82 research outputs found
Determining level of PCBs in skin and muscle tissue of Cyprinus carpio and Esox lucius in Anzali Wetland (Abkenar)
The aim of this research is to determine the levels of polycholoro biphenil (PCBs) in skin and muscle tissues of common carp (Cyprinus carpio) and common pike (Esox lucius) fishes in the west part of Anzali wetland (Abkenar) in the two seasons, autumn 2009 and winter 2010. In each seasons, nine fishes from each species were selected randomly. The samples, transferred in cool condition and the muscles and skins of them were removed. All of the preparations organs clean up and PCBS analysis were carried with GC-ECD (Gas chromatography). Mean concentrations of PCBS were 24.36пg/g dry.w in skin 14.36пg/g dry.w in muscle tissue for E. lucius and 21.84пg/g dry.w in skin and 20.86пg/g dry.w in muscle tissue of C. carpio. In the autumn, the values was less than FDI standard and food standard Australia/AZ MRL and skin tissue of E. lucius and muscle tissue of C. carpio was over of US EPA standard values. Mean concentration of PCBS were 29.43пg/g dry.w in skin and 10.10ng/g dry.w in muscle tissue for E. lucius and 33.06пg/g dry.w in skin and 11.00пg/g dry.w in muscle tissue for C. carpio. In the winter, the value was less than FDI standard and food standard Australia /AZ MRL and skin tissue of E. lucius and skin tissue of C. carpio was over of US EPA standard values. Mean concentration of PCBs in water in the autumn (0.0042ppb) was less than recommended water quality Criteria E.P.A and in the winter (0.1938ppb) was over recommended water quality Criteria E.P.A. Mean concentration of PCBs in sediment in the autumn (4.89ng/g dry.w) and winter (4.48ng/g dry.w) was less than Interim Canadian Sediment Quality Guidelines. There were significant differences between E. lucius mussels and C. carpio skin tissue in two seasons (autumn and winter) in water and ingredient suspension. But in sediments, no significant difference was detected in autumn and winter
Asymmetric Exclusion Processes with Disorder: Effect of Correlations
Multi-particle dynamics in one-dimensional asymmetric exclusion processes
with disorder is investigated theoretically by computational and analytical
methods. It is argued that the general phase diagram consists of three
non-equilibrium phases that are determined by the dynamic behavior at the
entrance, at the exit and at the slowest defect bond in the bulk of the system.
Specifically, we consider dynamics of asymmetric exclusion process with two
identical defect bonds as a function of distance between them. Two approximate
theoretical methods, that treat the system as a sequence of segments with exact
description of dynamics inside the segments and neglect correlations between
them, are presented. In addition, a numerical iterative procedure for
calculating dynamic properties of asymmetric exclusion systems is developed.
Our theoretical predictions are compared with extensive Monte Carlo computer
simulations. It is shown that correlations play an important role in the
particle dynamics. When two defect bonds are far away from each other the
strongest correlations are found at these bonds. However, bringing defect bonds
closer leads to the shift of correlations to the region between them.Comment: 11 pages, 15 eps figures, RevtexI
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