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Aims: Karun River, which is the largest river in Iran, represents a unique ecosystem. However, increased anthropogenic activities result in the formation of this river is seriously affected by a large range of pollutants especially the heavy metal pollutants which may be toxic to human and aquatic fauna. Therefore, there is a need for continuous monitoring of pollution levels in the river.
Materials & Methods: In this study, water, sediment, and algae samples were collected from six different stations along the course of the river in September 2015 to investigate the quality of Karun’s River in terms of heavy metals (Pb, Zn, Cr, and Cd) at the basin of drinking water treatment in Ahwaz and Mollasani cities. After drying and digestion of samples, heavy metal concentrations were determined using an atomic absorption spectrophotometry (Perkin Elmer-Analyst 300).
Findings: The highest concentration of trace metals was found in sediment samples with Zn having the highest mean concentration values in all stations. The heavy metal concentrations in the downstream indicated an increase in the pollution load due to the flow of water from upstream to downstream of the river resulted in the movement and accumulation of all contaminants to the river in the downstream; hence, there was the highest concentration
of metals in basin of the Kut Abdollah treatment (downstream) and the lowest in Mollasani (upstream).
Conclusion: Comparison of the concentration of metals in the sediments with some universal standards including EPA3050 and the criterion of sediments quality standard from NOAA and Canadian Environment Agency showed that the concentration of chromium and cadmium in stations was higher than the allowable limit of EPA3050 standards and some environmental standards of Canada among all metals. Since algae samples have been able to accumulate a significant amount of heavy metals, therefore, these are suitable bio-indicators to determine the concentration of heavy metals in this aquatic ecosystems.

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During late nineteenth century, Khuzistan was considered to be the most fertile land of Persia which at one time had yielded $ 50 million if calculated on 1962 price index. Many British officials presented in Iran and India office have recorded the abundance of water through a network of five rivers and canals, making Khuzistan a fertile ground for major staple and cash crops. At the time when the general populace was affected by the famine, Khuzistan stood unaffected. But thoroughly and gradually Khuzistan had faced deplorable condition owing to the British policy and power struggle. With the opening of the Karun River, the British influence had reached to the extent that they started interfering in the appointment of governors and granting of Khuzistan developmental projects to French, Dutch or Germans. The present article highlights the increasing influence of British in the political and economic affairs of Iran especially Khuzistan which was considered to be the 'second Egypt' next to Seistan. They had even assisted by the principle Arabs and Bakhtiaris tribes of Khuzistan as well as the influential trading and commercial figures to sabotage the irriga-tion project which could hamper the water flow to Karun River, a back bone for their commercial interest. In the first quarter of 20th century the British policy in Khuzistan proved detrimental to their vested interest.

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 In this study, the first symptom appearance of wheat leaf rust disease was monitored in Khuzestan Province every ten days from early December 2014, for three years. Also, the climate changes and their influence on the development of the disease were studied. During 2014-2015, the first symptoms, with the severity of 5 MS (Moderately Susceptible), appeared in the south and west parts in early and mid-March, respectively. In northern areas, the symptoms appeared with 10 MS severity in early May. In 2015-2016, the first symptoms appeared with the severity of 5 MS in February in the southern areas. In the west, symptoms appeared and reached 20 S (susceptible) on March 10. In the north, the disease started in late February with the severity of 10 MS and developed to 30 S. In 2016-2017, the first symptoms appeared around the Karun River with the severity of 5 MS on March 10 and eventually reached 10 MS in late March. In the western areas, the disease started in early March with the severity of 5 MS and then stopped. Symptoms appeared one week later in the north, with the severity of 5 MS, and reached 15 MS until the end of March. Based on the previous studies, the first symptoms of wheat leaf rust usually start from the west. However, now, the regional pattern of the symptom has changed dramatically, and it appears in the south near Karun River and the Sugar Cane Crop Industry. This might be due to implementation of preventive measures and dryness of a big part of Hoveyzeh Marshland.
 

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This experiment was conducted in order to determine the hydrodynamic performance of a Triangular Winged Bandal-Like (TWBL) structure, which is a combination of the Bandal-Like (BL) structure and Triangular Vane (TV). For the purposes of this study, the JFE ALEC magnetic velocity meter was used to measure the three components of flow velocity under non-submerged hydraulic conditions at a Froude number of 0.24. The three considered cases for this measurement were the non-structured case and the BL and TWBLs. The results showed that the flow deviation occurred through the impermeable upper part of both structures towards the middle of the channel. At downstream of both structures, bubbling flows were caused by the collision of upward flows with the near-surface flow, causing disturbances in the latter. Both the BL and the TWBL structure reduced the secondary flow strength along the bend within the structure range. Compared to the BL structure, the TWBL structure reduced the secondary flow strength by about 20%, which indicates the weaker inclination of the secondary flow toward the outer bank in the TWBL structure. The relative maximum shear stress in the TWBL structure is on average 17% lower than that of the BL structure.