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51.
Humanity faces an increasing possibility that unusual and extreme natural disasters will increase, compounded with climate change, including global warming. These compound events are designated as compounded natural hazards in this study. A methodology must be developed for predicting what events and risks will confront future societies, to propose countermeasures and adaptation strategies against these events, and to evaluate the influences of compound disasters on infrastructure which is particularly situated near coasts and rivers. Based on the above-stated background and demands, this study was undertaken with the intention of upgrading the methodology for estimating effects on infrastructure of compound events such as increased typhoon and rainfall severity caused by global warming occurring concurrently with a great earthquake in Japan. Such a methodology is expected to contribute to progress in the fields of natural disaster mitigation and land preservation, particularly benefiting coastal and river areas in Japan. Additionally in this study, risk and economic loss analyses for the possible occurrence of compound disasters for coastal infrastructure and foundations are produced for establishing environmental strategies at the governmental level. The authors further propose adaptation strategies and techniques as countermeasures against these events.  相似文献   
52.
We discuss the current status of waste to power generation (WPG) in Japan and various scenarios involving indirect reduction of carbon dioxide emissions by WPG. The number of WPG facilities domestically as of 2005 was 286. Power generation capacity attained 1,515 MW and power generation 7,050 GWh/year. This amount substitutes energy otherwise acquired from natural resources such as fossil fuels in thermal power plants. If the basic unit of carbon dioxide is 0.555 kg-CO2/kWh, then the corresponding carbon dioxide emission reduction is calculated to be 3.9 million tons, equivalent to 26.7% of the 14.6 million tons emitted by municipal solid waste incinerators (MSWI) in 2005. Using various existing technological options, the power generation efficiency could reach more than 20% in MSWI facilities with capacity of 300 tons/day, although present efficiency is only 12.0%. If about 85% of MSW were incinerated in MSWI with power generation efficiency of 20% as a feasible assumption, the total power generation and the corresponding carbon dioxide reduction would be 16,540 GWh/year and 9.18 million tons, respectively, equivalent to 62.7% of the carbon dioxide emitted by MSWI. Also, the ratio of the additional reduction of carbon dioxide emissions by WPG to the total additional reduction (20,000 ktons/year) in Japan during the first commitment period would be 26.3%, suggesting that promotion of WPG in MSWI is an effective option for prevention of global warming.  相似文献   
53.
BACKGROUND: The relation between the levels of dioxins in human breast milk and the smoking habits of the mothers is controversial. To clarify this relationship, we analyzed data from the human milk survey in Japan. METHODS: The human milk survey has been conducted in Japan since 1997. Healthy pregnant women aged 20-39 years were recruited and 50 ml of breast milk was collected from them at 30 days after delivery. PCDDs, PCDFs, and dioxin-like PCBs were measured by using GC/MS. The smoking habits of the mothers were established by interviewing them soon after delivery and were classified into four categories: current smokers, ever smokers who quit smoking at the pregnancy, ever smokers who quit smoking before the pregnancy, and never smokers. The levels of dioxins in breast milk were compared in the four categories of smoking among 853 primiparas. In addition, we analyzed the association between dioxin levels and passive smoking among never smokers. The geometric means of the dioxin concentrations were calculated in order to compare the differences between dioxins. RESULTS: The geometric means of dioxin-like PCBs in milk of never smokers was the highest (9.2 pg TEQ/g fat); followed by ever smokers who quit smoking before the pregnancy, ever smokers who quit smoking at the pregnancy, and current smokers (7.5, 7.2, and 6.6 pg TEQ/g fat, respectively). The differences between these levels were statistically significant (ANOVA, p<0.001). No significant difference was observed between the level of dioxins in milk from never smokers subjected to passive smoking status and those who had not experienced passive smoking. CONCLUSION: The levels of dioxin-like PCBs in human milk were negatively related to the smoking habits of mothers.  相似文献   
54.
Forest conversion is one of the greatest global threats to biodiversity, and land-use change and subsequent biodiversity declines sometimes occur over a variety of underlying geologies. However, how forest conversion and underlying geology interact to alter biodiversity is underappreciated, although spatial variability in geology is considered an integral part of sustaining ecosystems. We aimed to examine the effects of forest conversion to farmland, the underlying geology, and their interaction on the stream fishes’ diversity, evenness, and abundance in northeastern Japan. We disentangled complex pathways between abiotic and biotic factors with structural equation modeling. Species diversity of stream fishes was indirectly shaped by the interaction of land use and underlying geology. Diversity declined due to nutrient enrichment associated with farmlands, which was mainly the result of changes in evenness rather than by changes in species richness. This impact was strongest in streams with volcanic geology with coarse substrates probably because of the differential responses of abundant stream fishes to nutrient enrichment (i.e., dominance) and the high dependency of these fishes on large streambed materials during their life cycles. Our findings suggest that remediation of deforested or degraded forest landscapes would be more efficient if the interaction between land use and underlying geology was considered. For example, the negative impacts of farmland on evenness were larger in streams with volcanic geology than in other stream types, suggesting that riparian forest restoration along such streams would efficiently provide restoration benefits to stream fishes. Our results also suggest that land clearing around such streams should be avoided to conserve species evenness of stream fishes.  相似文献   
55.
The Chinese steel industry achieved even growth in the 1980s and China is now the world's fourth largest steel producing country. Two factors that have played important roles in this development of the Chinese steel industry are the reform of the system or the strengthening of enterprise autonomy accompanying market reform, and the introduction of advanced technology from Western countries as a continuing policy since the 1970s. The Chinese steel industry still lags far behind those of other steel producing countries in terms of equipment and production technology, however. The present situation and problems of the Chinese steel industry in the 1990s are discussed here, together with a review of its development in the 1980s.  相似文献   
56.
Resurrection of the iron and phosphorus resource in steel-making slag   总被引:4,自引:0,他引:4  
 This research focused on the treatment of steel-making slags to recycle and recover iron and phosphorus. The carbothermal reduction behavior of both synthesized and factory steel-making slag in microwave irradiation was investigated. The slags were mixed with graphite powder and heated to a temperature higher than 1873 K to precipitate a lump of Fe–C alloy with a diameter of 2–8 mm. The larger the carbon equivalent (Ceq, defined in the text), the higher the fractional reduction of iron and phosphorus. An increase in the SiO2 content of slag led to a considerable improvement in the reduction for both iron and phosphorus because of the improvement in the fluidity of the slags and an increase in the activity coefficient of P2O5 in the slags. The extraction behavior of phosphorus from Fe–P–Csatd alloy was also investigated at 1473 K by carbonate flux treatment. For all the experiments with a processing time longer than 10 min, the phosphorus in the fluxes could be concentrated to more than 9% (w/w) showing that it could be used as a phosphorus resource. Compared with K2CO3 flux treatment, that using Na2CO3 was more effective for the extraction of phosphorus, and this was attributed to the lower evaporation of Na2CO3. Finally, a recycling scheme for steel-making slag is proposed. Received: March 16, 2001 / Accepted: November 12, 2001  相似文献   
57.
Mealybugs, which include several agricultural pests, are small sap feeders covered with a powdery wax. They exhibit clear sexual dimorphism; males are winged but fragile and short lived, whereas females are windless and less mobile. Thus, sex pheromones emitted by females facilitate copulation and reproduction by serving as a key navigation tool for males. Although the structures of the hitherto known mealybug pheromones vary among species, they have a common structural motif; they are carboxylic esters of monoterpene alcohols with irregular non-head-to-tail linkages. However, in the present study, we isolated from the Matsumoto mealybug, Crisicoccus matsumotoi (Siraiwa), a pheromone with a completely different structure. Using gas chromatography–mass spectrometry and nuclear magnetic resonance spectroscopy, we identified the pheromone as 3-methyl-3-butenyl 5-methylhexanoate. Its attractiveness to males was confirmed in a series of field trapping experiments involving comparison between the isolated natural product and a synthetic sample. This is the first report of a hemiterpene mealybug pheromone. In addition, the acid moiety (5-methylhexanoate) appears to be rare in insect pheromones.  相似文献   
58.
Sustainability is achieved only when there is full reconciliation between: (1) economic development; (2) meeting, on an equitable basis, growing and changing human needs and aspirations; and (3) conserving the limited natural resources and the capacity of the environment to absorb the mulitple stresses that are a consequence of human activities. The linkages between climate and sustainability are examined in the context of both the wider Asia-Pacific region and local level climate risks and adaptation responses. These findings are used to underpin and illustrate several implications for sustainability science. Climate change is seen as both an impediment to increasing sustainability and as an opportunity, though in most cases the former far outweighs the latter. Assessments of climate change vulnerability and risk are shown to be of critical importance because they inform decisions as to where resources for adaptation are best invested. They also show whether global efforts to reduce greenhouse gas emissions need to be strengthened because of limits to adaptation. In practice, adaptation takes place at many levels, essentially ranging between tangible interventions at community and enterprise level and national and international efforts to strengthen the enabling environment for adaptation. It is informative to undertake regional assessments of adaptation, even though most adaptation interventions need to reflect local conditions, including local adaptive capacities. The foregoing findings, based in part on a series of regional and local case studies, lead to several recommendations for further research that will help reduce barriers to implementing responses that reduce climate related risks, including adverse consequences for sustainability. The recommendations relate to such themes as making optimum use of predictive capabilities, characterising the linkages between climate change and sustainability, implications of the required rates and magnitudes of adaptation, institutional responses that enhance adaptive capacity, use of new and traditional technologies, the multiple dimensions of social responsibility, and enhancing the enabling environment for adaptation at the community and enterprise level. If these recommendations are acted upon they will, in turn, help address much needed improvements in quantifying the costs and benefits of adaptation, prioritising adaptation options, assessing sustainable development tradeoffs, and monitoring the success of adaptation initiatives. Such improvements will have even greater utility if they are incorporated into user-friendly decision support tools for adaptation.  相似文献   
59.
Chinstrap, Pygoscelis antarctica, and gentoo, P. papua, penguins are sympatric species that inhabit the Antarctic Peninsula. To evaluate differences in the foraging habitat of these two species, we recorded their foraging locations and diving behavior using recently developed GPS-depth data loggers. The study was conducted on King George Island, Antarctica during the chick-guarding period of both species, from December 2006 to January 2007. The area used for foraging, estimated as the 95% kernel density of dive (>5 m) locations, overlapped partially between the two species (26.4 and 68.5% of the area overlapped for chinstrap and gentoo penguins, respectively). However, the core foraging area, estimated as the 50% kernel density, was mostly separate (12.8 and 25.0% of the area overlapped for chinstrap and gentoo penguins, respectively). Chinstrap penguins tended to use off-shelf (water depth > 200 m) regions (77% of the locations for dives >5 m), whereas gentoo penguins mainly used on-shelf (water depth < 200 m) areas (71% of dive locations). The data on foraging locations, diving behavior, and bathymetry indicated that gentoo penguins often performed benthic dives (28% of dives >5 m), whereas chinstrap penguins almost always used the epipelagic/mid-water layer (96% of dives >5 m). Diving parameters such as diving bottom duration or diving efficiency differed between the species, reflecting differences in the use of foraging habitat. The diving parameters also suggested that the on-shelf benthic layer was profitable foraging habitat for gentoo penguins. Conversely, the relationship between trip duration, date, and stomach content mass suggested that the chinstrap penguins went further from the colony to forage as the season progressed, possibly reflecting a reduction in prey availability near the colony. Our results suggest that chinstrap and gentoo penguins segregated their foraging habitat in the Antarctic coastal marine environment, possibly due to inter- and intra-specific competition for common prey resources.  相似文献   
60.
The control of Hg emissions from a municipal solid waste incinerator (MSWI) is very important, because more than 78% of municipal solid waste (MSW) is incinerated. The Hg content of coal used in utility boilers is relatively low in Japan. In this study, recent trends in the Hg content of MSW in Japan and activated carbon (AC) injection as a control technology of Hg emission from an MSWI are discussed. The effect of AC injection on Hg removal from flue gas in an MSWI was investigated by pilot-scale experiments using a bag filter (BF). The injection of AC increases the Hg reduction ratio by 20-30% compared with cases without AC injection. The Hg reduction ratio increases as the flue gas temperature decreases. The Hg reduction ratio is closely related to the inlet Hg concentration and was expressed with a Langmuir-type adsorption isotherm.  相似文献   
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