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Model Predictive Current Control for Low-Cost Shunt Active Power Filter

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1589-1598页

作者： Ali A.abdel-aziz mohamed A.Elgenedy Barry W.Williams the Electronic and Electrical Engineering Department Strathclyde UniversityGlasgowG11XQUK School of Computing Engineering and the Built Environment(SCEBE)Glasgow Caledonian UniversityGlasgowG40BAUK

Performance of a three-phase shunt active power filter(SAPF)relies on the capability of the controller to track the reference ***,designing an accurate current controller is crucial to guarantee satisfactory SAPF *** paper presents a model predictive current controller(MPCC)for a low-cost,four-switch,shunt active power filter for power quality improvement.A four-switch,B4,converter topology is adopted as an SAPF,hence offering a simple,robust,and low-cost *** addition,to further reduce overall cost,only two interfacing filter inductors,instead of three,are used to eliminate switching current *** proposed SAPF model MPCC is detailed for implementation,where simulation and experimental results validate effectiveness of the proposed control algorithm showing a 20%improvement in total harmonic distortion compared with a conventional hysteresis band current controller.

关键词： Four-switch converter harmonic distortion model predictive current control power quality shunt active power filter

Flavonoid chemical composition and antidiabetic potential of Brachychiton acerifolius leaves extract

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Asian Pacific Journal of Tropical Biomedicine 2017年第5期7卷 389-396页

作者： Aisha Hussein Abou Zeid mohamed Ali Farag Manal abdel aziz Hamed Zeinab abdel aziz Kandil Radwa Hassan El-Akad Hanaa mohamed El-Rafie Pharmacognosy Department National Research Centre Pharmacognosy Department College of PharmacyCairo University Therapeutic Chemistry Department National Research Centre

Objective:To evaluate Brachychiton acerifolius leaf extracts as antidiabetic potential agent and to identify the main active constituents using bioactivity guided ***:In vitro antioxidant activity was evaluated for *** different extracts using DPPH assay and vitamin C as *** activity was then determined using STZ-induced rats treated daily with ethyl acetate and 70% ethanol leaf extracts for4 weeks at a dose of 200 g/kg body weight against gliclazide reference *** glucose,a-amylase,lipid profile,liver function enzymes and oxidative stress markers were assessed along with histopathological study for liver and pancreatic *** and structural elucidation of active compounds were made using Diaion and Sephadex followed by spectral ***:The results indicated that ethyl acetate and ethanol leaf extracts exhibited the strongest antioxidant activity compared to that of vitamin C(IC500.05,0.03 and 12 mg/m L,respectively).Both extracts showed potent anti-hyperglycemic activity evidenced by a significant decrease in serum glucose levels by 82.5% and 80.9% and a-amylase by45.2% and 53.6%,as compared with gliclazide 68% and 59.4%,*** of ethanol extract resulted in the isolation of 9 flavonoids including apigenin-7-O-arhamnosyl(1/2)-b-D-glucuronide,apigenin-7-O-b-D-glucuronide,apigenin-7-O-b-Dglucoside and ***:This study highlights the potential use of *** leaf extract enriched in flavones for the treatment of diabetes that would warrant further clinical trials investigation.

关键词： STZ-induced diabetes Diaion fractionation Flavonoid glucuronides Brachychiton acerifolius

Antifouling evaluation of extracts from Red Sea soft corals against primary biofilm and biofouling

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Asian Pacific Journal of Tropical Biomedicine 2017年第11期7卷 991-997页

作者： Yosry abdel aziz Soliman Ahmed Mohammed Brahim Ahmed Hussein Moustafa mohamed abdel Fattah Hamed Marine Chemistry Lab. Marine Environment DivisionNational Institute of Oceanography and FisheriesSuezEgypt Department of Chemistry Faculty of ScienceZagazig UniversityZagazigEgypt

Objectives: To evaluate antifouling property of extracts from Red Sea soft corals against primary biofilm and ***: Seven species of soft corals Sarcophyton glaucum(a), Sinularia compressa,Sinularia cruciata(a), Heteroxenia fuscescens(a), Sarcophyton glaucum(b), Heteroxenia fuscescens(b) and Sinularia cruciata(b) were chosen to test their extracts as antibacterial and antifouling agents in Eastern Harbour of Alexandria, Mediterranean *** compounds of soft corals were extracted by using methanol and concentrated under vacuum. The residues of extracts were mixed in formulation of inert paint which consisted of rosin, chlorinated rubber and ferrous oxide against micro and macro fouling organisms. The formulated paints were then applied on PVC panels twice by brush,hanged in a steel frame and immersed in Eastern Harbour of Alexandria Mediterranean Sea followed by visual inspection and photographic ***: After 185 days of immersion in seawater, the antifouling results agreed with the antibacterial results where extracts of Sinularia compressa and Heteroxenia fuscescens(b) gave the best activity against marine fouling tubeworms and barnacles. The inhibition activity was correlated with the major functional groups(hydroxyl, amino, carbonyl,aliphatic(fatty acids), C]C of alkene or aromatic rings and CeC l of aryl halides) of the ***: The strong antifouling activity makes them promising candidates for new antifouling additives. After the screening and application of natural organic compounds from soft corals, marine organisms show activity against micro and macro fouling organisms.

关键词： Antibacterial Antifouling Paints Seawater Marine Organisms

The effect of atomic spontaneous decay on the dynamics of the negativity of the Wigner function of radiation

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Chinese Physics B 2011年第9期20卷 44-48页

作者： abdel-Baset A.mohamed Faculty of Science Assiut UniversityAssiutEgypt

The exact solution of the master equation for the case of a high-Q cavity with atomic decay is found. We use the negativity of the Wigner function （WF） as an indicator of nonclassicality. It is found that the negative values of the field WF are very sensitive to any change in the damping parameter. The atomic spontaneous decay leads to the simultaneous disappearance of both entanglement and nonclassicality of quantum states. Moreover, the purity of the field states is completely lost.

关键词： non-classicality entanglement atomic decay

Cartilage tympanoplasty in the treatment of adhesive otitis media with and without Eustachian tube balloon dilatation

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Journal of Otology 2022年第4期17卷 226-231页

作者： Ahmed abdel rahman abdel aziz Ahmed Mahmoud Youssef Mostafa mohamed Mostafa Mostafa talaat Khaled mohamed abdelzaher Ahmed Adel Sadeq Department of Otorhinolaryngology Faculty of MedicineEl MiniaEgypt Radiology Department Faculty of MedicineEl MiniaEgypt

Purpose:To compare cartilage tympanoplasty(CT)combined with eustachian tube balloon dilatation(ETBD)and cartilage tympanoplasty alone as a surgical treatment modality for adhesive otitis media(AdOM)in terms of graft healing,audiological outcomes,and impact on life style,using Chronic Otitis Media Outcome Test 15(COMOT-15).Methods:50 patients with AdOM were randomly classified into 2 groups:25 patients for cartilage tympanoplasty only(CT group)and 25 patients for cartilage tympanoplasty combined with eustachian tube balloon dilatation(CT t ETBD group).Clinical outcomes in both groups were compared at 3 and 6 months of follow ***:There was no significant difference in graft healing between the two *** COMOT-15 scores significantly decreased in both groups with a significant difference between the groups with regard to the decrease in COMOT-15 scores at 3 and 6 months of follow-up(P<0.05).Hearing improvement was achieved,as the mean preoperative ABG was 26.5±5.4 and 27.1±4.6 dB,and the mean postoperative ABG at 6 months was 19.4±4.4 and 14.6±3.9 dB in the CT and the CT t ETBD groups,*** difference in the magnitude of ABG reduction in the two groups was significant at 3 and 6 months of postoperative follow-up(P<0.05)in favour of the CT t ETBD ***:ETBD can increase the success rate of cartilage tympanoplasty in patients with AdOM by enhancing the audiological outcome and quality of life.

关键词： balloon healing otitis

Preparation and Characterization of Eco-friendly Carboxymethyl Cellulose Antimicrobial Nanocomposite Hydrogels

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Journal of Renewable Materials 2018年第5期6卷 536-547页

作者： Sawsan Dacrory Hussein Abou-Yousef Ragab E.Abou-Zeid Samir Kamel mohamed S.abdel-aziz mohamed Elbadry Cellulose and Paper Department National Research Centre33 El Buhouth St.DokkiGiza 12622Egypt Microbial Chemistry Department National Research Centre33 El Buhouth St.DokkiGiza 12622Egypt Department of Chemistry Faculty of ScienceAin Shams UniversityAbbassiaCairo 11566Egypt

Carboxymethyl cellulose hydrogels were developed through crosslinking process using eco-friendly crosslinkers such as maleic,succinic,and citric *** cellulose was prepared from the cellulosic fraction of olive industry residues.A series of hydrogels with varying crosslinker acid concentrations,reaction times,and reaction temperatures was produced to study the swelling capacities and gel fraction of the obtained *** study pertains to the preparation of antimicrobial nanocomposite hydrogels through in-situ incorporation of the silver nanoparticles during the crosslinking *** nanoparticles were prepared by reduction of AgNO3 with leaves of Ricinus *** particle size of prepared silver nanoparticles was detected by transmission electron microscopy(TEM).Chemical structure and morphological characterizations of the prepared hydrogels were performed using Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),and energy-dispersive X-ray spectroscopy(EDX).Finally,the antimicrobial activity of the loaded silver hydrogels against Gram negative(G-ve),Gram positive(G+ve),and Candida albicans yeast was demonstrated.

关键词： Hydrogel crosslinked carboxymethyl cellulose silver nanoparticles antibacterial activity

Geometric Phase of a Coupled System

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Communications in Theoretical Physics 2004年第5X期42卷 672-674页

作者： H.S.abdel-aziz MathematicsDepartment FacultyofScienceSouthValleyUniversitySohagEgypt

In this contribution, my main attention is paid to the study of the geometric phase ora two-level *** expansion of the eigenvalue and analytic information are obtained. The results are illustrated with an application ... 详细信息

关键词：几何相位二平面偏微分方程量子论

Attitude dynamics and control of spacecraft using geomagnetic Lorentz force

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Research in Astronomy and Astrophysics 2015年第1期15卷 127-144页

作者： Yehia A.abdel-aziz Muhammad Shoaib National Research Institute of Astronomy and Geophysics (NRIAG) Helwan Cairo 11721Egypt University of Hail Department of Mathematics PO BOX 2440 Kingdom of Saudi Arabia

Attitude stabilization of a charged rigid spacecraft in Low Earth Orbit using torques due to Lorentz force in pitch and roll directions is considered. A spacecraft that generates an electrostatic charge on its surface in the Earth’s magnetic field will be subject to perturbations from the Lorentz force. The Lorentz force acting on an electrostatically charged spacecraft may provide a useful thrust for controlling a spacecraft’s orientation. We assume that the spacecraft is moving in the Earth’s magnetic field in an elliptical orbit under the effects of gravitational, geomagnetic and Lorentz torques. The magnetic field of the Earth is modeled as a non-tilted dipole.A model incorporating all Lorentz torques as a function of orbital elements has been developed on the basis of electric and magnetic fields. The stability of the spacecraft orientation is investigated both analytically and numerically. The existence and stability of equilibrium positions is investigated for different values of the charge to mass ratio（α＊）. Stable orbits are identified for various values of α＊. The main parameters for stabilization of the spacecraft are α＊and the difference between the components of the moment of inertia for the spacecraft.

关键词： space vehicles atmospheric effects celestial mechanics kinematics and dynamics

Equilibria of a charged artificial satellite subject to gravitational and Lorentz torques

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Research in Astronomy and Astrophysics 2014年第7期14卷 891-902页

作者： Yehia A.abdel-aziz Muhammad Shoaib National Research Institute of Astronomy and Geophysics (NRIAG) HelwanCairo 11721Egypt University of Hail Department of MathematicsPO Box 2440Kingdom of Saudi Arabia

The attitude dynamics of a rigid artificial satellite subject to a gravity gradient and Lorentz torques in a circular orbit are considered. Lorentz torque is developed on the basis of the electrodynamic effects of the Lorentz force acting on the charged satellite＇s surface. We assume that the satellite is moving in a Low Earth Orbit in the geomagnetic field, which is considered to be a dipole. Our model of torque due to the Lorentz force is developed for an artificial satellite with a general shape, and the nonlinear differential equations of Euler are used to describe its attitude orientation. All equilibrium positions are determined and conditions for their existence are *** numerical results show that the charge q and radius ρ0of the center of charge for the satellite provide a certain type of semi-passive control for the attitude of the satellite. The technique for this kind of control would be to increase or decrease the electrostatic screening on the satellite. The results obtained confirm that the change in charge can affect the magnitude of the Lorentz torque, which can also affect control of the satellite. Moreover, the relationship between magnitude of the Lorentz torque and inclination of the orbit is investigated.

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