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Search Results: 1 - 10 of 13338 matches for " Fawzi El Desouki "
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Dielectric and Magnetic Properties of Nano-Structure BiFeO3 Doped with Different Concentrations of Co Ions Prepared by Sol-Gel Method  [PDF]
Inas Kamal Batttisha, Ibrahim Sayed Ahmed Farag, Mostafa Kamal, Mohamed Ali Ahmed, Emad Girgis, Fawzi El Desouki, Hesham Azmi El Meleegi, Fawzi El Desouki
New Journal of Glass and Ceramics (NJGC) , 2015, DOI: 10.4236/njgc.2015.53008
Abstract: BiFe1-xCoxO3 (x = 0, 0.03, 0.05 and 0.1) symbolic as (BFO, BF3CO, BF5CO and BF10CO) in powder form has been prepared by sol-gel technique using ethylenediamine tetraacetic acid (EDTA) as a chelating agent. X-ray diffraction (XRD) and FTIR analysis showed rhombohedra distorted BiFeO3 structure with compressive lattice distortion induced by the Co substitution at Fe sites. The transmission electron microscope (TEM) shows irregular particles. The additive of cobalt oxide has led to grains refining giving the following crystallite sizes of 18 nm for BF5Co. The scanning electron microscope (SEM) study reveals that the samples morphology shows relatively uniform grain size distribution. The dielectric properties of BiFeO3 nano-particles in the frequency range of 1 up to 5 MHz at RT revealed that the A.C. conductivity of the prepared samples reaches its maximum value in BF5CO. By decreasing BiFeO3 particle size as a result of doping with different Co ion concentrations, an enhancement in magnetization and a simultaneous suppression in current leakage occurred. The remnant magnetization Mr of BiFe1-xCoxO3 (x = 0, 0.03, 0.05, 0.1) ceramics significantly enhanced, which provides potential applications in information storage.
Wavelet Entropy Based Algorithm for Fault Detection and Classification in FACTS Compensated Transmission Line  [PDF]
Amany M. El-Zonkoly, Hussein Desouki
Energy and Power Engineering (EPE) , 2011, DOI: 10.4236/epe.2011.31006
Abstract: Distance protection of transmission lines including advanced flexible AC transmission system (FACTS) de-vices has been a very challenging task. FACTS devices of interest in this paper are static synchronous series compensators (SSSC) and unified power flow controller (UPFC). In this paper, a new algorithm is proposed to detect and classify the fault and identify the fault position in a transmission line with respect to a FACTS device placed in the midpoint of the transmission line. Discrete wavelet transformation and wavelet entropy calculations are used to analyze during fault current and voltage signals of the compensated transmission line. The proposed algorithm is very simple and accurate in fault detection and classification. A variety of fault cases and simulation results are introduced to show the effectiveness of such algorithm.
Driving Circuitry for Focused Ultrasound Noninvasive Surgery and Drug Delivery Applications
Munir M. El-Desouki,Kullervo Hynynen
Sensors , 2011, DOI: 10.3390/s110100539
Abstract: Recent works on focused ultrasound (FUS) have shown great promise for cancer therapy. Researchers are continuously trying to improve system performance, which is resulting in an increased complexity that is more apparent when using multi-element phased array systems. This has led to significant efforts to reduce system size and cost by relying on system integration. Although ideas from other fields such as microwave antenna phased arrays can be adopted in FUS, the application requirements differ significantly since the frequency range used in FUS is much lower. In this paper, we review recent efforts to design efficient power monitoring, phase shifting and output driving techniques used specifically for high intensity focused ultrasound (HIFU).
Power Quality Assessment via Coordinated Voltage Control in Distributed Power Generation
Shady A. El-Kashlan,Hussien El-Desouki Saied
International Journal of Electrical and Power Engineering , 2012,
Abstract: Rapidly increasing share of Distributed Generation (DG) in distribution networks introduced the need for active distribution network operation. As current distribution networks were not designed to integrate the power generation, the DG introduced many technical challenges in sense of power quality, network planning, protection schemes, voltage stabilit. This study presents the advantages of active approach in distribution network operation. The study focuses on a voltage quality problem and introduces the coordinated voltage control technique to increase the share of DG in distribution networks and at the same time supply the customers with the required voltage quality.
Hepatobiliary scintigraphy in the diagnosis of choledochal cysts in children
El Desouki Mahmoud,Mohamadiyeh Mohamad,Al Rabeaah Abdullah,Othman Saleh
Saudi Journal of Gastroenterology , 1997,
Abstract: The objective is to present the usefulness of hepatobiliary scintigraphy in the investigation of children with suspected choledochal cysts through our experience in King Khalid University Hospital at King Saud University, Riyadh. Seven patients aged between I and 10 years (average 4.8 yrs) comprising six females and one male were investigated. Laboratory tests, abdominal Ultrasound and/or CT, and cholangiography were performed whenever indicated. Persistent activity in a dilated common bile duct, with or without dilatation of intrahepatic bile ducts, was considered a positive indicator for choledochal cyst disease. Four children with cystic dilatation (type I) were diagnosed by hepatobiliary scintigraphy, one saccular (type II), and two cases of Caroli′s disease (type V). The diagnosis of choledochal cyst was proven by surgery with histological confirmation. Visualization of the gallbladder occurred in one case only. The common bile duct was seen in four cases. Late activity in the bowel was noted in two cases.
New Non-Invasive Index for Detecting Esophageal Varices in Patients with Liver Cirrhosis  [PDF]
Mona A. Amin, Ahmed E. El-Badry, May M. Fawzi, Dalia A. Muhammed, Shorouk M. Moussa
Open Journal of Internal Medicine (OJIM) , 2016, DOI: 10.4236/ojim.2016.64016
Abstract: Introduction: Many studies have shown that clinical, biochemical and ultrasonographic parameter are predictive of the presence and grading of esophageal varices. Aim of Study: Validation of a noninvasive test called P2/MS and its comparison with other noninvasive tests for the detection of high risk esophageal varices. Patients and Methods: We prospectively enrolled 125 consecutive patients with liver cirrhosis. Complete blood count [CBC], Platelet count by direct method, Liver functions [serum bilirubin, AST, ALT, prothrombin time and concentration and serum albumin], kidney functions, hepatitis markers for B & C, abdominal ultrasonography and upper gastrointestinal endoscopy were done for each patient. Calculation of P2/MS [Platelet count)2/{monocyte fraction (%) × segmented neutrophil fraction (%)], API [age-platelet index], APRI [AST-to-platelet ratio index], SPRI [spleen-to-platelet ratio index], ASPRI [age-spleen-to-platelet ratio index] scores and correlating the different scores with the grade of esophageal varices found on upper endoscopy. Results: During processing of our patient’s data, we found certain relation between segmented neutrophils, monocytes, platelet count, total bilirubin and the degree of esophageal varices for the detection of high risk varices and a new equation was formulated and we called it P2/MS-B. In predicting high risk esophageal varices HREV, the area under the curve for this new variable was [0.909, 95% confidence interval 0.858 - 0.961, p = 0.000] which was significantly higher than all the other variables including P2/MS for the detection of HREV. The sensitivity of the new equation for the detection of HREV is 85.3%, the specificity is 83.1%, the positive predictive value is 87.9%, the negative predicative value is 86.0 % and the overall accuracy of the test is 85.6%. Conclusion: A newly detected noninvasive variable for detecting HREV may reliably screen liver cirrhosis patients for HREV and avoid unnecessary endoscopy in low risk patients.
CMOS Image Sensors for High Speed Applications
Munir El-Desouki,M. Jamal Deen,Qiyin Fang,Louis Liu,Frances Tse,David Armstrong
Sensors , 2009, DOI: 10.3390/s90100430
Abstract: Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD) imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4~5 μm) due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps).
Evaluating regional blood spinal cord barrier dysfunction following spinal cord injury using longitudinal dynamic contrast-enhanced MRI
Ilkan Tatar, Peter Chou, Mohamed Desouki, Hanaa El Sayed, Mehmet Bilgen
BMC Medical Imaging , 2009, DOI: 10.1186/1471-2342-9-10
Abstract: C57BL/6 female mice (n = 5) were subjected to contusive injury at the thoracic T11 level and scanned on post injury days 1 and 3 using anatomical, dynamic contrast-enhanced (DCE-MRI) and diffusion tensor imaging (DTI). The injured cords were evaluated postmortem with histopathological stains specific to neurovascular changes. A computational model was implemented to map local changes in barrier function from the contrast enhancement. The area and volume of spinal cord tissue with dysfunctional barrier were determined using semi-automatic segmentation.Quantitative maps derived from the acquired DCE-MRI data depicted the degree of BSCB permeability variations in injured spinal cords. At the injury sites, the damaged barriers occupied about 70% of the total cross section and 48% of the total volume on day 1, but the corresponding measurements were reduced to 55% and 25%, respectively on day 3. These changes implied spatio-temporal remodeling of microvasculature and its architecture in injured SC. Diffusion computations included longitudinal and transverse diffusivities and fractional anisotropy index. Comparison of permeability and diffusion measurements indicated regions of injured cords with dysfunctional barriers had structural changes in the form of greater axonal loss and demyelination, as supported by histopathologic assessments.The results from this study collectively demonstrated the feasibility of quantitatively mapping regional BSCB dysfunction in injured cord in mouse and obtaining complementary information about its structural integrity using in vivo DCE-MRI and DTI protocols. This capability is expected to play an important role in characterizing the neurovascular changes and reorganization following SCI in longitudinal preclinical experiments, but with potential clinical implications.Damage to blood-spinal cord barrier (BSCB) occurs as a consequence of mechanical insult to spinal cord (SC) [1]. The damaged barrier becomes permeable to blood constituents,
TC-99m-labeled red blood cell scintigraphy in the investigation of patients with hepatic cavernous hemangioma
El-Desouki Mahmoud,Mohamadiyeh Mohammad,Al-Rashed Rashed,Othman Saleh
Saudi Journal of Gastroenterology , 1999,
Abstract: Objective: To evaluate the diagnostic accuracy of 99m Tc-red blood cell scintigraphy in the diagnosis of hepatic cavernous hemangiomas. Patients and Methods: Sixty three patients, 56 females (89%) and 7 males (1 I%), with ages between 22 and 54 years (median 33 years) were investigated for liver masses found on ultrasonography of the abdomen. All the patients had undergone 99m Tc-liver-spleen scan followed by 99m Tc-red blood cells scintigraphy. The size of the lesions ranged between 3 and 9 cm. The final diagnosis was reached through cytology, and/or histopathology or follow up for more than 3 years. Results: A total of 70 lesions were found as a single lesion in 60 patients and multiple (i.e. total of 10 lesions) in the other 3 patients. The results of 99m Tc-red blood cells scintigraphy, compared to the results of the final diagnosis, showed sensitivity and specificity rates of 100% and 89% respectively, positive and negative predictive values of 98% and 100% repectively, and accuracy rate of 98.6%. A single false positive case was a hepatocellular carcinoma. Conclusion: 99m Tc- red blood cell scintigraphy is highly accurate in the diagnosis of liver cavernous hemangioma and should characterize liver mass found on ultrasonography and suspected for hemangioma.
Hepatobiliary scintigraphy in the distinction between biliary hypoplasia and biliary atresia
El-Desouki Mahmoud,Mohamadiyah Mohammed,Al Rabeeah Abdullah,Othman Saleh
Saudi Journal of Gastroenterology , 1998,
Abstract: The aim of this work is to see whether distinction between biliary atresia and biliary hypoplasia is possible or not and to present the value and usefulness of hepatobiliary scintigraphy in the investigation of infants with persistent hyperbilirubinemia. Seventy-seven patients of the age between five days and six months (average 62 days), 43 females and 34 males of which 65 Saudi, and 12 non-Saudis were investigated. Laboratory tests, abdominal ultrasound, hepatobiliary scintigraphy, liver biopsy, explorative laparatomy and intraoperative cholangiography were performed whenever indicated. The findings on hepatobiliary scintigraphy of nonvisualization of the gallbladder and no activity in the bowel upto 24 hours post injection were considered consistent with the diagnosis of biliary atresia. Minimal bowel activity, or visualization of the gallbladder where consistent with biliary hypoplasia. In addition, the liver in the two entities appeared in a different shape and can be used as an additional distinctive feature. Thirty-four infants were diagnosed by hepatobiliary scintigraphy as having biliary atresia. Only 3 of the 34 were false positives as compared to cholangiogram and liver biopsy results. Five cases were biliary hypoplasia. Hepatobiliary scintigraphy in infants with persistent hyperbilirubinemia can be distinguished between BA and BH in a simple and noninvasive approach.
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