An Overview of Fabrication Methods and Applications of Carbon Nanotube Membrane in Environmental Engineering as Hydraulic Microstructures

The main purpose of this article is to study fabrication methods and applications of aligned carbon nanotube (CNT) membranes as a hydraulic microstructure in treatment processes. This paper emphasizes the use of CNTs as membrane in separation processes like water and wastewater treatment because of their exclusive advantages. Their most important characteristics are high mechanical strength against pressure, thermal stability and fast fluid transport with a very low pressure gradient inside CNTs. It is predictable to expand using CNT membranes in separation processes and environmental engineering because of their suitable mechanical properties

Root Cause Analysis of Delays in Dam Construction (Case Studies: Karun-3, Marun, Shafaroud and Jamishan Dams)

Completion of the project in due time at the predefined quality and cost is of the most important concern. Along with the increase of duration of project implementation, the total cost of the project will be raised due to annual inflation and other introduced costs. This research has investigated and identifies the most important causes of damage occurrences and time delay, then prioritized them throughout the project cycle from the pre-construction phase up to the end of the commissioning phase. Besides, solutions to prevent these damages and resolving the challenges ahead have been developed. Thus, a list of data from literature and field surveys have been gathered. After brain storming in experts panel and collecting data; data has been analyzed through Analytical Hierarchy Process utilizing the Expert Choice 11 software, which has resulted in seven major delay factors including: deficit budget allocation (27%), economic problems of the country (24%), the weakness of contractor's site management (13%), use of not qualified personnel in construction management (11%), delay in preparing and lots of mistakes/ modifications in detail design by the consultant (10%), inaccurate proposal in tenders by the contractor (8%), and improper selection of the contractor by the client (7%). The expert panel considers that the budget allocation is the most important cause of damage to project. Finally, damage causing factors have also been classified into six effective factors as project team, client, management consultancy, engineering consultant, contractor, and uncontrollable factors such as political, economic and social factors