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161.
ABSTRACT: The problem of allocating scarce water resources among competing uses and users over time in Hawaii is addressed within the context of analytical institutional economics. The nature of this problem has been, in recent years, highly complicated by important institutional changes that control operating decisions for water supply and water pollution. Whereas the imbalance in governmental initiatives regarding changes in the system of water rights (predominantly state) and environmental laws (predominantly federal) are based on U.S. constitutional provisions, the more fundamental roots of the crucial legal doctrines involved have been traced back to the common property concept. This suggests that the more promising opportunities for meeting the water policy challenges of the state are to be found in the historical common property system (ahupua'a) of Hawaii.  相似文献   
162.
Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.  相似文献   
163.
164.
Six products were formed by reaction of ethynylestradiol (EE2) with sodium hypochlorite in buffered solutions. 4-Chloroethynylestradiol (4-ClEE2) and 2,4-dichloroethynylestradiol (2,4-diClEE2) were identified as the two major reaction products, using preparative HPLC, MS, and NMR. When EE2 reacted with chlorine at different pHs (pH 5, 7, and 9) or chlorine concentrations (0.2, 1, 2, and 5 mmol/l, corresponding to molar ratios to EE2, 1, 5, 10, and 25, respectively), the formation of 4-ClEE2 and 2,4-diClEE2 was observed under the above conditions, and the highest yields were 20 and 52 mol%, respectively. EE2 was consumed almost completely within 5 min of chlorination by addition of chlorine of more than 1 mmol/l (molar ratio to EE2, 5). On the other hand, the two products existed in highly chlorinated solutions after 60 min (4ClEE2, 1-6 mol%; 2,4-diClEE2, 3-25 mol%). The estrogenic activities of 4-ClEE2 by estrogen receptor alpha or beta binding assay were similar to those of the parent EE2, and the activities of 2,4-diClEE2 were lower about 10 times.  相似文献   
165.
The characteristics of municipal wastewater treatment by electrolysis, ozonation, and combination processes of electrolysis and aeration using three gaseous species (nitrogen [N2], oxygen [O2], and ozone [O3]) were discussed in this research using ruthenium oxide (RuO2)-coated titanium anodes and stainless-steel (SUS304) cathodes. Electrolysis and electrolysis with nitrogen aeration were characterized by a rapid decrease in 5-day biochemical oxygen demand (BODs) and total nitrogen and a slow decrease in chemical oxygen demand (COD). In contrast, ozonation, electrolysis with oxygen aeration, and electrolysis with ozone aeration were characterized by transformation of persistent organic matter to biodegradable matter and preservation of total nitrogen. The best energy efficiency in removing BOD5 and total nitrogen was demonstrated by electrolysis, as a result of direct anodic oxidation and indirect oxidation with free chlorine produced from the chloride ion (Cl-) at the anodes. However, electrolysis with ozone aeration was found to be superior to the other processes, in terms of its energy efficiency in removing COD and its ability to remove COD completely, as a result of hydroxyl radical (*OH) production via cathodic reduction of ozone.  相似文献   
166.
Chemical synthesis and physical properties of two mercapturic acids suggested as urinary metabolites of m- and p-xylenes ace described. These compounds may be used for the identification and quantivative determination by high-performance liquid chromatography of the corresponding mercapturic acids in urine.  相似文献   
167.
Organic compounds emitted from combustion of waste plastics involving vinyl chloride polymer were investigated in an actual waste incinerator. The amounts of volatile aliphatic hydrocarbons and volatile chlorinated organic compounds decreased when the secondary combustion temperature was controlled over 900°C. On the other hand, the amounts of some aromatic hydrocarbons increased with a rise of the secondary combustion temperature.  相似文献   
168.
Ammonia volatilization from livestock manure is one of the most important pathways of nitrogen loss from agricultural cultivated fields. In this paper, we report the measurement of ammonia emission from cattle slurry manure applied to upland in Miyazaki, Japan. It has been determined that after the cattle slurry was sprayed on the upland surface, the emission flux of the first day was 110 microg N ha(-1) s(-1). The loss of NH4(+) -N in the applied slurry was 60% after 5 days following the spraying of cattle slurry.  相似文献   
169.
Nonylphenols (NPs) are the primary stable metabolites of alkylphenol polyethoxylates (APEs), a family of compounds widely used in industry and in some domestic products. As NPs accumulate in sediments in aquatic environments, the risk to benthic organisms needs to be assessed. In this study 4NP-spiked sediments were tested on larvae of the dipteran Chironomus riparius. First instar larvae obtained from populations at three different sources were used. To spike the sediments, an equilibration procedure between water and sediment was adopted to avoid the use of solvents. Lower 10-d LC50 values were determined for two populations of C. riparius from clean environments (315-465 and 315-350 microg g(-1) d.w., respectively) than those of a strain deriving from a population collected in a polluted river (600-680 microg g(-1) d.w.). Larval growth always decreased with increasing 4NP concentration but without any defined trend. The results of this study suggest that tolerance to the toxicant can be developed in populations of polluted environments and that testing procedures should be standardised.  相似文献   
170.
Hirai Y  Sakai S  Watanabe N  Takatsuki H 《Chemosphere》2004,54(10):1383-1400
Intake fractions (iFs) for emissions to air, water, and soil for 17 PCDDs/DFs and 12 Co-PCBs were calculated with a level III multimedia model and a food-chain exposure model in succession. The two integrated models were tested by comparing the predicted and measured concentrations in the environment and by comparing intakes through food. Measurement-based iFs were also calculated and compared with the model-based iFs. The air concentrations predicted by the fate model were close to the median of the observed concentrations, whereas the predicted soil and water concentrations were one-third to one-tenth the observed concentrations. This difference was large in case of PCDDs and Co-PCBs, which was explained by the past pollution such as commercial PCB products and PCDD impurities in chloronitrofen (CNP) and pentachlorophenol (PCP). For fish, the predicted and observed exposures agreed well each other. For meat and milk, the predicted exposures were about 10 times the observed exposures for PCDDs/DFs, whereas the predicted and observed values agreed well for Co-PCBs. When the model was modified to consider feeding of fish meal to livestock and geographic bias in feed-grass production, the predicted congener profile was comparable to the measured profile. The comparison also suggested that chickens should be modeled separately from other terrestrial livestock. The model-based iFs for air emission of OCDD and 2378-TCDD were 0.001% and 0.1%, respectively. The iFs of most Co-PCBs were higher than those of PCDDs/DFs. These iF differences suggest the importance of the fate factor in assessing emissions of the 29 congeners.  相似文献   
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