In this article, the sediment transport processes in the Khuran Strait between the mainland Iran and Qeshm Island at North Central Persian Gulf are studied in regional scale in a comprehensive manner. The objectives o...In this article, the sediment transport processes in the Khuran Strait between the mainland Iran and Qeshm Island at North Central Persian Gulf are studied in regional scale in a comprehensive manner. The objectives of this study include defining the type and origin of the sediment, the influencing factors, and the dominant mode of sediment transport. Four possible scenarios of sediment processes in terms of sediment sources and influential environmental forces are examined. The results of the conceptual and 2D numerical model of MIKE21 applied for this purposes indicate that the sediment sources in the transport processes are mainly provided by the sediments suspended from the central and eastern zones of the strait bed. Other sources including input from rivers do not have direct influence on the processes. The results are applied to the study of morphological changes for engineering applications including the pattern and amount of deposit in the Rajaee port approach channel and harbor basin. The pattern and amount of annual sediment deposits in the approach channel predicted by the model is satisfactory, compatible with annual dredging records.展开更多
Land subsidence as a result of the groundwater withdrawals in the Chao Phraya Delta in Thailand will be studied along with any successful remediation efforts. Most of the deltas of South East Asia are sinking for a va...Land subsidence as a result of the groundwater withdrawals in the Chao Phraya Delta in Thailand will be studied along with any successful remediation efforts. Most of the deltas of South East Asia are sinking for a variety of reasons. Thailand has national concerns related to land subsidence as a result of sea level rise, climate change, flooding, storm surges, skyscrapers, compaction, and groundwater extraction for rice paddies, shrimp ponds and the drinking water and household needs of approximately 15 million people living on the Chao Phraya Delta. The Chao Phraya River shoreline line is eroding and significant land areas and wetlands are being lost and becoming open water. Urban areas are periodically flooded and require earthen levees or floodwalls. The objective is to assess and mitigate land subsidence as a result of groundwater withdrawals for rice paddies, aquaculture, shrimp ponds, industry, drinking water and household needs of 15 million people living on Chao Phraya Delta in Bangkok. The impact of groundwater extraction and reduced sedimentation on land subsidence in the Chao Phraya Delta will be assessed and mitigation methods recommended. Lessons learned and successful remediation efforts in one Southeast Asia delta may or may not be applicable to other South East Asia deltas. There need to be mitigation methods identified to add sediment to existing Chao Phraya Delta wetlands. River water also needs to be injected deep into the underlying alluvial sediments in the delta. Navigation in the canal systems could be adversely affected by proposed massive Chao Phraya River water injections into the Chao Phraya Delta alluvial sediments underlying Bangkok.展开更多
Objective:To evaluate the antibacterial efficacy of different solvent extracts of Padina sp.against selected human pathogenic bacteria and fungi species such as Escherichia coli,Shigella sp.,Staphylococcus aureus(S.au...Objective:To evaluate the antibacterial efficacy of different solvent extracts of Padina sp.against selected human pathogenic bacteria and fungi species such as Escherichia coli,Shigella sp.,Staphylococcus aureus(S.aureus),Pseudomonas aeruginosa,Aspergillus flavus and Candida albicans.Methods:Various solvents including methanol,ethyl acetate,chloroform and hexane were used to acquire crude extracts from marine algae Padina sp.After crude preparation,antibacterial and antifungal activities were screened against clinically important human pathogenic bacteria using disc and well diffusion methods.For all the bacterial species used in this research,minimum inhibitory concentration was undertaken considering various solvent extracts of Padina sp.To ensure the accuracy of experiments,a positive control was also included.Results:Confirmed that hexane is the best solvent to extract antimicrobial agents from Padina sp.Among selected bacteria,S.aureus was the most sensitive test microorganism.While,all other microorganisms showed resistance against methanol,ethyl acetate,chloroform extracts.In fact,by increasing concentration of hexane extract,inhibition of S.aureus growth or antimicrobial activity was increased.Growth inhibition zone in well method showed better results compared to disc diffusion method.The minimum inhibitory concentration and minimum bactericidal concentration of hexane extract were 15 and 30 mg/mL against S.aureus,respectively.All Padina sp.extracts did not reveal any antifungal activities against fungi species in this study.Conclusions:Brown algae extracts showed sufficient antibacterial properties against S.aureus.Therefore,Padina sp.in this research can be a good candidate to design and manufacture novel antibacterial agents used in pharmaceutical industries.展开更多
文摘In this article, the sediment transport processes in the Khuran Strait between the mainland Iran and Qeshm Island at North Central Persian Gulf are studied in regional scale in a comprehensive manner. The objectives of this study include defining the type and origin of the sediment, the influencing factors, and the dominant mode of sediment transport. Four possible scenarios of sediment processes in terms of sediment sources and influential environmental forces are examined. The results of the conceptual and 2D numerical model of MIKE21 applied for this purposes indicate that the sediment sources in the transport processes are mainly provided by the sediments suspended from the central and eastern zones of the strait bed. Other sources including input from rivers do not have direct influence on the processes. The results are applied to the study of morphological changes for engineering applications including the pattern and amount of deposit in the Rajaee port approach channel and harbor basin. The pattern and amount of annual sediment deposits in the approach channel predicted by the model is satisfactory, compatible with annual dredging records.
文摘Land subsidence as a result of the groundwater withdrawals in the Chao Phraya Delta in Thailand will be studied along with any successful remediation efforts. Most of the deltas of South East Asia are sinking for a variety of reasons. Thailand has national concerns related to land subsidence as a result of sea level rise, climate change, flooding, storm surges, skyscrapers, compaction, and groundwater extraction for rice paddies, shrimp ponds and the drinking water and household needs of approximately 15 million people living on the Chao Phraya Delta. The Chao Phraya River shoreline line is eroding and significant land areas and wetlands are being lost and becoming open water. Urban areas are periodically flooded and require earthen levees or floodwalls. The objective is to assess and mitigate land subsidence as a result of groundwater withdrawals for rice paddies, aquaculture, shrimp ponds, industry, drinking water and household needs of 15 million people living on Chao Phraya Delta in Bangkok. The impact of groundwater extraction and reduced sedimentation on land subsidence in the Chao Phraya Delta will be assessed and mitigation methods recommended. Lessons learned and successful remediation efforts in one Southeast Asia delta may or may not be applicable to other South East Asia deltas. There need to be mitigation methods identified to add sediment to existing Chao Phraya Delta wetlands. River water also needs to be injected deep into the underlying alluvial sediments in the delta. Navigation in the canal systems could be adversely affected by proposed massive Chao Phraya River water injections into the Chao Phraya Delta alluvial sediments underlying Bangkok.
文摘Objective:To evaluate the antibacterial efficacy of different solvent extracts of Padina sp.against selected human pathogenic bacteria and fungi species such as Escherichia coli,Shigella sp.,Staphylococcus aureus(S.aureus),Pseudomonas aeruginosa,Aspergillus flavus and Candida albicans.Methods:Various solvents including methanol,ethyl acetate,chloroform and hexane were used to acquire crude extracts from marine algae Padina sp.After crude preparation,antibacterial and antifungal activities were screened against clinically important human pathogenic bacteria using disc and well diffusion methods.For all the bacterial species used in this research,minimum inhibitory concentration was undertaken considering various solvent extracts of Padina sp.To ensure the accuracy of experiments,a positive control was also included.Results:Confirmed that hexane is the best solvent to extract antimicrobial agents from Padina sp.Among selected bacteria,S.aureus was the most sensitive test microorganism.While,all other microorganisms showed resistance against methanol,ethyl acetate,chloroform extracts.In fact,by increasing concentration of hexane extract,inhibition of S.aureus growth or antimicrobial activity was increased.Growth inhibition zone in well method showed better results compared to disc diffusion method.The minimum inhibitory concentration and minimum bactericidal concentration of hexane extract were 15 and 30 mg/mL against S.aureus,respectively.All Padina sp.extracts did not reveal any antifungal activities against fungi species in this study.Conclusions:Brown algae extracts showed sufficient antibacterial properties against S.aureus.Therefore,Padina sp.in this research can be a good candidate to design and manufacture novel antibacterial agents used in pharmaceutical industries.
