Forest Ecosystem in addition to timber production has many social and environmental benefits. One of the most important benefits from the forest ecosystem is their role in air pollutants absorption and reducing the pollution level. In this study the economic value of SO2 absorption by forest has been estimated in a part of Caspian forest. At the first, the amount of absorbed SO2 has been calculated by existing models, separately for forest and rangeland that are two main land uses in the region. Then this function has been valuated with replacement cost method. The results show a value of 2475 thousand Rials for absorption of each ton of SO2. According to the area of region that is 20582 hectare, the total amount of SO2 absorption is 42.723 ton per year and its value is 106 million Rials per year for the ecosystem function of SO2 absorption.

Open-celled foams are capable to allow the passage of fluids through their structure, because of interconnections between the open cells or bubbles and therefore these structures can be used as a membrane and filter. In this work, we have studied the production of polystyrene open-celled microcellular foam by using CO2 as blowing agent. To achieve such structures, it is necessary to control the stages of growth in such a way that the cells would connect to each other through the pores without any coalescence. The required processing condition to achieve open-celled structures is predictable by a model theory of opened-cell. This model suggests that at least a 130 bar saturation pressure and foaming time between 9 and 58 s are required for this system. The temperature range has been selected for to be both higher than polymer glass transition temperature and facilitating the foaming process. Experimental results in the batch foaming process has verified the model quite well. The SEM and mercury porousimetry tests show the presence of pores between the cells with open-celled structure. Experimental results show that by increasing the saturation pressure and the foaming temperature, there is a drop in the time required for open-celled structure formation. A 130 bar saturation pressure, 150o C foaming temperature and 60 s foaming time, suggest the attainment of open-celled microcellular foam based on polystyrene/CO2 system in the batch process

The possibility of establishing a correlation between surface characteristics of the components and the distribution morphology of solid particles with mechanical properties of a filled coating is investigated. The surface characteristics of the polymer and filler particle, their adhesion strength and the state of dispersed phase distribution are determined by: contact angle measurement, Butt joint measurement between compact discs of particles and the matrix and scanning electron microscopy, respectively. The results showed that with curing of the unsaturated polyester resin on TiO2 particles, their thermodynamic affinity reduces (contact angle increment). On the other hand, the interfacial adhesion energy between the cured resin and TiO2 surfaces is about 6.7 kJ/m2. Also, with interfacial area increment between the filler and matrix via improvement of the state of mixing, the impact strength (I) and wear (W) of the cured coatings were increased and the W~ I-1 scaling correlation was found between them.

Introduction: Sulfur oxidizing bacteria are important in agriculture. The aim of this study was to identify the sulfur oxidizing bacteria in Sarcheshmeh (Kerman, Iran) agricultural soil.Materials and methods: Sampling was conducted from agricultural soil in Kerman province, Iran. After enrichment, samples were purified in the basic mineral culture containing sulfur as the only source of energy. Sulfur oxidation capability was evaluated based on the variation of pH and sulfate content and then strains of sulfur oxidizing were isolated and identified using morphological characteristics and phylogenic techniques. The best strains were selected and were evaluated for variation of pH and sulfate content by isolates in different pH and temperature.Results: Six sulfur-oxidizing strains were isolated and identified which had similarity to Thiobacillus and Starkeya genous. Isolates of 103, 129, 190 and 158 were mesophyll and neutrophil, but isolates of 192 and 156 were thermophile and alkalophill. Of these isolates, isolate 103 was 99.86% similar to Starkeya novella, identified as superior isolate, due to the most sulfur oxidation capability in the synthetic mineral medium containing sulfur.Discussion and conclusion: Isolate 103 was able to grow in neutral to slightly alkaline conditions with pH 7.5. Most of the growth of this isolate was at 30oC as aerobic. This isolate was facultative chemolithotroph and the results of this research showed capacity of the isolate for oxidizing sulfur, so that it could be used as a practical isolate in bio-fertilizers for neutral to alkaline and saline conditions in agriculture.

Sulfur is mainly used to reduce soil pH and increasing nutrients availability in the calcareous soils. However, this process strongly depends on oxidation rate and its affecting factors (e. g. soil moisture content). In this research, the impacts of two soil moisture regimes (40 and 60 % of saturation) and four Sulfur levels (0, 500, 1000 and 10000 kg ha-1) inoculated with Thiobacillus bacteria on sulfur oxidation rates and some chemical soil characteristics were assessed in a complete randomized blocks design with three replications and two soil types (Kharghani and Khaldar) during one year and under constant 25 Co temperature. In this research, soil pH, electrical conductivity (EC), Phosphorus (P), Iron (Fe), Zinc (Zn) and sulfate concentration (SO42-) were measured. The results revealed that the pH adversely significantly (P<0. 01) decreased with increasing sulfur amount, while EC, Fe, Zn and SO4increased. The highest amount of pH reduction, increasing of EC, Fe, Zn and SO42-observed with application of 10, 000 kg Sulfur ha-1. Finally, the respective difference for pH, EC and SO42-compared withcontrol treatment in the Khargani soil were 0. 38 units, 1. 72 dS m-1, 2588 mg kg-1 and 60 days’ incubation; and in khaldar soil 2. 1 units, 3. 2 dS m-1and 4984 mg kg-1 in 360 days’ incubation. The amount of Fe and Zn available were found 3. 53 and 0. 87 mg kg-1, respectively indicating significant increasing compared with control plot in Khaldar soil. The highest P content was observed 0. 5 and 4. 1 mg kg-1 in Khargani and khaldar soils, respectively followed by 1000 kg Sulfur ha-1 application. It is concluded that the amount of sulur oxidation decreased followed by increasing in both sulfur content and incubation period. The highest increment was observed by applying 500 kg Sulfur ha-1. According to the results, Sulfur application up to 1000 kg ha-1 is suggested.

Sulfur is one of the essential elements needed for plant growth and development. In addition, it has been used for disease control as well as for pH reduction in alkaline soils. The chemical oxidation of sulfur in soils is generally very slow. Microbial activity of some microorganisms in soils could enhance the process of oxidation of sulfur, which eventually results in pH decline. A variety ranges of heterotrophic microorganismsplay role in sulfur oxidation, but their role is unclear in the different ecosystems and it is possible that the role of heterotrophic species, could be more important than chemolithotrophic ones in some special cases. Heterotrophic microorganisms with growth in different pH, range are classified into two groups of: acidophilic and neutrophilic. The objective of this study was to investigate the effect of organic matter and sulfur on the population of sulfur oxidizing heterotrophic microorganisms. Two soil samples containing acidophilic and neutrophilic heterotroph microorganisms, with a high pH along with different sulfate and CaC03 contents, were selected. The following four treatments were tested: time in days following the start of the experiment {0(T1), 10(T2), 20(T3), 40(T4) and 80(T5)}, soil {Takestan (S1) and Ajabshir (S2)},organic matter {0(O1) and 1.5%(02)} and sulfur rates {0(G1) and 0.2%(G2)}. At five stages of the experiment, samples were taken from pots for chemical and biological analysis (pH, EC, sulfate and the population of microorganisms).The results indicated that the population of acidophilic and neutrophilic heterotrophs was on the increase till 20th day, decreasing afterwards. Simple and interactionary effects of all factors on soil sulfur oxidizing microorganism’s reactionary soil´OM, and OM´S on heterotrophic acidophylic microorganisms by the simple effect of soil and the interactionary effect of O. M. xS on the population of heterotrophic neutrophylic S oxidizing microorganisms. An application of 1.5% O. M. increased the population of heterotrophic acidophylic and neutrophylic microorganisms by 166 and 265 percent respectively. An application of S too increased the population of the two groups by 20, 39%. There exists a close relationship between the population of S oxidizing microorganisms (heterotrophic acidophylic and neutrophilic) and soil pH. With an increase in pH their population decreases. Variation in population of 38 and 49 percent respectively is explainable with regard to soil pH.