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Search Results: 1 - 10 of 401718 matches for " Samy M. Ghania "
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Internal Fault/In-Rush Currents Discrimination Based on Fuzzy/Wavelet Transform in Power Transformers
Samy M. Ghania
International Journal of Electrical and Power Engineering , 2012, DOI: 10.3923/ijepe.2012.100.110
Abstract: Transformers are major elements of any power systems. Normally they must be properly protected by differential relays. This protection system should be precise and reliable via implementation of strong algorithms that able to differentiate between faulted and unfaulted condition to fully grantee of power continuity. This system should be able to detect the non-faulted condition such as inrush currents which should not be activated in this condition meanwhile it must be activated in internal fault conditions as fast as possible. This study presents an approach for differential protection of power transformers this uses Wavelet Transform (WT) and Adaptive Network-based Fuzzy Inference System (ANFIS) to discriminate internal faults from inrush currents. The proposed algorithm has been designed based on the differences between both amplitudes of wavelet transform coefficients in a specific frequency band and rising and decaying duration generated by faults and inrush currents. The performance of this simulated model is demonstrated by simulation of different faults and switching conditions on a power transformer using Matlab/Simulink software package.
Three-Dimensional Electric Field Analysis and Measurement Inside High Voltage Substations
Sayed A. Word,Samy M. Ghania,Essam M. Shaalan
International Journal of Electrical and Power Engineering , 2012, DOI: 10.3923/ijepe.2011.150.156
Abstract: The exposure to electric field now-a-days is an integral part in the design area of electrical power apparatus and systems. Moreover, the electric field produced by power lines, busbars and all high voltage equipments inside High Voltage (HV) substations is receiving more and more concerns to guarantee the life insurance of workers inside these substations. Therefore, the possible effect of the electric field exposure raises the question of how electric fields are created and what effects they may have. Therefore, monitoring the electric field inside Air Insulated Substation (AIS) and Gas Insulated Substation (GIS) is achieved in this study. This study not only depict the electric field distribution inside AIS using Charge Simulation Method (CSM) in three Dimensional (3D) and many Matlab M-files modeling programs developed by the researchers but also measured it inside AIS under 500 and 220 kV busbars and inside GIS nearby the 500, 220 and 66 kV busbars. The simulation results of AIS are compared with the measured values and the simulation results are matched with the measured values with very small tolerance about 1.4% for 220 kV model and about 4.4% for 500 kV model.
Effect of Annealing Temperature on Prepared Nanoparticles Li-Ferrite Using Positron Annihilation Lifetime Technique  [PDF]
A. M. Samy, E. Hassan Aly
Materials Sciences and Applications (MSA) , 2015, DOI: 10.4236/msa.2015.65047
Abstract: Lithium ferrite nanoparticles were synthesized by a sol-gel auto-combustion method. For prepared samples, the nanograins were increased with increasing the annealing temperature. Positron annihilation lifetime spectroscopy (PALS) was used to study defects at different sites for nanograins Li-ferrites. The analysis of the PAL spectrum indicated two lifetime components τ1 and τ2 for the annihilation of the positrons, and their corresponding relative intensities I1% and I2%. For nanoparticles Li-ferrite there are correlations between: 1) I2, τ2, annealing temperature and the total porosity (Pt) with the grain size; 2) I1, μi, Ms and the homogeneity with grain size.
Molecular investigation of the Arabian horse breeds of racing, productivity and longevity  [PDF]
Mohamed M. Ahmed, Sayed A. M. Amer, Samy. M. Sayed
Advances in Bioscience and Biotechnology (ABB) , 2011, DOI: 10.4236/abb.2011.26066
Abstract: The Arabian; horse Equus caballus is belonging to family Equidae that all of its species are in danger of extinction. We sequenced 1059 nucleotides from three mitochondrial DNA protein coding genes for some breeds of the Arabian and English horses designated for race, productivity and longevity in order to investigate their genetic variation. The sequenced genes were NADH dehydrogenase subunit 2 (ND2), cyto-chrome C oxidase subunit 1 (CO1) and ATPase subunit 6 (ATP6). ATP6 discriminated among the different breeds where seven substitutions were recorded of which 2 were non-synonymous. The other loci recoded 8 synonymous substitutions of transitions most of which were among the breeds of longevity. The data of CO1 gene were used to construct the relationship of the Arabian horse to the thoroughbreds. Maximum-likelihood (ML) and Neighbor-joining (NJ) analytical methods were used. The two analytical methods showed clustering of the Arabian breeds in one group and the non-sister relationship within the thoroughbreds. One of the thoroughbreds clustered within the Arabian breeds suggesting the possibility of their out breeding. Increasing tendency in the variation of the studied genes was proportional to the utility of these genes in energy production within the mitochondria. The present study is therefore a preliminary step in the conservational efforts of the Arabian horse of equestrian..
Induction of Labor at 39 Weeks versus Expecting Labour till 41 Weeks: Randomized Controlled Trial on Class I Obese Egyptian Women, with Mode of Delivery Being a Study Endpoint  [PDF]
M. Samy, Sarah Safwat
Open Journal of Obstetrics and Gynecology (OJOG) , 2019, DOI: 10.4236/ojog.2019.96085
Abstract: Background: Maternal obesity is reported to be associated with increased incidence of gestational diabetes mellitus and hypertension. These cause failure of labour induction, leading to higher incidence of cesarean section (CS). The aim of this study was to assess which reduces CS rate, labor induction at 39 weeks or leaving women for spontaneous labor onset till 41 weeks. Methodology: A randomized controlled trial was conducted in Ain Shams Maternity Hospital in Egypt from 2016 to 2018. Study population consisted of 200 term primigravida pregnant obese women delivered in Ain Shams Maternity Hospital. They were divided into two groups: Group A: induction of labor at 39 + 0 weeks (n = 100) by vaginal administration of 25 μg misoprostol (PGE1) every 6 hours for 5 doses; Group B: waiting spontaneous labor onset till 41 + 0 weeks (n = 100), and if no spontaneous labor occurred at 41 weeks, induction was performed in the same way. Results: Induction (Group A) vs. waiting spontaneous labor (Group B) showed the followings, which were significant: CS: 22% vs 39%, p = 0.009; maternal birth injury: 4% vs 12%, p = 0.037; non-assisted vaginal deliveries: 93.6% vs 78.7%, p = 0.034; APGAR scores at 1 & 5 min: 7.6 ± 0.8 vs 7.3 ± 1.1 p = 0.038, 8.4 ± 1.0 vs 8.1 ± 1.3 p = 0.040, respectively; birth weight; 3.3 ± 0.1 vs 3.5 ± 0.2 kg, p < 0.001. The following did not show significance between Group A vs Group B but Group A showed lower incidence; postpartum hemorrhage: 3% vs 5%, blood transfusion: 1% vs 3%. Conclusion: CS rate was significantly lower in women with induction of labor at 39 weeks than those waiting for spontaneous labor onset till 41 weeks in obese Egyptian pregnant women.
Pathogenic Bacteria Associated with Different Public Environmental Sites in Mecca City  [PDF]
Samy S. Ashgar, Hamdy M. El-Said
Open Journal of Medical Microbiology (OJMM) , 2012, DOI: 10.4236/ojmm.2012.24020
Abstract: Background: The hygiene of environmental surfaces from shopping, ATM machines, telephones and computers and miscellaneous sites play role in spreading fecal and total coliform bacteria as well as pathogenic bacteria. Objectives: This study addresses the contaminated common sites by pathogenic or potentially pathogenic bacteria in Mecca, SA. Materials and Methods: A total 648 swab samples were collected and analyzed for presence or absence of pathogenic bacteria. Results: Of the total samples 422 were negative bacterial count (71%) and 226 (29%) were positive. All collected samples (100%) of glass windows in the fish markets were bacterial counted; most dominated was Bacillus spp. (n = 97) and the highest population of species was Enterococcus faecalis (n = 40) and E. coli (n = 16). Conclusion: Some public sites were very contaminated with different types of fecal coliform group of bacteria such as shopping cart handles, inner surfaces and child seats in supermarkets, and the glass windows in the fish market. Acinetobacter haemolyticus and other hemolytic bacteria were isolated from more than site.
Evaluation of Venous Ammonia Level, Splenic Longitudinal Diameter, Portal Vein and Splenic Vein Diameters as Non-Invasive Indicators for the Presence of Portosystemic Collaterals in Egyptian Cirrhotic Patients  [PDF]
Mohamed F. Montasser, Heba M. Abdella, Amir Helmy Samy
Open Journal of Gastroenterology (OJGas) , 2014, DOI: 10.4236/ojgas.2014.46039
Abstract: Introduction and Aim of the Work: The identification of cirrhotic patients with esophageal varices or other portosystemic collateral by non-invasive means is appealing in that it could decrease the necessity of endoscopic screening. This study was to evaluate the diagnostic utility of venous ammonia level with other ultrasonographic parameters as non-invasive markers for the presence of portosystemic shunts. Patients and methods: The study included 3 groups of Child Pugh class A and early B patients. Group (A): 25 patients with evidence of both esophageal varices and portosystemic collaterals; group (B) 25 patients with neither evidence of varices nor portosystemic collaterals and group (C): 25 patients with evidence of varices but no collaterals. Measurement of venous ammonia level was done for all patients. Results: serum ammonia level was significantly higher in group A (222.8 ± 54 μg/dL) than that in group B (85 ± 21.1 μg/dL) and group C (148.2 ± 19.6 μg/dL). The cut-off value of serum ammonia level 113 μg/dL was a good predictor for the presence of esophageal varices, while the cut-off value of serum ammonia level at 133 μg/dL was a good predictor for the presence of both esophageal varices and abdominal collaterals. Combination of portal vein diameter > 13mm + splenic vein diameter > 8.9mm + ammonia level > 133 μg/dL gives 100% of sensitivity and 96% of specificity for the prediction of the presence of portosystemic shunts. Conclusion: Determination of serum ammonia level, splenic, portal vein and splenic vein diameters are considered as good predictors for the presence of portosystemic shunts in patients with liver cirrhosis.
Design Methodology of a Micro-Scale 2-DOF Energy Harvesting Device for Low Frequency and Wide Bandwidth  [PDF]
Mahmoud M. Magdy, Ahmed M. R. Fath El-Bab, Samy F. M. Assal
Journal of Sensor Technology (JST) , 2014, DOI: 10.4236/jst.2014.42005
Abstract:
A detailed design methodology of a micro-scale 2-DOF energy harvesting device that can harvest human motion energy of low frequency and wide bandwidth is developed. Based on the concept of the 2-DOF vibration absorber, device parameters are selected to harvest energy at low frequency of 1-10 Hz and wide bandwidth with ±20% of the mean frequency, which matches the human motion. The device dimensions are limited to 40 × 30 × 10 mm3 to fit with the human wrist size. Then, a finite element model is developed to investigate the system performance with the selected parameters. When subjected to harmonic excitation of 1 g, the proposed 2-DOF device is able to provide a power of at least 10 μW in between the two close resonant peaks of 4 Hz and 6 Hz, which is the target frequency range. The device shows very high power per square frequency compared with the reported harvesters.
New Method for Preparation of 1-Amidoalkyl-2-Naphthols via Multicomponent Condensation Reaction Utilizing Tetrachlorosilane under Solvent Free Conditions  [PDF]
Samy B. Said, Mohammad M. A. Mashaly, Ahmed M. Sheta, Saad S. Elmorsy
International Journal of Organic Chemistry (IJOC) , 2015, DOI: 10.4236/ijoc.2015.53019
Abstract: An efficient and direct procedure for the synthesis of amidoalkylnaphthol derivatives employing a multi-component and one-pot condensation reaction of 2-naphthol, aromatic aldehyde and ace-tonitrile in the presence of tetrachlorosilane (TCS). A binary reagent from (TCS)/ZnCl2 was used upon applying benzonitrile.
Bionomics of phlebotomine sand flies (Diptera: Psychodidae) in the province of Al-Baha, Saudi Arabia
Doha, Said Abdallah;Samy, Abdallah M;
Memórias do Instituto Oswaldo Cruz , 2010, DOI: 10.1590/S0074-02762010000700002
Abstract: the bionomics of phlebotomine sand flies (diptera: psychodidae) were studied for two successive years (january 1996-december 1997) at 12 collecting stations representing six sectors of the province of al-baha, saudi arabia. the predominant species was phlebotomus bergeroti (41.7%), followed by lesser numbers of phlebotomus sergenti (11%), phlebotomus arabicus (10.6%), sergentomyia tiberiadis (10.5%), phlebotomus papatasi (10.2%), sergentomyia antennata (9.6%), phlebotomus alexandri (3%), phlebotomus orientalis (2.3%) and sergentomyia clydei (1.1%). the distribution of the collected species including species that are elsewhere known to act as vectors of human cutaneous leishmaniasis were distributed across different altitudes in al-baha. p. bergeroti, p. papatasi and p. arabicus were more abundant indoors; however, p. sergenti was more abundant outdoors. sand fly populations exhibited three patterns of seasonal abundance in terms of their monthly activity. p. bergeroti, p. sergenti and p. arabicus were found to be naturally infected with leishmania-like flagellates at an infection rate of 0.2%.
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