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1.
Surface complexation modeling of Cu(II) adsorption on mixtures of hydrous ferric oxide and kaolinite
Tracy J Lund Carla M Koretsky Christopher J Landry Melinda S Schaller Soumya Das 《Geochemical transactions》2008,9(1):9
Background
The application of surface complexation models (SCMs) to natural sediments and soils is hindered by a lack of consistent models and data for large suites of metals and minerals of interest. Furthermore, the surface complexation approach has mostly been developed and tested for single solid systems. Few studies have extended the SCM approach to systems containing multiple solids. 相似文献2.
3.
The Hassi R’Mel field, which is the largest gas field in Algeria, produces principally gas condensate. The produced gas and oil comes from four reservoirs of Triassic age (reservoir A, reservoir B, reservoir C, and the Lower Series). All the previous studies in this field focused only on the upper reservoirs (A, B, and C), which have shown an excellent petrophysical properties. However, due to the presence of shale facies as well as volcanic intrusions, the Lower Series reservoir has been less explored. Thus, our study is mainly focused on this Lower Series in order to find the best sandy levels. The aim of this paper was to determine the facies types in the area, their distribution in the southern area of the Hassi R’Mel gas field, and their depositional environment. The Triassic rocks in this field are divided into four formations. From the youngest to oldest, these are S4, Lower Shale, Horizon A, and the Lower Series. The Lower Series formation can be further divided into three members (shaly sandstone, andesite, and lower shale). The shaly sandstone member within the Lower Series is composed of four units that are present all over the study area with an important pinch-out toward the northern part. The depositional environment within the defined units is a braided fluvial system in the southern part that evolves into a meandering fluvial system toward the north. Thus, the study area is considered to be a transitional zone between two depositional systems. 相似文献
4.
Spatio‐temporal prediction and forecasting of land surface temperature (LST) are relevant. However, several factors limit their usage, such as missing pixels, line drops, and cloud cover in satellite images. Being measured close to the Earth's surface, LST is mainly influenced by the land use/land cover (LULC) distribution of the terrain. This article presents a spatio‐temporal interpolation method which semantically models LULC information for the analysis of LST. The proposed spatio‐temporal semantic kriging (ST‐SemK) approach is presented in two variants: non‐separable ST‐SemK (ST‐SemKNSep) and separable ST‐SemK (ST‐SemKSep). Empirical studies have been carried out with derived Landsat 7 ETM+ satellite images of LST for two spatial regions: Kolkata, India and Dallas, Texas, U.S. It has been observed that semantically enhanced spatio‐temporal modeling by ST‐SemK yields more accurate prediction results than spatio‐temporal ordinary kriging and other existing methods. 相似文献
5.
Dhruba Mukhopadhyay Tapas Bhattacharya Tapan Chakraborty Arun Kanti Dey 《Journal of Earth System Science》1990,99(2):249-268
In the western part of the North Singhbhum fold belt near Lotapahar and Sonua the remobilized basement block of Chakradharpur
Gneiss is overlain by a metasedimentary assemblage consisting of quartz arenite, conglomerate, slate-phyllite, greywacke with
volcanogenic material, volcaniclastic rocks and chert. The rock assemblage suggests an association of volcanism, turbidite
deposition and debris flow in the basin. The grade of metamorphism is very low, the common metamorphic minerals being muscovite,
chlorite, biotite and stilpnomelane. Three phases of deformation have affected the rocks. The principal D1 structure is a
penetrative planar fabric, parallel to or at low angle to bedding. No D1 major fold is observed and the regional importance
of this deformation is uncertain. The D2 deformation has given rise to a number of northerly plunging major folds on E-W axial
planes. These have nearly reclined geometry and theL
2lineation is mostly downdip on theS
2surface, though some variation in pitch is observed. The morphology of D2 planar fabric varies from slaty cleavage/schistosity
to crenulation cleavage and solution cleavage. D3 deformation is weak and has given rise to puckers and broad warps on schistosity
and bedding. The D2 major folds south of Lotapahar are second order folds in the core of the Ongarbira syncline whose easterly
closure is exposed east of the mapped area. Photogeological study suggests that the easterly and westerly closing folds together
form a large synclinal sheath fold. There is a continuity of structures from north to south and no mylonite belt is present,
though there is attenuation and disruption along the fold limbs. Therefore, the Singhbhum shear zone cannot be extended westwards
in the present area. There is no evidence that in this area a discontinuity surface separates two orogenic belts of Archaean
and Proterozoic age. 相似文献
6.
Methods reported in the literature for rock fracture simulations include approaches based on stochastic geometry, multiple-point
statistics and a combination of geostatistics for fracture density and object-based modelling for fracture geometries. The
advantages and disadvantages of each of these approaches are discussed with examples. By way of review, the authors begin
with the geostatistical indicator simulation method, based on the truncated–Gaussian algorithm; this is followed by multiple-point
statistical simulation and then the stochastic geometry approach, which is based on marked point process simulation. A new
approach, based on pluriGaussian structural simulation, is then introduced. The new approach incorporates in the simulation
the spatial correlation between different sets of fractures, which in general, is very difficult, if not impossible, to accomplish
in the three methods reviewed. Each simulation method is summarised together with detailed simulation procedures for each.
A published two-dimensional fracture dataset is used as a means of assessing the performance of each simulation method and
of demonstrating the concepts discussed in the text. 相似文献
7.
Bimal Kanti Paul 《The Professional geographer》1998,50(3):287-301
On May 13, 1996, a disastrous tornado hit the Tangail district of Bangladesh, killing more than 700 people and causing extensive damage to homes, crops, and livestock. This paper explores and analyzes how tornado victims adjusted to this destruction. Data collected from two study sites show that victims received emergency assistance from people both in neighboring areas and from more distant areas, as well as from government agencies and non-governmental organizations (NGOs). At both sites, NGOs played the leading role in minimizing the hardships of victims through extraordinary disaster relief and rehabilitation efforts. Because of the extensive support received, the tornado victims were able to return to their “normal” lives very quickly. This study concludes with several recommendations to help cope with future tornado disasters. 相似文献
8.
Onkari Prasad Sant Prasad Kanti Prasad R. R. Kelkar 《Journal of Earth System Science》1998,107(1):5-18
Moisture profiles have been estimated over the region bounded by the latitudes 40°N and 40°S and longitudes 30°E to 130°E
using INSAT digital infra red cloud imagery data. The representativeness of these profiles in representing moisture field
associated with the development and movement of synoptic scale systems during the period September 15th, 1996 to March 31st,
1997 has been examined. It has been shown that the changes in the moisture field associated with the withdrawal of the southwest
and northeast monsoons from the Indian sub-continent, development and movement of synoptic scale sytems (depressions, tropical
cyclones and waves in easterlies) and equatorial troughs in the Indian Ocean could be clearly seen in humidity profiles. The
initial development of tropical systems is first seen in the humidity field in the upper troposphere. These profiles could
be used in monitoring the initial development and subsequent movement of tropical systems. Further the data on moisture distribution
from the data gap regions of the Indian Ocean could be used as an additional source of moisture in numerical analysis and
prognosis. 相似文献
9.
Bimal Kanti Paul 《Natural Hazards》2010,54(2):483-495
The objectives of this paper are to examine the extent of human injuries caused by Cyclone Sidr, which made landfall in Bangladesh
coast on November 15, 2007, and report on the circumstances, type and causes of injuries, along with selected risk factors
associated with such injuries. Relevant data was collected through a questionnaire survey administered among the cyclone victims.
Semi-structured interviews with key personnel were also conducted to obtain information regarding the circumstances causing
injuries and public response to care for the injured. The questionnaire survey data reveals that among the respondent families,
132 persons sustained various types of injuries. Since the respondent families comprised of 1,443 members, the injury rate
was 9.15%. All injured victims were treated either onsite or in local hospitals. The most common types of injuries were soft-tissue
injuries (cuts, bruises, and scrapes) and fracture/dislocations. The most common causes of injuries for survivors were associated
with falling trees. Analysis of risk factors reveals that age is significantly correlated with injuries. Both formal and informal
interviews suggest that injured persons and their family members were in general pleased with medical response they received
from various sources. Several recommendations have been suggested to reduce future cyclone-related injuries in Bangladesh. 相似文献
10.
With a 2.4 million people living with Human Immunodeficiency Virus (HIV), India is among the countries in the world most vulnerable to the spread of HIV. This study focuses on understanding what makes female college students (ages 18–24) in Kolkata, India willing to comply with HIV/AIDS preventive measures; these students are widely believed to be at low risk of infection with HIV. Through a questionnaire survey, the data used in this study was collected from 232 female students attending five higher education institutes. Multiple regression analysis reveals that religion, household income, perception of whether preventive measures would hamper freedom, and respondents’ perception of the effectiveness of preventive measures all influence the students’ willingness to comply with preventive measures. Based on its findings, the study makes several recommendations to improve HIV/AIDS prevention in Kolkata and West Bengal, India. 相似文献