Habitat change leads to differences in the rate of decomposition and nutrient dynamics of leaflitters, which has many effects on the controlling factors of the decomposition process. In the present study, the rate of decomposition and nutrient dynamics of Norway spruce were evaluated for 363 days in the two forestation sites in the natural and foreign habitats, Strå san and Lajim. Nutrients such as nitrogen, phosphorus, potassium, calcium, magnesium, manganese and lignin, as well as Limit value, constant coefficient of decomposition and production capacity of humus were investigated using standard methods in both habitats. Nutrient and lignin concentrations were measured individually in each country using the same measurement method. The results showed that the initial quality of needles, except for calcium and manganese, in Lajim habitat (the concentrations of nutrients in nitrogen, phosphorus, potassium and magnesium were 12. 63, 1. 23, 9. 85, and 1. 51 mg/g) was better than Strå san (the concentrations of calcium and manganese were 13. 4 and 1. 38 mg/g). The dynamics pattern of nutrients in two habitats was similar during the study period, but in 363 day, there were significant differences (p <0. 05) in the concentrations of manganese and phosphorus. The remaining weight in two habitats at the end of the period did not show any significant difference (Lajim and Strå san habitats were 77. 69% and 77. 92% respectively). The constant coefficient of decomposition and production capacity of humus in Lajim habitat was higher (respectively, 0. 24% per day and 66 fractions) than Strå san habitat (respectively, 0. 1% per day and 55 fractions). Based on the stepwise regression, in the Lajim habitat the concentrations of phosphorus and manganese and in the Strå san the concentrations of lignin, magnesium and calcium were the only variables which explained mass loss var iation. In general, the results of this study showed that Norway spruce in Lajim habitat was successful in the view point of the decomposition and nutrient dynamism and in the compared to its natural habitat, and could be used in the Hyrcanian mountain forest for reforestation projects.

Oxovanadium (IV) symmetrical complexes have been papered from the reaction of VO (acac)2 with tetradentate schiff bases. The compounds were characterized by elemental analyses, 1H-NMR, 13C-NMR, infrared, and thermal analysis (DSC). The thermal characteristic data of the complexes were determined from differential scanning calorimetry (DSC). The DSC data indicated that these complexes had very large decomposition enthalpy and released a lot of energy. Thus, thermal decomposition kinetics of these compounds was studied using DSC technique. The results showed that g-Fe2O3 nanoparticles catalyzed decomposition rate of synthesized complexes.

Incorporation of plant residues in soils is an important agricultural practice for maintaining soil fertility under organic management systems. Plant residues quality, soil physical and chemical properties, and the microbial population diversity of soils are the most important factors influencing the decomposition of added organic matter to soils. Decomposition rate of wheat, alfalfa and tomato residues was studied in two different soil samples with contrasting texture under laboratory condition.Soil moisture was adjusted at 50% water holding capacity and soil samples were incubated at 25 oC. The CO2 production was used as an index for decomposition rate of plant residues. Result showed that decomposition rate of alfalfa residue was higher than those of tomato and wheat residues.The CO2 evolution data and the rate of plant residual decomposition fallowed y = a0 + a1 x e(x/a2) , and V= - A.e(-kt) equations respectively. The results also showed that there was a good correlation between decomposition rate and K. The K value for wheat, alfalfa and tomato residues was 0.02, 0.075 and 0.061, respectively.

Functional grouping of nitrogen fixing trees into discrete groups is a good approach to understanding their influence on ecosystem functioning in their new environment. Most of previous studies have reported faster leaf litter decomposition rates of nitrogen fixing than non-nitrogen fixing species. Meta-analysis using published data is the best way for functionally grouping of nitrogen fixing trees from non-nitrogen fixing trees based on litter decomposition rate. Meta-analysis was used for analyzing litter decomposition rate from published data. The data extracted from 5 papers and 16 species that used laboratory method and 27 papers and 41 species that used litterbag method. Leaf litter decay constant (k year-1) of the nitrogen fixing trees was not different from non-nitrogen fixing trees. Initial leaf litter quality (N or C/N, lignin/N, Tannin and Phenolics) of nitrogen fixing trees in all studies was higher than non-nitrogen fixing trees. Totally, it could be highlighted that leaf litter decomposition is species dependent and functional grouping of the tree species based on nitrogen fixing ability is not reasonable, although it is apparent that the litter quality of the two groups is different.

One of the important issues in the financial markets topic is the relation between the prices of valuable commodities like oil and gold and the various exchange rates. Wavelets are mathematical functions for analyzing the time series into their components in various time scales. In this paper firstly the time series of oil price, various exchange rate & gold price are analysis to their components in various time scales by wavelet transform and then the correlation between these components are studied. The results showed that the correlation between these variants are different in the various time scales and also is different from the direct correlation of them. In the case that the direct correlation between the variants is not meaningful we can get valuable correlation in various time scales.

Evaluating the cutting rate (CR) of stones is important in the cost estimation and the planning of the stone processing plants. This research used regression models to estimate the stones’ CR based on their physico-mechanical characteristics. Stone processing factories in Mahallat City (Markazi province, Iran) were visited, and the CR of diamond circular saws was recorded on six different travertine stones. Next, the stone block samples were collected from the quarries for laboratory tests. Stones’ porosity (n), uniaxial compressive strength (UCS), and Schmidt hammer hardness (SH) were determined in the laboratory as their physico-mechanical characteristics. Correlation relationships of CR with physico-mechanical characteristics were evaluated using simple and multiple regression analyses, and estimator models were developed. Results showed that multiple regression models are more reliable than simple regression for estimating the stones’ CR. The validity of the developed multiple regression models was verified with the published data of one researcher. The findings indicated that these models are accurate enough for estimating the CR of stones. Consequently, the multiple regression models provide practical advantages for estimating the CR and save time and cost during the planning and design of the stone processing factories.