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Mohamed A.,NRIAG
Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics | Year: 2014

Ground vibrations induced by blasting in the cement quarries are one of the fundamental problems in the quarrying industry and may cause severe damage to the nearby utilities and pipelines. This research paper presents the results of ground vibration measurements induced by blasting at the National Cement Company (NCC) southeast of Helwan city, Egypt. The aim of this study is to investigate the influence of the quarry blasts on the oil pipelines of SUMED Company. The seismic refraction for compressional waves and the shear wave velocity obtained from the Multi channel Analysis of Surface Waves (MASW) are used to evaluate the closest site of the two pipelines to the quarry blasts. The results demonstrate that, the closest site of the two pipelines is of class B, according to the International Building Code (IBC) and the safe distance to avoid any environmental effects is 650 m, following the deduced Peak Particle Velocity (PPV) and Scaled Distance (SD) relationship (PPV = 440.64 × SD-1.225) in mm/s and the Air over Pressure (Air Blast) formula (Air Blast = 152.87 × SD-0.071) in dB. In the light of the prediction analysis. Source


BIF from Umm Nar, Eastern Desert, Egypt is competitive for test of the geophysical gravity techniques in mineral exploration, including subsurface locating, mapping, and assessing high-density contrasts between host and mineralized rocks, and cost-effective methodological approach. The gravity measurements showed high anomalies of BIF and low anomalies of the metasedimentary country rock. Several results are in preparation. Recommendations for using other geophysical tools are taken into consideration for confirmation our results. Source


Salem A.S.K.,University of Leeds | Fairhead J.D.,GETECH | Aboud E.,NRIAG
72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010: A New Spring for Geoscience. Incorporating SPE EUROPEC 2010 | Year: 2010

The Extended Tilt-depth method builds on the existing Tilt-depth method to remove one of its constraints - that of relying on the source model being a vertical contact. To achieve this, there is a need to go to the tilt of the local wavenumber, a second order derivative which is independent of structural index. The Extended Tilt-depth method is thus a new interpretation tool for the initial evaluation of high resolution aeromagnetic survey data. The method is tested using a theoretical model and a field example from the North Western Desert of Egypt. In the former, the method estimated the correct depth for the model. For the field data, The Extended Tilt-depth method successfully identifies a number of important tectonic elements known from geologic mapping and known areas of sedimentary basins. Further testing and application of this new method, using known models and field examples, is needed to fully appreciate its strengths and weaknesses. © 2010, European Association of Geoscientists and Engineers. Source


Mohammed H.M.,NRIAG | Ahmed M.K.M.,Cairo University | Owis A.H.,Cairo University
Advances in the Astronautical Sciences | Year: 2012

In this work we investigate the orbit-attitude perturbations of a rigid spacecraft due to the effects of several forces and torques. The spacecraft is assumed to be of a cylindrical shape and equipped with a charged screen with charge density ε. Clearly the main force affecting the motion of the spacecraft is the gravitational force of the Earth with uniform spherical mass. The effect of oblate Earth up to J2 is considered as perturbation on both the orbit and attitude of the spacecraft, where the attitude of the spacecraft is acted upon by what is called gravity gradient torque. Another source of perturbation on the attitude of the spacecraft comes from the motion of the charged spacecraft in the geomagnetic field. This motion generates a force known as the Lorentz force which is the source of the Lorentz force torque influencing the rotational motion of the spacecraft. In this work we give an analytical treatment of the orbital-rotational dynamics of the spacecraft. We first use the definitions of Delaunay and Andoyer variables in order to formulate the Hamiltonian of the orbit-attitude motion under the effects of forces and torques of interest. Since the Lorentz force is a non-conservative force, a potential like function is introduced and added to the Hamiltonian. We solve the canonical equations of the Hamiltonian system by successive transformations using a technique proposed by Lie and modified by Deprit and Kamel to solve the problem. In this technique we make two successive transformations to eliminate. Source


Pinto C.C.,National Laboratory of Energy and Geology | Carvalho J.P.,National Laboratory of Energy and Geology | Costa M.,National Laboratory of Energy and Geology | Rabeh T.,NRIAG | And 5 more authors.
72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010: A New Spring for Geoscience. Incorporating SPE EUROPEC 2010 | Year: 2010

The Lisbon and Lower Tagus Valley area have suffered the effect of historical earthquakes that caused important damages and loss of lives. Some of these earthquake sources are local but they are still poorly known due to the difficulty in finding geological outcrops, together with low-slip rates and erosion/sedimentation processes that erase surface ruptures. Identification of seismogenic sources capable of producing large earthquakes from low magnitude instrumental seismicity has also proved unreliable in other areas of the world. Therefore, for a proper assessment of seismogenic sources for seismic hazard purposes we have used recently reprocessed and reinterpreted seismic reflection, potential-field data and overlaid relocated epicentres. Here we present a revised structural interpretation of the area based on seismic data and a basement map produced by magnetic modelling, 2D Euler deconvolution and trend analysis. This basement map, which greatly enlarges the seismic coverage of the study area, has shown new insights into deep-seated structures of the Lower Tagus Valley area and their relationship with seismicity. The information from fault parameters collected in this work will also help to locate the sources of historical events such as the 1909 Benavente earthquake using finite-element strong-motion simulation and comparison with observed seismic intensities. © 2010, European Association of Geoscientists and Engineers. Source

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