oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 46 )

2018 ( 278 )

2017 ( 290 )

2016 ( 280 )

Custom range...

Search Results: 1 - 10 of 150139 matches for " H;Kamel "
All listed articles are free for downloading (OA Articles)
Page 1 /150139
Display every page Item
Numerical Study of Slip Effect of Unsteady MHD Pulsatile Flow through Porous Medium in an Artery Using Generalized Differential Quadrature Method (Comparative Study)  [PDF]
Islam M. Eldesoky, Mohamed H. Kamel, Ramzy M. Abumandour
World Journal of Engineering and Technology (WJET) , 2014, DOI: 10.4236/wjet.2014.22015
Abstract: The unsteady pulsatile flow of blood through porous medium in an artery has been studied under the influence of periodic body acceleration and slip condition by considering blood as incompressible Newtonian electrically conducting fluid in the presence of magnetic field. In this paper, a new technique of differential quadrature method is introduced to find numerical solution of non-linear partial differential equations such as the equation of motion of this problem “Navier-Stokes equation”. The presence of the nonlinearity in the problem leads to severe difficulties in the solution approximation. In construction of the numerical scheme “a new algorithm” a generalized differential quadrature method (GDQM) is to use for derivatives with respect to space variables of differential equations and for the time derivative applying fourth order RungeKutta Method (RKM). The GDQM changed the nonlinear partial differential equations into a system of nonlinear ordinary differential equations (ODEs). The obtained system of ODEs is solved by 4th order RKM. This combination of DQM and 4th order RKM gives a very good numerical technique for solving time dependent problems. The algorithm is coded in Matlab 7.14.0.739 and the simulations are run on a Pentium 4 CPU 900 MHz with 1 GB memory capacity. The effects of slip condition, magnetic field, porous medium, and body acceleration have been discussed. The numerical results show that the proposed method is more accurate and convergent than other numerical methods in literature. The method is illustrated and compared with the exact and analytical solutions and it is found that the proposed method gives a better accuracy and is quite easy to implement.
The Behaviour of 134Cs, 60Co, and 85Sr Radionuclides in Marine Environmental Sediment
Nariman H.M. Kamel
The Scientific World Journal , 2002, DOI: 10.1100/tsw.2002.290
Abstract:
Arrhythmias as Early Post-operative Complications of Cardiac Surgery in Children at Cairo University
Yasser H. Kamel,M. Sewielam
Journal of Medical Sciences , 2009,
Abstract: Arrhythmias are a recognized complication of cardiac operations in pediatrics. The aim of the study was to assess the incidence and type of arrhythmias in early post pediatric cardiac surgery patients and to analyze possible risk factors. This is a retrospective study conducted on patients who were followed in post-operative clinic at Cairo University Children’s Hospital during the period from September 2007 till January 2009. The following data were collected for each patient; demographic data, pre-operative arrhythmia present, surgical data and post-operative intensive care course. During the study period, 110 patients were enrolled; including 15/110 who had palliative surgery, while 95 out of 110 had corrective surgery. Thirty patients (27.2%) developed post-operative arrhythmias and most of them on day one (60%). Of them 20/30 (66.6%) were cyanotic, while 10/30 (33.3%) were acyanotic. Two (6.6%) had palliative surgery, while 28/30 (93.3%) had corrective surgery. The most common acute post-operative arrhythmias were junctional ectopic tachycardia and Supraventricular tachycardia (33.3%) for each. Out of 95 patients who had corrective surgery, 28 (29.4%) developed arrhythmias most of them (96.4%) within first 48 h post-operatively. they were early after repair of tetralogy of Fallot (18.1%) and (12.1%), respectively. Risk factors for arrhythmias in corrective surgery; such as young age, lower body weight and cyanosis (p<0.05), longer cardiopulmonary bypass time (p<0.05), redooperation (p<0.01), post-operative acidosis, high inotropic support, hypotension and mechanical ventilation (p<0.01), patient with moderate operative risk, post-operative higher doses of inotropic support, longer ventilation time were statistically significance with p<0.001. Younger age, lower body weight, cyanosis, longer cardiopulmonary bypass time, Re-do procedure, acidosis, mechanical ventilation and high inotropic support are the risk factors for post-operative arrhythmias. Junctional ectopic tachycardia and supraventricular tachycardia were the most common post-operative arrhythmias.
Ground Water in Certain Sites in Egypt and Its Treatments Using a New Modified Ion Exchange Resin—Characterization of Water and Modified Ion Exchange  [PDF]
Nariman. H. Kamel, AlSaid M. Sayyah, Ahmed. A. Abdel-aal
Journal of Environmental Protection (JEP) , 2011, DOI: 10.4236/jep.2011.24050
Abstract: The present work is a comprehensive of drinking water quality. Eleven groundwater samples were taken from various rural regions of Egypt, the groundwater samples were investigated for chemical, radiometric and heavy metals analyses, the major cations including; sodium ( ), potassium ( ), calcium ( ) and magnesium ( ) ions species, the major anions of chloride ( ), sulphate ( ), nitrite ( ), phosphate ( ). Radiometric analyses in water expressed as the gross alpha and beta activity concentrations, heavy metals analyses including arsenic ( ), lead ( ), cobalt ( ), manganese ( ), iron ( ) and cadmium ( ) ions. The groundwater samples were found to contain high concentrations of heavy metals than the limited values of the world health organization (WHO). Heavy metals speciation were performed using MinteqA2 geochemical code. A modified exchange resin was prepared by polymerization of the condensed dioxalayl p-sulphanilamide with phenol, this ion exchange resin was examined by the different techniques such as; x-ray diffraction, infra red spectra (IR), and electronic microscopic, it was found a good adsorbent material that used for the reduction of heavy metals from contaminated groundwater samples.
Insulin-Like Growth Factor-1 and Osteocalcin Are Correlated with Markers of Osteoporosis in Postmenopausal Women with Type-2 Diabetes  [PDF]
Maher A. Kamel, Madiha H. Helmy, Anna N. Abou Rayah, Nevine Mohannad, Huda M. N. Hania
Open Journal of Endocrine and Metabolic Diseases (OJEMD) , 2013, DOI: 10.4236/ojemd.2013.35033
Abstract:

Objective: The study was conducted to evaluate the relation between insulin-like growth factor-1 and osteocalcin and markers of bone modulation (osteoprotegerin; OPG, receptor activator nuclear kappa B; RANK and RANK ligand; RANKL) in postmenopausal Type 2 diabetic women with and without osteoporosis. Methods: The study was conducted on 90 female divided into three groups (30 each). Group I included healthy postmenopausal women as a control, Group II included diabetic postmenopausal women without osteoporosis Group III included diabetic postmenopausal women with osteoporosis. Fasting blood samples were obtained for the determination of blood glucose, HbA1c, total and ionized calcium, OPG, RANK and RANKL. Also the levels of IGF-1 and osteocalcin were assessed. Results: In postmenopausal Type 2 diabetic women, the osteoporosis resulted in derangement in OPG/sRANKL system. The serum level of OPG was elevated while sRANKL declines in osteoporotic postmenopausal Type 2 diabetic women. IGF-1 level decreased in diabetic postmenopausal women but those women with osteoporosis showed a great decline by about 60%. IGF-1 level in osteoporotic diabetic postmenopausal women was correlated with BMD and most bone turnover markers (OPG, sRANKL, OPG/sRANKL). Osteocalcin declined significantly only in those women with osteoporosis not without osteoporosis. Conclusions: The circulating levels of OPG and sRANKL were not useful markers for bone status in postmenopausal women while the circulating levels of IGF-1 and osteocalcin might give useful information about bone status in postmenopausal diabetic women.

Study of angiotensin converting enzyme and genotype among Egyptian preeclampsia patients  [PDF]
Hassan A. Alsokary, Mostafa A. Kamel, Sameh S. Sadek, Nermine H. Zakaria, Iman A. Abdel Fatah
American Journal of Molecular Biology (AJMB) , 2014, DOI: 10.4236/ajmb.2014.41005
Abstract:

Preeclampsia is a frequent disorder with reported incidence in pregnancies. In Egypt, it complicates 6%-8% of pregnancies and reaches 15% in referral centers. The renin-angiotensin system activation during the early stages of Preeclampsia proved to be a direct cause. Women carrying the D allele of the ACE-I/D polymorphism have higher measures of uterine artery resistance, which is a marker for development of intrauterine growth retardation and preeclampsia. The maternal syndrome of preeclampsia (PE) during the latter half of pregnancy is believed to result from impaired placentation in early gestation and a failure to develop low resistance uteroplacental circulation. Aim: The aim of this study was to evaluate the association with angiotensin converting enzyme gene polymorphism and changes in its enzyme serum level in preeclamptic patients compared to non preeclamptic control group together with studying the changes in umbilical artery and uterine artery Doppler. Subjects: The study was conducted on 180 pregnant women allocated into two groups having the same inclusion and exclusion criteria except for hypertension and proteinuria; each group comprised of 90 pregnant women with matched age. Methods: Doppler study of umbilical and uterine arteries and the detection of Angiotensin converting gene polymorphism by PCR with Estimation of serum ACE in serum by ELISA technique. Results: The distribution of the ACE-I/D genotypes and allelic frequencies in the present study of polymorphism was 37.8% for the DD, 48.9% for the ID, 13.3% for the II in preeclampsia group while it was 33.3% for the DD, 46.7% for the ID, and 20% for the II in the control group. There was no significant difference between cases and controls regarding the cumulative D effect. Conclusions: No existence of a relation between preeclampsia and ACE gene polymorphism considering different modes of inheritance whether is dominance or recessiveness. No effect of ACE gene polymorphism is

Effect of Maternal Diabetes on Pre- and Post-Natal Redox Status of F1 Rat Offspring  [PDF]
Maher A. Kamel, Madiha H. Helmy, Mervat Y. Hanafi, Shimaa A. Mahmoud, Hanan Abo Elfetooh
Open Journal of Endocrine and Metabolic Diseases (OJEMD) , 2014, DOI: 10.4236/ojemd.2014.45012
Abstract:

Background: The oxidative stress and disturbed redox signaling during gestation my play an important role in the fetal programming of adult diabetes. Objective: The study aimed to investigate the effects of maternal diabetes on pre- and post-natal pancreatic and peripheral tissues redox and oxidative status in order to clarify their role in the diabetogenic programming of F1 offspring. Methods: Two groups of female Wistar rats were used (diabetic and control); diabetes was neonatally induced by STZ injection to 5-day old rats. 10 pregnancies of each group were terminated at GD 17 to obtain placentas and fetal pancreas, liver, muscle and adipose tissues for prenatal measurements. The rest of pregnancies were completed to term and the offspring were weaned to control diet or high-caloric (HCD) diet and followed up for 30 weeks. Every 5 weeks 10 male rats were sacrificed and serum and tissues were obtained for assessment of fasting blood glucose, tissues content of 8-oxo-dG, TBARS, GSH, GSSG, antioxidant enzymes and caspase-3. Results: The results indicated that, prenatally redox status of the foetuses of diabetic mothers is shifted toward more oxidizing environment which results from elevated oxidative stress and impaired antioxidants as indicated by elevated fetal tissues content of 8-oxo-dG, TBARS and GSSG and decreased GSH and GSH/GSSG ratio. All of these induce the apoptotic pathway in fetal pancreas. Postnatally, impaired glucose tolerance in the offspring of diabetic mothers is detected at 15th week of age and no hyperglycemia was detected until age of 30 weeks in the offspring under CD while some of offspring under HCD at age 25 weeks and most of them at 30 weeks have developed hyperglycemia. The pancreas of the offspring of diabetic mothers suffers from oxidative stress from the 5th week of age as indicated by elevated levels of nuclear and mitochondrial 8-oxo-dG contents and TBARS. Also, GSH level showed depletion with age and the activity of glutathione reductase was lower in the β

Effect of Tubular Chiralities and Diameters of Single Carbon Nanotubes on Gas Sensing Behavior: A DFT Analysis  [PDF]
A. A. EL-Barbary, Kh. M. Eid, M. A. Kamel, H. M. Osman, G. H. G. H. Ismail
Journal of Surface Engineered Materials and Advanced Technology (JSEMAT) , 2014, DOI: 10.4236/jsemat.2014.42010
Abstract:

Using density functional theory, the adsorption of CO, CO2, NO and CO2 gas molecules on different chiralities and diameters of single carbon nanotubes is investigated in terms of energetic, electronic properties and surface reactivity. We found that the adsorption of CO and CO2 gas molecules is dependent on the chiralities and diameters of CNTs and it is vice versa for NO and NO2 gas molecules. Also, the electronic character of CNTs is not affected by the adsorption of CO and CO2 gas molecules while it is strongly affected by NO and NO2 gas molecules. In addition, it is found that the dipole moments of zig-zag CNTs are always higher than the arm-chair CNTs. Therefore, we conclude that the zig-zag carbon nanotubes are more preferred as gas sensors than the arm-chair carbon nanotubes, especially for detecting NO and NO2 gas molecules.

Adsorption of CO, CO2, NO and NO2 on Boron Nitride Nanotubes: DFT Study  [PDF]
A. A. El-Barbary, Kh. M. Eid, M. A. Kamel, H. O. Taha, G. H. Ismail
Journal of Surface Engineered Materials and Advanced Technology (JSEMAT) , 2015, DOI: 10.4236/jsemat.2015.53017
Abstract: The adsorption of CO, CO2, NO and CO2 gas molecules on different chiralities of single boron nitride nanotubes (BNNTs) is investigated, applying the density functional theory and using basis set 6 - 31 g (d,p). The energetic, electronic properties and surface reactivity have been discussed. We found that the best BNNT for adsorbing the CO, CO2, NO and NO2 gas molecules is (5,0) BNNT with adsorption energy of -0.27, -0.37 eV, -0.23 and -0.92 eV, respectively. Also, the electronic character of (5,0), (9,0), (5,5) and (6,6) BNNTs is found to be not affected by the adsorption of CO, CO2, NO and NO2 gas molecules. It is found that the dipole moments of zig-zag (5,0) and (9,0) BNNTs are always higher than the arm-chair (5,5) and (6,6) BNNTs. Also, it is noticed that the highest dipole moment is for (9,0) BNNT.
Adsorption of CO, CO2, NO and NO2 on Carbon Boron Nitride Hetero Junction: DFT Study  [PDF]
A. A. El-Barbary, Kh. M. Eid, M. A. Kamel, H. O. Taha, G. H. Ismail
Journal of Surface Engineered Materials and Advanced Technology (JSEMAT) , 2015, DOI: 10.4236/jsemat.2015.54019
Abstract: The adsorption of CO, CO2, NO and CO2 gas molecules on different diameters and chiralities of carbon nanotube-boron nitride nanotube (CNT-BNNT) heterojunctions is investigated, applying the density functional theory and using basis set 6 - 31 g (d,p). The energetic, electronic properties and surface reactivity have been discussed. We found that the best CNT-BNNT heterojunctions for adsorbing the CO, NO, CO2 and NO2 gas molecules is (5,0) CNT-BNNT heterojunction through forming C-N bonds with adsorption energy of -0.26, -0.41 eV, -0.33 and -0.63 eV, respectively. Also, the adsorption of CO, NO, CO2 and NO2 gas molecules on (5,5) and (6,6) CNT-BNNT heterojunctions does not affect the electronic character of the CNT-BNNT heterojunctions, however the adsorption of NO and NO2 gas molecules on (5,0) and (9,0)CNT-BNNT heterojunctions in case of forming C-B bonds increases the band gaps to 1.21 eV and 1.52 eV, respectively. In addition, it is reported that the values of dipole moment for armchair (5,5) and (6,6) CNT-BNNT heterojunctions are not affected by gas adsorption. Also, for the zig-zag (5,0) and (9,0) CNT-BNNT heterojunctions, the values of dipole moment increase through forming C-N bonds and decrease through forming C-B bonds. In addition, it is reported that the highest dipole moment is obtained for (9,0) CNT-BNNT heterojunctions. Therefore, the zig-zag CNT-BNNT heterojunctions can be selected as good candidate for gas sensors.
Page 1 /150139
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.