Spatial modeling of Dengue prevalence and kriging prediction of Dengue outbreak in Khyber Pakhtunkhwa (Pakistan) using presence only data     

Ahmad  Hammad  Ali  Asad  Fatima  Syeda Hira  Zaidi  Farrah  Khisroon  Muhammad  Rasheed  Syed Basit  Ullah  Ihsan  Ullah  Saleem  Shakir  Muhammad 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(7):1023-1036

Stochastic Environmental Research and Risk Assessment - During the span of August–October, 2017 a major outbreak of Dengue fever happened in Khyber Pakhtunkhwa province of Pakistan. Cases...  相似文献   

Effects of porosity and composition on seismic wave velocities and elastic moduli of lower cretaceous rocks,central Lebanon     

Mohamed K. Salah  Mohammad Alqudah  Ahmad K. Abd El-Aal  Christophe Barnes 《Acta Geophysica》2018,66(5):867-894

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Analysis of attenuation and dispersion of propagating wave due to the coexistence of three fluid phases in the pore volume     

Qazi Adnan Ahmad  Guochen Wu  Zong Zhaoyun  Wu Jianlu  Li Kun  Du Tianwei  Nasir Khan 《Geophysical Prospecting》2020,68(2):657-677

In exploration geophysics, the efforts to extract subsurface information from wave characteristics exceedingly depend on the construction of suitable rock physics model. Analysis of different rock physics models reveals that the strength and magnitude of attenuation and dispersion of propagating wave exceedingly depend on wave-induced fluid flow at multiple scales. In current work, a comprehensive analysis of wave attenuation and velocity dispersion is carried out at broad frequency range. Our methodology is based on Biot's poroelastic relations, by which variations in wave characteristics associated with wave-induced fluid flow due to the coexistence of three fluid phases in the pore volume is estimated. In contrast to the results of previous research, our results indicate the occurrence of two-time pore pressure relaxation phenomenon at the interface between fluids of disparate nature, that is, different bulk modulus, viscosity and density. Also, the obtained results are compatible with numerical results for the same 1D model which are accounted using Biot's poroelastic and quasi-static equation in frequency domain. Moreover, the effects of change in saturation of three-phase fluids were also computed which is the key task for geophysicist. The outcomes of our research reveal that pore pressure relaxation phenomenon significantly depends on the saturation of distinct fluids and the order of saturating fluids. It is also concluded that the change in the saturation of three-phase fluid significantly influences the characteristics of the seismic wave. The analysis of obtained results indicates that our proposed approach is a useful tool for quantification, identification and discrimination of different fluid phases. Moreover, our proposed approach improves the accuracy to predict dispersive behaviour of propagating wave at sub-seismic and seismic frequencies.  相似文献   

海洋工程试验池中风场模拟     

彭涛  杨建民  李俊 《海洋工程》2009,27(2):8-13

在考虑海洋工程装备在极端海况和运行海况下的载荷与受力,风载荷也是一个不可忽视的因素.目前物理模型试验仍是研究海洋工程结构物载荷与运动性能的重要手段,而深海结构物在水平漂移运动较大,如何在较大范围内得到满足试验要求的风场,是提高试验能力的重要问题.应用数值计算方法对大范围的风场模拟进行了分析,并进行了相应的物理实验,在此基础上对海洋工程试验的风场模拟提出了若干建议.  相似文献