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381.
Traditionally, uncertainty in parameters are represented as probabilistic distributions and incorporated into groundwater flow and contaminant transport models. With the advent of newer uncertainty theories, it is now understood that stochastic methods cannot properly represent non random uncertainties. In the groundwater flow and contaminant transport equations, uncertainty in some parameters may be random, whereas those of others may be non random. The objective of this paper is to develop a fuzzy-stochastic partial differential equation (FSPDE) model to simulate conditions where both random and non random uncertainties are involved in groundwater flow and solute transport. Three potential solution techniques namely, (a) transforming a probability distribution to a possibility distribution (Method I) then a FSPDE becomes a fuzzy partial differential equation (FPDE), (b) transforming a possibility distribution to a probability distribution (Method II) and then a FSPDE becomes a stochastic partial differential equation (SPDE), and (c) the combination of Monte Carlo methods and FPDE solution techniques (Method III) are proposed and compared. The effects of these three methods on the predictive results are investigated by using two case studies. The results show that the predictions obtained from Method II is a specific case of that got from Method I. When an exact probabilistic result is needed, Method II is suggested. As the loss or gain of information during a probability2013;possibility (or vice versa) transformation cannot be quantified, their influences on the predictive results is not known. Thus, Method III should probably be preferred for risk assessments. 相似文献
382.
Wolfgang Babisch Danny Houthuijs Gran Pershagen Ennio Cadum Klea Katsouyanni Manolis Velonakis Marie-Louise Dudley Heinz-Dieter Marohn Wim Swart Oscar Breugelmans Gsta Bluhm Jenny Selander Federica Vigna-Taglianti Salvatore Pisani Alexandros Haralabidis Konstantina Dimakopoulou Ioannis Zachos Lars Jrup HYENA Consortium 《Environment international》2009,35(8):1169-1176
In the HYENA study (HYpertension and Exposure to Noise near Airports) noise annoyances due to aircraft and road traffic noise were assessed in subjects that lived in the vicinity of 6 major European airports using the 11-point ICBEN scale (International Commission on Biological Effects of Noise). A distinction was made between the annoyance during the day and during the night. Lden and Lnight were considered as indicators of noise exposure. Pooled data analyses showed clear exposure2013;response relationships between the noise level and the noise annoyance for both exposures. The exposure2013;response curves for road noise were congruent with the EU standard curves used for predicting the number of highly noise annoyed subjects in European communities. Annoyance ratings due to aircraft noise, however, were higher than predicted by the EU standard curves. The data supports other findings suggesting that the people's attitude towards aircraft noise has changed over the years, and that the EU standard curve for aircraft noise should be modified. 相似文献
383.
The environmental psychology of research 总被引:1,自引:1,他引:0
384.
Sorption of three polycyclic aromatic hydrocarbons (PAHs, phenanthrene, anthracene and pyrene) on three charcoals and their precursor substance (sawdust) was studied. The charcoals obtained by heating at 400 °C for different periods were different in chemical composition and structure. Sorption characteristics were described by a Polanyi2013;Dubinin2013;Manes model combined with poly-parameter linear free energy relationships. The results revealed that though partition could not be neglected for sawdust and charcoal containing large sawdust residue, adsorption controlled the sorption of PAHs on matured charcoals, where π2013;π electron donor2013;acceptor (EDA) exerted as the main molecular-scale interactions. Charring elevated partition coefficients (Koc) of the three PAHs more than one order of magnitude, which ranged from 105.74 to 106.58 on charcoals (for PAHs at equilibrium concentration Ce = 0.005Sw). Adsorption increased with the aromaticity of the charcoals, however, polar aromatic structure may stimulate sorption of PAHs due to the presence of π2013;π EDA interactions. 相似文献
385.
Enhanced coagulation of ferric chloride aided by tannic acid for phosphorus removal from wastewater 总被引:1,自引:0,他引:1
Phosphorus removal from wastewater is of great importance. In the present study, ferric chloride was selected as the coagulant, and tannic acid (TA), a natural polymer, as the coagulant aid to develop an effective coagulation process with the emphasis of phosphorus recovery from different types of wastewater. The results showed that TA can accelerate the settling speed by forming flocs with large size, reduce the residual Fe(III) to eliminate the yellow color caused by Fe(III), and slightly increase the phosphorus removal efficiency. The precipitate formed by TA-aided coagulation showed the advantage of releasing phosphorus faster than ferric phosphate, indicating the possibility of phosphorus recovery from wastewater as slow release fertilizer. To further understand the structural characteristics of the precipitate, analytical techniques such as Raman spectroscopy, X-ray photoelectron spectroscopy and matrix-assisted laser desorption ionization-time of flight mass spectrometry were employed. The analytical results indicated that TA2013;Fe2013;P complex was formed during the coagulation/flocculation processes. Solid phase in the precipitate consisted of TA2013;Fe2013;P complex, Fe2013;TA complex and/or ferric hydroxyphosphate. 相似文献
386.
A new glass2013;ceramic was synthesized by crystal growth from a homogenous glass obtained by melting a mixture of fly ash collected from a power plant in Hebei province of China, titanium slag collected from a titanium factory in Sichuan province of China, and MgCO3 as an additive. According to the measurement results of differential thermal analysis, a thermal treatment of nucleating at 850 °C for 2 h and crystallizing at 985 °C for 1.5 h was used to obtain the crystallized glass. X-ray diffraction and scanning electron microscopy measurements showed that the main crystalline phase of this material was iron-ion substituted cordierite, (Mg,Fe)2Al4Si5O18, which is homogeneously dispersed within the parent glass matrix. The infrared radiance and thermal expansion coefficient of this material have been examined, and the results demonstrate that this glass2013;ceramic material has potential for application in a wide range of infrared heating and drying materials. 相似文献