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Introduction: As one of the most valuable parts of a municipal system, the green space has long been praised. For that matter, all the data related to street-side trees must be assessed and recorded. A large part of old plane trees (Platanus orientalis) planted in industrial, dense populated cities are subjected to all kinds of air and water pollutions, frequent droughts and various physical stresses, which make them less likely to sustain. Identification of the most vulnerable tree individuals can be prioritized by a variety of statistical methods. A less applied statistical model in this field is the Artificial Neural Network (ANN). In this study, we present the results of applying ANN model in risk assessment of plane trees planted along Kuala Lumpur Avenue in Isfahan in 2018. Material and methods: In the current study, the risk level of keeping plane trees in Kuala Lumpur Ave. Isfahan was studied using data acquired by a full survey method, and using quantitative tree body proportions and few risk factors (qualitative or imperfect properties). Following coining the share of each of seven hazard criteria and their trio importance indices, a Kruskal-Wallis test compared the number of trees in different risk levels. Then, all the trees were scored via the biased levels of their risk level. Accordingly, based on the weighted scores, they were divided into five hazardous categories. To develop an understanding of the quantitative variables, risk factors, weight parameters, and hazard classes, we carried out a principle component analysis (PCA) and a multi-layer perceptron (MLP) network procedure. Results and discussion: The results of the proportion of each hazard index revealed the importance of the trunk and root wounds (83%), the structural tree weakness (61%), root problems (54%), and branch and twig dieback (50%). Also, results of Kruskal-Wallis test showed that the risk levels of the planted trees can be significantly classified into four classes of: with no risk or healthy, low, moderate, and high-risk classes, at one percent error level. The results of Duncan's mean test showed that the number of trees in no risk and low-risk classes were significantly higher than the other classes at one percent error level. The results of the PCA indicated that the first and second components explained 44.69 percent of the total variation. The risk and weighting parameters of the branch and twig dieback, the tree diameter, advanced decay, and wound on the trunk and root were highly and positively correlated. In general, the two variables of the trunk and root wounding, as well as branch and twig dieback, were among the most important variables in terms of risk assessment of the plane trees. The high coefficient of determination values of training, validation, verification, and finally, all neural network data (0.999, 0.949, 0.996, and 0.991) and the least mean square error values (training data = 0.052, verification 0.114, and validation = 0.044) indicated the accuracy and desirability of the ANN in the prediction of the risk classes for street side trees. Conclusion: According to the results of risk assessment diagnostic criteria and main components analysis, the two variables of trunk wound and root and branch mortality of plane trees should be regularly reviewed. Moreover, decision-makers may use the neural network method to identify and detect the risk possibility of planted trees. Therefore, this approach can be proposed as a suitable and useful solution in urban green space management and preventive measures.

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.

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.

The main goal of this work was to evaluate the importance of vascular bundles on the physical and mechanical properties of date palm. To prepare experimental samples, two trees (Phoenix dactylifera) with the average diameter of 47 cm were freshly cut from Ahvaz countryside in Khoozestan Province. Cubic samples with dimensions of 2 cm (tangential) × 2 cm (radial) × 2 cm (longitudinal) were taken from different heights of date palm trunk (2, 5 and 7 meter). The anatomical (number, diameter and cross-cut area of single vascular bundles), physical (density) as well as mechanical properties (vascular bundles tension strength and modulus of elasticity) were studied. The results showed that the calculated total area of vascular bundles per 400 mm2 was maximum for samples near the bark (33% of total area) and the value gradually decreased to 27% for specimens around the pith. The number of vascular bundles increase was observed while moving from the pith to the bark. The same variation also attained when the height of date palm stem increased. But for the average values of single vascular bundles diameter and cross-cut area, no regular trend of increase or decrease was observed. For mechanical properties of vascular bundles, the results revealed that tensile strength and modulus of elasticity were greater for specimens close to the pith in comparison with the values of samples near the bark. Finally the highest correlation was found between mechanical properties of vascular bundles and the position of them in transversal direction of date palm stem.

In this investigation the effect of using of UF and MUF Resins on Physical and mechanical Properties of Particleboards Produced from Rice Straw and Aspen Particles has been studied. The aim of this study was to determine of physical and mechanical properties of rice straw– particleboard. Single-layer particleboard was produced. That was produced with 11% MUF and 11% UF. For using of UF and MUF 2% hardener was added to adhesives. The Press condition for MUF was: 1750C for 4 minutes and also for UF application was 1750C for 6 minutes. Another variable factor was the rice straw content in three levels (15%, 30% and 45%). Other factors such as board density (0/7gr/cm3), mat moisture (12%) were constant factors. The results indicate that increasing rice straw to wood particles cause some reduction in modulus of rupture , and internal bonding , and some increase in thickness swelling , and water absorption of manufactured boards. But comparing and grouping means by Duncan test showed that in the most case these effects were insignificant when rice straw add to wood particle up to 30%. Particleboard bonded with 11% MUF had the highest bending strength. Particleboards bonded with MUF had better bending strength, shear strength, thickness swelling and water absorption after 2, 24 hours immersion. Grouping the experimental data while using Duncan method was indicated of the fact that an optimum condition for manufacturing particleboard while using a mixture of rice straw and wood particles is to add 30% rice straw to the mixture , use 11% melamine urea formaldehyde resin and employ a pressing time of 4 minutes.