Investigating the removal of ethylbenzene from aqueous solutions using modified graphene oxide: application of response surface methodology     

A. Azizi  A. Torabian  E. Moniri  A. H. Hassani  H. Ahmad Panahi 《International Journal of Environmental Science and Technology》2018,15(12):2669-2678

This research focused on the application of response surface methodology (RSM) for the removal of ethylbenzene by the graphene oxide grafted with polymethyl vinyl ketone and aniline (GO-MVK-ANI) from wastewater. The adsorbent was prepared through polymerization of graphene oxide with methyl vinyl ketone using ammonium persulfate initiator and further modification by aniline. The synthesized material was characterized via Fourier transform infrared resonance spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and Brunauer–Emmett–Teller analysis. RSM was used to minimize the number of experiments and investigate the effect of three selected parameters (contact time, initial pH and adsorbent dose) on the removal efficiency of ethylbenzene. Additionally, the affecting parameters were optimized based on the selected target (ethylbenzene removal efficiency). The results show that 73% ethylbenzene could be adsorbed with initial ethylbenzene concentration of 20 mg/l under the optimum conditions (the contact time of 11 min, pH of 5.64 and adsorbent dose of 3.75 g/l). In this paper, high R ²-value (97.18%) for ethylbenzene removal and a good agreement with adjusted R ²-value (94.65%) indicated that the model was successful and the results demonstrated a reasonable proportion of the experimental and the predicted results.  相似文献   

Hyperspectral satellite data analysis for pure pixels extraction and evaluation of advanced classifier algorithms for LULC classification   总被引：1，自引：0，他引：1  

Gopal Krishna  Rabi N. Sahoo  Sanatan Pradhan  Tauqueer Ahmad  Prachi M. Sahoo 《Earth Science Informatics》2018,11(2):159-170

The study was carried out for Indian capital city Delhi using Hyperion sensor onboard EO-1 satellite of NASA. After MODTRAN-4 based atmospheric correction, MNF, PPI and n-D visualizer were applied and endmembers of 11 LCLU classes were derived which were employed in classification of LULC. To incur better classification accuracy, a comparative study was also carried out to evaluate the potential of three classifier algorithms namely Random Forest (RF), Support Vector Machines (SVM) and Spectral Angle Mapper (SAM). The results of this study reemphasize the utility of satellite borne hyperspectral data to extract endmembers and also to delineate the potential of random forest as expert classifier to assess land cover with higher classification accuracy that outperformed the SVM by 19% and SAM by 27% in overall accuracy. This research work contributes positively to the issue of land cover classification through exploration of hyperspectral endmembers. The comparison of classification algorithms’ performance is valuable for decision makers to choose better classifier for more accurate information extraction.  相似文献   

Erosion potential assessment of watersheds through GIS<Emphasis Type="Bold">-</Emphasis>based hypsometric analysis: a case study of Kurram Tangi Dam     

Wasif Yousaf  Syed Ghulam Mohayud-Din-Hashmi  Usman Akram  Urooj Saeed  Sajid Rashid Ahmad  Muhammad Umar  Ambreena Mubashir 《Arabian Journal of Geosciences》2018,11(22):711

Sediment discharge due to soil and rock erosion within the watersheds is the major cause of siltation in water reservoirs. Siltation in reservoirs reduces the capacity for power production, irrigation water supply, and other domestic purposes. Hypsometric analysis has widely been used to identifying the geomorphic development stages (stabilized, equilibrium, and un-stable) to assess the erosion proneness of watersheds. In this study, watershed of Kurram Tangi Dam and its four sub-watersheds (SWs) were considered to determine their sediment discharge capacity through hypsometric analysis. The boundaries of watershed and sub-watersheds were delineated from Digital Elevation Model (DEM). The hypsometric parameters i.e., hypsometric integral (HI) and curves were generated using Geographic Information System (GIS) techniques. The HI values of SW-1 (0.41) and SW-2 (0.36) indicated that these two SWs were relatively more prone to erosion and contributed higher sediment discharge in Dam siltation. The results were validated through sampling the main drainage channel (Kurram River) to determine the sediment concentration at 12 sites during summer, winter, and spring seasons. Comparison of HI and sediment concentration of SWs presented high correlation (R²?=?0.87). The results emphasized the effective watershed management, extensive afforestation, and construction of silt-control structures at appropriate locations in sub-watersheds. This will ultimately maintain the water and power generation capacity as well as extending the life span of the Dam.  相似文献   

Hydrological behaviour of a drained agricultural peat catchment in the tropics. 1: Rainfall,runoff and water table relationships     

Ayob Katimon  Shamsuddin Shahid  Ahmad Khairi Abd Wahab  Md. Hazrat Ali 《水文科学杂志》2013,58(6):1297-1309

Abstract

Hydrological data of a drained tropical peat catchment have been analysed through conventional quantitative hydrological approaches to characterize its hydrological behaviours and changes due to continuous drainage for a long period. The results show that the hydrology of the catchment is extremely dynamic and the catchment is flashy in nature. A decreasing trend in peak flow amount and an increasing trend in baseflow amount was observed in the catchment, indicating that continuous drainage has reduced the risk of both flooding and water scarcity in the catchment. Correlation analysis among rainfall, runoff and groundwater table reveals that saturation excess-near surface flow is the dominant mechanism responsible for rapid runoff generation in the catchment. Therefore, any physical alterations or disturbances to the upper part of the peat profile would definitely affect the overall hydrological behaviour of the peat catchment.

Editor Z.W. Kundzewicz; Associate editor D. Hughes

Citation Katimon, A., Shahid, S., Abd Wahab, A.K., and Ali, M.H., 2013. Hydrological behaviour of a drained agricultural peat catchment in the tropics. Part 1: Rainfall, runoff and water table relationships. Hydrological Sciences Journal, 58 (6), 1297–1309.  相似文献   

Producing landslide-susceptibility maps for regional planning in data-scarce regions   总被引：1，自引：0，他引：1  

Jerome V. De Graff  H. Charles Romesburg  Rafi Ahmad  James P. McCalpin 《Natural Hazards》2012,64(1):729-749

In many of the lesser developed areas of the world, regional development planning is increasingly important for meeting the needs of current and future inhabitants. Expansion of economic capability, infrastructure, and residential capacity requires significant investment, and so efforts to limit the negative effect of landslides and other natural hazards on these investments are crucial. Many of the newer approaches to identifying and mapping relative landslide susceptibility within a developing area are hindered by insufficient data in the places where it is most needed. An approach called matrix assessment was specifically designed for regional development planning where data may be limited. Its application produces a landslide-susceptibility map suitable for use with other planning data in a Geographical Information System (GIS) environment. Its development also encourages collecting basic landslide inventory data suitable for site-specific studies and for refining landslide hazard assessments in the future. This paper illustrates how matrix assessment methodology was applied to produce a landslide-susceptibility map for the Commonwealth of Dominica, an island nation in the eastern Caribbean, and how with a follow up study the relative landslide-susceptibility mapping was validated. A second Caribbean application on Jamaica demonstrates how this methodology can be applied in a more geologically complex setting. A validated approach to mapping landslide susceptibility which does not require extensive input data offers a significant benefit to planning in lesser developed parts of the world.  相似文献   

Upper Bound Solution for the Bearing Capacity of Submerged Jointed Rock Foundations     

Meysam Imani  Ahmad Fahimifar  Mostafa Sharifzadeh 《Rock Mechanics and Rock Engineering》2012,45(4):639-646

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Microstructures and compositional variation in the intravolcanic bole clays from the eastern Deccan volcanic province: Palaeoenvironmental implications and duration of volcanism     

J. P. Shrivastava  Mansoor Ahmad  Surabhi Srivastava 《Journal of the Geological Society of India》2012,80(2):177-188

Clay minerals associated with intra-volcanic bole horizons of varied colours and thicknesses contain montmorillonite, halloysite and kaolinite, show distinct microstructures and microaggregates. In kaolinite, Fe³⁺ ions substitute for Al³⁺ at octahedral sites. Most of these clays are dioctahedral type, show balance between net layer and interlayer charges. The interstratified illite — smectite (I/S) mixed layers containing variable proportions of montmorillonite. Illite contains sheet-like, well oriented microaggregates. The parallel stacks of chlorite sheets show chlorite/smectite (C/S) mixed layers. Progressive enrichment of Fe and depletion of Al ions with the advancement of kaolinization process is observed. High order of structural and compositional maturity observed in these bole clays, indicate long hiatus between the two volcanic episodes.  相似文献   

Mantle-derived fluids in the basement of the Deccan Trap: evidence from stable carbon and oxygen isotopes of carbonates from the Killari borehole basement, Maharashtra, India     

Priyanka Tripathi  G. Parthasarathy  S. Masood Ahmad  O. P. Pandey 《International Journal of Earth Sciences》2012,101(5):1385-1395

We report here for the first time geochemical, mineralogical and stable carbon and oxygen isotopic data on the crystalline basement rocks of the 1993 Killari earthquake region of Maharashtra (India), which is covered by a thick suite of Deccan volcanics. Our results revealed the hitherto unknown amphibolite–granulite nature of the 2.5?Ga basement, which contains 2.00–2.28?wt% of CO₂. The stable carbon (δ¹³C) and oxygen (δ¹⁸O) isotopic measurements on carbonates separated from two basement samples KIL-13 (440.5?m depth) and KIL-20 (499.6?m depth) collected from the KLR-1 borehole drilled in the epicentral region showed the respective values of ?6.23 and ?6.22‰ versus PDB for δ¹³C and 7.94 and 8.11‰ versus SMOW for δ¹⁸O. The samples plot in the primary igneous carbonatite field, indicating the mantle origin of the carbonates, derived through the process of mantle metasomatism from the deep mantle carbon reservoir. This would suggest large-scale crust-mantle thermal fluid interaction beneath the Killari seismogenic region, which is characterized by massive upwarping of the high-velocity mafic crust and retrograde metamorphism.  相似文献   

Seismicity patterns associated with the September 10th, 2008 Qeshm earthquake, South Iran     

Mohammad Reza Sorbi  Faramarz Nilfouroushan  Ahmad Zamani 《International Journal of Earth Sciences》2012,101(8):2215-2223

The b value of the Gutenberg-Richter relation and the standard deviate, Z, were calculated to investigate the temporal and spatial variations in seismicity patterns associated with the September 10th, 2008 (Mw?=?6.1) Qeshm earthquake. The temporal variations of b value illustrate a distinct dramatic drop preceding the Qeshm earthquake, and the spatial changes in b value highlight a zone with an abnormally low b value around the epicenter of this event. The cumulative number and Z value as a function of time show a precursory seismic quiescence preceding the 2008 Qeshm earthquake that observed for 1?year in a circle with R?=?50?km around its epicenter. The spatial distribution map of the standard deviate, Z, also exhibits an obvious precursory seismic quiescence region before the 2008 Qeshm event around the epicenter of this event. Interestingly, the precursory seismic quiescence region is approximately consistent with low b value anomaly region, and both have E–W to NE–SW trend. These two precursory anomalies took place in relatively large regions, which were possibly relevant to the preparation zone of the 2008 Qeshm event.  相似文献   

Xanthan gum biopolymer: an eco-friendly additive for stabilization of tropical organic peat     

Nima Latifi  Suksun Horpibulsuk  Christopher L. Meehan  Muhd.Zaimi Abd Majid  Ahmad Safuan A. Rashid 《Environmental Earth Sciences》2016,75(9):825

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