In this work, we drew the experimental or the true creep-recovery curves of Entandrophragma cylindricum known as sapelli from the values obtained during many four points flexural tests carried out on several samples of this hardwood. Thereafter, the experimental values have been perturbed by the white Gaussian noise of the gauges and this allowed us to draw the noisy curves of deformations. The creep test lasted ten hours and the recovery forty hours. Our main target in this work was to implement the recursive discrete Kalman filter, in order to predict or to estimate the deformation of this species undergoing a constant stress. From the simulation, since our estimate and our state have the same expected value, then our estimate is not biased. The true deformation and the estimated deformation curves are almost too close to distinguish from one another. Once the Kalman filter applied to our system satisfied these two preceding criteria, we are able to mention that our estimator has a good response therefore, it is an optimal filter.
Studies on the content and distribution of mineral substances including calcium (Ca), potassium (K), magnesium (Mg), manganese (Mn), iron (Fe), sodium (Na), zinc (Zn), aluminum (Al), lead (Pb) and strontium (Sr) were performed. Samples of Scots pine were gained from stems with Ist degradation degree of tree (considered to grow in the area with weak environmental pollution), IInd degradation degree (strong pollution) and IIIrd degradation degree (very strong pollution). Nitrogen industrial plant was acknowledged as the source of pollution. Samples were collected from butt-end, middle- and top sections of the stem in following zones: sapwood, heartwood adjacent sapwood, heartwood and bark. Results indicate that nitrogen industrial plant causes the decrease of mineral substances content in bark from butt-end section of stems with IInd and IIIrd degradation degree in relation to stems with Ist degradation degree. Calcium content is the highest in heartwood and decreases in the direction to stem perimeter, regardless of stem section and environmental pollution degree. Very strong pollution decreases potassium content in wood in comparison to samples collected in areas with strong and weak pollution. Environmental pollution also decreases sodium content in wood, and increases content of manganese, aluminum, lead and strontium.
The manufacture process, specification and mechanical properties of arc bamboo were studied to support the biomaterial “arc-bamboo recombined in original status (A-BROS)” manufactured by bionic technology. The results indicated that the iso-curvature processed with milling technology is the key technology for arc bamboo, and arc bamboo monomer increases utilization rate of bamboo by 30% and the monomer width (≥40 mm) by more than 90%, as well as excellent bending resistance, these confirm relatively greater thickness of monolayer A-BROS material with slighter glue spread and superior mechanical property. The novel recombinant made by arc bamboo with elegant texture and original status could be used as board and timber, and form new structure, furniture and building materials.
Pine (Pinus pinaster Ait.) wood samples were subjected to a combined treatment by densification and heat treatment. Samples were densified before and after heat treatment. The heat treatment was made inside an oven at 190ºC during 2 to 6 h and wood densification was made in a hot press at around 48 bar pressure and temperatures between 160ºC and 200ºC for 30 min. Compression-set, compression-set recovery after three cycles of water soaking followed by oven drying, density, hardness, bending strength and stiffness and durability against subterranean termites were determined after the treatment. Results show that densification increases density, hardness, bending strength, stiffness and durability against termites. Heat treatment applied after the densification is more effective in reducing compression-set recovery than if applied before.
The advent of lean (waste reduction), six sigma (process variation minimisation) and proper raw material selection are the essential challenges to achieve the required quality on the overall industrial processes. Accordingly a laboratory experiment for the dissolving wood pulping process was conducted on nine Eucalyptus genotypes to measure the change in lignin, viscosity and α-cellulose at each of the six pulp processing stages. The changes to these properties were modelled using the Generalised Additive Models (GAM) and Fractional Polynomial (FP) models. These models proved to be equally important in their unique ways and produced complementary results. The results revealed that Emearnsii genotype produced the best results for both α-cellulose and viscosity, while Enitens genotype was selected for the optimal lignin reduction. Egrandis genotype is the only genotype that proved to have adverse effects on the viscosity property.
In this study, wood modification (thermo-processing and impregnation) and outdoor conditions of storage (natural aging) the effects on the mechanical performance of industrial woodwork was investigated. For this purpose, naturally grown in Turkey and the commercial value of high Scots pine (Pinus sylvestris L.) and chestnut (Castanea sativa Mill) wood was used. Experimental examples are specifically woodwork has been applied in actual size. Considering the previously conducted research literature only diagonal L-type samples used, not on the actual size samples of woodwork. In addition, there is no study that the combination of the heat-treatment and impregnation. This reveals the original values of this study. For preparing of samples is used the double tenon-mortise corner joint from constructions method and as glue polyurethane based Desmodur VTKA and Polyvinyl acetate based two-component D4. Diagonal woodwork test samples prepared by Thermo S class (185°C temperature with a thermo-vapor process protections) applying. After application of the heat treatment, the test samples impregnated with a solution of 95 % natural pine cone resin and %5 pine tannin by dip method (2 hours). Then, the untreated samples (control), only heat-treated samples and heat treatment + impregnated samples kept for 1 year with outdoor conditions (aging). At the end of the aging, the samples tested according to the principles stated in TS 2472 and TS 7251 EN 107 standard. As result, the performance of woodwork decreased after aging in untreated and heat treatment pieces, the other side after aging – heat treatment, impregnation materials increased the values. The deformation value of woodwork increased after aging most untreated materials, Heat treatment and heat treatment-impregnated reduced aging effectiveness.
In this study, Moment resistance performance of column-beam joints using cylindrical laminated veneer lumber (LVL) column and glulam beam were evaluated. Two types of jointing methods – Type-A, in which the beam is put on the end side of column and Type-B, in which the beam is inserted into column – were applied. As a result of Type A, Moment resistance of the cylindrical-LVL column jointed with drift pins was shown to be 67 % higher than that of the larch log column jointed with drift pins. The larch log column jointed with GFRP Plate reinforced wooden pins was shown to be 14 % higher than that jointed with drift pins. In Type-B joint, the rotational stiffness of two specimens were 139.4 kN•m/rad. (Non-reinforced specimen) and 272.2 kN•m/rad. (reinforced specimen), respectively, and reinforced specimen was 95 % higher than Non-reinforced specimen. Based on this result it was assured that glass fiber reinforcement is able to reinforce the column.
The paper presents the experimental results of a research aimed at the distribution of the temperature on thecircular saw blade body. The temperature was measured at four distances from the centre of the circular saw blade body (60 mm, 70 mm, 80 mm, 90 mm) by means of an infrared thermometer. Three circular saw blades with the diameter of 350 mm and a variable adjustment of the body (without slots and coating, with slots and without the coating, with both slots and coating) were used for the longitudinal sawing of the spruce wood (Picea excelsa) with the thickness of h = 25 mm. Feed speed vf = 12 m•min-1 and cutting revolutions n = 4000 min-1 were constant. The measured temperature was in the range from 22°C to 30°C. The highest measured temperatures were recorded on the circular saw blade with the slots and coating.
Water borne wood preservatives have been widely used for a long time in the protection of wood either in ground contact or above ground. Copper is still major biocide component used today in treatment plant for wood protection despite the environmental concerns over copper-rich preservative systems. On the other hand, water repellents are considered to be potential additives for biocides, resulting in the decreased moisture content, reduced biocide leaching and increased dimensional stabilization. In the present study, copper azole (CA) was used as wood preservatives to the natural weathering for 6, 12 and 24 months respectively. In addition, semitransparent wood stain was used as post treatment with CA, and paraffin and silicon additives were incorporated in to biocide to be water repellent. Paraffin additives reduced the retention values as compared to other formulations. The highest color change and gloss loss were obtained with Scots pine control samples within the six months. CA pretreatment before wood stain was promising by indicating the lowest color change. Color change was reduced by the increasing ratio in paraffin and silicone additives. Combination of CA with wood stain and silicon additive could reduce the copper leaching to some extent.
The variations in number and method of applied joints within storage furniture gave idea for this investigation. Importance of joint selection and its geometrical characteristic is clear if we bear in mind that the joints are critical points in the structure, and the rigidity and durability of storage furniture are in direct correlation with the type of the applied joint. Results presented in scientific papers provide little useful information to the engineer for the safe selection of the optimal joint. Number of joints along the connecting line (depth of the box type element) engineers determined empirically. In order to define stress state in the storage furniture, data on size of the load, that the box element has to with stand during its use, should be determined. The aim of this study was to determine the size and character of the loads in corner joints in storage furniture. Based on this data, as well as on the basis of information about the strength of the corner joints it is possible to calculate the required number of appropriate joining elements for each separate case.
This article deal with investigation of mean arithmetic deviation of the waviness profile (Wa) on edge surface after edge milling of medium-density fiberboard, medium-density fiberboard with single-sided lamination and spruce edge-glued panel. Edge milling afftected feed rate 4, 8, and 11 m.min-1 and cutting speed 20, 30, 40 a 60 m.s-1. There were used for milling 3 types of tungsteen carbide blades with different composition and treatment (HW1, HW2 and HW1 + CrTiN coating). Working results show that the lowest values of waviness were found with a spruce glulam. Considering the machined surface quality the most suitable blade is HW1, then HW1 + CrTiN coating and the worst one is HW2. The lowest measured values of Wa were found with the feed rate of 4 m.min-1 and cutting speed of 60 m.s-1. The increase in cutting speed resulted in the drop in the values of average Wa, while the increase in feed rate had the opposite effect.
Buried wood samples of gold “Phoebe sp.” (Samples #1, #2 and #3) were identified based on their microstructures and on the comparison of their characteristics with relevant specimen types. The result showed all the samples belong to the family Lauraceae. Samples #1 and #3 of the Machilus Nees were identified as Phoebe sheareri and P. zhennan, respectively, they are also known as “Nanmu”. Meanwhile #2 was also referred to as Machilus Nees, but named as “Nanmu with black bark”. Significant differences in anatomical characteristics were determined amongst the three samples; thus, they could not be classified as gold Phoebe sp. Moreover, the practical densities of the samples showed no marked increase relative to the species in literature. Microscopy also exhibited no rare mineral enrichment in the cell lumen or the intercellular space. Results of this study indicated that the three samples do not belong to the category of buried wood or ebony.
This paper concentrated on the production of torrefied without an additional binder from different raw wood materials. The torrefaction and pelletizing was carried out at the Torrec Ltd. pilot plant located in Eastern Finland and its effective capacity was 2,200 tonnes per year. Six different woodchips lots were tested in the pilot runs. The test was to identify whether the pelletizing process requires an additional sealant as a binder. The pelletizing process only exploited condensation water that came about from the torrefaction process. The temperature control range and the holding time were varied, regarding the driving parameters. Finally, quality factors were analysed from torrefied pellets and its raw wood materials after each pilot run. The maximum temperature of the reactor, 260°C, was perhaps too low to manufacture pellets of high energy content. Based on the study, the pelletizing process will not require an additional binder in the future.
The aim of this work is to study the effects of different ages and damage of the oak wood (Quercus petraea Mattusch) in relation to its flash point temperature and ignition temperature, as well as on determination of the ratio of changes in extractives, cellulose and lignin, in the heat loaded samples of 5 – years old oak wood, 160 – years old oak wood, and also 160 – years old oak wood degraded by wood-destroying insects and fungi. The results of the analyses showed that the flash point temperatures were in the range of 357.52°C – 360.63°C.The ignition temperatures were at interval of 398.93°C – 414.92°C. The time to reach the ignition point was at the interval between 344 and 365 seconds. Under the thermal loading of oak wood, there comes to the significant changes, especially in the surface layers. These are, in addition to colour changes, demonstrated the chemical changes of the main components of wood and extractives. Increasing the temperature, there increases also the content of the substances extractable with ethanol and toluene. Increase in their amount is mainly due to the lignin, but partially also due to the polysaccharides decomposition products.
The aim of this present study was to promote the quality of living environment, and create a healthy living environment through advocating for low carbon and green buildings. An additional aim is gaining recognition for wood structured housing, thus gaining recognition in customers and consumption to further promote the green ecological and sustainable development of wood structured houses. This work examined the physical environment indexes and physiological indexes of the participants in three different structure types of housing environment with behavioral analysis (CAPTIV) and environmental data (BAPPU) synchronous test system. The results of the MANOVA revealed a significant main effect for the housing environment indexes with temperature, moisture content, noise, illumination, air flow rate and skin temperature, ECG, and respiration of three different structure types (log, glulam, reinforced concrete). In comparison, the influence of the physical environment factors in both the log structure and the glulam structure housing were better than the reinforced concrete structure housing. It indicated that woody housing environment was benefit to the health of habitants. Participants were interested in the log structure and glulam structure housing environment with joy and comfortable feelings. Different proportion of building environment and interior wooden decoration proportion can influence different cognitive and feelings of habitants. Therefore, wooden housing environment is helpful to adjust emotion, relieve work pressure and improve tasty, which would provide people with both physical and mental benefits.