排序方式: 共有28条查询结果,搜索用时 15 毫秒
11.
Kurokawa Daisuke Nakaguchi Ayuka Hirano Yoko Iida Tatsuo Mori Taiichiro Matsuzawa Kazuki Sakai Etsuo 《Journal of Material Cycles and Waste Management》2021,23(3):1270-1275
Journal of Material Cycles and Waste Management - This paper estimates the effects of a composition change of ordinary Portland cement on waste utilization and CO2 emissions in the Japanese cement... 相似文献
12.
13.
Degradation of microcystins using immobilized microorganism isolated in an eutrophic lake 总被引:4,自引:0,他引:4
The final purpose of our series of studies is to establish a biological removal method of cyanobacteria and their toxic products using immobilized microorganisms that can lyse cyanobacteria and decompose microcystins. To establish the biological removal method in non-point areas and water purification plants, as the first step, we explored bacteria active against the cyanobacterial hepatotoxin microcystin in the present study. Eleven active bacteria were isolated from samples taken from Lakes Tsukui and Sagami, Japan. Among 3 strains (B-9 to B-11) with degradative activity, strain B-9 exhibited the strongest activity. The 16S rDNA sequence of the strain B-9 showed the highest similarity to that of Sphingomonas sp. Y2 (AB084247, 99% similarity). Microcystins-RR and -LR were completely degraded by strain B-9 (SC16) within 1d, which led to an immobilized microorganism with a polyester resin. The degradation of microcystin-RR in a bioreactor using the immobilized strain B-9 was observed and microcystin-RR (> 90%) was completely degraded after 24 h. Microcystin-RR was added to the lake water at regular intervals and the degradation after 24 h was observed in the bioreactor over a 72-d period. An over 80% removal efficiency continued for 2 months, showing that the life of the immobilized B-9 in terms of activity was at least 2 months under the optimized conditions. From these results, this immobilized B-9 is feasible for the practical treatment of microcystins in non-point areas and water purification plants. 相似文献
14.
15.
The excess growth of cyanobacteria in semi enclosed water areas caused by eutrophication brings about coagulation inhibition in drinking water treatment processes. In this study, coagulation inhibitor proteins produced by Microcystis aeruginosa, a major cyanobacterium in algal bloom, were acquired by a phage display technique, an aluminum-immobilized affinity chromatography and a protein expression technique using Escherichia coli cells. Two cyanobacterial peptides with a high ratio of metallophilic amino acids were recovered, which were a part of homologues of a thiol oxidase enzyme Ero1p and a trans-acting repressor ArsR. It was also shown that the homologue of ArsR exhibited a stronger inhibitory effect on the coagulation of kaolin suspension with polyaluminum chloride than the control proteins. This is the first report to identify a cyanobacterial cell component to inhibit coagulation. The compositions of polar amino acids were critical to explain the strength of coagulation inhibition potential. Polar proteins from cyanobacteria could collectively consume coagulants or stabilize clay particles, which would be plausible explanations for causing coagulation inhibition. Meanwhile, results from the kaolin coagulation tests using the control proteins implied that the neutralization of positive charges of coagulant constituents by simple electrostatic interactions might not be the key mechanism on the protein-induced coagulation inhibition. 相似文献
16.
17.
Crinoids have been diverse organisms in marine epifaunal filter feeding communities at any level of tiering above the substrate
since they appeared in the Ordovician. Feeding is regarded as the most important factor in producing the crinoid tiering,
which is primarily defined by stalk length. The gut contents of five sympatric crinoid species (three isocrines and two comatulids)
were observed, and these were compared with the stalk length and the fan density. We have classified these crinoid species
into four groups based on the stalk length and fan density, e.g., long stalk with low fan density, long stalk with high fan
density, short stalk with low fan density, and short stalk with high fan density. In the gut contents, diatom crusts were
found mainly from species with longer stalks, and chlorophyll-like fluorescent material were only detected from the groups
with a shorter or no stalk. The group with lower fan density contained more inorganic particles than the group with higher
fan density. Therefore, the gut contents and their amounts depend on their stalk lengths and their fan densities. The results
imply that diversified morphologies in the crinoids have evolved through adaptations to different ecological factors such
as difference in their diets. 相似文献
18.
Tatsuo Suzuki 《Chemistry and Ecology》2013,29(3-4):249-258
A new material with high content of fly ash named ‘Ashcrete’ has been developed. to examine the applicability of Ashcrete to marine structures, strength characteristics, resistance to sea water attack, and safety in the marine environment have been studied. the following results have been obtained: 1) the strength characteristics of high-volume fly ash concrete depend upon the type and proportions of chemical activators as well as curing conditions. 2) Ashcrete using sodium chloride (NaCI) as a chemical activator shows high initial strength and good strength development with age. 3) Ashcrete containing NaCI activator shows good resistance to sea water from the viewpoint of its strength characteristics, volume changes and microstructurcs. 4) Since 1980 many types of large-scale artificial reefs made of Ashcrete have been installed in the sea. As a result of long-term studies and underwater observations, the Japanese Government has demonstrated the durability of the material, safety in the marine environment and attractiveness to fish. 5) It is therefore proposed that Ashcrete might be used in constructing large-scale sea mounts in deep water for the purpose of generating upwelling. 相似文献
19.
Nakanishi T Zheng J Aono T Yamada M Kusakabe M 《Journal of environmental radioactivity》2011,102(8):774-779
Using a sector-field ICP-MS the vertical distributions of the 99Tc concentration and 99Tc/137Cs activity ratio were measured in the coastal waters off Aomori Prefecture, Japan, where a spent-nuclear-fuel reprocessing plant has begun test operation. The 99Tc concentrations in surface water ranged from 1.8 to 2.4 mBq/m3, no greater than the estimated background level. Relatively high 99Tc/137Cs activity ratios (10-12 × 10−4) would be caused by the inflow of the high-99Tc/137Cs water mass from the Japan Sea. There is no observable contamination from the reprocessing plant in the investigated area. The 99Tc concentration and the 99Tc/137Cs activity ratio in water column showed gradual decreases with depth. Our results implied that 99Tc behaves in a more conservative manner than 137Cs in marine environments. 相似文献
20.
Regular sea urchins show pentaradial symmetry: they have round bodies made of five almost identical sectors. There is no preference
in which sector should be anterior in their locomotion. Anthocidaris crassispina is exceptional among regular sea urchins. Morphometry showed that their tests had radial symmetry but the overall body shape
showed bilateral symmetry because of the uneven distribution of spine length. This bilateral axis did not correspond to the
ambulacrum III—interambulacrum 5 axis, which is the bilateral axis of irregular sea urchins. Their behavior in relation to
this bilaterality was observed in the aquarium. At rest, most of them stayed in the upper corner of the aquarium keeping the
sector with the shortest spine length (the shortest sector) toward the water surface. At walking, most of them moved on the
vertical wall just under the water surface keeping the shortest sector directing to the water surface. When they walked in
the open space, they moved in a random direction with respect to the bilaterality of the spines. The bilaterality and the
behavior of this sea urchin were interpreted as the adaptation to defense not to efficient locomotion. 相似文献