Expansion of the first-order planetary disturbing function by Smart's method     

Osman M. Kamel  Adel S. Soliman 《Earth, Moon, and Planets》1989,47(3):241-263

We expand the principal part of the planetary disturbing function, by Smart's method, using Taylor's theorem. In our expansion we neglect terms of degree higher than the fourth in the eccentricities and tangents of the inclinations.Now at the JPL Pasadena, California.  相似文献   

Cr(VI) Immobilization Process in a Cr‐Spiked Soil by Zerovalent Iron Nanoparticles: Optimization Using Response Surface Methodology     

Leila Alidokht  Ali Reza Khataee  Adel Reyhanitabar  Shahin Oustan 《洁净——土壤、空气、水》2011,39(7):633-640

The response surface methodology involving the five‐level central composite design (CCD) was employed to model and optimize the Cr(VI) immobilization process in a Cr‐spiked soil using starch‐stabilized zerovalent iron nanoparticles (ZVIn). ZVIn were synthesized via a borohydride reduction method and characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). All Cr(VI) immobilization experiments were conducted in a batch system. The variables for the CCD optimization were the ZVIn dosage (% w/w), reaction time (min), and initial Cr(VI) concentration in soil (mg/kg). The predicted response values by the second‐order polynomial model were found to be in good agreement with experimental values (R² = 0.968 and adj‐R² = 0.940). The optimization result showed that the Cr(VI) immobilization efficiency presented the maximal result (90.63%) at the following optimal conditions: ZVIn dosage of 1.5% w/w, reaction time of 60 min, and an initial Cr(VI) concentration of 400 mg/kg.  相似文献   

Petrophysical characteristics of Wakar Formation, Port Fouad marine field, north Nile Delta, Egypt     

Adel Mohamed  Elkhedr Ibrahim  Ahmed Sabry 《Arabian Journal of Geosciences》2013,6(5):1485-1497

Petrophysical characteristics of the late Miocene Wakar Formation of Port Fouad Marine Field have been evaluated through the analysis of well-logging records of nine exploratory and development wells, distributed in the northeastern offshore area of the Nile Delta. These records have been analyzed through utilizing the ELAN Plus petrophysics software in order to identify the lithological constituents and fluid saturation parameters. The gas potentialities of the studied formation have been evaluated through number of isoparameteric maps. The litho-saturation analysis indicates that the Wakar Formation in the studied wells is mainly gas-bearing with some water-bearing sand levels. The analytical formation evaluation reveals that the lithological facies consists mainly of sandstone, shale, and siltstone. The disseminated shale is mainly of dispersed type and some of laminated habitat. It also points to the dominance of the intergranular porosity. The isoparametric maps of the petrophysical parameters show that the level S1 of Wakar Formation is the main reservoir.  相似文献   

Seismic behaviour of pile in three-layered soil (case study: Babol City Center Project)     

Adel Javdani Naeini  A. J. Choobbasti  M. Saadati 《Arabian Journal of Geosciences》2013,6(11):4487-4497

The significance of liquefaction-related damage to pile foundations has been clearly demonstrated by the major earthquakes occurring during past years. The current project investigates the seismic behaviour of a single pile in the three-layered soil of the Babol City centre site (located in Babol City, Mazandaran Province, Iran). The site soil consists of sandy and clayey soils modelled based on the data collected from drilled boreholes. Numerical analysis was performed using Flac2D finite difference program. Three different natural ground motion records are considered, and the influence of each earthquake on the bending moment and lateral displacement of the simulated pile is investigated. In addition, the effect of vertical surcharge on the settlement of the pile during the earthquakes is investigated. Results illustrate that the maximum bending moment has occurred on the interface of liquefiable and non-liquefiable soil layers.  相似文献   

Utilities of Landsat 7 data and selective image processing in characterization of radioactivity zones of Wadi Baba–Wadi Shalal Area, Westcentral Sinai, Egypt     

Adel Zein Bishta 《Arabian Journal of Geosciences》2013,6(9):3513-3526

Wadi Baba–Wadi Shalal area locates in the westcentral part of Sinai, Egypt. It is covered by a Precambrian basement rocks comprise the northern part of the Precambrian Arabo-Nubian crystalline massive. The lithologic and structural setting of the investigated area was interpreted from the digital Landsat-7 Enhanced Thematic Mapper Plus (ETM+) data. The structural lineament analyses for the lithologic units and their relationships to the high-radioactivity zones (HRZ) and the characterizations of HRZ of the study area are the main tasks of this article. Extraction algorithm was applied using Geomatica PCI package under the user defined parameters. The extracted structural lineaments have been evaluated and chicked using the visual interpretation and published works. The short-wave infrared spectral ETM+ band-7 was selected as an optimum data for automatic lineaments extraction since it scored the highest lineament frequency (1856) compared to the other visible and near infrared bands. The aeroradiometric color raster total count equivalent thorium (eTh) and equivalent uranium (eU) maps were used to delineate the highest radioactivity zones of the study area. A selective image processing technique (SIPT) is a new approach in Geomatica (9.1), which gives rise to valuable results in this work. The SIPT was carried out for the subset of the ETM+ data of the highest radioactivity zones. The spatial distribution of the structural lineament pattern maps for some low-radioactivity zones (LRZ) and for the highest radioactivity zones of the study area are prepared with their frequency rose diagrams. The NE–SW trend is the predominant structural lineaments trend in the investigated area. The NE–SW to the ENE–WSW directions are the predominant structural lineament trends in both the LRZ and the HRZ. These high-radioactivity zones of the investigated area are characterized by high lineaments density and lineaments-intersection density, restricted to Um Bogma Formation and younger granitic rocks and are not controlled by structural lineament trends.  相似文献   

Simulating urban growth under planning policies through parcel-based cellular automata (ParCA) model     

Somaie Abolhasani  Mohammad Taleai  Mohammad Karimi  Adel Rezaee Node 《International journal of geographical information science》2016,30(11):2276-2301

In recent decades, the cellular automata model, among the urban development prediction models, has been applied considerably. Studies show that the output of conventional cellular automata models is sensitive to cell size and neighborhood structure, and varies with changes in the size of these parameters. To solve this problem, vector-based cellular automata models have been introduced which have overcome the mentioned limitations and presented better results. The aim of this study was to present a parcel-based cellular automata (ParCA) model for simulating urban growth under planning policies. In this model, undeveloped areas are first subdivided into smaller parcels, based on some geometric parameters; then, neighborhood effect of parcels is defined in a radial structure, based on a weighted function of distance, area, land-use, and service level of irregular cadastral parcels. After that, neighborhood effect is evaluated using three components, including compactness, dependency and compatibility. The presented model was implemented and analyzed using data from municipal region 22 of Tehran. The obtained results indicated the high ability of ParCA model in allocating various land-uses to parcels in the appropriateness of the layout of different land-uses. This model can be used in decision-making and urban land-use planning activities, since it provides the possibility of allocating different urban land-use types and assessing different urban-growth scenarios.  相似文献   

Effects of Lime‐Based Waste Materials on Immobilization and Phytoavailability of Cadmium and Lead in Contaminated Soil     

Jung Eun Lim  Mahtab Ahmad  Sang Soo Lee  Christopher L. Shope  Yohey Hashimoto  Kwon‐Rae Kim  Adel R. A. Usman  Jae E. Yang  Yong Sik Ok 《洁净——土壤、空气、水》2013,41(12):1235-1241

Low cost lime‐based waste materials have recently been used to immobilize metals in contaminated soils. This study was conducted to evaluate the effects of oyster shells and eggshells as lime‐based waste materials on immobilization of cadmium (Cd) and lead (Pb) in contaminated soil, as well as their effects on metal availability to maize plants (Zea mays L.). Oyster shells and eggshells were applied to soils at 1 and 5% w/w, after which they were subject to 420 days of incubation. The toxicity characteristic leaching procedure (TCLP) test was employed to determine the mobility of Cd and Pb in soils. The results showed that the addition of waste materials effectively reduced the metal mobility as indicated by the decrease in the concentration of TCLP‐extractable Cd and Pb, and this was mainly due to significant increases in soil pH (from 6.74 in untreated soil to 7.85–8.13 in treated soil). A sequential extraction indicated that the addition of such alkaline wastes induced a significant decline in the concentration of Cd in the exchangeable fraction (from 23.64% in untreated soil to 1.90–3.81% in treated soil), but it increased the concentration of Cd in the carbonate fraction (from 19.59% in untreated soil to 36.66–46.36% in treated soil). In the case of Pb, the exchangeable fraction was also reduced (from 0.67% in untreated soil to 0.00–0.01% in treated soil), and the fraction of Pb bound to carbonate was slightly increased (from 16.61% in untreated soil to 16.41–18.25% in treated soil). Phytoavailability tests indicated that the metal concentrations in the shoots of maize plant were reduced by 63.39–77.29% for Cd and by 47.34–75.95% for Pb in the amended soils, with no significant differences being observed for the amendment types and the application rates. Overall, these results indicate that oyster shells and eggshells can be used as low cost lime‐based amendments for immobilizing Cd and Pb in contaminated soils.  相似文献   

Mineralogy, Chemical Characteristics and Upgrading of Beach Ilmenite of the Top Meter of Black Sand Deposits of the Kafr Al-Sheikh Governorate, Northern Egypt     

Abdel-Aal M.?ABDEL-KARIM  Mohamed I. MOUSTAFA  Adel H. El-AFANDY  Mohamed G. BARAKAT 《《地质学报》英文版》2017,91(4):1326-1338

Egyptian beach ilmenite occurs in a relatively high content in the naturally highly concentrated superficial black sand deposits at specific beach zones in the northern parts of the Nile Delta at Rosetta. Microscopic study shows that the ilmenite occurs as fresh homogeneous black or heterogeneous multicoloured altered grains and exhibits three types (homogeneous, exsolved and altered) of ilmenite varieties. XRD data of ilmenite indicates their association with minor hematite and quartz, whereas leucoxene shows its association with Nb‐rutile, pseudorutile and hematite. Grain size distribution suggests a very fine sand size of >89% and 80% and a fine sand size of 10.5% and 18.3% for fresh and altered ilmenites, respectively. The density of fresh, altered ilmenite and leucoxene concentrates varies from 2.70, 2.50 to 2.40 ton/m³, suggesting a gradual decrease from high grade fresh to leucoxene and consistent with variation in magnetic susceptibility as a consequence of the leaching of iron. Mass magnetic susceptibility reveals 97.6% of ilmenite and 92% of the altered form are obtained at 0.20 and 0.48 ampere. Fresh ilmenite exhibits variable TiO₂ (47.18%) and Fe₂O₃^T (46.10%) with minor MnO, MgO and Cr₂O₃ (1.22, 1.10 and 0.51%). The altered ilmenite is higher in TiO₂ (76.16%) and SiO₂ (4.68%) and lower in Fe₂O₃^T (14.45%), MnO, MgO and Cr₂O₃ (0.39, 0.52 and 0.11%) compared with the fresh form. Three concentrates of ilmenites (G1, G2 and G3) were prepared from crude ore using a Reading cross belt magnetic separator under different conditions, revealing a gradual increase of TiO₂, SiO₂, Al₂O₃ and CaO accompanied by a decrease of Fe₂O₃^T, MgO and Cr₂O₃ with repetition of the separation processes. Several ore dressing techniques were carried out to upgrade the ilmenite concentrate.  相似文献   

Reduction of Nitrate Loadings to Ground Water     

Adel Shirmohammadi  William L. Magette  Leslie L. Shoemaker 《Ground Water Monitoring & Remediation》1991,11(1):112-118

Non-point source pollution of ground water systems has become a national concern in recent years. Researchers and regulatory agencies are investigating the source and processes of the contamination. Agricultural best management practices (BMPs) traditionally developed to reduce non-point source pollution of surface water resources are being investigated for their impact on ground water quality. This study used the CREAMS model to simulate the long-term effects of seven different BMPs on nitrate nitrogen (NO₃-N) loadings to a shallow, unconfined ground water system. Two representative watersheds, 5.8 and 8.9 hectares (14.3 and 22 acres) in area, in the Coastal Plain physiographic region of Maryland were selected for study. Soils in these watersheds belong to the Matapeake silt loam series and have moderate infiltration capacity. Results from this study indicated that BMPs used in conjunction with winter cover (barley) reduced NO₃-N leaching to the ground water system. It was also found that turfgrass reduced surface losses of water and nitrogen, but increased leaching losses of water and NO₃-N significantly. All of the BMPs simulated in this study resulted in leachate NO₃-N concentrations exceeding 10 ppm, the U.S. EPA health standard for public drinking water, indicating a need for alternate practices for reducing nitrate leaching.  相似文献   

Etude de l'uranium,du thorium et de leurs isotopes dans quelques carottes du Bassin angolais (Atlantique Sud-Est)     

Adel P. Boulad  Gil Michard 《Earth and Planetary Science Letters》1976,32(1):77-83

Uranium and thorium distributions are studied in top-oxidized, bottom-reduced cores. In sediments uranium is more abundant in the reducing zones than in the oxidized ones. In pore water also, uranium is more abundant in the reducing zones. In the cores studied, the Io/U chronology is completely disturbed.The general model of steady-state diagenesis cannot be applied to the uranium pattern.  相似文献