检索结果-南通市图书馆

Journal of Electronics Cooling and Thermal Control 2017年第3期7卷 63-77页

作者： ibrahim m.abdel-motaleb Syed m.Qadri Department of Electrical Engineering Northern Illinois UniversityDeKalbILUSA

We report on the fabrication and characterization of multi-leg bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3) thermoelectric devices. The two materials were deposited, on top of SiO2/Si substrates, using Pulsed Laser Deposition (PLD). The SiO2 layer was used to provide insulation between the devices and the Si wafer. Copper was used as an electrical connector and a contact for the junctions. Four devices were built, where the Bi2Te3 and Sb2Te3 were deposited at substrate temperatures of 100°C, 200°C, 300°C and 400°C. The results show that the device has a voltage sensitivity of up to 146 μV/K and temperature sensitivity of 6.8 K/mV.

关键词： Thermoelectric Devices Bismuth Telluride Bi2Te3 Antimony Telluride Sb2Te3 Pulsed Laser Deposition PLD Seebeck Effect

Congruent Feature Selection method to Improve the Efficacy of machine Learning-Based Classification in medical Image Processing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer modeling in Engineering & Sciences 2025年第1期142卷 357-384页

作者： mohd Anjum Naoufel Kraiem Hong min Ashit Kumar Dutta Yousef ibrahim Daradkeh Department of Computer Engineering Aligarh Muslim UniversityAligarh202002India College of Computer Science King Khalid UniversityAbha61413Saudi Arabia School of Computing Gachon UniversitySeongnam13120Republic of Korea Department of Computer Science and Information Systems College of Applied SciencesAlMaarefa UniversityRiyadh13713Saudi Arabia Department of Computer Engineering and Information College of Engineering in Wadi AlddawasirPrince Sattam bin Abdulaziz UniversityAl-Kharj16273Saudi Arabia

machine learning(mL)is increasingly applied for medical image processing with appropriate learning *** applications include analyzing images of various organs,such as the brain,lung,eye,etc.,to identify specific flaws/diseases for *** primary concern of mL applications is the precise selection of flexible image features for pattern detection and region *** of the extracted image features are irrelevant and lead to an increase in computation ***,this article uses an analytical learning paradigm to design a Congruent Feature Selection method to select the most relevant image *** process trains the learning paradigm using similarity and correlation-based features over different textural intensities and pixel *** similarity between the pixels over the various distribution patterns with high indexes is recommended for disease ***,the correlation based on intensity and distribution is analyzed to improve the feature selection ***,the more congruent pixels are sorted in the descending order of the selection,which identifies better regions than the ***,the learning paradigm is trained using intensity and region-based similarity to maximize the chances of ***,the probability of feature selection,regardless of the textures and medical image patterns,is *** process enhances the performance of mL applications for different medical image *** proposed method improves the accuracy,precision,and training rate by 13.19%,10.69%,and 11.06%,respectively,compared to other models for the selected *** mean error and selection time is also reduced by 12.56%and 13.56%,respectively,compared to the same models and dataset.

关键词： Computer vision feature selection machine learning region detection texture analysis image classification medical images

Investigation of Inhomogeneity in Single Crystal SiC Wafers Using C-Scan Acoustic Scanning microscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Crystal Structure Theory and Applications 2020年第1期9卷 1-11页

作者： ibrahim m. abdel-motaleb Department of Electrical Engineering Northern Illinois University DeKalb IL USA

In this work, C-Scan Acoustic Scanning microscopy (ASm) is used to map the defects of three SiC samples. The acoustic images indicate that numerous defects with different shapes and area?sexist in the wafers. Some of the defects have areas of more than 100,000 μm2. The number of defects ranges from 1 to 50 defects/wafer. Defect mapping is essential for defect repairing or avoidance.?This work shows that ASm can locate the precise positions of the crystallographic defects, which?enables?defects repair and yield enhancement.

关键词： SiC Lattice Defects Acoustic Scanning microscopy ASm Wafers

A ROUGH SET APPROACH TO FEATURE SELECTION BASED ON SCATTER SEARCH mETAHEURISTIC

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2014年第1期27卷 157-168页

作者： WANG Jue ZHANG Qi abdel-RAHmAN Hedar abdel-mONEm m ibrahim Center for Forecasting Science Academy of Mathematics and System Science Chinese Academy of ScienceBeijing 100190 China. Department of Computer Science Faculty of Computers and Information Assiut University Assiut 71516Egypt.

Rough set theory is an effective method to feature selection, which has recently fascinated many researchers. The essence of rough set approach to feature selection is to find a subset of the original features. It is, however, an NP-hard problem finding a minimal subset of the features, and it is necessary to investigate effective and efficient heuristic algorithms. This paper presents a novel rough set approach to feature selection based on scatter search metaheuristic. The proposed method, called scatter search rough set attribute reduction （SSAR）, is illustrated by 13 well known datasets from UCI machine learning repository. The proposed heuristic strategy is compared with typical attribute reduction methods including genetic algorithm, ant colony, simulated annealing, and Tabu search. Computational results demonstrate that our algorithm can provide efficient solution to find a minimal subset of the features and show promising and competitive performance on the considered datasets.

关键词： Attribute reduction computational intelligence metaheuristics rough set scatter search.

SiC THz Sensors for Harsh Environment Applications

在线全文

学校读者我要写书评

暂无评论

Open Journal of Antennas and Propagation 2021年第3期9卷 45-55页

作者： ibrahim abdel-motaleb Sai Dittakavi Department of Electrical Engineering Northern Illinois University DeKalb USA

Gold (Au) and ITO bow-tie antenna sensors built on silicon carbide (SiC) substrates are designed and analyzed using the Comsol multiphysics program. The study shows that the output electric field across the antenna gap decreases with gap separation but increases with metal thickness. The antenna width does not directly affect the output, but it indirectly increases the output as a result of increased radiation absorption and conductivity. The length does not affect the strength of the output, but it affects the resonant frequency. The output field from ITO antennas is found to be much lower than that from Au antennas, which can be attributed, in part, to the lower conductivity of ITO. Using the bow-tie antenna structure, it is possible to build either narrowband or wideband antenna or sensor arrays, for THz applications.

关键词： Silicon Carbide SiC Sensor Terahertz THz ITO Numerical Analysis COmSOL

On the nonclassical dynamics of cavity-assisted four-channel nonlinear coupler

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第11期27卷 498-505页

作者： Rafael Julius abdel-Baset m A ibrahim Pankaj Kumar Choudhury Hichem Eleuch Faculty of Applied Sciences Universiti Teknologi MARA (UiTM) Faculty of Applied Sciences Universiti Teknologi Mara (UiTM) Perak Tapah Campus Institute of microengineering and Nanoelectronics Universiti Kebangsaan Malaysia Department of Applied Sciences and mathematics College of Arts and Sciences Abu Dhabi University Institute for Quantum Science and Engineering Texas A&M University College Station

The non-classical properties of light propagating in four-channel Kerr waveguides, confined in an optical cavity, are studied. The solution to the Hamiltonian of field operators is obtained semi-analytically by using symmetrically ordered phase-space representation. Full quantum analysis of the input coherent fields displays a strong transition of photon property between the super-Poissonian and sub-Poissonian statistics. It is found that the cavity-assisted multichannel system exhibits enhanced squeezing both in single-and compound-mode. This multichannel system may be utilized as an efficient quantumlight generator.

关键词： squeezed states Kerr effects Langevin equation

multi-Physics Numerical Simulation of Thermoelectric Devices

在线全文

学校读者我要写书评

暂无评论

Journal of Electronics Cooling and Thermal Control 2017年第4期7卷 123-135页

作者： ibrahim m. abdel-motaleb Syed m. Qadri Department of Electrical Engineering Northern Illinois University DeKalb IL USA

To optimize the performance of a thermoelectric device for a specific application, the device should be uniquely designed for the application. Achieving an optimum design requires accurate measurements and credible analysis to evaluate the performance of the device and its relationship with the device parameters. To do that, we designed, fabricated, and tested four devices based on Bi2Te3 and Sb2Te3. To evaluate the accuracy of our analysis, experimental measurements were compared with the numerical simulation performed using COmSOLTm. The two sets of results were found to be in full agreement. This is a proof of the accuracy of our experimental measurements and the credibility of our simulation. The study shows that testing or simulating the devices without heat sink will lead to skewed results. This is because the junction will not hold its temperatures value, but will, instead, automatically change its value to the direction of thermal equilibrium. The study shows also that there is no reciprocity between the input and the output characteristics of the devices. Therefore, a device optimized for cooling and heating may not be automatically optimized for energy harvesting. For heating and cooling, temperature sensitivity should be optimized;while for energy harvesting, voltage sensitivity should be optimized. Using heat sink, our devices achieved a voltage sensitivity of 187.77 μV/K and a temperature sensitivity of 6.12 K/mV.

关键词： Thermoelectric Devices multi-Leg Devices Bi2Te3 Sb2Te3 COmSOL Fi-nite Element Simulation Voltage Sensitivity Temperature Sensitivity

Utilization of iron oxide bearing pellets waste for preparing hard and soft ferromagnetic glass ceramics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2014年第4期3卷 259-268页

作者： Salwa A.m.abdel-HAmEED ibrahim m.HAmED Nehal A.ERFAN Glass Research Department National Research CenterDokkiCairoEgypt Chemical Engineering Department Faculty of EngineeringMinia UniversityMiniaEgyp

About 8%of the imported iron oxide pellets burdens to Egypt are *** this paper,broken pellets waste(BPW)is used as raw material for the preparation of hard magnetic glass ceramics(HmGC)as well as soft magnetic glass ceramics(SmGC).About 54 wt%and 37 wt%of BPW are used to prepare SmGC and HmGC,*** thermal analysis(DTA)reveals two broad exothermic peaks for HmGC at 591℃and 697℃,whereas one exothermic peak at 820℃is detected for SmGC.X-ray diffraction(XRD)shows the crystallization of hematite as the sol phase in BPW,and meanwhile,Zn-ferrite and Ba-hexaferrite are identified in SmGC and HmGC,*** electron microscopy(TEm)reveals the crystallization of nanosize particles of~20 nm for SmGC and~12 nm for *** scanning magnetometer(VSm)reveals an increase in saturation magnetization from~1 emu/g for BPW to~77 emu/g for SmGC and 21 emu/g for HmGC.

关键词： magnetic materials nanostructure pellets waste

Geochemistry and spectrometric prospection of younger granites and granitic pegmatites bearing uranium mineralization at *** El Rakeb area, Central Eastern Desert, Egypt

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geochimica 2021年第4期40卷 575-601页

作者： Gehad m.Saleh Bahaa m.Emad ibrahim B.abdel Kader Nuclear materials Authority El MaadiP.O.Box 530CairoEgypt

The present study deals with the detailed field geology,mineralogy,geochemistry,and spectrometric prospection of rare metals and radioactive minerals associated with granitic pegmatites in the Gabal Um LassafAbu Dob-Um Atelia-Kadabora-Kab El Rakeb area(LDAKK),which are situated in the central Eastern Desert of *** study area is composed of granodiorites and *** latter is dissected by granitic pegmatites with a discriminatory distribution of economically important mineralization(rare-metals and U-Th minerals).The granitic pegmatites display a zoning structure composed of feldspar-rich zones enveloping pockets of mica(mostly muscovite) and all zoning internal quartz ***,the monzogranite and granitic pegmatites are composed of potash-feldspar,albite,and quartz with a small amount of biotite and *** mineralogical investigation of the highly radioactive zones in the granitic pegmatite shows enrichment in kasolite,uranothorite,thorite,xenotime,columbite,zircon,bismuth,and ***,the granitic pegmatites are enriched with high field strength elements(HFSE;Zr,Nb,Th,and U) and ion lithophilic elements(LILE;Rb,and Pb) and depleted in Ba,Sr,and *** are strongly peralkaline to metalumainous except for two samples,which are *** are formed by partial melting of metagreywackes at *** studied granitic pegmatites could belong to the NYF family(Niobium-Yttrium-Fluorine family) according to the geochemistry of the trace *** studied granitic pegmatites show deep negative Eu anomaly and display a strong m-type tetrad effect of rare earth *** field spectroscopy measurements showed the localization of the radiometric anomalous associated with the granitic pegmatites,which are intruded in the granitic host *** eU and eTh contents reached up to 316 and 1367 ppm,*** and thorium occurrences in the investigated granitic pegmatites are related to magmatic(syngenetic)ori

关键词： Geochemistry Gabal Um Lassaf-Abu Dob-Um Atelia-Kadabora-Kab El Rakeb area(LDAKK) Uranium REE Egypt

Electromagnetic effects on the orbital motion of a charged spacecraft

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2014年第5期14卷 589-600页

作者： Yehia Ahmed abdel-Aziz Khalil ibrahim Khalil National Research Institute of Astronomy and Geophysics (NRIAG) Helwan Cairo 11721Egypt Department of mathematics Hail University Hail 2440 Kingdom of Saudi Arabia

This paper deals with the effects of electromagnetic forces on the orbital motion of a spacecraft. The electrostatic charge which a spacecraft generates on its surface in the Earth＇s magnetic field will be subject to a perturbative Lorentz force. A model incorporating all Lorentz forces as a function of orbital elements has been developed on the basis of magnetic and electric fields. This Lorentz force can be used to modify or perturb the spacecraft＇s orbits. Lagrange＇s planetary equations in the Gauss variational form are derived using the Lorentz force as a perturbation to a Keplerian orbit. Our approach incorporates orbital inclination and the true anomaly. The numer- ical results of Lagrange＇s planetary equations for some operational satellites show that the perturbation in the orbital elements of the spacecraft is a second order perturba- tion for a certain value of charge. The effect of the Lorentz force due to its magnetic component is three times that of the Lorentz force due to its electric component. In addition, the numerical results confirm that the strong effects are due to the Lorentz force in a polar orbit, which is consistent with realistic physical phenomena that occur in polar orbits. The results confirm that the magnitude of the Lorentz force depends on the amount of charge. This means that we can use artificial charging to create a force to control the attitude and orbital motion of a spacecraft.

关键词： space vehicles -- atmospheric effects -- celestial mechanics -- kine-matics and dynamics