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201.
The effect of various environmentally friendly chemical additives on the dissolution of colloidal silica is systematically
studied. These silica scale dissolvers are principally polycarboxylates with one to five –COOH groups, mixed polycarboxylates/phosphonates
and aminoacids. Based on these results, an effort is made to link their dissolution performance to structural features in
this structure/function study. Presence of additional groups (eg. –PO3H2, –NH2, or –OH) in the dissolver molecule augments the dissolution process. 相似文献
202.
全球温室效应正在缓慢地进行。本文首次探讨气候变暖对岩溶发育环境的影响,并预测了大气CO2浓度加倍时中国南北方碳酸盐岩化学溶蚀速率。 相似文献
203.
“绿色食品”,是出自最佳生态环境,带来最强生命活力的无公害健康食品。本文从介绍我国开发“绿色食品”的概况入手,阐述了保护农业生态环境对开发“绿色食品”的重要性和必要性。结合四川实际,从农业环境保护的角度,提出了加快发展“绿色食品”,必须抓好“四个结合”的对策措施,供有关部门领导参考。 相似文献
204.
Michele?ArestaEmail author Angela?Dibenedetto Marcella?Narracci Immacolata?Tommasi 《Environmental Chemistry Letters》2003,1(1):13-18
A bench-scale pilot plant has been developed for the treatment of olive-mill water. The plant is fed in a continuous mode
and implements a primary treatment (sand filtering and irradiation with UV-rays) and a secondary treatment (anoxic and aerobic
biological treatment). Satisfactory results were obtained and the treated green water falls under the limits of the Italian
legislation. Veratric and ferulic acid biodegradation were studied under anoxic conditions in order to verify the requirements
for optimal biodegradation.
Electronic Publication 相似文献
205.
206.
ABSTRACT: Regionalization of design storms can enhance their utility. Otherwise they have to be separately developed for different regions. Huff curves developed from point rainfall data collected at Coshocton, Ohio, and Chicago, Illinois, and from area-averaged Illinois and Texas precipitation data, are compared. The curves are similar in shape and position, with some visual differences depending on quartile. Kolmogorov-Smirnov tests showed no significant differences in moat of the comparisons. Where significant differences existed, they may not represent real differences due to the small number of storms sampled. Consequently, regionalization of Huff curves from Ohio to Illinois to Texas may be appropriate. The comparison of Huff curves is affected to an unknown degree both by the effects of area averaging of data and by basis. of-development differences. The effects of observed differences in Huff curves on watershed response variables (e.g., peak flow) requires further study. 相似文献
207.
Satoru Fujita Kenzi Suzuki Yasuo Shibasaki 《Journal of Material Cycles and Waste Management》2002,4(1):41-45
In this study, an attempt was made to synthesize hydrogrossular, a group of garnet minerals, under hydrothermal conditions
at temperatures below 180°C, using coal ash, which is the solid waste from thermal power plants, as a starting material. A
single phase corresponding to hydrogrossular was found at around 120°C, and the hydrogrossular coexisted with 11-Å tobermorite
above 140°C. The hydrogrossular phase decreased with increasing reaction temperature, while that of 11-Å tobermorite increased
concurrently. The physicochemical properties of the hydrogrossular obtained from the hydrothermal synthesis was characterized
by X-ray diffraction thermogravimetry/differential thermal, analysis, scanning electron microscopy, Fourier transform infrared
spectroscopy, and X-ray fluorescence spectroscopy.
Received: September 4, 2000 / Accepted: March 7, 2001 相似文献
208.
本文在总结绿色建筑概念及其涵义的基础上,论述了发展绿色建筑的意义,提出了推进绿色建筑发展的措施。 相似文献
209.
Donald Bruce 《Journal of Agricultural and Environmental Ethics》2002,15(1):7-16
Three interpretations of theprecautionary principle are identified, namely``soft,' ``hard,' and outright rejection. The ECCommunication of February 2000 is largely aresponse to the latter, to provide alegitimation in trade-related WTO disputes.This context leads to an over stress onscientific closure. This is critiqued asidealistic in respect of resolving long termuncertainties inherent in the GM food issue.While offering some useful guidelines in riskmanagement, the EC report seriously fails totake into account the ethical and societaldimension of risk. These are crucial both indetermining when precautionary principle isinvoked and the action to be taken. The EC viewleans too much to a scientific rationalist riskperspective. However, the ``Green'interpretation of the precautionary principleas a reversal of the burden of proof is alsocriticized as inconsistent both with the natureof technology and with the nature of reality asseen in a Christian perspective. Biblicalinsights on risk reveal a balance ofintervention and conservation in a world whererisk is inherent. The notion of risk as asocial contract reveals that ethical andsocietal issues have a crucial role to play inapplying the precautionary principle. 相似文献
210.
The environmental performance of hemp based natural fiber mat thermoplastic (NMT) has been evaluated in this study by quantifying carbon storage potential and CO2 emissions and comparing the results with commercially available glass fiber composites. Non-woven mats of hemp fiber and polypropylene matrix were used to make NMT samples by film-stacking method without using any binder aid. The results showed that hemp based NMT have compatible or even better strength properties as compared to conventional flax based thermoplastics. A value of 63 MPa for flexural strength is achieved at 64% fiber content by weight. Similarly, impact energy values (84–154 J/m) are also promising. The carbon sequestration and storage by hemp crop through photosynthesis is estimated by quantifying dry biomass of fibers based on one metric ton of NMT. A value of 325 kg carbon per metric ton of hemp based composite is estimated which can be stored by the product during its useful life. An extra 22% carbon storage can be achieved by increasing the compression ratio by 13% while maintaining same flexural strength. Further, net carbon sequestration by industrial hemp crop is estimated as 0.67 ton/h/year, which is compatible to all USA urban trees and very close to naturally, regenerated forests. A comparative life cycle analysis focused on non-renewable energy consumption of natural and glass fiber composites shows that a net saving of 50 000 MJ (3 ton CO2 emissions) per ton of thermoplastic can be achieved by replacing 30% glass fiber reinforcement with 65% hemp fiber. It is further estimated that 3.07 million ton CO2 emissions (4.3% of total USA industrial emissions) and 1.19 million m3 crude oil (1.0% of total Canadian oil consumption) can be saved by substituting 50% fiber glass plastics with natural fiber composites in North American auto applications. However, to compete with glass fiber effectively, further research is needed to improve natural fiber processing, interfacial bonding and control moisture sensitivity in longer run. 相似文献