimetric analysis (TGA).
The world’s expanding population presents a challenge through its rising demand for wood products. This requirement contributes to increased production and, ultimately, the high-quality and efficient ...utilization of basic materials. Detecting defects in wood elements, which are inevitable when working with a natural material such as wood, is one of the difficulties associated with the issue above. Even in modern times, people still identify wood defects by visually scrutinizing the sawn surface and marking the defects. Industrial scanners equipped with software based on convolutional neural networks (CNNs) allow for the rapid detection of defects and have the potential to accelerate production and eradicate human subjectivity. This paper evaluates the suitability of defect recognition software in industrial scanners against software specifically designed for this task within a research project conducted using Adaptive Vision Studio, focusing on feature detection techniques. The research revealed that the software installed as part of the industrial scanner is more effective for analyzing knots (77.78% vs. 70.37%), sapwood (100% vs. 80%), and ambrosia wood (60% vs. 20%), while the software derived from the project is more effective for analyzing cracks (70% vs. 65%), ingrown bark (42.86% vs. 28.57%), and wood rays (81.82% vs. 27.27%).
This study investigated the variations in tracheid length of Pseudotsuga menziesii (Mirb.) Franco from three sites in Croatia in relation to cambium age, within- and between-site differences, and ...growth rate. Tracheids are the main structural element in P. menziesii wood, varying in length following different patterns that should be precisely determined. After the maceration procedure, earlywood tracheid length (EWTL), latewood tracheid length (LWTL), annual growth ring tracheid length (RTL), earlywood ring width (EWW), latewood ring width (LWW), and annual ring width (ARW) were measured in selected annual growth rings. The significant effect of annual growth rings and zone interaction for EWTL and LWTL, as well as of annual growth rings, trees, and sites for RTL, was determined. The results conclude on the differences between the trends in EWTL and LWTL from pith toward the bark. In addition, the correlation analysis between the tracheid length and different growth patterns was investigated, and very weak or no association between the variables was detected. This research contributes to better understanding the degree of wood uniformity of P. menziesii from the technological perspective, as well as the variability factor in the optimization of forest management with favoring overall wood quality.
There is a growing trend in the world of planting fast growing species (rotations 5 to 10 years). Their primary purpose is the production of wood fibers and biomass, but they certainly represent the ...potential in making solid wood products as well. One of the fast-growing species is Paulownia sp., a species of extremely fast growing wood. Plantation breeding of Paulownia sp. in Croatia is increasing, although there is a little knowledge about the technical properties of Paulownia wood and its end use is questionable. This paper presents preliminary results of some physical properties of juvenile wood of two Paulownia hybrids planted in the area near the town of Glina in the Republic of Croatia. One hybrid is 9501 ((Paulownia fortunei × Paulownia elongata) × (Paulownia fortunei × Paulownia tomentosa)) and the other hybrid is Shan Tong (Paulownia fortunei × Paulownia tomentosa). The aim of this study was to investigate physical properties of juvenile wood of two Paulownia hybrids from one site in Croatia, to determine differences in physical properties of wood between two hybrids and to evaluate the correlation between density and shrinkages of each hybrid. Significant differences in oven dry density, basic density and density at maximum MC, between the two hybrids were determined. There is no statistically significant difference in longitudinal, radial, tangential and volumetric shrinkages between the two hybrids.
U današnje je vrijeme zamjetan sve češći trend sadnje brzorastućih vrsta drveća (ophodnje od 5 do 10 godina). Te su vrste primarno namijenjene proizvodnji drvnih vlakana i biomase, ali svakako je vidljiv i njihov potencijal u proizvodima od cjelovitog drva. Jedna od brzorastućih vrsta je Paulownia sp., koju odlikuje izrazito brz rast. Iako se malo zna o tehničkim svojstvima drva paulovnije, a njegova je krajnja upotreba upitna, u Hrvatskoj je u porastu plantažni uzgoj paulovnije. U ovom su radu prikazani preliminarni rezultati istraživanja nekih fizičkih svojstava juvenilnog drva hibrida paulovnije s lokaliteta u blizini grada Gline u Hrvatskoj. Prvi je hibrid 9501 ((Paulownia fortunei × Paulownia elongata) × (Paulownia fortunei × Paulownia tomentosa)), a drugi Shan Tong (Paulownia fortunei × Paulownia tomentosa). Cilj rada bio je istražiti fizička svojstva juvenilnog drva hibrida paulovnije s lokaliteta u Hrvatskoj, utvrditi razlike u fizičkim svojstvima drva tih hibrida te odrediti međusobni odnos gustoće i utezanja unutar hibrida. Utvrđene su značajne razlike u gustoći drva u apsolutno suhom stanju, u nominalnoj gustoći i gustoći pri maksimalnom sadržaju vode između tih dvaju hibrida. Među hibridima nisu utvrđene statistički značajne razlike u longitudinalnome, radijalnome, tangentnome ni volumnom utezanju.
There is a growing trend in the world of planting fast growing species (rotations 5 to 10 years). Their primary purpose is the production of wood fibers and biomass, but they certainly represent the ...potential in making solid wood products as well. One of the fast-growing species is Paulownia sp., a species of extremely fast growing wood. Plantation breeding of Paulownia sp. in Croatia is increasing, although there is a little knowledge about the technical properties of Paulownia wood and its end use is questionable. This paper presents preliminary results of some physical properties ofjuvenile wood of two Paulownia hybrids planted in the area near the town of Glina in the Republic of Croatia. One hybrid is 9501 ((Paulownia fortunei x Paulownia elongata) x (Paulownia fortunei x Paulownia tomentosa)) and the other hybrid is Shan Tong (Paulownia fortunei x Paulownia tomen-tosa). The aim of this study was to investigate physical properties ofjuvenile wood of two Paulownia hybrids from one site in Croatia, to determine differences in physical properties of wood between two hybrids and to evaluate the correlation between density and shrinkages of each hybrid. Significant differences in oven dry density, basic density and density at maximum MC, between the two hybrids were determined. There is no statistically significant difference in longitudinal, radial, tangential and volumetric shrinkages between the two hybrids. Keywords: hybrid 9501; hybrid Shan Tong; juvenile wood; Paulownia wood; physical properties U dananje je vrijeme zamjetan sve ceci trend sadnje brzorastucih vrsta drveca (ophodnje od 5 do 10 godina). Te su vrste primarno namijenjene proizvodnji drvnih vlakana i biomase, ali svakako je vidljiv i njihov potencijal u proizvodima od cjelovitog drva. Jedna od brzorastucih vrsta je Paulownia sp., koju odlikuje izrazito brz rast. Iako se malo zna o tehnickim svojstvima drva paulovnije, a njegova je krajnja upotreba upitna, u Hrvatskoj je u porastu plantani uzgoj paulovnije. U ovom su radu prikazani preliminarni rezultati istraivanja nekih fizickih svojstava juvenilnog drva hibrida paulovnije s lokaliteta u blizini grada Gline u Hrvatskoj. Prvi je hibrid 9501 ((Paulownia fortunei x Paulownia elongata) x (Paulownia fortunei x Paulownia tomentosa)), a drugi Shan Tong (Paulownia fortunei x Paulownia tomentosa). Cilj rada bio je istraiti fizicka svojstva juvenilnog drva hibrida paulovnije s lokaliteta u Hrvatskoj, utvrditi razlike u fizickim svojstvima drva tih hibrida te odrediti medusobni odnos gustoce i utezanja unutar hibrida. Utvrdene su znacajne razlike u gustoci drva u apsolutno suhom stanju, u nominalnoj gustoci i gustoci pri maksimalnom sadraju vode izmedu tih dvaju hibrida. Medu hibridima nisu utvrdene statisticki znacajne razlike u longitudinalnome, radijalnome, tangentnome ni volumnom utezanju. Kljucne rijeci: hibrid 9501; hibrid Shan Tong; juvenilno drvo; drvo paulovnije; fizicka svojstva
U današnje je vrijeme zamjetan sve češći trend sadnje brzorastućih vrsta drveća (ophodnje od 5 do 10 godina). Te su vrste primarno namijenjene proizvodnji drvnih vlakana i biomase, ali svakako je ...vidljiv i njihov potencijal u proizvodima od cjelovitog drva. Jedna od brzorastućih vrsta je Paulownia sp., koju odlikuje izrazito brz rast. Iako se malo zna o tehničkim svojstvima drva paulovnije, a njegova je krajnja upotreba upitna, u Hrvatskoj je u porastu plantažni uzgoj paulovnije. U ovom su radu prikazani preliminarni rezultati istraživanja nekih fizičkih svojstava juvenilnog drva hibrida paulovnije s lokaliteta u blizini grada Gline u Hrvatskoj. Prvi je hibrid 9501 ((Paulownia fortunei × Paulownia elongata) × (Paulownia fortunei × Paulownia tomentosa)), a drugi Shan Tong (Paulownia fortunei × Paulownia tomentosa). Cilj rada bio je istražiti fizička svojstva juvenilnog drva hibrida paulovnije s lokaliteta u Hrvatskoj, utvrditi razlike u fizičkim svojstvima drva tih hibrida te odrediti međusobni odnos gustoće i utezanja unutar hibrida. Utvrđene su značajne razlike u gustoći drva u apsolutno suhom stanju, u nominalnoj gustoći i gustoći pri maksimalnom sadržaju vode između tih dvaju hibrida. Među hibridima nisu utvrđene statistički značajne razlike u longitudinalnome, radijalnome, tangentnome ni volumnom utezanju.
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