Use of natural chabazite–phillipsite tuff in wastewater treatment from electroplating factories in Jordan     

K. Ibrahim  Nasser T. Ed-Deen  H. Khoury 《Environmental Geology》2002,41(5):547-551

Chabazite-phillipsite tuff from Tell Rimah volcano was evaluated in industrial wastewater treatment. Samples of two different size fractions have suitable zeolite content and cation exchange capacity, and are characterized by good attrition resistance and high packed bed density. Such properties enable these fractions to be used as ion exchangers under column operation condition. In the presence of high concentration of competing ions, such as Na⁺, Ca⁺² and K⁺, and under conditions of high total ionic concentration of toxic metals, the chabazite-phillipsite tuff exhibits successful performance in removing Cu⁺², Cr⁺³, Ni⁺², Zn⁺² and Fe⁺² from electroplating effluents. The factors that influence selectivity and efficiency of the zeolitic tuff were evaluated. The experimental work indicates that both selectivity and efficiency of the zeolite shows similar trends. The selectivity sequence exhibited by the zeolitic tuff is Ni⁺²>>Zn⁺² and Cr⁺³>Cu⁺²>>Fe⁺².  相似文献   

Origin and Petrogenetic Implications of Spessartine Garnet in Highly-Fractionated Granite from the Central Eastern Desert of Egypt     

Mabrouk SAMI  Theodoros NTAFLOS  Haroun A. MOHAMED  Esam S. FARAHAT  Christoph HAUZENBERGER  Nasser M. MAHDY  Khaled M. ABDELFADIL  Douaa FATHY 《《地质学报》英文版》2020,94(3):763-776

A highly-fractionated garnet-bearing muscovite granite represents the marginal granitic facies of the Abu-Diab multiphase pluton in the Central Eastern Desert of Egypt. New electron microprobe analyses(EMPA) and laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS) data from garnets are reported, in order to constrain their origin and genesis. Garnet in the Abu-Diab host granite is euhedral to subhedral, generally homogeneous and, in rare cases, it shows weak zonation. The garnet contains appreciable amounts of MnO and FeO, with lesser amounts of MgO and CaO, yielding an end-member formula of Sps_(61–72)Alm_(25–35)Prp_(1–4)Adr_(0–1). Moreover, it is depleted in large ion lithophile elements(LILE) with lower values of Ba, Nb and Sr relative to the primitive mantle. Additionally, it contains high concentrations of HREE and Y and their REE pattern shows strong negative Eu anomalies. The garnet was crystallized under relatively low temperature(646°C–591°C) and pressure( 3 kbar) conditions. The textural and chemical features indicate that the garnet is magmatic in origin and is chemically similar to that from highly-fractionated A-type granite. It was probably formed at the expense of biotite in a highly-evolved MnO-rich magma and/or by hydroxyl complexing of Mn during the ascending fluid phases.  相似文献   

How severely was the Persian Gulf affected by oil spills following the 1991 Gulf War?     

Nasser Mostafawi 《Environmental Geology》2001,40(10):1185-1191

Ostracods from 14 surface sediment samples taken from the northwest part of the Persian Gulf (Iranian side) at water depths of 32-54 m were studied to evaluate the environmental pollution caused by oil spills following the 1991 Gulf War. With the exception of two live ostracods, which show no response to the contamination, at least 58 closed carapaces from 18 taxa of herbivorous and sediment-feeding species were found containing dark brown oil. All contaminated specimens were restricted to the uppermost part of the sediments (0.0-0.5 cm). The extent of the impact and the number of affected species varies within the samples. The most heavily contaminated ostracods were encountered in samples 1, 3, 14, 21 and 26 in which 3-5% of the complete carapaces contain oil residues. Compared to a previous sampling in 1965, seven additional ostracod species occur in the modern Persian Gulf. This indicates an intact environmental state prior to the Gulf War.  相似文献   

A hypoplastic model for mechanical response of unsaturated soils     

David Mašín  Nasser Khalili 《国际地质力学数值与分析法杂志》2008,32(15):1903-1926

A new constitutive model is developed for the mechanical behaviour of unsaturated soils based on the theory of hypoplasticity and the effective stress principle. The governing constitutive relations are presented and their application is demonstrated using several experimental data from the literature. Attention is given to the stiffening effect of suction on the mechanical response of unsaturated soils and the phenomenon of wetting‐induced collapse. All model parameters have direct physical interpretation, procedures for their quantification from test data are highlighted. Quantitative predictions of the model are presented for wetting, drying and constant suction tests. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Catchment lithology as a major control on alluvial megafan development,Kohrud Mountain range,central Iran   总被引：1，自引：0，他引：1  

Nasser Arzani 《地球表面变化过程与地形》2012,37(7):726-740

The relative importance of tectonics, climate, base level and source lithology as primary factors on alluvial‐fan evolution, fan morphology and sedimentary style remain in question. This study examines the role of catchment lithology on development and evolution of alluvial megafans (>30 km in length), along the flanks of the Kohrud Mountain range, NE Esfahan, central Iran. These fans toe out at axial basin river and playa‐fringe sediments towards the centre of basin and tectonics, climatic change and base‐level fluctuations, were consistent for their development. They formed in a tectonically active basin, under arid to semiarid climate and a long term (Plio‐Pleistocene to Recent) change from wetter to drier conditions. The key differences between two of these fans, Soh and Zefreh fans, along the west and south flanks of this mountain range, is that their catchments are underlain by dissimilar bedrock types. The source‐area lithologies of the Soh and Zefreh fans are in sedimentary and igneous terrains, respectively, and these fans developed their geometry mainly in response to different weathering intensities of their catchment bedrock lithologies. Fan surface mapping (based on 1/50000 topographic maps, satellite images, and fieldwork), reveals that the geomorphic evolution of these fans differs in that the relatively large‐scale incision and through trenching of the Soh fan is absent in the Zefreh fan. Whereas the limited sediment supply of the Soh fan has resulted in a deep incised channel, the Zefreh fan has remained aggradational with little or no trenching into proximal to medial fan surface due to its catchment bedrock geology, composed mainly by physically weathered volcaniclastic lithology and characterized by high sediment supply for delivery during episodic flash floods. Sediment supply, which is mainly a function of climate and source lithology, is a dominant driver behind the development of fan sequences in alluvial megafans. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Scalar and vector probabilistic seismic hazard analysis: application for Algiers City     

Gherboudj Faouzi  Laouami Nasser 《Journal of Seismology》2014,18(2):319-330

This study deals with the application of probabilistic seismic hazard analysis (PSHA) for a rock site located in Algiers city. For this purpose, recent ground motion prediction equations developed in the world for similar sismotectonic context are used through logic tree in PSHA framework; the obtained results reflect clearly the high seismicity of the considered region. Moreover, deaggregation analysis is conducted to obtain the mean scenario in terms of magnitude and distance. In addition to the scalar-PSHA, a new method named vector-PSHA developed in recent years is performed in this study. Based on the multivariate probability theory, the software used in scalar approach is modified allowing the application of this approach for a real site in Algiers city with a vector of two and three parameters of intensity measure. The results are presented in terms of the joint annual rate of exceeding several thresholds such as PGA, PSA(T) of multiple vibration periods, peak ground velocity and Arias intensity and comparison between results of PSHA and V-PSHA is done.  相似文献   

Stochastic model of seismic torsional ground motion: Application to Lotung soft site     

Nasser?LaouamiEmail author  Pierre?Labbé  Ramdane?Bahar 《Journal of Seismology》2005,9(4):463-472

The purpose of this paper is to present a stochastical approach, which analyse the torsional ground motion, induced by the spatial variability of seismic motions. For this purpose, a torsional ground motion analytical model is proposed and a normalised differential motion parameter is introduced. The approach regards the seismic motion as the combination of a travelling wave on the site (coherent component) and a zero mean randomizing factor that introduces a loss of correlation effect. The soil parameters as fundamental frequency and damping coefficient are integrating by modeling the coherent component with the commonly used Kanai-Tajimi power spectral density. The parametric analysis of the model shows an increase of the induced torsion with both the soil frequency and the motion scattering parameter, and a decrease with the separation distance, the apparent wave velocity and the correlation length. Finally, in order to test the proposed torsional ground motion model prediction, it is compared to the experimental results recorded by the EPRI LSST array in Lotung, Taiwan (Laouami and Labbé, 2002). The comparison leads to the identification of the model parameters for the Lotung soft site.  相似文献   

Origin and geochemical reaction paths of sabkha brines: Sabkha Jayb Uwayyid, eastern Saudi Arabia     

Nasser A. Alsaaran 《Arabian Journal of Geosciences》2008,1(1):63-74

Sabkhas are ubiquitous geomorphic features in eastern Saudi Arabia. Seven brine samples were taken from Sabkha Jayb Uwayyid in eastern Saudi Arabia. Brine chemistry, saturation state with respect to carbonate and evaporate minerals, and evaporation-driven geochemical reaction paths were investigated to delineate the origin of brines and the evolution of both brine chemistry and sabkha mineralogy. The average total dissolved solids in the sabkha brines is 243 g/l. The order of cation dominance is Na⁺   >>  Mg²⁺ >>  Ca²⁺>K⁺, while anion dominance is Cl⁻ >> SO₄ ²⁻ >> HCO₃ ⁻. Based on the chemical divide principle and observed ion ratios, it was concluded that sabkha brines have evolved from deep groundwater rather than from direct rainfall, runoff from the surroundings, or inflow of shallow groundwater. Aqueous speciation simulations show that: (1) all seven brines are supersaturated with respect to calcite, dolomite, and magnesite and undersaturated with respect to halite; (2) three brines are undersaturated with respect to both gypsum and anhydrite, while three brines are supersaturated with respect to both minerals; (3) anhydrite is a more stable solid phase than gypsum in four brines. Evaporation factors required to bring the brines to the halite phase boundary ranged from 1.016 to 4.53. All reaction paths to the halite phase boundary follow the neutral path as CO₂ is degassed and dolomite precipitates from the brines. On average, a sabkha brine containing 1 kg of H₂O precipitates 7.6 g of minerals along the reaction path to the halite phase boundary, of which 52% is anhydrite, 35.3% is gypsum, and 12.7% is dolomite. Bicarbonate is the limiting factor of dolomite precipitation, and sulfate is the limiting factor of gypsum and anhydrite precipitation from sabkha brines.  相似文献   

A visualization-oriented 3D method for efficient computation of urban solar radiation based on 3D–2D surface mapping     

Jianming Liang  Wenhang Li  Abdoul Nasser Ibrahim 《International journal of geographical information science》2014,28(4):780-798

The temporal and spatial distribution of solar energy in urban areas is highly variable because of the complex building structures present. Traditional GIS-based solar radiation models rely on two-dimensional (2D) digital elevation models to calculate insolation, without considering building facades and complicated three-dimensional (3D) shading effects. Inspired by the ‘texture baking’ technique used in computer graphics, we propose a full 3D method for computing and visualizing urban solar radiation based on image-space data representation. First, a surface mapping approach is employed to project each 3D triangular mesh onto a 2D raster surface whose cell size determines the calculation accuracy. Second, the positions and surface normal vectors of each 3D triangular mesh are rasterized onto the associated 2D raster using barycentric interpolation techniques. An efficient compute unified device architecture -accelerated shadow-casting algorithm is presented to accurately capture shading effects for large-scale 3D urban models. Solar radiation is calculated for each raster cell based on the input raster layers containing such information as slope, aspect, and shadow masks. Finally, a resulting insolation raster layer is produced for each triangular mesh and is represented as an RGB texture map using a color ramp. Because a virtual city can be composed of tens of thousands of triangular meshes and texture maps, a texture atlas technique is presented to merge thousands of small images into a single large image to batch draw calls and thereby efficiently render a large number of textured meshes on the graphics processing unit.  相似文献   

Study of Shoreline Changes Through Digital Shoreline Analysis System and Wave Modeling: Case of the Sandy Coast of Bou-Ismail Bay,Algeria     

Kaddour  Said  Hemdane  Yacine  Kessali  Nasser  Belabdi  Khalid  Sallaye  Miloud 《Ocean Science Journal》2022,57(3):493-527

Ocean Science Journal - This work aims to analyze the evolution of Bou-Ismail coastline in Algeria using aerial photographs and quick-bird satellite image during the elapsed period from 1959 to...  相似文献