Wood Grain Research Articles

Examination of Cinnamomum camphora interlocked grain adopting X-ray computed tomography combined with particle image velocimetry

Trees develop wood grain more or less parallel to the tree axis as they grow laterally. However, many tree species also develop interlocked grain that is expressed as a change in the wood grain orientation, periodically switching between left- and right-handed spirals over the years. Wood grain information is critical to determining the wood quality and is an important record of cellular events in a cambium. This study examined the wood grain of axial xylem cells in the semi-ring porous hardwood Cinnamomum camphora by first visualizing the three-dimensional structure using a conventional X-ray computed tomography instrument producing tomography images. We propose the use of particle image velocimetry (PIV) and the two-dimensional fast Fourier transform (2D-FFT) to analyze computed tomography images in obtaining grain angle (δ) information from the vessel deviation. We found undulation on the radial variation of the grain angle (δ) that indicates periodical changes in the wood grain orientation as left- and right-handed spirals ranging from − 25° to 16° and − 22° to 18° using the 2D-FFT and PIV, respectively. Furthermore, despite the major orientation of vessels inclining in the tangential direction, the PIV result revealed a minor deviation with vessels inclining in various orientations along the tree radius.

Teredolites driftwood from the Arkadelphia Formation–Midway Group Contact (K–Pg), Malvern, Arkansas, USA

Partially carbonized driftwood recovered from a lag deposit at the Arkadelphia Formation–Midway Group Contact (K–Pg) near Malvern, Arkansas contains an abundance of macrobioerosion. Macroborings are oriented perpendicular and oblique to the wood grain, straight to sinuous in shape, ≤8 cm long, may have calcitic linings, and belong to Teredolites clavatus (Kelly & Bromley, 1984). The abundance and tightly spaced position of borings on all driftwood surfaces suggests the wood was afloat and/or exposed on or near the seafloor in a shallow marine setting for an extended period of time before becoming buried. Transverse, radial, and tangential thin section analysis of the driftwood identifies distinct growth rings, tracheid and ray cells, ray pits, and resin canals of the bald cypress genus, Taxodium. The presence of Taxodium wood in addition to a diverse and abundant assemblage of transitional to shallow marine vertebrates in the Gulf Coastal Plain of southwestern Arkansas indicate that brackish water swamps were in proximity to the ancestral shoreline around the K–Pg boundary and that these remains were concentrated into a lag deposit as the result of storm events, sea-level cyclicity, and possibly impact generated tsunamis.

An Example of the Use of Traditional Woodworking Hand Tools in Product Design Studies at the Institute of Design Technologies of the Faculty of Materials Science and Applied Chemistry of Riga Technical University

Initially, hand tools were created to facilitate the processing of materials in manufacturing utility items. Tool design, technology, and ergonomics evolved along with the growing human ability to process new materials. The tool range has expanded to meet more diverse needs of the woodworking industry, adapting the tools for both universal use and specific functions. Understanding of the functionalities of woodworking hand tools is essential for observing the sequence of material processing and practical processing operations, as well as in building awareness of the properties of the wood material. This is ensured by the interaction between the operator, the tool, and the workpiece. An important aspect in raising awareness is the relatively low processing speed and the processing of the material with human-controlled movements. Treatment of wood with craft methods and tools reveals the characteristic properties of the material, including specifics of wood grain direction, the difference in the density of earlywood and latewood, and the difference in the longitudinal and transverse grain direction. It also allows understanding the most typical wood defects. To make the process of learning a wood material meaningful in the study process, it is integrated with product manufacturing, making students create a wooden puzzle. This process implies running a sequential crafting process from a solid pine board to a finished and functional product – a puzzle. Students have to make it following a uniform design drawing showing the proportions of the pieces and joints. While making a wooden puzzle, students choose the most appropriate tools for each processing stage. In the process, it is necessary to check, measure, mark, and cut the workpiece. The result is a three-dimensional product that may be assembled and disassembled. The assembly and disassembly process allows appreciating the role of processing accuracy in the course of work and its impact on the end result.

Tradicionālo kokapstrādes rokas instrumentu lietojuma piemērs produktu dizaina studijās Rīgas Tehniskās universitātes Materiālzinātnes un lietišķās ķīmijas fakultātes Dizaina tehnoloģiju institūtā

Initially, hand tools were created to facilitate the processing of materials in manufacturing utility items. Tool design, technology, and ergonomics evolved along with the growing human ability to process new materials. The tool range has expanded to meet more diverse needs of the woodworking industry, adapting the tools for both universal use and specific functions. Understanding of the functionalities of woodworking hand tools is essential for observing the sequence of material processing and practical processing operations, as well as in building awareness of the properties of the wood material. This is ensured by the interaction between the operator, the tool, and the workpiece. An important aspect in raising awareness is the relatively low processing speed and the processing of the material with human-controlled movements. Treatment of wood with craft methods and tools reveals the characteristic properties of the material, including specifics of wood grain direction, the difference in the density of earlywood and latewood, and the difference in the longitudinal and transverse grain direction. It also allows understanding the most typical wood defects. To make the process of learning a wood material meaningful in the study process, it is integrated with product manufacturing, making students create a wooden puzzle. This process implies running a sequential crafting process from a solid pine board to a finished and functional product – a puzzle. Students have to make it following a uniform design drawing showing the proportions of the pieces and joints.

Modelling the process of splitting wood and chipless cutting Pinus sylvestris L. wood in terms of designing the geometry of the tools and the driving force of the machine

The size of wood is reduced by splitting or chipless cutting whilst logging trees, limbing, or preparing wood to be a fuel, for example, or in order to improve the efficiency of wood drying processes. Low costs of wood processing are desirable in each of these processes. The article presents experimental and simulation tests run in ABAQUS software, which allow for an analysis of the geometry of cutting tools used during the splitting or chipless cutting of wood in order to determine the cutting force and driving force of the machine executing such a process. The tests involved wood of Pinus sylvestris L. (moisture content: 8.74% ± 0.1%) in four configurations (chipless cutting transverse to the fibres (90°–90°), splitting along the fibres (0°–90°), splitting radially to the grain (90°–0°) and splitting tangentially to the grain (90°–0°)). Analysis of the force and strength of the blade proved that an effective tip angle of the knife blade falls between 30° and 45°. The presented results also suggested that splitting wood along the fibres (0°–90°) is preferable in a machine process, while splitting tangentially and radially to the wood grain (90°–0°) is preferable when splitting wood using manual tools.

Analysis of behavior and failure modes of timber beams prestressed with CFRP strips

The article presents research on timber beams strengthened with pre-tensioned carbon fiber reinforced polymer (CFRP) strips. The prestress level was different in individual series of beams as the result of different prestressing forces introduced into the strips. The reference non-strengthened beams were also prepared. The beams were tested in four-point bending. Special attention is paid to the analysis of their failure modes and the influence of the prestress level on the crack pattern. The longitudinal strains of the strip and adjoining wood grain were also measured and their differences were analyzed. It was proved that the prestress level influences the number and length of cracks depending on the prestress level as well as the beams’ stiffness and consequently their deflection. The analysis revealed that the slip between the strip and timber occurred due to the deformability of the adhesive used for strip gluing.

PEAT IS AN EFFECTIVE ALTERNATIVE FUEL

The article considers peat as an effective alternative fuel. Its reserves and directions of use in the world and in Ukraine presented and analyzed. The analysis showed that the geological reserves of peat in Ukraine are equivalent to 600 billion cubic meters of natural gas. The main reserves of peat are concentrated in the districts of Polissia. Industrial peat extraction can take place in 12 regions: Volyn, Rivne, Zhytomyr, Kyiv, Cherkasy, Poltava, Sumy, Chernihiv, Khmelnytskyi, Ternopil, Lviv, and Ivano-Frankivsk. It has been shown that, compared to traditional energy carriers, peat fuel has a lower heat of combustion and a fairly high ash content, but during combustion it emits almost no toxic substances and, accordingly, pollutes the environment much less. In home furnaces, peat fuel burned with a higher efficiency than coal, and the ash used as fertilizer. The estimated cost of 1Gj of lower heat of combustion of various types of fuel according to the data of recent years shows a noticeable advantage of peat fuels. The cost of thermal energy obtained from burning 1 ton of peat briquettes is 2 times cheaper than when using coal, 3 times cheaper than gas, and 4 times cheaper than fuel oil. Peat fuel is suitable for use in all types of modern solid fuel combustion devices, which increases the prospect of its implementation on the domestic and foreign fuel markets. The technology for using plant biomass as a filler in peat briquettes and granules developed. Special attention paid to wood, buckwheat husk, sunflower and other grain crops, which have a lower ash content and a higher heat of combustion, the potential of which waste is significant, and the fuel characteristics are able to increase the heat of combustion of composite peat briquettes or peat granules and reduce their ash content. Taking into account that peat used in large quantities as fertilizer for agriculture, a technology developed according to which humic substances first removed from peat for fertilizer, and then biomass added to this peat and a composite peat fuel obtained. This technology involves the integration of technology and extraction of humic substances into the production cycle of a peat briquette plant for the production of composite fuel. The wide implementation of the developed technology of composite peat briquettes at peat briquette factories will allow to increase the production of briquettes by almost 2 times without increasing the consumption of peat raw materials and to produce peat fuel in the range of 0.18-0.2% of geological reserves, which is equivalent to the replacement of more than 1 billion m3 of natural gas. All this allows us to draw a conclusion about the positioning of peat fuel as an effective local type of fuel, which is an alternative to gas and coal.

Wooden Watch Design Inspired by Gedung Sate's tower Visual

Wooden watches are part of a fashion commodities that created from the needs of eco-friendly and sustainable materials demands. Wooden watches also give a certain unique aesthetical value because of the exposed wooden grain. This research summarizes the process of designing a wooden watch by using Gedung Sate’s tower as visual inspiration. The design method used in this research is Form generation through styling cue synthesis with Gedung Sate’s tower as the main object. The target user of this research are involved in the design process through survey so the writer acquires valid data for the intended market segment. The result of this research process is a wooden watch design that can give novelty to the wooden watches market by inovating in a form of involving Gedung Sate as a inspiration for form exploration.

Thermal Modification of Spruce and Maple Wood for Special Wood Products.

This article presents a proposal of thermal modification of Norway spruce and sycamore maple for special wood products, mainly for musical instruments. Selected physical and acoustical characteristics (PACHs), including the density (ρ), dynamic modulus of elasticity along the wood grain (EL), specific modulus (Esp), speed of sound along the wood grain (cL), resonant frequency (fr) and acoustic constant (A), logarithmic decrement (ϑ), loss coefficient (η), acoustic conversion efficiency (ACE), sound quality factor (Q), and the timbre of sound, were evaluated. These two wood species were chosen regarding their use in the production or repair of musical instruments. For the thermal modification, a similar process to the ThermoWood process was chosen. Thermal modification was performed at the temperatures 135 °C, 160 °C and 185 °C. The resonant dynamic method was used to obtain the PACHs. Fast Fourier transform (FFT) was used to analyze the sound produced. The changes in the observed wood properties depended on the treatment temperature. Based on our results of all properties, the different temperature modified wood could find uses in the making of musical instruments or where the specific values of these wood characteristics are required. The mild thermal modification resulted in a decrease in mass, density, and increased speed of sound and dynamic modulus of elasticity at all temperatures of modification. The thermally modified wood showed higher sound radiation and lower loss coefficients than unmodified wood. The modification also influenced the timbre of sound of both wood species.

Hardwood Grain Image Restoration and Enhancement via Gaussian Histogram Specification and Adaptive Color Adjustment

Hardwood is widely used in the surface decoration of furniture and wood products due to its rich texture and durable surface, and the improvement of wood grain images is vital to promote the aesthetics of wood surfaces. In order to restore the Gaussian distribution of distorted wood grain images and reproduce a sharp and clear wood surface, a Gaussian histogram specification algorithm based on the constant mean and variance values of red (R), green (G), and blue (B), and an adaptive color adjustment algorithm based on the color extension of R, G, and B histograms was proposed, respectively. Objective evaluation methods of histogram distribution, colorfulness index, contrast index, and sharpness index were used independently to evaluate the visual effect of the images processed by the two algorithms. Objective and subjective evaluation results showed that although the Gaussian method had only a small influence on the visual effect of hardwood grain images, it could restore the distorted images by repairing the irregular color points to weaken the adverse impact on visual impression. Meanwhile, extra attention should be paid to the processing of images with prominent uneven color transitions, because the Gaussian method might have an imperceptible smoothing or enhancing effect. The adaptive color adjustment method had a favorable enhancement effect on most hardwood grain images. However, the color extension coefficients of the over-enhanced images should be reduced to eliminate overcompensation and color shift. Compared with the traditional enhancement method unsharp mask (USM) and the methods designed for sand-degraded images and underwater images, the proposed adaptive color adjustment at the 1.5 coefficient could effectively enhance the images from the perspective of wood grain visibility and color retention.

IR Reflectography, Pulse-Compression Thermography, MA-XRF, and Radiography: A Full-Thickness Study of a 16th-Century Panel Painting Copy of Raphael

The potential of any multi-analytical and non-invasive approach to the study of cultural heritage, both for conservation and scientific investigation purposes, is gaining increasing interest, and it was tested in this paper, focusing on the panel painting Madonna della Tenda (Musei Reali, Turin), identified as a 16th-century copy of the painting by Raffaello Sanzio. As a part of a broader diagnostic campaign carried out at the Centro Conservazione e Restauro, La Venaria Reale in Turin, Italy, the potential of the combination of X-ray radiography, pulse-compression thermography, macro X-ray fluorescence, and IR reflectography was tested to investigate the wooden support and all the preparatory phases for the realization of the painting. The results of the optical microscopy and SEM/EDS analyses on a multi-layered micro-sample were used for a precise comparison, integration, and/or confirmation of what was suggested by the non-invasive techniques. Particularly, the radiographic and thermographic techniques allowed for an in-depth study of a hole, interestingly present on the panel’s back surface, detecting the trajectory of the wood grain and confirming the presence of an old wood knot, as well as of a tau-shaped element—potentially a cracked and unfilled area of the wooden support—near the hollow. The combination of radiography, macro X-ray fluorescence, Near Infrared (NIR), and Short Wave Infrared (SWIR) reflectography allowed for an inspection of the ground layer, imprimitura, engravings, and underdrawing, not only revealing interesting technical-executive aspects of the artwork realization, but also highlighting the advantages of an integrated reading of data obtained from the different analytical techniques.

Influence of basic wood density on the specific cutting energy

The density of the wood influences directly on the quality of the surface, on the resistance to cutting as well as on the energy required for processing. The aim of this study was to obtain the association between specific cutting energies and basic wood densities in peripheral milling with the use of a computer numerical control. For this purpose, wood from nine species with a wide range of basic densities were used. The specimens were milled in a router with a CNC. Both the feeding and routing speeds were constant, and there was no source of variation among treatments. The values of specific energy were calculated taking into account the active power, the cutting time and the volume of wood removed. Results showed that there was a moderate correlation (r=0.61) between specific cutting energy and basic wood density data. However, by observing the particularities of each species, it was noticeable that the specific cutting energy varied as a result of factors such as the anatomical structure and the type of wood grain. It was concluded that the basic wood density has a positive correlation on the specific cutting energy required, yet it does not explain this relationship alone.

Seismic behavior of variable friction timber dampers: Experimental and numerical investigation

This paper proposed variable friction timber dampers (VFTDs) made of replaceable grooved timber plates, seismic behavior of such dampers and its influence on the lateral performance and dynamic response of heavy timber frames were investigated. Firstly, in total four specimens with different geometry characteristics and pre-stressing forces were conducted with reversed cyclic loading test. Typical damage and failure modes were identified and hysteretic curves were analyzed. Secondly, a modelling method on the hysteretic behavior of VFTDs was proposed by using multiple materials in OpenSees. Combined an existing test of a simple timber frame, the lateral performance and dynamic response of timber frames with VFTDs were numerically investigated and compared to those of a simple frame and a frame with a conventional friction timber damper. The experimental results indicated that timber plates of VFTDs cracked perpendicular to wood grain under combined compression and friction. The cracking weakened the integrity of timber plates, resulting to asymmetry of hysteretic curves of VFTDs. VFTDs were able to dissipate energy meanwhile provide higher damping force when timber plates slid on slope surfaces. Increasing pre-stressing force in a certain range considerably improved damping force and energy dissipation capacity of VFTDs. The numerical simulation demonstrated that VFTDs increased the lateral load-resisting capacity and energy dissipation capacity of timber frames more than 55% and 710%, respectively. Owing to superior lateral load-resisting capacity and extraordinary energy dissipation capacity of VFTDs, the peak drift and acceleration of timber frames decreased up to 55%. VFTDs with slope sliding surfaces outperformed VFTDs with consecutive flat and slope sliding surfaces and conventional friction timber dampers in seismic response reduction.

ANALISIS PENGARUH PEMBERIAN PENGATUR TEGANGAN BLOWER PADA KOMPOR TERHADAP EFISIENSI PEMBAKARAN

A biomass stove is one of the alternative tools made from bio pellet as a substitute for LPG gas stove (Liquefied Petroleum Gas). Biomass stoves are currently less known by the public due to their traditional use and lack of socialization of biomass fuels. Starting from the problem, biomass stoves currently need further development in order to be used in daily life. Therefore, it is necessary to develop the biomass stove by adding a 12-volt lithium-ion battery as the main power source and a circuit dimmer as a fan speed regulator. The treatment variable in this study is to provide variations in fan speed. Variations used are low, medium, and high fan speeds. The main fuel of the biomass stove is a wood grain bio pellet with the weight of each bio pellet used per treatment as much as 300 grams. The method used in this study used a one-way ANOVA that produced a difference in variation had no real differences and had a noticeable effect on the rate of combustion, the temperature of the fire, and the length of time the water was boiled.

Induction of compression wood inhibits development of spiral grain in radiata pine

Summary Spiral grain refers to the helical patterns formed by the wood grain in the trunks of many tree species. In most gymnosperms, grain near the pith is vertical but wood formed after several years of growth has a slight to pronounced left-handed twist. Grain changes presumably involve the slow rotation of cells within the vascular cambium, but the mechanisms that allow this reorientation to occur remain unclear. Understanding this process is, however, important as the presence of strong spiral grain within the corewood of gymnosperms is a major wood quality issue devaluing cut timber. In this study, we measured wood grain in stems of Pinus radiata (radiata pine) saplings through reconstructions of resin canals that follow the grain, visualised by serial sectioning and scanning with circularly polarised light, and through X-ray computed microtomography (μCT) and image analysis in ImageJ. Vertical trees retained a symmetrical grain pattern that was weakly right-handed near the pith, but which became progressively more left-handed during the first eight months of growth. In tilted trees, however, the development of left-handed grain was inhibited by the formation of compression wood on the lower side of the tree whereas the wood on the upper side of the tree developed increasingly more left-handed grain as in the vertical controls. These results demonstrate that a previously unidentified link exists between compression wood formation and the inhibition of grain development.

The Divine Feminine in Mormon Art

The Divine Feminine in Mormon Art

SISTEM REKOMENDASI DALAM MENENTUKAN KAYU TERBAIK UNTUK BAHAN GITAR DENGAN MENGGUNAKAN METODE WASPAS

This research occurred because there were complaints from consumers against one of the guitar shops located in Dongkelan, Krapyak, Yogyakarta with the condition of the guitar that was purchased quickly weathered and dull in terms of color. Based on these problems, the solution is to use the Weighted Aggregated Sum Product Assessment (WASPAS) Decision Support method which is assisted by experts in determining the right criteria related to the best in making guitar materials, after calculating the exact results based on the problem, in the form of wood strength criteria, wood grain, texture, and wood weight. All these criteria are then managed using WASPAS, with the data used as many as 28 types of wood data, which were obtained from craftsmen in the area. After obtaining the results, 3 woods that are suitable for use as guitar making materials in sequence are Bubinga wood with a value of 6.38884, Ebony wood with a value of 5.98133, and Bocote wood with a value of 5.98133 from several alternative wood choices. Proving the results of the WASPAS method, the respondents carried out directly by providing the results of the method to guitar makers. Of the 17 expert guitar makers, 15 said they agreed with the top 3 rankings, and 2 said they did not agree. So that the level of assessment based on the assessment is 88.24%

A Modeling Approach on the Correction Model of the Chromatic Aberration of Scanned Wood Grain Images

There always exists subjective and objective color differences between digital wood grain and real wood grain, making it difficult to replicate the color of natural timber. Therefore, we described a novel method of correcting the chromatic aberration of scanned wood grain to maximally restore the objective color information of the real wood grain. A point-to-point correction model of chromatic aberration between the scanned wood grain and the measured wood grain was established based on Circle 1 by adjusting the three channels (sR, sG, and sB) of the scanned images. A conversion of the color space was conducted using the mutual conversion formulas. The color change of the scanned images before and after the correction was evaluated through the L∗a∗b∗ color-mode-based ΔE∗. and the lαβ color-model-based CIQI (Color Image Quality Index) and CQE (Color Quality Enhancement). The experimental results showed that the chromatic aberration ΔE∗ between the scanned wood grain and the measured wood grain decreased and the colorfulness index CIQI of the scanned wood grain increased for most wood specimens after the correction. The values of ΔE∗ of the twenty kinds of wood specimens decreased by an average of 3.1 in Circle 1 and 2.3 in Circle 2, thus the correction model established based on Circle 1 was effective. The color of the scanned wood grain was more consistent with that of the originals after the correction, which would provide a more accurate color information for the reproductions of wood grain and had an important practical significance.

Fire performance of hybrid mass timber beam-end connections with perpendicular-to-wood grain reinforcement

PurposeThe fire resistance of timber structures is heavily dependent on the fire behaviour of the connections between its structural elements. The experimental study presented in this paper aimed to investigate the fire performance of glued-laminated timber beam connections reinforced perpendicular-to-wood grain with self-tapping screws (STS).Design/methodology/approachTwo full-size fire experiments were conducted on glulam beam-end connections loaded in flexure bending. Two connection configurations, each utilizing four steel bolts arranged in two different patterns, were reinforced perpendicular to wood grain using STS. The bolt heads and nuts and the steel plate top and bottom edges were fire protected using wood plugs and strips, respectively. Each connection configuration was loaded to 100% of the ultimate design load of the weakest unreinforced configuration. The test assemblies were exposed to elevated temperatures that followed the CAN/ULC-S101 standard fire time–temperature curve.FindingsThe experimental results show that the influence of the STS was significant as it prevented the occurrence of wood splitting and row shear-out and as a result, increased the fire resistance time of the connections. The time to failure of both connection configurations exceeded the minimum fire resistance rating specified as 45 min for combustible construction in applicable building codes.Originality/valueThe experimental data show the effectiveness of a simple fire protection system (i.e. wood plugs and strips) along with the utilization of STS on the rotational behaviour, charring rate, fire resistance time and failure mode of the proposed hybrid mass timber beam-end connection configurations.

INFLUENCE OF THE TIMBER ELASTIC MODULUS ON THE GEOMETRIC NONLINEAR STRUCTURAL ANALYSIS OF TRUSS ARCHES

ABSTRACT In this work, it was numerically evaluated the influence of the modulus of elasticity parallel to the wood grain on the stability of trussed arches considering a nonlinear geometric analysis based on the Finite Element Method (FEM). This approach was carried out according to a positional formulation of the FEM, considering the structural nodes as main variables of the nonlinear equations system, whose resolution was obtained using the Newton-Raphson method. Altogether, seven arch models were evaluated, consisting of coniferous and hardwoods, with properties defined according to the strength classes of the Brazilian standard ABNT NBR 7190. The subroutines were written in MATLAB to solve the system of nonlinear equations and perform the analysis, including the graphical representation of the results and configurations of the trussed arch. Internal loads and displacements were obtained, in addition to the instability loads of the trussed arches. It was found that the instability load of the arch made with the stiffest hardwood (D60) was approximately equal to 700% of the instability load of the C20 coniferous class and equivalent to 257.8% of the D20 hardwood class-related load. It was verified that the modulus of elasticity significantly influences the nonlinear geometric behavior of the timber trussed arch. Furthermore, the nonlinear geometric analysis allowed calculating more accurate parameters and the verification of the stability of the structural system.