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11.
Mohammad Hossein Sowlat Kazem Naddafi Masud Yunesian Peter L. Jackson Saeedeh Lotfi Abbas Shahsavani 《洁净——土壤、空气、水》2013,41(12):1143-1151
Source apportionment of particulate matter <10 µm in diameter (PM10), having considerable impacts on human health and the environment, is of high priority in air quality management. The present study, therefore, aimed at identifying the potential sources of PM10 in an arid area of Ahvaz located in southwest of Iran. For this purpose, we collected 24‐h PM10 samples by a high volume air sampler. The samples were then analyzed for their elemental (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Pb, Se, Si, Sn, Sr, Li, Ti, V, Zn, Mo, and Sb) and ionic (NH, Cl?, NO, and SO) components using inductively coupled plasma optical emission spectrometry and ion chromatography instruments, respectively. Eight factors were identified by positive matrix factorization: crustal dust (41.5%), road dust (5.5%), motor vehicles (11.5%), marine aerosol (8.0%), secondary aerosol (9.5%), metallurgical plants (6.0%), petrochemical industries and fossil fuel combustion (13.0%), and vegetative burning (5.0%). Result of this study suggested that the natural sources contribute most to PM10 particles in the area, followed closely by the anthropogenic sources. 相似文献
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As a part of our calibration/validation activities five months of SARAL/AltiKa wave data have been analyzed in this study. A robust quality control procedure using threshold values on signal and retrieved wave heights was implemented before the assimilation. Assimilation runs in the wave model Météo-France (MFWAM) were performed for a long period. The validation of the model outputs was performed with independent wave observations from altimeter and buoy data. The results indicate good performance in terms of bias and scatter index for the significant wave height and the peak wave period. Statistical analyses were performed for different ocean basins (high and intermediate latitudes and tropics). The use of SARAL/AltiKa and Jason-2 wave data combined was also investigated. This leads to further improvements for the analysis and forecast periods. In other respects, the impact of the assimilation of SARAL/AltiKa wave data is discussed for waves under strong wind conditions such as typhoons Fitow and Danas which occurred in early October 2013. 相似文献
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Application of water pinch technology for water and wastewater minimization in aluminum anodizing industries 总被引：1，自引：1，他引：0
S. M. Khezri Ph.D. F. Lotfi M.Sc. S. Tabibian M.Sc Z. Erfani M.Sc. 《International Journal of Environmental Science and Technology》2010,7(2):281-290
This study aims to describe the application of water pinch technology in industrial water consumption management in aluminum anodizing industry. Water pinch analysis is a systematic technique for designing, optimization and retrofitting of energy, mass and water recovery networks. The selection of different operations existing in an industry has an important role in correctness of application of pinch technology. Water usages in anodizing industry are various, but researches have been shown that, it has the best efficiency on the selection of rinsing chambers to pinch technology. There are different methods in pinch technology mostly based on mass transfer of single or multiple contaminants. In this research, a new method is used to select effective contaminant to be applied to pinch analysis. This research is based on Mann and Liu’s method in single contaminant. But “the guide for classification of raw water, wastewater and recycled water for industrial and recreation” is chosen to use a complex of index contaminants as a single contaminant. This method is very simple and applicable for various industrial processes. By an index contaminant like total dissolved solids, the water usage reduced about 6.7 %. Using pinch technology and this new approach in three rinsing chambers, water usage reduced about 14.4 %. 相似文献
14.
A new analytical development of the seismic hydrodynamic pressure inside pre-existing cracks on the upstream face of concrete dams is presented. The finite control volume approach is utilized to derive an expression for the seismic hydrodynamic pressure using the continuity principle and the linear momentum theorem for the fluid inside the crack. The derived pressure expression is a function of the relative crack-opening acceleration and velocity. The acceleration and velocity terms are then recast in the form of added mass and damping matrices which can then be included at the nodes inside the discrete crack of a finite element model. This procedure linearizes the solution of the problem. A dam, 55 m high and having an initial crack opening of 2 mm at the base or near the crest and subjected to two different accelerograms, is analysed. For high-frequency ground motion, the seismic hydrodynamic pressure inside the crack, at the base of the dam, appears to be 50 per cent higher than the corresponding hydrostatic pressure. 相似文献
15.
Djamel Bengora Lotfi Khiari Jacques Gallichand Noureddine Dechemi Silvio José Gumiere 《国际泥沙研究》2018,33(4):518-524
The capacity of water reservoirs may be considerably reduced by sediment transport and accumulation. This phenomenon may occur quickly in regions prone to erosion, such as Hammam Debagh Dam region in Algeria. For better management of water resources, it is important to estimate the volume of a reservoir by regular and frequent topo-bathymetric surveys. Topo-bathymetric surveys with a high point measurement density are expensive and time-consuming. To reduce this expense and to increase the frequency of topo-bathymetric surveys, it is required to optimize their size and density. The complete survey of the reservoir created by the Hammam Debagh Dam in Algeria was examined in comparison with 19 reduction subsets using geostatistics. The study showed that the complete dataset of 32,164 points, corresponding to a density of 42 points ha-1 could be reduced to 10,000 points, i.e. 13 points ha-1, without affecting the estimation of the water volume in the reservoir. This reduction could considerably simplify the work load, reduce the expenses to do these surveys, and, therefore, allow for an increased frequency of topo-bathymetric surveys. 相似文献
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Temporal and bathymetric variation of epiphyte cover and leaf biomass in a southern Posidonia oceanica (L.) meadow: the case of Mahdia coast,Tunisia 
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下载免费PDF全文 The aim of this research was to study spatial and temporal variation in epiphyte cover and leaf biomass of Posidonia oceanica in Eastern Tunisia. Sampling was conducted at four stations on the Mahdia coast during October and December 2010, and April and August 2011, which correspond respectively to autumn, winter, spring and summer in this area. Posidonia oceanica shoots were collected at two depths (5 and 10 m). Cover of macroinvertebrates and macroalgae was estimated on adult leaves. The results showed that leaf and epiphyte biomasses vary significantly according to sampling date, with the highest values recorded in August. We found a high diversity of epiphytic assemblages on the leaves of P. oceanica with clear qualitative and quantitative dominance of Rhodophyceae compared to other groups, followed by Phaeophyceae. Most epiphyte species on the leaves of P. oceanica in Eastern Tunisia are the same as those in other parts of the Mediterranean Sea. No bathymetrical variation in the epiphytic community was found in our study area, which can be explained by the high levels of water clarity in Mahdia. 相似文献
18.
Amel Dhib Mounir Ben Brahim Boutheina Ziadi Fourat Akrout Souad Turki Lotfi Aleya 《Marine pollution bulletin》2013
We studied the distribution of planktonic and epiphytic ciliates coupled with environmental factors and microalgae abundance at five stations in Ghar El Melh Lagoon (Tunisia). Planktonic ciliates were monitored for a year and epiphytic ciliates were sampled during summer 2011 in concordance with the proliferation of the seagrass Ruppia cirrhosa. Ciliate assemblage was largely dominated by Spirotrichea followed respectively by Tintinnida of and Strombidiida. No significant difference was found in the distribution of ciliate species among the stations. Redundancy analysis indicates that abiotic factors (temperature and nutriments) have a significant effect on the dynamics of certain ciliates. For epiphytic ciliates, 4 species were identified: Tintinnopsis campanula, Aspidisca sp., Strombidium acutum and Amphorides amphora. Based on PERMANOVA analyses, ciliates exhibit significant correlations among months and stations. According to ACP, epiphyte distribution follows roughly those of R. cirrhosa and pH. Significant correlations were found between harmful dinoflagellates and both planktonic and epiphytic ciliates. 相似文献
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Law-Chune Stéphane Aouf Lotfi Dalphinet Alice Levier Bruno Drillet Yann Drevillon Marie 《Ocean Dynamics》2021,71(3):357-378
Ocean Dynamics - As part of the Copernicus Marine Service, WAVERYS is the multi-year wave reanalysis that provides global wave data with a fine grid resolution of 1/5°. This wave reanalysis... 相似文献
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The use of more efficient energy consuming devices, which are closely associated with reduction of environmental pollution, has gained significant interest in the recent decades. The reduction of drag coefficient also improves safety and durability of environmental structures subjected to high-velocity fluid flow, and causes the noise and vibration to decrease as well. This paper describes the efficiency improvement in energy management by means of reducing drag coefficient in a practical divergent tubular-truncated cone. Extensive numerical simulations with emphasis on the shape optimization study were performed in order to find minimum drag coefficient for both laminar and turbulent flows (9.41?×?102????Re????1.882?×?107) around the mentioned cone. The numerical results were validated with experimental data, obtained by performing tests in an open circuit wind tunnel. The results showed that the minimum drag coefficient of optimum model within the shape modification process, comparable to the value for the primary model in turbulent flow decreased by 69.8% (the maximum discrepancy) at the highest considered Reynolds number of 1.882?×?107. Furthermore, the study of streamwise velocity profile led to more useful result. In this regard, the velocity magnitude inside the inlet span of the primary model, close to the entrance was approximately 1.6 times as great as the free upstream velocity. This is a noticeable result for the use of efficiency important structures in industrial applications. 相似文献