فهرست مطالب شهاب الدین منتظمی

Wind erosion and thunderstorms bring about significant adverse consequences, including air pollution, reduced visibility, wear and tear of industrial machinery, soil structure destruction, and adverse effects on soil fertility. In recent years, the aerosol pollution caused by sand storms has turned into a serious health threat for Iranian people. In addition to being detrimental to human health, the adverse consequences mentioned above will also cause many problems for ecosystem processes. That is why the fight against erosion has received worldwide attention. The application of mulch is a method widely used to control wind erosion and stabilize sand grit and dust hotspots. Mulch is defined as any natural and artificial material that is promoted and applied to the soil surface together with crop residues, plastic films, asphalt, emulsion mulch, oil, petroleum residue, nano-clay matters, and livestock manure. Therefore, this study sought to examine the chemical properties of soils covered by two emulsion mulches.

This experimental study was conducted in some parts of large desert areas located in Aran and Bidgol counties. The treatment items examined in this study were the type of mulch, time of mulch application, and soil depth. In addition to harvesting soil samples covered with mulch, control soil samples were also collected for comparison. PH, EC, concentration of cations (Ca, Mg, K and Na), and anions (NO3, HCO3, SO4, Cl) were other parameters examined in this study.

The results showed that the application of emulsion mulch reduced the soil's pH and EC. In fact, reducing soil salinity leads to a decrease in soil cations and anions concentration, providing suitable conditions for plant growth and establishment by maintaining moisture and reducing evaporation. It was also found that moisture in soils covered by emulsion mulches was significantly higher than that of the control soil during the study period (12 months), reducing the concentration of cations. Considering the fact that the presence of emulsion mulch in the soil surface leads to a decrease in its concentration of cations compared to that of the control soil, this study's analysis of the dominant sodium cation in soil showed a significant decrease in treatment mulch compared to that of the control mulch. Moreover, the concentration of chlorine and sulfate anions was found to have decreased after the application of emulsion mulch, resulting in the creation of suitable conditions for plant cultivation in the region. In contrast, the study found that bicarbonate concentration in the soil increased due to the presence of carbon in the emulsion mulch structure compared to that of the control soil sample.

There was a significant decrease in the amount of salinity in the soil treated with both types of mulch compared to the control soil that received no mulch, the amount of which increased over time. The main reason for the reduction of salinity in the soil treated with the two types of mulch could be the reduced water evaporation from the soil surface caused by an increase in the soil's moisture. Code 1 emulsion mulch was more efficient in maintaining the soil moisture than the other type of mulch. Increasing moisture affects the soil's aggregation by increasing the adhesion between particles and, therefore, the velocity of wind erosion threshold will be decreased. Furthermore, the study found a decrease in the pH of the soil covered by mulches. This decrease in pH was more evident in surface samples, indicating a relative decrease in pH than that of the subsoil.As soil salinity decreases after mulch application, the concentration of cations is also expected to decrease. Among the cations examined in this study, the soil's dominant sodium cation suggested a significant decrease in treated emulsion mulch compared to that of the control mulch. Possessing a lower sand percentage, Code 2 emulsion mulch was found to have a more decreasing effect on the cation concentration after 12 months of its application. The study's results also revealed a reduction in the concentration of all studied cations, which occurred 12 months after the application of Code 2 emulsion mulch, while the concentration of the cations had not changed after six months of the application of the mulch.  The study also found that chlorine and sulfate anions significantly reduced in the studied anions of the treated soils. The final results of this study suggested that both types of applied mulch could contribute to reducing the effects of harmful cations and anions on plant growth and that the application of the mulches would allow more plants to be grown in such areas. Moreover, the results of long-term tests showed the efficacy of the two applied mulches in terms of their stability.

Environmental pollution and the role of chemical reactions in these pollutions caused the chemists to design chemical methods without pollution. In this regard, “Green Chemistry” defines the classification and principals in order to this aim. Green Chemistry that has been suggested by Paul Anastas, means invention, design, production and usage of synthesis productions and procedures in order to reduce or eliminate the use or product of toxic substances. Also Green Chemistry is caused to prevent or reduce the resource pollutions and has an important role in achieve the sustainable development of human society. Some principals of Green Chemistry are the use of renewable resources, reducing the number of process steps, increasing energy efficiency, design the materials and chemical products, increase the efficiency of chemical processes, and the use of raw materials with low-risk. Nowadays, the chemical-based technologies as a new and efficient approach have been attached. This paper tried to investigate and study of important growing methods of green solvents.

Genetic diversity of Iranian wolf populations and domestic/free-ranging dogs were examined using microsatellite markers. The Iranian wolf and domestic/free-ranging dog were sampled in 2010 and 28 wolves and 28 dogs were genotyped with 15 microsatellite loci. Parameters of variability such as allelic richness (Rs), expected heterozigosity (HE) and observed heterozigosity (HO) showed that genetic diversity in Iranian wolves is comparable in magnitude to that of other wild populations of wolf. The average of HE and Rs were 0.85, 11 and 0.83, 9.35 in wolves and dogs respectively. We identified 159 and 141 alleles in autosomal microsatellites in wolf and dog samples respectively. High genetic diversity may result from immigration of outside individuals and habitat diversity in Iran. The average inbreeding coefficient was - 0.148 and -0.122 in wolf and dog samples. The low and negative FIS values revealed no inbreeding problem in Iranian wolf and dog populations. We used Nei and Weir-cockerham F-statistics for investigating level of differentiation between wolves and dogs. Average values of FST, RST and Fit were 0.05, 0.36 and -0.084 reflecting relatively high genetic differentiation between two species. The neighbor joining tree between wolf and dog individuals based on ADS genetic distance showed wolves and dogs were split into two distinct clusters. Even though our sample did not cover the entire range of the wolf in Iran, our results emphasize the high genetic diversity of this species. Also, the results confirm that gene flow between wolves and domestic dogs is low and they show discrete genetic structure, although the two species are in contact around rural areas.

In order to study of nucleotide variation of wild sheep populations of Tangsayad and Korayi guardianship regions, individual feces were taken from two populations. Then, in order to genetic comparison between two populations using D-loop region and Cyt-b gene of mitochondrial genome, DNA was extracted. After amplifying by PCR, the samples were sequenced. Then, sequences were analyzed using MEGA4 software. Results indicated that D-loop region has 552 base pair and Cyt-b gene has 589 base pair and no significant genetic variation was observed between the two populations.