The Long-term Corrosion Behaviour of Abandoned Wells Under CO2 Geological Storage Conditions: (2) Experimental Results for Corrosion of Casing Steel

AbstractRegarding the geological storage of CO2 in aquifers or in depleted gas fields, the reactivity of the well casing left in the abandoned well is important in order to investigate the potential for leakage. The corrosion behavior of the casing steel tube was investigated in highly pressurized CO2 environments.The corrosion test of the J55 and N80 steel tube in API specification 5CT was conducted. Those steel tubes have been frequently used as casing tube and are found in abandoned natural gas wells. The following test conditions were achieved with the autoclave apparatus: temperature at 50 to 70°C, CO2 pressure at 5 to 18MPa with/without the impurities of 20ppm H2S and 2000ppm CO, in/above stagnant 0.5M NaCl solution of simulated formation water. The test durations were 100, 300 and 1000hours.After the corrosion test, the specimens were analyzed by Energy dispersive X-ray spectrometry and X-ray diffractometry. The specimens were found to be covered mainly with FeCO3, which is considered to be formed from dissolved Fe2+ and environmental CO2. The corrosion rate was evaluated via the weight loss of the specimens after the removal of the surface corrosion products, containing FeCO3. No significant differences were observed between J55 and N80 in terms of FeCO3 formation and corrosion weight loss. It was found that the weight loss by corrosion, around 100mg/cm2 after 100hours, was remarkably large when the specimen was placed in the solution and was, in contrast, two orders of magnitude smaller when the specimen was above the solution. In the case with the impurities of 20ppm H2S and 2000ppm CO, the weight loss in the solution was less relative to the pure CO2 condition. The weight loss in the solution reached a plateau in initial 100hours, and was only slightly increased in the 300- and the 1000-hour tests. The ‘plateau’ was considered to be due to the protective effect of the FeCO3 formed on the specimen. Considering the protective effect of the FeCO3, the corrosion of the steel casing over a long period of time is small under the stagnant condition, and would be expected to remain in place with little structural degradation

Characterization of Aquimarina hainanensis isolated from diseased mud crab Scylla serrata larvae in a hatchery

Mass mortality due to necrosis signs occurred in hatchery‐reared zoea stage larvae of the mud crab Scylla serrata in Okinawa, Japan, and a causative bacterium was isolated. In this study, we identified and characterized the bacterium by genome analysis, biochemical properties and pathogenicity. The bacterium was a Gram‐negative, non‐motile, long rod, forming yellow colonies on a marine agar plate. It grew at 20–33°C (not at 37°C) and degraded chitin and gelatin. Phylogenetic analysis of the 16S rRNA gene sequence identified the bacterium as Aquimarina hainanensis. Genome sequence data obtained from Illumina MiSeq generated 29 contigs with 3.56 Mbp in total length and a G + C content of 32.5%. The predicted 16 chitinase genes, as putative virulence factors, had certain homologies with those of genus Aquimarina. Experimental infection with the bacterium conducted on larvae of four crustacean species, brine shrimp Artemia franciscana, freshwater shrimp Caridina multidentata, swimming crab Portunus trituberculatus and mud crab S. serrata, revealed that this bacterium was highly virulent to these species. The present study suggests that the bacterium caused mass mortality in mud crab seed production was A. hainanensis and can be widely pathogenic to crustaceans

先天性表皮水疱症に対する理学療法-症例報告-

先天性表皮水疱症は厚生省による特定疾患治療研究対象疾患で，いわゆる「難病」指定疾患である．表皮水疱症では，日常生活で外力が加わる部位に反復する水疱を臨床症状の主体とし，軽微な外力による水疱発生が基本であるが，病変活発な時期では特に誘因なく発生する場合もあるという．著者らは，7年間にわたって表皮水疱症接合部型の男児に理学療法を実施してきた．体表面が外界と接触するということは乳幼児の感覚一運動学習過程において必要不可欠な体験であるにもかかわらず，水疱発生によってそのことが阻害され結果的に運動発達の遅れを呈した．今回，問題を残しながらも普通小学校への就学ゴールに達したので，これまでの理学療法経過と若干の考察を加えて報告する．The purpose of this paper is to report on the course and physical therapy for epidermolysis bullosa. Epidermolysis bullosa is designated as a specific rare disease by the Ministry of Health and Welfare. The clinical feature is repeated blister formation that occurs following mechanical stimulation in daily living. The blisters may occur without cause especially at an active time of morbid change, although these are actually caused by slight stimulations. It is absolutely indispensable for sensori-motor learning in the baby that the body surface make contact with the environment. Motor learning is based on having experiences with the interaction between perception and motor. However, it is guessed that no comfort was experienced by the patient via sensory information from the skin. It is probable that he experienced of continuous pain and pruritus, felt as itching of the entire body. Therefore, it is inferred that biased perceptions would be generated and learned. In addition, blisters, erosions, and markedly fragile skin were actually aggravated by sensory inputs made to facilitate developmental intervention. Therapeutic exercise for the patient has been going on since four months from birth, but the patient has been continuing to exhibit retarded motor development. However, the patient was able to enter school normally in spite of having a few problems at present