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Hafeez Amna Ehsan Muhsan Abbas Ayesha Shah Munawar Shahzad Rasim 《Natural Hazards》2022,111(2):2097-2115
Natural Hazards - Satellite based thermal anomaly occurs as a substantial precursor for strong earthquakes, as the need for earthquake precursor detection has very important for impending main... 相似文献
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Noori Hirad Shamimi Shirinabadi Reza Moosavi Ehsan Gholinejad Mehran 《Geotechnical and Geological Engineering》2022,40(4):2051-2062
Geotechnical and Geological Engineering - In this study, peak particle velocity (PPV) values for driving three piles with diameters of 40 cm, 50 cm, and 70 cm in a clayey... 相似文献
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Polycyclic aromatic hydrocarbons (PAHs) are types of hazardous contaminants, which their ingestion could cause severe consequences on human health. Leakages from storage tanks, underground pipelines, and evaporation ponds are the main sources of soil and groundwater contaminations at the Tehran Oil Refinery area (TOR site), located in south of Tehran, Iran. In this study, soil samples were collected from different locations at and adjacent to a polluted stream in the south of the refinery. The samples were analyzed for two hazardous PAH compounds, namely benzo[a]anthracene and acenaphthene. The clean up levels due to the accidental ingestion of contaminated soils at the site were also investigated in accordance to the U.S.EPA guidelines. Comparing the soil analysis results indicated that the benzo[a]anthracene concentrations in the samples varied from 53 to 299 mg/kg, which were higher than the clean up level of 1.17 mg/kg. Thus, soil remediation is required for this contaminant. The acenaphthene analysis results denoted that the average concentration of this contaminant was below the clean up level of 116.67 mg/kg, indicating that no treatment for this contaminant is necessary at the TOR site. Also, because the slope of the ground extends to the south of the stream, which stimulates the migration of the contaminants in this direction due to advection and dispersion mechanisms, the average of benzo[a]anthracene concentrations in south samples was higher than north samples (i.e., Cavg(S) = 160 ppm, Cavg(N) = 113 ppm). Various treatment techniques such as thermal desorption, soil vapor extraction (SVE), and solidification/stabilization (S/S) were investigated for this site. Due to moderate to high plasticity and relatively low permeability of the soil and low volatility of benzo[a]anthracene, however S/S method is recommended as a practical approach for the remediation of the soil at the site. 相似文献
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Supervised injection facilities (SIFs) are medical facilities where injection drug users can inject their illicit drugs under the supervision of nurses and doctors. Currently, there is only one legal SIF in operation in North America and it has been operating in Vancouver, British Columbia for over a decade. The purpose of this study is to determine whether the current facility needs to be expanded to other locations in British Columbia, Canada. We employ mathematical modeling to estimate the number of new human immunodeficiency virus (HIV) and hepatitis C infections prevented based on the available secondary data. Additionally, we also estimate the number of prevented overdose deaths attributable to the SIF. With very conservative estimates, it is predicted that establishing two SIFs locations outside Vancouver in British Columbia’s capital city, Victoria, is cost-effective, with a benefit-cost ratio of 1.25:1. It appears that expanding SIFs to Victoria could offer significant savings for local health care institutions. 相似文献
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利用支持向量分类(SVC)估算断层深度和特征选择(英文) 总被引：1，自引：0，他引：1
Mohammad Ehsan Hekmatian Vahid E. Ardestani Mohammad Ali Riahi Ayyub Memar Koucheh Bagh Jalal Amini 《应用地球物理》2013,10(1):88-96
地下断层深度的估算是重力解释难题之一,我们试利用支持向量分类(SVC)法进行计算。使用正演和非线性反演技术,通过相关误错使检测地下断层深度成为可能。但必要有一个深度初始猜测值,而且这猜测值通常不是由重力资料得。本文我们介绍以SVC作为利用重力数据估算断层深度的一种手段。在这项研究中,我们假设一种地下断层深度可归为一种类型,SVC作为一个分类算法。为了有效地利用此SVC算法,我们基于一个正确的特征选择算法去选择正确的深度特征。本次研究中我们建立了一套基于不同深度地下断层的合成重力剖面训练集,用以训练用于计算实际的地下断层深度的SVC代码。然后用其它合成重力剖面训练集测试我们训练的SVC代码,同时也用实际资料验证了我们的训练SVC代码。 相似文献
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Elsayed Yousef Ahmed Ehsan M. Azhar Almazroui Mansour Assiri Mazen E. Al-Khalaf Abdulrahman K. 《Theoretical and Applied Climatology》2017,127(3-4):779-791
A new closure and a modified detrainment for the simplified Arakawa–Schubert (SAS) cumulus parameterization scheme are proposed. In the modified convective scheme which is named as King Abdulaziz University (KAU) scheme, the closure depends on both the buoyancy force and the environment mean relative humidity. A lateral entrainment rate varying with environment relative humidity is proposed and tends to suppress convection in a dry atmosphere. The detrainment rate also varies with environment relative humidity. The KAU scheme has been tested in a single column model (SCM) and implemented in a coupled global climate model (CGCM). Increased coupling between environment and clouds in the KAU scheme results in improved sensitivity of the depth and strength of convection to environmental humidity compared to the original SAS scheme. The new scheme improves precipitation simulation with better representations of moisture and temperature especially during suppressed convection periods. The KAU scheme implemented in the Seoul National University (SNU) CGCM shows improved precipitation over the tropics. The simulated precipitation pattern over the Arabian Peninsula and Northeast African region is also improved.
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Neda?Yousefi Saeed?Reza?KhodashenasEmail author Saeid?Eslamian Zahra?Askari 《Arabian Journal of Geosciences》2016,9(4):321
Predicting behavior and the geometry of the channels and alluvial rivers in which the erosion and sediment transport are in equilibrium is one of the most important topics in river engineering. Various researchers have proposed empirical equations to estimate stable river width (W). In this research, empirical equations were examined and tested with a comprehensive available data set consisting of 1644 points collected from 29 stable rivers in various parts of the world. The data set covers a wide range of flow conditions, river geometry, and bed sediments. This data set is classified in two groups (W < 600 m and W ≥ 600 m) for presenting the new models. The new linear and nonlinear multivariable equations were fitted to these two groups, and the best models were selected by preliminary tests and diagnostic determined for each group. The determination coefficient of these models ranged from 0.87 to 0.96. The results show that the models presented in this paper are more accurate with respect to the previously presented models. In the second part, “Artificial neural networks,” perceptron was used and a new methodology for estimating stable channel width was developed. Comparison of the statistical methods presented in this paper and the results of perceptron neural network revealed preferential recent method. 相似文献
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To obtain rigorous upper-bound solutions for the bearing capacity of strip footings subjected to combined loadings, a new collapse mechanism consisting of three rigid blocks undergoing impending rotational or translational movements is proposed. The proposed mechanism improves the efficiency of the previously-developed rigid block mechanisms to account for eccentric loading condition in restricted bearing capacity problems. The comparisons show a good agreement between the results obtained using the present method and those of the known solutions. The effectiveness of the proposed mechanism was examined through investigating the bearing capacity of eccentrically loaded strip footings over thin layer foundation soils. 相似文献