Empirical correlation between standard penetration resistance (SPT-N) and shear wave velocity measured by seismic downhole techniques are prepared of the alluvial soil of quaternary age for the Kanpur city. The Kanpur city is having seismic threat from Himalaya and it falls in seismic zone III according to seismic zones of India. Standard penetration test as well seismic downhole test has been carried out up to 30 m at twelve different locations of Kanpur city. The measured SPT-N values and shear wave velocity values are used to develop empirical correlation between SPT-N and shear wave velocity. The proposed correlations have been compared with the existing regression equations by various other investigators. It is found that the proposed correlation exhibit good performance (10 % error bar). Also the measured shear wave velocity has been used to prepare spatially distributed contour map of 50, 75 and 100 m/s using ArcGIS-9 software. It is observed that the shear wave velocity values for the northern part of Kanpur city vary from 125 to 825 m/s. In southern part, it is varying from 125 to 500 m/s where as in the central part of the city the shear wave velocity varies from 125 to 375 m/s. The eastern part of the city also shows some variation in shear wave velocity which ranges from 250 to 625 m/s. The western part of the city shows the variation of shear wave velocity from ≤125 to 500 m/s. The soil type of the study area are classified as per NEHRP and new Italian O.P.M.C classification system as B, C and D type soil with having site period of 0.1–0.9 s and Poisson’s ratio varying from 0.1 to 0.4. 相似文献
Coal-mining activities are precursors to land degradation, a part of which is directly related to the generation of huge quantity of overburden (OB) material. The problem of managing OB is mitigated through reclamation, which is directly associated with the geotechnical properties of these dumps. The main objective of this study was to assess the potential of an alternative management plan of OB by analyzing physical properties of these dumps. This alternative management plan of OB could enhance reclamation success by fostering conditions conducive for vegetation growth. This is especially required in old mining areas, where salvaging of topsoil was not done, and as a result, reclamation was affected. For the present study, 12 representative OB samples were collected from two open-cast coal mines (OCP-A and OCP-B) of Bastacolla area in Jharia Coalfield, Dhanbad, India. The samples were analyzed for different geotechnical properties. The results revealed that optimization of these parameters could help in enhancing the reclamation success of the area. From land-use classification, it was observed that about 242 ha of the study area was OB dump; if these areas are reclaimed successfully, then they can act as a potential source of carbon sequestration, and furthermore, they will improve the esthetics and the overall environmental quality at these degraded areas. 相似文献
Contamination of groundwater by nitrates leaching from intensive agricultural and livestock operations have become a major concern for surrounding communities that use groundwater as their water supply. High levels of nitrate in drinking water poses a significant risk to human health, i.e., methaemoglobinaemia (“blue baby” syndrome).
The traditional pump-and-treat method is ineffective in medium to fine-textured agricultural soils due to the low hydraulic conductivity. This paper presents the results of a laboratory experiment investigating the feasibility of using electrokinetic treatment in retaining, accumulating, moving and remediating nitrates in a silty loam soil under hydraulic gradients.
A hydraulic gradient of 1.25 was applied to the horizontal soil columns to simulate a groundwater movement system. The study was performed in two stages. During the first stage of the experiment, the anode located at the inflow end of the columns was able to retard the movement of nitrates even under a hydraulic gradient of 1.25. After 15 days of flow, the effluent nitrate concentration in the control column rose to 90 mg l−1 while no nitrates were detected in the effluent from columns subjected to the electrokinetic treatment.
After 15 days, the polarity of the electrodes was switched and this second stage lasted another 20 days. The cathode near the inflow end promoted the conversion of nitrates entering the column to other forms. The anode near the outflow end promoted the migration and accumulation of negatively charged nitrate ions towards the outflow end. By the 12th day, the nitrate concentrations in the electrokinetically treated columns were brought down to <5 mg NO3-N l−1. Electrokinetic treatment retarded nitrate movement against a hydraulic gradient of 1.25 and effectively restored a medium-textured soil contaminated with NO3-N.
The NO2-N level remained below 1 mg l−1 throughout the experiment. The hydraulic conductivity varied between 1.0E–7 and 3.6E–7 m s−1. The current requirement varied between 3 and 6 mA. 相似文献
In this paper we present an application of an artificial neural network model based on a multi-layered backpropagation algorithm for spectral classification of UV data from the International Ultraviolet Explorer (IUE) low dispersion spectra reference atlas. The model used is similar to that of von Hippel et al. (1994), and is found to reduce the classification error as compared to the recently reported results on the same data set (Gulati et al. 1994b). The improved version of the network is much simpler in structure and the training time is reduced by a factor of almost 20. Such networks will prove very useful in efficient classification of large databases
Subject headings: neural networks, stellar spectra, classification 相似文献
We examine the management of livestock diseases from the producers‘ perspective, incorporating information and incentive asymmetries
between producers and regulators. Using a stochastic dynamic model, we examine responses to different policy options including
indemnity payments, subsidies to report at-risk animals, monitoring, and regulatory approaches to decreasing infection risks
when perverse incentives and multiple policies interact. This conceptual analysis illustrates the importance of designing
efficient combinations of regulatory and incentive-based policies.
ABSTRACTThe temporal variations in electrical conductivity and the stable isotopes of water, δD and δ18O, were examined at Chhota Shigri Glacier, India, to understand water sources and flow paths to discharge. Discharge is highly influenced by supraglacially derived meltwater during peak ablation, and subglacial meltwaters are more prominent at the end of the melt season. The slope of the best fit linear regression line for δD versus δ18O, for both supraglacial and runoff water, is lower than that for precipitation (snow and rain) and surface ice, indicating strong isotopic fractionation associated with the melting processes. The slope of the local meteoric water line (LMWL) is close to that of the global meteoric water line (GMWL), reflecting that the moisture source is predominantly oceanic. The d-excess variation in rainwater confirms that the southwest monsoon is the main contributor during summer while the remainder including winter is mostly influenced by westerlies. 相似文献
This paper estimates the expected annual impacts of the Pink Hibiscus Mealybug infestation on the economies of Florida and the rest of the United States. The approach involves a Markov chain analysis wherein both short run and long run expected damages from infestation are calculated. Use is made of the CLIMEX model that predicts the potential pest-establishment regions in the US. While predictions based upon the CLIMEX model extend the scope of damages beyond Florida, the damages are significantly dependent upon the rate of arrival and detection of species in those regions. Damages are significantly higher when a longer time horizon is considered. When nursery owners bear the full cost of quarantines in the form of loss of sales and treatment costs of infected plants, the cost-effectiveness of quarantines as a regulatory tool is diminished. The long run propensity of the system, in terms of the fraction of time spent in the possible ‘states’ of infestation and control, determines the extent of damages, and not the annual value of crops that could be potential hosts to the pest.