An Onboard Air Conveyer Oil Skimmer
A high power air conveyer oil skimming system and implementation on a real oil recovery vessel are presented. Port and Airport Research Institute (PARI) has succeeded in development of a new type of onboard oil recovery system. Development of the project has been in cooperation with the Shikoku Regional Bureau, Ministry of Land Infrastructure and Transport Japan (MLIT). The system employs a high-power vacuum blower for sucking liquid in gas-liquid multiphase form. Its applicability to an onboard oil recovery system has been experimentally investigated. The experiments have shown that the method can respond to the wide range of viscosity of the spilled oil and works well even in wavy sea condition. These results have been applied to the oil skimming system mounted on ISHIZUCH - an oil recovery vessel owned and operated by MLIT recently refitted by Mitsui Engineering & Shipbuilding Co., LTD
About construction of simulation tank for oil recovery in marine situations
Since "NAKHODKA" oil spill incident in 1997, several new equipments or systems for oil recovery have been researched and developed in Japan. New oil skimming vessels were launched and expected to work well. It is hard to judge how effectively each equipment or product performs at the site of coasts without experience. Canada and U.S. test the equipments in a large tank of Ohmsett with towing bridge; Norway does in big circulating tank and on the sea. They can improve their outcomes with many data from the experiments in such real situations. However, we did not have such a test tank in Japan, and we could not have any opportunities to test in real situations. The government appropriated funds for constructing new tank at PARI for research and development of oil spill response in supplementary budget for 2002. The tank's specifications were planned to test equipments for oil recovery as if we test them at the site of coasts. This work collects requirements that the tank should satisfy and themes that we should do with this tank. Objective of the tank is to advance researches and developments about recovery of emulsified heavy oil that causes hard damages in marine environments. We should simulate waves, velocities of vessels (or currents), water temperatures, viscosities of the oil, and winds at the site of coasts, and test several skimmers, oil booms, oil recovery systems in order to judge their performances and behaviors under being influenced by several factors. Therefore, the tank dimensions are that the width for 6 m, length for 20 m, and water depth for 2.5 m. Salty water is filled in and controlled its temperature by chiller and heater, and leftovers of the oil are cleaned through oil filter. We can generate waves for the max 0.5 m, current for the max 1 m/s. Physics and chemistry analyzing room and a cylindrical tank (depth for 10 m) are placed as supplementary facilities and the plant is appreciated synthetic.
A single amino acid substitution in elongation factor Tu disrupts interaction between the ternary complex and the ribosome
Elongation factor Tu (EF-Tu).GTP has the primary function of promoting the efficient and correct interaction of aminoacyl-tRNA with the ribosome. Very little is known about the elements in EF-Tu involved in this interaction. We describe a mutant form of EF-Tu, isolated in Salmonella typhimurium, that causes a severe defect in the interaction of the ternary complex with the ribosome. The mutation causes the substitution of Val for Gly-280 in domain II of EF-Tu. The in vivo growth and translation phenotypes of strains harboring this mutation are indistinguishable from those of strains in which the same tuf gene is insertionally inactivated. Viable cells are not obtained when the other tuf gene is inactivated, showing that the mutant EF-Tu alone cannot support cell growth. We have confirmed, by partial protein sequencing, that the mutant EF-Tu is present in the cells. In vitro analysis of the natural mixture of wild-type and mutant EF-Tu allows us to identify the major defect of this mutant. Our data shows that the EF-Tu is homogeneous and competent with respect to guanine nucleotide binding and exchange, stimulation of nucleotide exchange by EF-Ts, and ternary complex formation with aminoacyl-tRNA. However various measures of translational efficiency show a significant reduction, which is associated with a defective interaction between the ribosome and the mutant EF-Tu.GTP.aminoacyl-tRNA complex. In addition, the antibiotic kirromycin, which blocks translation by binding EF-Tu on the ribosome, fails to do so with this mutant EF-Tu, although it does form a complex with EF-Tu. Our results suggest that this region of domain II in EF-Tu has an important function and influences the binding of the ternary complex to the codon-programmed ribosome during protein synthesis. Models involving either a direct or an indirect effect of the mutation are discussed.