The aim of this study was to evaluate the differences between juvenile and mature woods Populus alba trees in axial radial directions stem. For purpose, three stands P. were randomly chosen cut from at their diameter breast height. Three disks with a thickness 5 cm taken different height levels along tree stems. specimens sequentially position according ISO standards method. results indicated t...

Dendroclimatology offers the unique opportunity to reconstruct past climate at annual resolution and wood from historical buildings can be used extend such information back in time up several millennia. However, varying often unclear origin of timbers affects sensitivity individual tree-ring samples. Here, we compare width density 143 living larch (Larix decidua Mill.) trees seven sites along a...

three k-tree distance and fixed-sized plot designs were used for estimating tree density in sparse oak forests. these forests cover the main part of the zagros mountain area in western iran. they are non-timber-oriented forest but important for protection purposes. the main objective was to investigate the statistical performance of k-tree distance and fixed-sized plot designs in the estimation...

In this study, B12N12 Nano ring has been selected because it consist of four 6-side rings and polar bonds B-N which in comparison with non-polar bonds C-C, is more suitable for the study of the absorption of other compounds. So reactivity and stability of Benzene alone and in the presence B12N12 nano ring field checked. To determine the non-bonded interaction energies between Benzene and B12N12...

To investigate non-bonded interaction of Phenanthrene and BN nanostructure, geometric structure of Phenanthrene and B12N12 nano-ring with B3LYP method and 6-31g* basis set are optimized by using ab initio gaussian quantum chemical package. The main purpose of this study was to evaluate changes of electronic properties of aromatic compound in presences Nano ring field. Therefore reactivity and s...

Four regional Scots pine ring-width chronologies at the northern forest-limit, and in the northern, middle and southern boreal forest belts in Finland cover the last fourteen centuries. Tree-ring statistics and response functions were examined, and tree-ring width variation was also compared to North Atlantic Oscillation (NAO) and volcanic forcing. The tree-ring statistics show evidence of an e...

Thermal dissipation probes (the Granier method) are routinely used in forest ecology and water balance studies to estimate whole-tree transpiration. This method utilizes an empirically derived equation to measure sap flux density, which has been reported as independent of wood characteristics. However, errors in calculated sap flux density may occur when large gradients in sap velocity occur al...