مهران روح نیا

From the limitations of detecting the amount of useful life remaining in the components of the structures in the conditions of use with acoustic methods is the impossibility of calculating the modulus of elasticity due to the impossibility of removing the part from the structure. Therefore, most of the classifications during use in the components of structures such as historical buildings are based on measuring the speed of sound. In this research, to calculate the local and global density with the method of pin penetration rate in wooden tie in order to calculate the amount of their remaining useful life by combining stress wave and free longitudinal vibration methods has been studied. There was no significant difference between the values of global sound velocity and global modulus of elasticity with the local results of these factors at the five tested points in each of the wooden tie.

The number of three saturated wooden tie from Iran Railway Company and with the dimensions of 15x25x260 cm, which are made of beech species (Fagus orientalis) and the density was measured by pin penetration method at 5 points of each wooden tie (50 cm distance between each point) and the average results of 5 points were compared with the results of ISO 13910 standard method. The stress wave test was carried out at the same 5 points of density determination by pin penetration rate method to determine the local modulus of elasticity and the results of each point were compared with the global modulus of elasticity of the beam. Longitudinal vibration test was also performed to calculate the damping factor values of the samples.

The results showed that there was no significant difference at the 95% level between the values calculated with both the ISO 13910 standard methods and the pin penetration rate method, and there was a favorable linear correlation between the results of the two methods. According to the results, there was no significant difference between the global sound speed of the beams and their local sound speed in any of the five measured points at the 95% level and there was a linear correlation between the values of the global sound speed and each of the five local points. There was no significant difference at the 95% level between the values of the global modulus of elasticity and the values of the local modulus of elasticity calculated in each of the five points. Also, there was a linear correlation between the values of the global modulus of elasticity and the results of the local modulus of elasticity in each of the five points. There was an exponential correlation between the values obtained from the global modulus of elasticity and the damping factor of each of the wooden tie.

The equality of density according to the ISO 13910 standard method and the nail penetration method, as well as the equality of the modulus of elasticity calculated by the stress wave method and the free longitudinal vibration method, make it possible to obtain all the data required for calculations without removing the part from the structure. The remaining strength of wooden components should be provided according to EN338 standard.

In this research, the effect of soaking process and ethanol-acetone washing as well as fermentation pre-treatment by bread yeast in Cypress (Cupressus arizonica) has been investigated. The samples were subjected to pre-treatment with bread yeast and without pre-treatment, washing with pure water and removal of extractives in organic solvent and subjected to dynamic test by forced vibration test in free-free beam. Both methods of soaking process and ethanol-acetone washing resulted in a significant decrease in density and vibration damping, while the values of acoustic conversion efficiency showed an increase. The amount of improvement of acoustic properties due to ethanol-acetone washing was more than water washing. Fermentation pretreatment increased the changes in both water washing and ethanol-acetone washing methods. The dynamic modulus of elasticity did not show any significant change water washing, ethanol-acetone washing and fermentation pretreatment. In general, the ethanol-acetone washed samples under fermentation pretreatment left the highest acoustic indices.

Nowadays, the importance of treatments such as water washing and ethanol-acetone washing to improve the acoustic properties of wood has been noticed by the makers of musical instruments. Wood extractives are in the list of those materials that often do not have a construction role, and their purposeful and correct evacuation can lighten the wood without reducing the stiffness. Carrying out pre-treatments such as fermentation with bread yeast (before water washing and ethanol-acetone washing processes) can lead to the extraction of more extractable substances from wood. In this study, the effect of water washing and ethanol-acetone washing treatments as well as fermentation pre-treatment on the acoustic properties of Ash wood (Fraxinus excelsior) has been investigated.

Ash wood species (Fraxinus excelsior) was prepared from the wood of a commercial timber and 38 small radial beams with nominal dimensions of 150×12×2 mm (longitudinal×radial×tangential) were extracted from the hardwood. After reaching the equilibrium humidity of 12% in air-conditioned conditions, the selected samples were subjected to the forced vibration test in the free-free beam in order to measure the basic physical and acoustic characteristics. After that, the initial tests were randomly divided into two groups of 19 tests. The first group without pretreatment and the second group with fermentation pretreatment were placed in the process of removing the extractives by water and then by ethanol-acetone mixture. After each step of water washing and removing the extractive substances soluble in ethanol-acetone mixture, the forced vibration test in the free-free beam was performed on the samples and the acoustic properties of the samples were measured.

Water washing without pretreatment with bread yeast caused a slight decrease and with pretreatment, it caused a significant decrease in density values (respectively: 1.75 and 7.39%). While the process of removing extractives (with and without pretreatment) by ethanol-acetone mixture caused a significant decrease in density values (Respectively: 2.27 and 8.71%). The modulus of elasticity values showed a significant decrease due to water washing without pretreatment and with pretreatment. (Respectively: 11.37 and 16.47%). The process of removing the extractives by ethanol-acetone mixture also resulted in a significant decrease in the modulus of elasticity values in untreated and pretreated samples (Respectively: 13.87 and 20.93%). Water washing without pre-treatment with bread yeast and with pre-treatment has caused a significant decrease in the values of damping factor, among which the pre-treated samples had a greater percentage of drop in the values of damping factor (Respectively: 13/87 and 20.93%). The process of removing the extractive materials by ethanol-acetone mixture as washing has caused a significant decrease in the damping factor values, which among the pre-treated samples showed a greater percentage drop in the values resulting from this property (Respectively: 3.03 and 18.01%). In this factor, the process of removing the extractive substances soluble in ethanol-acetone mixture (with and without pretreatment) has resulted in a greater drop in damping values (respectively: 6.67% and 20.85%). Acoustic conversion efficiency due to water washing process without pretreatment with baker's yeast caused a slight increase, while pretreatment caused a significant increase in acoustic conversion efficiency values (Respectively: 0.44 and 25.24%). The process of removing extractive materials by ethanol-acetone mixture also caused a significant increase in the acoustic conversion efficiency values, which among the pre-treated samples showed a higher growth percentage in the values of this characteristic (Respectively: 3.41 and 28.90%). Both water washing methods and ethanol-acetone mixture washing were effective in improving the physical (density) and acoustic properties (modulus-elasticity, damping and acoustic conversion efficiency). Meanwhile, the effect of ethanol-acetone mixture washing was more than the effect of water washing. Fermentation pretreatment with bread yeast improved the performance of water washing and ethanol-acetone mixture washing treatments.

Proper designing of green space in educational centers increases vitality and ensures the safety of users and reduces costs. The purpose of this study was to estimate the lack of root and canopy growth space of the most important green space trees of Yazd University. At first 124 pine and 102 elm trees were randomly selected in different parts of the University and their morphological characteristics were measured. The height/diameter coefficient was used to determine the susceptibility to wind-throw. To determine the shortage of canopy growth space, the canopy area of ​​5% of the largest trees and to calculate the shortage of root growth space, the British standard were used. Then, classification of frequencies was done. Results showed that the mean height coefficient of pine and elm were 56.85 and 51.21 respectively. About 87.1% of the pines and 42.2% of the elms were in a stable condition. About 96% of the elm trees and 94.4% of the pine trees had insufficient planting distance and therefore, do not have enough space to reach the maximum dimensions of the crown. According to the results, 77% of pines and 54% of elm trees lacked root growth space. Tomographic examination via ultrasonic technology showed decay only in some broken trees. Based on the results, it is recommended to assign enough space for the growth of canopies and roots in order to reduce the possibility of uprooting, before designing the planting areas and building curbs and sidewalks.

The knot is the branch impact on the tree's trunk which reduces the quality of the wood. Knots or occlusion branches are the most important factor in the grading of woods. The purpose of this research is to detect and distinguish the size of the knot in the beech tree stem by non-destructive stress wave method. In this research, five one-meter stems were examined and according to the knot size, the stems were classified into four parts without knots, with small, medium and large knots. By using the FAKOPP microsecond timer device, stress waves were passed along the length of the stem and the width of the knots in the four parts of the stem. The amount of the stress waves velocity were calculated according to the transit time of the stress waves and also percentage of the Relative Velocity decrease of Stress waves were calculated. Analysis variance of the data showed between the four parts there is a significant difference at the 95% confidence level. The results showed that the size of knot has effective on the Relative Velocity decrease of Stress waves in the beech tree stem. As the knot gets bigger, its angle decreases with the main stem axis. consequently more length is placed in the stem, and the speed of its occlusion increases. In this method,very small knots whose percentage of the Relative Velocity decrease of Stress waves was less than 10% were not detected. Therefore, for small, medium and large knots, the range of Relative Velocity decrease of Stress waves were obtained 10-20%, 20-45% and more than 45%, respectively.

The purpose of this study was to identify the factors affecting the production companies in the laminate flooring industry in terms of competitiveness using nonparametric tests. The statistical population of this research includes experts and specialists in two areas of competitiveness and structure of the laminate flooring industry; managers in companies producing and importing this product and customers of laminate flooring. The sampling method was randomly classified. The Cochran formula was used to determine the sample size. In order to determine the effective indicators while studying the available sources and using the Porter model, as a basic model and after conducting the necessary studies and factor analysis, the conceptual model of the research was designed in form of three main criteria including environmental factors, intra-organizational factors and factors creating perceptual value as well as 9 sub-criteria. After conducting the necessary studies, preparing a researcher-made questionnaire and data factor analysis, the conceptual research model was designed and by conducting a field research and analyzing the results using student's t-test and Friedman test, the relationship between laminate flooring competitiveness with 3 criteria and 9 sub-criteria was examined. The reliability of the data was confirmed by Cronbach's alpha method. The mean of all studied indices was evaluated as moderate based on the results of descriptive statistics. Based on the results of the t-test, environmental factors, intra-organizational factors and factors creating perceptual value have a more than average role on competitiveness. Also, based on Friedman test, prioritization of indicators was obtained respectively based on environmental factors, factors creating perceptual value and intra-organizational factors.

This study aims to identify the expectations and preferences of consumers of home and office furniture using nonparametric tests. The statistical population consists of customers of the home and office wood furniture industry in Tehran and a stratified sampling method was used in this study. Cochran formula was used to determine the sample size. To determine the effective indicators, the researcher studied the available resources and the Van et al.’s model as the basic model and conducted a factor analysis to design the conceptual model of the research. Using a field research, the student t-test and Friedman test, she examined the relationship between consumer preferences and 5 factors and 17 subindices.

The reliability of the questionnaire was confirmed by the data obtained from 100 questionnaires using Cronbach's alpha. The results of descriptive statistics indicated that the mean of all the indices was at an average level. The minimum and maximum values and the standard deviation showed that there were no outliers. The results of inferential statistics in SPSS software indicated that as the significance level for Kolmogorov-Smirnov test was greater than 5%, all variables are assumed to be normally distributed. The results indicated a significant relationship between all indicators and consumer preferences regarding home and office furniture. The results of the one-sample t-test indicated that consumers consider corporate responsibility factors, product and vendor’s characteristics and internal factors above average while they consider environmental and safety factors at the average level in the purchase of home and office furniture. The results of the Friedman test indicated the priorities as follows: vendor’s characteristics, internal factors, corporate responsibility factors, product characteristics and safety and environmental characteristics.

One of the problems of non-destructive tests in the detection of the inhomogeneities in wood and wood products is their location relative to the vibrating node and antinode. Thus, the hidden inhomogeneities located at the vibration node in such materials may not have any effects on the dynamic modulus of elasticity and may not be detectable. In this study, we investigated the development of simple end-to-end joint in oak beams (Quercus castaneifolia) with dimensions of 72×4×2 cm (longitudinal×Radial×Tangential), with blocks removed from the areas of 0.06 and 0.50 cm of the beam length. The blocks were removed from the same beam as the joint was developed. The results indicated that developing a joint in 0.50 cm of the beam length has no significant effect on values obtained from the dynamic modulus of elasticity while creating this joint in 0.06 cm of the beam length has a significant effect on values obtained from the dynamic modulus of elasticity. Also, in both joints, the damping and acoustic converting efficiency values were increased and decreased, respectively. The amount of these changes was more in the area of 0.06 cm of beam length. In general, it can be said that due to the effect of vibrating node and antinode and on the other hand, the location of the joint in both areas, the acoustic conversion efficiency factor is a suitable factor to estimate the location of the joint or the inhomogeneity itself.

Acoustic tomography technology is a non-destructive method that can reveal the hidden defects of trees. As a result, the aim of this study is to detect the internal defects of the oak tree (Quercus castaneifolia) using acoustic tomography. For this purpose, samples were randomly prepared from ten trees in the Asalem region of Gilan province and then discs were cut from trunks. Doe to the lack of natural decay, artificial cavities were drilled inside the disks in four stages: 25% - 50% - 75% - 100%.  Healthy and defective samples were obtained and the sound wave velocity was calculated using FAKOPP Microsecond Timer device. The results show that the average speed of sound waves passing through the oak wood is 1500 meters per second, which decreases greatly with increasing internal defects. If internal decay progresses from 25% to 100%, the amount of reduction in the speed of sound waves varies from 15% to 36%. The size of the crack or shake is also effective in reducing the speed of sound waves. In large shakes, the speed of waves was reduced by more than 50%. The speed of waves is different in the sapwood and the heartwood. Tomographic images are green in the healthy parts, yellow in the primary decay, and orange and red in the decay, and blue in the cavity parts. Generally, The Acoustic Tomograph accurately revealed the presence and magnitude of the defect without differentiating between decay and crack.

In this study, the effect of artificial inhomogeneity of density in the initial and middle of Oak wood beams (Quercus castaneifolia) by the changes in the dynamic shear modulus values obtained from the free vibration in free-free beam method have been investigated. For this purpose, 10 specimens of Oak wood species with a dimension of 720×40×20 mm (longitudinal, radial, and tangential) were tested by the free flexural vibration method to determine the shear modulus in the solid wood beams. After that, the samples were divided into two groups and from the first group, the blocks with a dimension of 40×40×20 mm from the initial part, and from the second group, the blocks with the mentioned dimension were extracted from the middle part of the solid beams, and jointed to each other by polyvinyl acetate adhesive. After the jointing, the free bending vibration test was performed on both groups again. Afterward, the Oak blocks were removed from the junction and in two stages, blocks of two species of Poplar wood (Populus nigra) and Iron wood (Parrotia persica) were replaced and in order to the effect of artificial inhomogeneity created by each of the replaced blocks on the values of the shear modulus, the flexural vibration test was performed on them. The results showed that the development of artificial inhomogeneity of density in the initial area of the beam by all three species of Oak, Poplar, and Iron wood did not have a significant effect on the values of dynamic shear modulus, while creating inhomogeneity in the middle of the beam has caused a significant drop in the values of this factor. Heterogeneous beams by Iron wood species had the highest, and heterogeneous beams by Oak wood species had the lowest percentage decrease in dynamic shear modulus values.

Non-destructive tests today play a vital role in human life. Non-destructive evaluation technology is widely used in industries, especially wood based industries and wood based products and has led to advances in Strength grading lumber, determine the disadvantages of wooden materials, Inspection of timber and wooden structures. The purpose of this research was to estimate the flexural strength of dynamic tests and compare them with the results of static standard tests in two Forest Pine species (Pinus sylvestris) and Rush (Fagus orientalis). The results of the comparison of the estimation of the modulus of elasticity and the estimated modulus of rupture by a non-destructive free vibration method in a free supported beam with similar results from the static test showed a very good correlation So, according to calculations done by applying a safety coefficient of 18% for beech species and 11% for pine species, a non-destructive vibration test can be substituted by a static destructive standard test for estimating the factors mentioned in these two species.

This study deals with the possibility of evaluation and estimating the wood density in Quercus castaneifolia and Fagus orientalis. Wood samples were prepared and cut firstly in 4×20×30 cm (thickness×width×length). Then their density was calculated after 72 hours of conditioning in an oven at 60°C temperature. In thermography process, the temporal temperature was monitored in 1st, 5th, 10, 20, 30, 45 and 60th minutes of cooling (monitoring steps). Investigating the effects of shape factor and dimension on thermographic density evaluation errors, the specimens were cut down in two more steps to 3×20×30 cm and 2×15×20 cm and the course of thermography experiments was repeated. The relationships of shape factor, density and the ratio of density to the shape factor with the logarithmic cooling rate were evaluated separately. Results showed that density without considering the shape factor variations was not sufficiently correlated to the cooling rate. But the ratios of the density to their proper shape factors were promising for the density evaluations from the cooling rates. However, it is suggested to revise this non-destructive method using a larger variety of the wood specimens and species.

The goal of this study was to determine the modulus of elasticity and modulus of rapture of two kinds of date palm (Khasi and Hajmohammadi) using static bending and dynamic (flexural vibration) techniques. To reduce the difference between static and dynamic stiffness values, the static bending modulus of elasticity was modified by taking into account the value of the shear deflection. In addition to, for better understanding of the mechanical properties of date palm, values were compared with those measured for poplar samples. The results showed that, in Khasi the mean values of the modulus of elasticity obtained by flexural vibration, the static modulus of elasticity, the modified static modulus of elasticity and as well as the modulus of rapture were 47, 67,68 and 38% less than those measured for Hajmohammadi respectively. In comparing with date palm, values measured for poplar samples were more pronounced. The difference between dynamic and static values of modulus recorded for Khasi, Hajmohammadi and poplar samples were 63, 40 and 19% respectively. After modification of the static values, the difference was reduced in to 3% for Khasi, 6% for Hajmohammadi and 7 % for poplar experimental samples. Finally the significant correlation coefficients were found between the static and the dynamic modulus of elasticity for both two kinds of date palm.

Reaching to the technology of acoustical Tomography and imaging, this project was ordered for facilitating the work for green space researchers and managers in urban standing trees. Comparing the sensors and micro-second timers with those of a certified European device in radial to tangential and longitudinal directions showed a good agreement for the Iranian made device. So, a new horizon was opened for the researchers of this approach supported by the local scientific knowledge and technology. Holding this technology, the selected trees concerning the collar defect symptoms were firstly inspected visually, then the visual accuracy was monitored by sonic tomography. Some trees were extremely defected internally, while the visual inspection showed their intactness (9 from 23). Meanwhile some trees holding visually defect signs were proved to be intact after carrying the tomography images (up to 10 from 53). It is concluded that the visual tree defect inspection is not satisfactory for saving or omitting the individual and these kinds of decision makings must be supported by the methods showing the hidden discontinuities.

In this study the effect of coating with lacquer (Shellac) on acoustic properties by forced flexural vibration in free-free beam in white mulberry (Morus alba) and walnut (Juglans regia) have been investigated. For this purpose, the samples of both species with dimensions of 2 × 15 × 140 (length, width, height) were prepared. The samples of both species for integrated humidity were kept in climatic chamber for three week in climatic chamber (20 ± 2C0 and 65 ± 5 % rH) and then the first step of forced vibration test for measure basic properties of the both test samples were performed on them. Aftter that the samples of both species were coated by lacquer and after integrated humidity in samples to assess the effect of lacquer on acoustic properties forced flexural vibrations test was performed on them again. The results showed equal variations in the specific gravity in both coated species in mulberry and walnuts samples. The modulus of elasticity, acoustic coefficient and acoustical conversion efficiency values after coating were reduced in both that drop in values in mulberry more than walnut species.The reason of this results caused with variations in the frequency and specific gravity of the test specimens in both species that variations in frequency in mulberry more than walnut species. Damping vibration values under the influence of coating was increasing in both species that's results obtained because the different influence of alcohol in withdrawal extractives in mulberry and walnut species and different nature and role of these substances in each species that mulberry that this factor values referred to in mulberry species was over than walnut species because of the different nature of the extractives in each species.

This paper investigated the radial variations of acoustical and mechanical properties of date palm from the pith to the bark. Cubic samples with dimensions of 2×2×35 cm3 (Radial× tangential ×longitudinal)) were taken in distance of 3, 6, 9, 12 and 15 cm toward the bark. To evaluate dynamical properties of date palm, flexural vibration method was applied on cubic experimental samples. Further the specimen then were utilized for measuring MOE and MOR in static bending test. More details were also attained by anatomical analyzes. The results showed that the acoustical parameters of the propagated wave (the internal friction, the acoustic conversion efficiency as well as the acoustical impedance) were constant while increasing the distance between pith and bark. The highest values of acoustic coefficients found for samples near the pith and partially increased while moving to the bark. The density variations were less important in radial direction of date palm disk. The MOE and MOR values significantly radially varied and were maximum for samples in distance 3 cm. As they reached to the distance of 15 cm from the center, the given parameters dramatically decreased. Finally it can be conclude that the quality assessment of date palm based on the acoustical parameters is not reliable. It is suggested to provide samples from the outer parts of date palm disk when construction materials need more strength.

In this research, the effect of different welding parameters on residual stress and microstructure of the weld region, as well as the comparison of two methods of measuring residual stress using critical fracture longitudinal wave method and preformation method have been investigated. For this purpose, the taguchi DOE methodology is used as a statistical method to optimize four parameters of pulse current, base current, and pulse on time% and pulse frequency to minimize longitudinal residual stresses in austenite 304 AISI stainless steel. After welding, stress measurements were performed using two methods critical fracture longitudinal and perforation, and hardness, tensile and OM tests were performed on the specimens. The tests results show that at all levels of the pulse parameters arranged with the standard L9 Taguchi array, the incident heat input is irrefutable and the effect of this parameter is move then 50%. The optimum conditions obtained while the highest frequency level should be considered. The general trend is achieved from the residual stress measurement charts is consistent with the logic of stress distribution in both methods. Sample number 1 with stress equivalent to 232 MPa and sample number 9 with stress of MPa 126 in ultrasonic method with frequency 4 MHz have the highest and lowest stress among different samples, respectively. The size of the coaxial grains weld was directly related to the incoming heat, so that the least amount of coaxial grains in the welding center was related to specimens NO. 3 and 9 with grain size of 8 µm and 9 µm, which in these samples had the lowest amount of welding heat is measured. The samples 1 and 4 with HV 128 and HV 144 hardness and MPa 633 and MPa 639 have the least hardness and tensile strength and the highest strength and hardness of sampled 3 and 9 with 166 and 161 hardness and tensile strength MPa 703 and MPa 695.

The capability of soft and fibrous tissues of plants to absorb noise; has been paid attention to be replaced with synthetic insolation boards. The use of lignocellulose materials has been widely considered because of some important factors like porous structure, high quantity availability, renewability as well as friendly environmental impacts (in contrast with fiber glasses). The lack of raw materials needed for industry also has diverted the attention to other new lignocellulose sources in Iran. So, in the present paper, the possibility of use of date palm (Phoenix dactylifera) as a leftover abundant source in south of Iran was studied in order to control and reduce acoustic pollutions. Two date palm trees with approximate diameters of 40 cm were freshly cut. Then, a disk with the average diameter of 12 cm was taken from every tree. The cubic experimental samples with dimensions of 12×12×2 were prepared from every disk and kept in plastic covers at freezing temperature. Before testing, cross section of samples were covered with epoxy adhesive and dried smoothly using a program. Finally the circular disks were prepared with two different diameters of 3 and 10 cm. To reach equilibrium moisture content, all samples were kept in a temperature-controlled room at 21°C and 65% relative humidity. Then disks were faced with two kinds of paperboards made with original date palm fibers (cortex and leaves fibers). Paperboards were provided in different basic weight of 130, 300 and 500 gr/cm2. Noise reduction coefficients (NRC) measurements were conducted on experimental samples in frequency range of 125 to 8000 (Hz) using impedance tube at the acoustic lab. The results showed that the insulation boards made from date palm had a high potential to absorb sound waves. In addition, their ability to dissipate acoustical waves were more pronounced when faced with a single layer of paperboard. A critical point was observed for NRC values at frequency of 2000 Hz. To compensate the given loss, applying a light paperboard (130 gr/cm2) of cortex fiber as well a heavy cover of leaves fiber (500 gr/cm2) could significantly increase NRC values. The high damping capacity of date palm samples was due to its particular anatomical structure. The vascular bundles embedded in parenchyma tissue provided a soft and porous surface to trap sound waves. An additional improvement on NRC values were obtained while facing disk samples with a layer of paperboard from low to high frequency range.

The effect of compounding process applying two methods of one and two step mixing on the properties of nanocomposite is investigated. Nanocomposites were produced using polypropylene, cellulosic fibers, MAPP and nanolay as reinforcement. 1.5 and 3% MAPP and 0,2, and 4% nanoclay were used as the variable factor and 20% fibers was used. Melt flow index was measured on compounds produced using one or two steps mixing. Either compounds were mixed with fibers and MAPP and then the test specimens were made and tested according to ASTM test procedures. The results revealed that the two steps mixing increased the mechanical properties. The melt flow index of one step mixing was lower and the melt flow index of initial mixing of polypropylene with nanoclay was very high and it was reduced after compounding with fibers and MAPP. The results revealed that at higher dosages of the nanoclay tensile and bending modulus of the composite increased and tensile strength and modulus of rupture decreased.

In this study, 10 samples of beech wood, without apparent defect, with dimensions of 360 × ýý16 × 16 ýcm (length × radial × tangential) were selected, and after being exposed to variable ýtemperature (60, ýý80, 100, 120, 140, 160, and 180°C) and moisture content conditions ýý(moisture content in conditions ýof: saturated with water (EMC=35±5%), equilibrium moisture content ýexposed to air (EMC=19±5%), ýand conditioning moisture content in a climatic chamber (EMC=12±2%), they underwent free ýflexural ývibration test in two longitudinal-tangential and longitudinal-radial planesýþ,þý and some ýof the physical, ýmechanical, and acoustical properties in both planesý were investigated. The ýresults showed that the ýcorrelation coefficient of the first three modes of flexural vibration in ýboth planes under ýclimatic ýchamber had a similar situation, but when the samples were in the ýwater-saturated condition, they ýshowed an adverse behavior in each plane. The effect of ýincreasing the temperature above 100°C ýcaused stresses resulting from shrinkage leading to ýthe development of micro-cracks and reduction in ýthe modulus of elasticity of cell walls and ýultimately reduction in wave propagation ability of wood, ýthus increase in the damping ývibration values in both longitudinal-tangential and longitudinal-radial ýplanes of the samples. ýAlso, the concurrent changes in modulus of elasticity and damping vibration in ýboth vibration ýplanes are a desirable indicator for monitoring the process from the primary logging ýprocess ýstages to processes such as wood drying and heat treatment.ý