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111.
Production of activated carbons from waste tire--process design and economical analysis 总被引:2,自引:0,他引:2
The process design and economic analysis of process plants to produce activated carbons from waste tires and coal have been performed. The potential range of products from each process has been considered, namely for waste tire--pyro-gas, active carbon, carbon black and pyro-oil; for coal--pyro-gas and active carbons. Sensitivity analyses have been carried out on the main process factors; these are product price, production capacity, total production cost, capital investment and the tipping fee. Net present values for the two plants at various discount factors have been determined and the internal rates of return have been determined as 27.4% and 18.9% for the waste tire plant and the coal plant, respectively. 相似文献
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Tsang-Ming Ko Hsiao-Ling Hwa Li-Hui Tseng Fon-Jou Hsieh Shiu-Feng Huang Tzu-Yao Lee 《黑龙江环境通报》1994,14(1):57-60
We report on a woman with four successive pregnancies affected with X-linked hydrocephalus (XLH). The first child had prenatal craniocentesis and died in utero. The second child had a postnatal shunting operation, but suffers from severe growth and mental retardation at 5 years of age. In the third pregnancy, prenatal ultrasound detected hydrocephalus at the 16th and 20th weeks of gestation and the pregnancy was terminated. In the fourth pregnancy, ultrasound scanning at the 17th and 20th weeks of gestation revealed no remarkable findings, but hydrocephalus was detected at the 24th week. Autopsy confirmed the prenatal diagnosis. DNA polymorphism analysis of the Bell site of exons 17–18 of factor VIII gene of the woman and her last two fetuses seemed to be compatible with a linkage between the XLH locus and factor VIII gene. Although XLH has a variable presentation of ventriculomegaly, ultrasound scanning is still a useful tool for prenatal diagnosis at present. Earlier and more accurate prenatal diagnosis will be feasible with molecular analysis of the XLH locus or its flanking regions. 相似文献
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Beta-cypermethrin, a synthetic pyrethroid pesticide and potential toxic pollutant, contaminating aquatic ecosystems was investigated in the present study for acute toxicity. Guppy fish (Poecilia reticulata) was selected for the bioassay experiments. The experiments were repeated three times and the 48-h LC50 was determined for the guppies. The static test method of acute toxicity test was used. Water temperature was regulated at 22 +/- 1 degrees C. In addition, behavioral changes at each beta-cypermethrin concentration were observed for the individual fish. Data obtained from the beta-cypermethrin acute toxicity tests were evaluated using the probit analysis statistical method. The 48-h LC50 value for guppy was estimated as 21.4 microg/l. 相似文献
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Permethrin, a synthetic pyrethroid pesticide and potential toxic pollutant contaminating aquatic ecosystems, was investigated in the present study for acute toxicity. Guppy fish (Poecilia reticulata) were selected for the bioassay experiments. The experiments were repeated 3 times and the 48-h LC(50) was determined for the guppies. The static test method of acute toxicity test was used. Water temperature was regulated at 20+/-1 degrees C. In addition, behavioral changes at each permethrin concentration were observed for the individual fish. Data obtained from the permethrin acute toxicity tests were evaluated using the probit analysis statistical method. The 48-h LC(50) value for guppy was estimated as 245.7 microg/l. Values in the range of 0.05-97.0 microg/l have been reported for various other fish species. 相似文献
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We investigated the influence of mating frequency on lifetime reproductive success in females of the bulb mite, Rhizoglyphus robini. This species is highly promiscuous, and its colonial lifestyle promotes mating frequencies of at least several times a day. We manipulated mating frequencies either by keeping females continuously in the presence of a male, with males replaced every second day, or by exposing females to a new male for 4 h every second day (4 h is enough for a male to complete at least one copulation). We used males that were isolated from females either for 2 days, and thus had large reserves of sperm and seminal fluid, or for 2 h. We found that females with continuous access to a male had lower lifetime egg output than those exposed to males intermittently. This effect was mediated through decreased fecundity and not longevity. Male mating history had no significant effect on female fecundity or longevity. These results confirm that mating frequencies observed in bulb mite colonies exceed those necessary for sperm replenishment, and suggests that frequent mating is costly to females. We discuss possible explanations for the maintenance of mating frequencies that are detrimental to females. 相似文献
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