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Search Results: 1 - 10 of 402367 matches for " Ghada M. SAMI "
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Radio Wave Propagation Characteristics in FMCW Radar  [PDF]
Ghada M. SAMI
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2009, DOI: 10.4236/jemaa.2009.14042
Abstract: FMCW Radar (Frequency Modulated Continuous Wave Radar) is used for various purposes, such as atmospheric Remote Sensing, inter-vehicle ranging, etc. FMCW radar systems are usually very compact, relatively cheap in purchase as well as in daily use, and consume little power. In this paper, FMCW radar determines a target range by measuring the beat frequency between a transmitted signal and the received signal from the target, and Combines between PO and radar single. The approach based on frequency domain physical optics for the scattering estimation and the linear system modeling for the estimation of time domain response, and FMCW Radar signal processing.
Time-Domain Analysis of a Rectangular Reflector Antenna  [PDF]
Ghada M. Sami
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.410172

Rectangular reflector antennas have motivated the time-domain analysis of electromagnetic scattering problems. The asymptotic time domain physical-optics (TDPO) is applied to the analysis of a rectangular reflector illuminated by a Gaussian-impulse. The effects of time-delayed mutual coupling between points on the surface will be ignored as a result of utilizing the TDPO method for determining the equivalent surface-current density on the reflector. Finally, in this work the scattered signals at the specular reflection point, at the edges, and at the corners can be clearly distinguished.

The Electromagnetic Field Propagation in a Spherical Core  [PDF]
Osama M. Abo-Seid, Ghada M. Sami
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2012, DOI: 10.4236/jemaa.2012.412067
Abstract: A simple and explicit derivation for the electric and magnetic fields in the ferromagnetic cores has been studied. An improved model for analyzing the distribution of electric and magnetic fields in a toroidal core is given. This leads to a basis system for the theoretical analysis of iron loss in the magnetic cores, so, the theoretical results have been evaluated. A method is used to perform numeric calculations of the magnetic field produced by the eddy current and displacement current due to the electric field which shield the magnetic flux from the inner portion of the core cross section. The results obtained from this work could be used to evaluate the skin effect in the conductors of a winding.
Determination of the Electromagnetic Field Created by Line Current and Sheet Current Source at the Earth’s Surface  [PDF]
Ghada M. Sami, Maryam I. Al-Nami
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.513129
Abstract: The electromagnetic field that generated by line current and sheet current at the surface of the earth can be expressed in analytical form. The line current created at the earth’s surface by an infinitely long line current is given by the inverse Fourier integrals over a horizontal wave number. The sheet current can be obtained by integrating the line current expansions using a Neumann and Struve functions; these functions have known mathematical properties, including the series expansions. The series expansions are exact with neglecting the displacement currents. Assuming a uniform earth and that there is no propagation, the three nonzero field components can be expressed in terms of the Neumann and Struve functions. The integrals of line current expansions are calculated by using the numerical methods. The results represented graphically and illustrated by figures. Results can be used to evaluate numerical solutions of more complicated modeling algorithms.
Vascularity of a breast lump  [PDF]
Ghada M. Mansour
Open Journal of Obstetrics and Gynecology (OJOG) , 2013, DOI: 10.4236/ojog.2013.39120

The aim of this study was to find if Doppler ultrasound of the axillary and lateral thoracic arteries in breast cancer cases would differ from benign breast lesions and normal controls. Two hundred patients with breast lumps were included in the study. Clinical examination, mammography, breast ultrasound and fine needle aspiration or tru-cut biopsies were done for all cases. Breast ultrasound included morphological criteria of lump, lateral thoracic artery (LTA) Doppler, axillary lymph nodes, and axillary artery Doppler. All malignant cases had undergone mastectomy or lumpectomy. Lump size ranged from 1 to 5.1 (2.93 ± 1.6) cm. Eighty one cases were diagnosed as breast cancer and one hundred and nineteen cases were benign conditions. There was no significant difference regarding axillary artery and lump Doppler between the two groups while there was a difference of LTA Doppler with a cut off value of 0.67. Lateral thoracic artery resistance index measured by Doppler ultrasound was significantly lower in the malignant group in this study with a cut off value of 0.67.

Multidimensional electrostatic energy and classical renormalization  [PDF]
Sami M. ALJaber
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.27095
Abstract: Recent interest in problems in higher space di mensions is becoming increasingly important and attracted the attention of many investigators in variety of fields in physics. In this paper, the electrostatic energy of two geometries (a charged spherical shell and a nonconducting sphere) is calculated in higher space dimension, N. It is shown that as the space dimension increases, up to N = 9, the electrostatic energy of the two geometries decreases and beyond N = 9 it increases. Furthermore, we discuss a simple example which illustrates classical renormalization in electrostatics in higher dimensions.
Magnetic Properties and Hyperfine Interactions in M-Type BaFe12-2xMoxZnxO19 Hexaferrites  [PDF]
Sami H. Mahmood, Ghada H. Dushaq, Ibrahim Bsoul, Mufeed Awawdeh, Hassan K. Juwhari, Bashar I. Lahlouh, Murad A. AlDamen
Journal of Applied Mathematics and Physics (JAMP) , 2014, DOI: 10.4236/jamp.2014.25011
Abstract: A series of M-Type barium hexaferrites with the general composition BaFe12-2xMoxZnxO19 were synthesized at 1100°C by a simple wet chemical mixture route. The properties of the prepared samples were examined by X-ray diffraction, scanning electron microscopy, vibrating sample magnetometry, and Mössbauer spectroscopy. The diffraction patterns for all samples were found to agree well with the standard pattern of BaFe12O19 hexaferrite with no extraneous diffraction peaks. The products formed as well crystallized hexagonal platelet-like particles while the EDS measurements revealed the stoichiometric cationic ratios of the prepared samples. The spectral variations elucidated by Mössbauer spectroscopy were utilized to determine the different cation preferential site occupations as a function of x. Finally, the saturation magnetizations, magnetic anisotropies, and the anisotropy fields, determined from the magnetic measurements, showed consistency with the relative subspectral Mössbauer intensities and the single ion model for the anisotropy constant.
Uncertainty Relations for Some Central Potentials in N-Dimensional Space  [PDF]
Sami M. AL-Jaber
Applied Mathematics (AM) , 2016, DOI: 10.4236/am.2016.76047
Abstract: We study the uncertainty relation for three quantum systems in the N-dimensional space by using the virial theorem (VT). It is shown that this relation depends on the energy spectrum of the system as well as on the space dimension N. It is pointed out that the form of lower bound of the inequality, which is governed by the ground state, depends on the system and on the space dimension N. A comparison between our result for the lower bound and recent results, based on information-theoretic approach, is pointed out. We examine and analyze these derived uncertainties for different angular momenta with a special attention made for the large N limit.
On the Dynamics of Transition of a Classical System to Equilibrium State  [PDF]
Sami M. AL-Jaber
Applied Mathematics (AM) , 2018, DOI: 10.4236/am.2018.98062
In this work we consider a spring with one end is fixed and the other is connected to a block of mass M located on a horizontal rough table. The other side of the block is connected to a massless rope that passes over a frictionless pulley at the end of the table and a second block of mass m is hanged at the rope’s other end. For this system, we analyze and discuss its dynamics of motion as function of time when the second block is released. In particular, the displacement of the system at the end of each half-cycle of motion, the total distance, and the work done against friction are derived. An interesting result is obtained for the case when the table is frictionless. It is found that there is still a work done by friction whose magnitude is exactly the same as the stored energy in the spring.
Computational Aspects of Electromagnetic Fields near H.V. Transmission Lines  [PDF]
Ossama E. GOUDA, Ghada M. AMER, Waleed A. SALEM
Energy and Power Engineering (EPE) , 2009, DOI: 10.4236/epe.2009.12010
Abstract: Biological effects of electromagnetic fields on the human body, animals and plants have been a subject of scientific interest and public concern for their risk on the living organisms such as blood leukemia and others. The high voltage transmission and distribution lines, which pass beside some houses, factories and schools are source of electromagnetic fields. This paper presents the field calculations around and near of high voltage transmission lines 220 kV and 500kV. To calculate the induced current, the power density, the electric field and the magnetic field of grounded and ungrounded human body cylindrical model are used. MATLAB program package is used for mathematical calculation of the distribution of the EMF in human body under high voltage power transmission lines.
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