Experimental study on elastic behaviors of two tandem risers in constant flow

Journal of Marine Science and Technology - Multiple pipes bundled with a certain distance are used for deep ocean development for such as lifting seafloor massive sulfides (SMS), pumping up a large...     

CO2 ocean sequestration by moving ships

Ocean sequestration of the CO₂ captured from fossil-fuel burning is a possible option to mitigate the increase in CO₂ concentration in the atmosphere. It can isolate huge amounts of CO₂ from the atmosphere for a long time at relatively low cost, if it is acceptable from the viewpoint of the environmental impact on the ocean. The concept of CO₂ dispersion in the ocean depths by ships is a promising method for efficient dilution. That is, liquefied CO₂ is delivered to the site and injected into the ocean at depths of 1000–2500 m with a suspended pipe towed by a slowly moving ship. In addition to the horizontal movement of the release point, the vertical journey of CO₂ droplets until they disappear by dissolution is effective for the dilution of CO₂ in seawater. In this paper, the possibility of the generation of relatively large-sized droplets from a moving nozzle is investigated experimentally. In addition, the terminal velocity of CO₂ droplets in deep-sea circumstances is measured in a large high-pressure tank to investigate the influence of the hydrate film formed on the surface of the droplet. Finally, it is shown by simulation that an initial dilution ratio of one to some ten thousandths is possible on a realistic engineering scale in the moving ship type of CO₂ ocean sequestration. Received: August 7, 2001 / Accepted: September 13, 2001     

Technical standardization of ITS and Asian initiatives for intelligent mobility

User-centric intelligent mobility businesses emerge and prosper in Asian metropolitan areas by utilizing the progress if information and communication technology (ICT). Under the rise of private lead initiatives on intelligent transport systems (ITS), the roles of public sectors are still large. Public sectors should precisely identify the extensive ITS services by considering the regional conditions and deploy them by collaboration between the public and private. Public sectors also are strongly encouraged to identify the benefits acquired by development and compliance of the international technical standards. Furthermore, in order to maximize the potential capacity of ICT, improvements of social infrastructures are required by the public sectors together with private businesses. With the realization of the collaboration works, Asian regions are well deserved to take the lead in future ITS initiatives.