مجله ایرانی علوم و تکنولوژی-الف
سال:1391 | دوره:36 | شماره:2-الف |تعداد مقالات:10

In this paper, we introduce a considerable machinery which permits us to characterize a number of special (fuzzy) subsets in AG -groupoids. Generalizing the concepts of (Î,ÎÚq) -fuzzy bi-ideals (interior ideal), we define (Î,ÎÚqk)-fuzzy bi-ideals, (Î,ÎÚqk)-fuzzy left (right)-ideals and (Î,ÎÚqk)-fuzzy interior ideals in AG -groupoids and discuss some fundamental aspects of these ideals in AG -groupoids. We further define (`Î,`ÎÚ`qk)-fuzzy bi-ideals and (`Î,`ÎÚ`qk)-fuzzy interior ideals and give some of their basic properties in AG -groupoids. In the last section, we define lower/upper parts of (Î,ÎÚqk)-fuzzy left (resp. right) ideals and investigate some characterizations of regular and intera-regular AG -groupoids in terms of the lower parts of (Î,ÎÚqk) -fuzzy left (resp. right) ideals and (Î,ÎÚqk) -fuzzy bi-ideal of AG -groupoids.

Maji et al. introduced the concept of fuzzy soft sets as a generalization of the standard soft sets and presented an application of fuzzy soft sets in a decision making problem. In this paper, we apply fuzzy soft sets to G- hyperrings. The concept of (Îg, ÎgÚqd) -fuzzy soft G -hyperideals of G -hyperrings is first introduced. Some new characterizations are investigated. In particular, a kind of new G -hyperrings by congruence relations is obtained.

In this paper, we introduce a new type of almost statistical convergence of generalized difference sequences of fuzzy numbers. We give the relations between the strongly almost Cesaro type convergence and almost statistical convergence in these spaces. Furthermore, we study some of their properties like completeness, solidity, symmetricity etc. We also give some inclusion relations related to these classes.

The chemical speciation of heavy metals (arsenic, chromium, copper, lead, zinc and tin) in the sediments of former tin mining catchment Bestari Jaya, Peninsular Malaysia was determined by using the latest version of the Community Bureau of Reference, usually called the BCR 3-step sequential extraction procedure. Furthermore, a fourth step was introduced for digestion and analysis of the residue. The analysis of total metal content was carried out by using microwave acid digestion. The percentage of each metal obtained from the 4 step extraction (acidsoluble + reducible + oxidizable + residual) is in good agreement with the percentage of total metal content obtained from microwave digestion, which implies the accuracy of the procedure. The degree of pollution in catchment sediments was assessed using geoaccumulation index Igeo and pollution intensity IPOLL. The results indicate that (1) the sediments have been polluted with arsenic (8.8%), chromium (12.9%), copper (17.4%), lead (19.5%), zinc (14.9%) and tin (33.8%) and have high anthropogenic influences; (2) the calculation of geoaccumulation index suggests that catchment sediments have the background concentration for all studied metals (Igeo<0); (3) High IPOLL showed that all of these heavy metals pose high environmental risk. (4) the mobility order of metals in sediments at S1 and S2 was Sn>Pb>Zn>Cr >Cu >As, whereas at S3, S4 and S5, Cu>Pb>Zn>Cr>Sn>As; In conclusion, acidic pH, total organic carbon, scavenging ability and co-precipitation (inclusion, occlusion and adsorption) of studied metals with non-metals could account for change in the geochemistry of the catchment sediments.

Plants are potent biochemists; biologically active compounds present in the medicinal plants have always been of great interest to scientists working in this field. Thus, the aim of the current study was to screen the antimicrobial activity of Acacia nilotica, Ziziphus mauritiana, Bauhinia variegate and Lantana camara against some selected clinical isolated strains. Although previous studies have documented the antimicrobial properties of these plants, this work is designed to evaluate the specific antibacterial activity of different extracts of these plants against tested microorganisms, in order to know the best extract against specific microorganisms. In this study the fresh parts (leaves, barks & pods) of the test medicinal plant were collected and methanol, ethanol and ethyl acetate extracts were prepared. Antibacterial susceptibility test was done by using Agar diffusion assay method. Statistical analysis was carried out with SPSS 17.0 Windows version. The results of the current study showed that a total of 8 extracts from 4 different plant species were investigated including pods of ethyl acetate extracts of Lantana camara, which showed the highest antimicrobial activity against tested clinical isolates (Bacillus subtilus 2±0.1mm, Bacillus circulans 2.6±0.2mm, Bacillus sphaericius 2±0.1mm, Staphylococcus aureus 2.5±0.1, and Serratia liquefaciens 2.2±0.1mm), followed by its ethyl acetate extracts of leaves. Bark extracts of four tested medicinal plants possess a lower zone on inhibitory activity as compared to the leaves extracts of these plants. Noticeably no antimicrobial activity was found in the methonolic bark extract of Acacia nilotica against the tested bacteria except Bacillu ciurlans. The results of the present investigation clearly indicate that the antibacterial activity varies with the species of the plants and plant material used. Thus, the study ascertains the value of plants used in ayurveda, which could be of considerable interest to the development of new drugs. Studies are in progress to further evaluate the mechanisms of action of these active test extracts on study organisms associated with certain human diseases.