Groundwater is one of the most important water sources in arid and semi-arid areas. With the increasing world population and the water demand for agriculture and urban use, the need for water resources has increased, especially in arid and semi-arid regions, where groundwater resources play a significant role. To prevent the pollution of groundwater resources, various studies for their preservation and maintenance should be carried out, including a detailed plan for proper management of water resources and establishing a balance between water quality and how to use them. It becomes important to understand the spatial change of the quality of groundwater resources. In this study, Sabzevar plain, a typical region of semi-arid climate in Iran, was selected as a case study to assess the groundwater quality of the region, using data from 24 observation wells between 2015 and 2019. Using Arc GIS software, a map of groundwater quality parameters in the study area was prepared for quality assessment and comparison with existing international standards. The results showed that (except pH and HCO3−) the concentration of Sodium, Magnesium, and other anions and cations is higher than the corresponding WHO standard limit, suggesting that the study area is unsuitable for drinking and agricultural use. According to the Wilcox chart, 87.5% of the samples are in the C4S4 class while 8.33% are in the C4S3 class, showing the groundwater unsuitable for agricultural use due to its high salinity and alkalinity. Piper diagrams show that more than 50% of the samples are non-carbonate alkalis, indicating a very high salinity in the area. According to the pie chart, chlorine ion and sodium ion are the dominant anions and cations in the Sabzevar plain, respectively. The Schuler diagram shows that none of the samples examined were in a good class for drinking. Therefore, considering the importance of water for agricultural activities in the study area, it is recommended to have agricultural management solutions to prevent groundwater mixing with freshwater resources.
1 February 2023 in Journal of Hydraulic Engineering
The mean velocity distribution of open channel flows with fully submerged two-layered vegetation can be divided into three zones. Zone 1 represents the lower region of short vegetation, where the flow has high drag because of highly dense vegetation, Zone 2 represents the middle flow zone from the edge of the short vegetation to the top of the tall one, and Zone 3 denotes the upper region with the free surface flow. A new analytical model is developed based on the momentum equation of vegetated flow, where turbulent eddy viscosity is approximated as a linear relationship with local velocity. The analytical model was evaluated using seven experimental data sets under different flow conditions with distinctive densities and formations of vegetation. Three sets of data available from other researchers were also used to check the applicability of the proposed model. An agreement between the analytical model and experimental data indicates the validity and robustness of the model.
Vegetation plays a vital role in the flow characteristics of natural open channels, such as rivers. Typically, vegetation density is higher in the lower layer and sparser in the upper layer of these channels. In this research, Ansys Fluent and the k–ϵ model have been employed to simulate various vegetation configurations to capture intricate flow complexities within vegetation regions. Numerical analysis demonstrated that the numerical results align with anticipated Turbulence Kinetic Energy data obtained from analytical and experimental studies. Our findings revealed that double-layer vegetation induces a more intricate flow distribution. In the spaces between vegetation zones, Turbulence Kinetic Energy decreases due to the resistance imposed by the vegetation patches. This resistance has positive implications for sustaining aquatic life and facilitating sediment deposition, promoting a more environmentally sustainable outcome.
Drug-induced liver injury is a major concern in clinical studies as well as in post-marketing surveillance. Previous evidence suggested that drug exposure during periods of inflammation could increase an individual’s susceptibility to drug hepatoxicity. The antithyroid drugs, methimazole (MMI) and propylthiouracil (PTU) can cause adverse reactions in patients, with liver as a usual target. We tested the hypothesis that MMI and PTU could be rendered hepatotoxic in animals undergoing a modest inflammation. Mice were treated with a nonhepatotoxic dose of LPS (100 µg/kg, i.p) or its vehicle. Nonhepatotoxic doses of MMI (10, 25 and 50 mg/kg, oral) and PTU (10, 25 and 50 mg/kg, oral) were administered two hours after LPS treatment. It was found that liver injury was evident only in animals received both drug and LPS, as estimated by increases in serum alanine aminotransferase (ALT), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and TNF-α. An increase in liver myeloperoxidase (MPO) enzyme activity and tissue lipid peroxidation (LPO) in addition of liver glutathione (GSH) depletion were also detected in LPS and antithyroid drugs cotreated animals. Furthermore, histopathological changes including, endotheliitis, fatty changes, severe inflammatory cells infiltration (hepatitis) and sinusoidal congestion were detected in liver tissue. Methyl palmitate (2 g/kg, i.v, 44 hours before LPS), as a macrophage suppressor, significantly alleviated antithyroids hepatotoxicity in LPS-treated animals. The results indicate a synergistic liver injury from antithyroid drugs and bacterial lipopolysaccharide coexposure.