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Energy Efficiency Behavior in Heterogeneous Networks under Various Operating Situations of Cognitive Small Cells

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Wireless Engineering and Technology 2015年第1期6卷 9-23页

作者： Amr A. Fahmy Asmaa M. Saafan hesham M. el-Badawy Salwa el-Ramly Faculty of Engineering Ain-Shams University Cairo Egypt National Telecommunication Institute (NTI) Cairo Egypt

Recently, several approaches were followed for the enhancement and better resource utilization in mobile networks;this is to achieve energy efficient consumption for production and delivery of an information bit. Using Cognitive Femto cells (as a member of the small base stations’ family) proves that, it is an efficient solution for achieving this goal[1]. The use of Energy Efficiency term η has become one of the major indices for measuring the performance of these systems. η is the measure of the overall system Capacity (C)?in bps/Hz versus the Consumed Energy (E) in Joules [2]. In consistence with many researches, analytic models and empirical measurements, η will be investigated throughout the course of this work. Cognitive Base Stations (CBS) (as an element of the system model) which performs the traffic offloading operations is proved to enhance η performance. In this work, a combination of both analytic and simulation models are used to construct a practical system model. The obtained model is then used to illustrate the effect of different operational parameters that are involved in the η problem. On the other hand, the current paper tries to focus on the selection criteria that may be used to design the cooperative cognitive networks in order to achieve the best η indices. Both of CBSs radii as well as the inter-separation distances (between CBSs and MBS location) are examined to obtain best η index for different operation scenarios;in addition, both of capacity and energy consumption are taken into consideration based on practical operating measures. This work proposed several nonlinear equations with fixed parameters to be used by field engineers to achieve the results with minimum reduced computation complexity. So, the current work may be of importance for the regulator bodies as well as the cognitive mobile operators.

关键词： Energy Efficiency Capacity Energy Cognitive Radio Wireless Communications Green Radio

Hydrodynamic Modeling of the Gulf of Aqaba

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Journal of Environmental Protection 2012年第8期3卷 922-934页

作者： Ahmed Sayed Mohamed Ahmed Mohamed E. Abou-elhaggag hesham el-Badry Department of Irrigation and Hydraulics Faculty of Engineering Cairo University Senior Environmental Engineer Resources and Environment Department Dar Al-Handasah (Shair and Partners) Cairo Egypt Geotechnical and Heavy Civil Engineering Department Dar Al-Handasah (Shair and Partners) Cairo Egypt Irrigation and Hydraulic Department Ain Shams University Cairo Egypt and Principal Resources and Environment Department Dar Al-Handasah (Shair and Partners) Cairo Egypt

The Gulf of Aqaba (GOA) is unique as it contains significant percentage of the world’s natural marine biodiversity. This unique environment is potentially vulnerable to pollution particularly at its northern tip. One of the major activities affecting the environment of the gulf is the man-made desalination plants that abstract sea water and dispose desalinated brine. In this context, the paper discusses the impact of the abstract and disposal activities on the GOA environment. A 3D hydrodynamic model was developed to cover the GOA. Relevant data were collected for 3D hydrodynamic modeling construction. Delft-3D model developed by Deltares was applied in this study. The 3D model reliability was confirmed since the model results have revealed the existence of a structure of primary eddies along the axis of the Gulf which was previously reported by different researchers. Further numerical simulations were carried out by incorporating various alternatives of seawater abstraction and desalinated brine disposal off the north and north east coast of the GOA. The developed GOA hydrodynamic model, at the present stage, is preliminary where the results provide qualitative assessment on the potential impacts on the water circulation. Accordingly, this study is considered a pace ahead for a better model development and validation in the future studies.

关键词： 3D Hydrodynamic Simulations Gulf of Aqaba Circulation Delft-3D Desalination

A comparative dosimetric study of 3-dimensional conformal radical radiotherapy for bladder cancer patients versus conventional 2-dimensional radical radiotherapy in NCI-Cairo, Egypt

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The Chinese-German Journal of Clinical Oncology 2012年第11期11卷 632-634页

作者： Mohamed Mahmoud hesham A. el-Hossiny Nashaat A. Diab Marwa A. el Razek The Department of Radiation Oncology National Cancer Institute Cairo University The Departement of Radiation Physics National Cancer Institute Cairo University

Objective: This study was to compare this multiple-field conformal technique to the 2-dimensional (2D) conventional technique with respect to target volume coverage and dose to normal tissues. Methods: We conducted a single institutional prospective comparative dosimetric analysis of 15 patients who received radical radiation therapy for bladder cancer presented to Radiotherapy Department in National Cancer Institute, Cairo (Egypt), in period between November 2011 to July 2012 using 3-dimensional (3D) conformal radiotherapy technique for each patient, a second 2D conventional radiotherapy treatment plan was done, the two techniques were then compared using dose volume histogram (DVH) analysis. Results: Comparing different DVHs, it was found that the planning target volume (PTV) was adequately covered in both (3D & 2D) plans while it was demonstrated that this multiple field conformal technique produced superior distribution compared to 2D technique, with considerable sparing of rectum and to lesser extent for the head of both femora. Conclusion: From the present study, it is recommended to use 3D planning for cases of bladder cancer especially in elderly patients as it produces good coverage of the target volume as well as good sparing of the surrounding critical organs.

关键词： dosimetric study bladder cancer radiotherapy

Performance Enhancement for Adaptive Beam-Forming Application Based Hybrid PSOGSA Algorithm

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Journal of electromagnetic Analysis and Applications 2015年第4期7卷 126-133页

作者： Ahmed Magdy Osama M. el-Ghandour hesham F. A. Hamed Department of electrical Engineering Minia University Minia Egypt Department of electronics Communications and Computer Engineering Helwan University Cairo Egypt

Recently researchers were interested in hybrid algorithms for optimization problems for several communication systems. In this paper, a novel algorithm based on hybrid PSOGSA technique (combination of Gravitational Search Algorithm and Particle Swarm Optimization) is presented to enhance the performance analysis of beam-forming for smart antennas systems using N elements for Uniform Circular Array (UCA) geometry. Complex excitations (phases) of the array radiation pattern are optimized using hybrid PSOGSA technique for a set of simultaneously incident signals. Our results have shown tremendous improvement over the previous work was done using Uniform Linear Array (ULA) geometry and standard GSA in terms of normalized array factor and computational speed for normalized fitness values.

关键词： Smart Antennas UCA Optimization Techniques Beam-Forming

Performance Analysis on a Dual External Cavity Tunable Laser ECTL Source

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Journal of electromagnetic Analysis and Applications 2015年第4期7卷 134-139页

作者： Ahmed Fawzy Osama M. el-Ghandour hesham F. A. Hamed Department of electrical Engineering Minia University Minia Egypt Department of electronics Communications and Computer Engineering Helwan University Cairo Egypt

This paper presents the diffraction effects on the performance of a dual external cavity tunable laser source, whose external cavities are constructed by micro electro mechanical systems (MEMS). One of the main problems in these structures is the optical diffraction as the emitting surface of the laser diode is usually quite limited in the transverse directions. The emitted beam diffracts rapidly in the air and only a small amount of light is coupled back to the source that usually limits the tuning range of the source. Device characteristics such as tuning range, wavelength shift and sensitivity are evaluated. New expression is used and multiple reflections inside external cavities are considered. The simulation results have shown that single external cavity has limited tuning range. It is shown that multiple reflections have significant effect in our model. To get a better engineering for the dual ECTL dimensions, diffraction effects must be taken into account.

关键词： External Cavity Laser Tunable Laser MEMS Optical Diffraction

Comparative Phenomenological Description of Even-Even Isotopes at Mass Region A ≈ 70

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Journal of Applied Mathematics and Physics 2016年第3期4卷 511-518页

作者： Samir U. el-Kameesy hesham Shahbunder Karima E. Abdelmageed Heba elwany Department of Physics Faculty of Science Ain Shams University Cairo Egypt Department of Physics Collage of Sciences and Humanities Sattam Bin Abdulaziz University Kharj Saudi Arabia Department of Physics Faculty of Science Benha University Benha Egypt

In the present work the nuclear structure properties and the backbending phenomena of even-even isotopes at A ≈ 70 mass region are analyzed using two simultaneous theoretical models based on a simple modified version of the collective model predictions besides an improved version of exponential model with the inclusion of pairing correlation. In general, both models successfully describe the backbending phenomena in that region. From the comparison between the predictions of the two proposed models a firm conclusion is obtained concerning the superiority of the simple improved version of the exponential model in describing the forward and down-bending region of the φ-ω2 plots.

关键词： Energy Levels Moment of Inertia Yrast Bands Backbending Cr Ge Se and Kr Even Mass Isotopes Collective Model Exponential Model

A comparative dosimetric study of neoadjuvant 3D conformal radiotherapy for operable rectal cancer patients versus conventional 2D radiotherapy in NCI-Cairo

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The Chinese-German Journal of Clinical Oncology 2012年第4期11卷 224-228页

作者： Mohamed Mahmoud hesham A.el-Hossiny Nashaat A.Diab Marwa A.el Razek Department of Radiation Oncology National Cancer InstituteCairo University Departement of Radiation Physics National Cancer InstituteCairo University

Objective:This study was to compare this multiple-field conformal technique to the AP-PA technique with respect to target volume coverage and dose to normal ***:We conducted a single institutional prospective comparative dosimetric analysis of 22 patients who received neoadjuvant radiation therapy for rectal cancer presented to radiotherapy department in National Cancer Institute,Cairo in period between June 2010 to September 2011 using 3D conformal radiotherapy technique for each patient,a second radiotherapy treatment plan was done using an anteroposterior (AP-PA) fields,the two techniques were then compared using dose volume histogram (DVH) ***:Comparing different DVHs,it was found that the planning target volume (PTV) was adequately covered in both (3D & 2D) plans while it was demonstrates that this multiple field conformal technique produces superior distribution compared to 2D technique,with considerable sparing of bladder,ovaries and head of both ***:From the present study,it shows that it is recommended to use 3D planning for preoperative cases of cancer rectum so far it produces good coverage of the target as well as good sparing of the surrounding critical organs.

关键词： dosimetric study cancer rectum

Influence of Nanocrystalline ZrO<sub>2</sub>Additives on the Fracture Toughness and Hardness of Spark Plasma Activated Sintered WC/ZrO<sub>2</sub>Nanocomposites Obtained by Mechanical Mixing Method

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Open Journal of Composite Materials 2012年第1期2卷 1-7页

作者： M. Sherif el-Eskandarany hesham M. A. Soliman M. Omoric 不详

The present study reports the formation of ultrafine hard particles of nanocomposite WC with different additions of ZrO2 powders (0.5 - 20 vol.%). The initial mixed powders of WC with the desired ZrO2 concentrations were mechanically mixed for 360 ks (end-product) under argon gas atmosphere at room temperature, using high energy ball mill. The end-product consists of average grain size of about 17 nm in diameter. The obtained nanocomposite powders were consolidated into fully dense compact, using spark plasma sintering (SPS) technique in vacuum. The experimental results revealed that the consolidation step, which was conducted at 1673 K with uniaxial pressure ranging from 19.6 to 38.2 MPa for short time (0.18 ks), does not lead to dramatic grain growth in the powders so that the consolidated nanocomposite bulk objects maintain their nanocrystalline behavior, being fine grains with an average size of 63 nm in diameter. The relative densities of consolidated nanocomposite WC/ZrO2 materials increase from 99.1% for WC-0.5% ZrO2 to 99.93% for WC-20% ZrO2. The indentation fracture toughness of the composites can be tailored between 7.31 and 19.46 MPa/m1/2 by controlling the volume fraction of ZrO2 matrix from 0.5% to 20%. The results show that the Poisson’s ratio increased monotonically with increasing the ZrO2 concentrations to get a maximum value of 0.268 for WC-20% ZrO2. In the whole range of ZrO2 concentrations (0.5 - 20 vol.%), high hardness values (20.73 to 22.83 GPa) were achieved. The Young’s modulus tends to decrease with increasing the volume fraction of the ZrO2 matrix to reach a minimum value of 583.2 GPa for WC-20% ZrO2. These hard and tough WC/ZrO2 nanocomposites are proposed to be employed as higher abrasive-wear resistant materials.

关键词： Nanocomposite Tungsten Carbide Zirconia Spark Plasma Sintering Powder Metallurgy Mechanical Alloying Microstructure SEM HRTEM

Timed Intercourse versus Intrauterine Insemination with Mild Ovarian Stimulation for Unexplained Infertility

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Open Journal of Obstetrics and Gynecology 2022年第12期12卷 1279-1288页

作者： Hany Mahmoud Abd el Hamid Manal Abdel-Wanees Alsayed hesham Mohammed Hamed Shaimaa Belal Department of Obstetrics and Gynecology El-Sahel Teaching Hospital Cairo Egypt Department of Obstetrics and Gynecology Faculty of Medicine Helwan University Helwan Egypt

Background: Infertility is unexplained in about 22% - 28% of infertile couples. Spontaneous pregnancy may occur in them. If did not happen, Expectant management will be via clomiphene citrate (CC) administration, intrauterine insemination (IUI), and IVF & ICSI. Aim: to assess the effectiveness of intrauterine insemination with mild controlled ovarian stimulation compared with expectant management in couples with unexplained infertility more than one year. Methods: 160 couples with unexplained infertility were selected, The couples were randomly divided into two groups: Group (A) “80 couples”: Intrauterine insemination (IUI) with mild controlled ovarian stimulation (combination of CC + hMG) using prepared semen and was performed 36 hours after hCG injection, Group (B) “80 couples”: Couples had no ovulation induction. They encouraged for timed intercourse in the most fertile days of female cycle guided by folliculometry for 6 months. Data were collected quantitatively, coded and analyzed using SPSS. The power of study is 80% and 95% confidence interval. Result: The pregnancy rate was calculated in both groups: In group (A) (IUI/COS): OPR (Ongoing pregnancy rates) was 27.5% and PR (pregnancy rates)/cycle was 8.6%. In group (B) (Expectant management): OPR was 25% and PR/cycle was 5.3%. Conclusion: Mild controlled ovarian stimulation CC + hMG with IUI offers no statistical significance in terms of pregnancy outcomes over expectant management in this study however significance in the response to stimulation.

关键词： Intrauterine Insemination Ovarian Stimulation Unexplained Infertility