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Search Results: 1 - 10 of 232987 matches for " Ahmed R. Abul’Wafa "
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Reliability Evaluation of Distribution Systems under μ Grid-Tied and Islanded μ Grid Modes Using Monte Carlo Simulation  [PDF]
Ahmed R. AbulWafa, A. T. M. Taha
Smart Grid and Renewable Energy (SGRE) , 2014, DOI: 10.4236/sgre.2014.53006

Reliability evaluation of distribution networks under grid-tied and islanded μ grid modes is presented. The Monte Carlo simulation (MCS) algorithm is applied to a modified RBTS Bus 2 distribution network. The network includes three types of distributed energy resources, namely, solar photovoltaic (PV), wind turbine (WT), and diesel turbine generator (DTG). These distributed generators contribute to supply part of the load during grid-connected mode, but supply 100% of the load in the islanded μ grid mode. A storage system is included to decrease the peak load since the peak of the output power of the PV’s and the peak load do not match time wise in most load profiles. The impact of implementing renewable distributed generation, storage systems, and conventional generation on the reliability of distribution network is studied. This study shows that the penetration of distributed generations can improve the reliability indices of the distribution network.

Impact of Thyroglobulin on Survival and Prognosis of Differentiated Thyroid Cancer  [PDF]
Hanan Ahmed Wahba, Hend Ahmed El-Hadaad, Abeer Hussien Anter, Alaa M. Wafa, Ahmed Negm
Journal of Cancer Therapy (JCT) , 2018, DOI: 10.4236/jct.2018.99058
Abstract: Proper assessment of risk factors contributes to the principle management of differentiated thyroid carcinoma post operatively. Aim of the study: to investigate the effect of Thyroglobulin (Tg) levels on prognosis together with other risk factors for Differentiated Thyroid Cancer (DTC). Patients and methods: Medical records of all patients with DTC presented to Clinical Oncology and Nuclear Medicine Department referred from Diabetes & Endocrine unit (Internal Medicine Hospital) and Surgery Department Mansoura University from 2011-2016 were retrospectively reviewed. Patients with distant metastasis or who lost follow-up were excluded. So data of 220 patients were analyzed. Data collected included pre-surgical assessment, also surgical interference either total or near total thyroidectomy with or without lymph node neck dissection were reviewed. Different prognostic factors that affect progression free survival (PFS) include age, umorsize, ymph node status, ex, multifocality, capsular infiltration, vascular invasion and Tg level were evaluated through multivariate analysis. Results: Most of the patients included were <45 years (69.1%). Incidence of the disease was higher in female (80%) with papillary type predominance (80.9%). About 59.5% of cases presented with tumor size ≤ 2 cm and
Bathymetric and Geochemical Analysis of Lake Al-Saad, Abha, Kingdom of Saudi Arabia Using Geoinformatics Technology  [PDF]
Javed Mallick, Mohd Abul Hasan, Yasser Alashker, Mohd Ahmed
Journal of Geographic Information System (JGIS) , 2014, DOI: 10.4236/jgis.2014.65038
Abstract: This study investigates the potential for remote sensing of lake water bathymetry and geochemical by 1) examining the empirical based technique for retrieving depth information from passive optical image worldview-2 satellite data, 2) performing atmospheric correction, 3) assessing the accuracy of spectrally based depth retrieval under field condition via field measurement, 4) producing bathometry and geochemistry mapping by examining spectral variations for identifying pairs of wavelengths that produce strong linear correlation coefficient between the band ratio. The results indicate that optical remote sensing of bathymetry and geochemical investigation is not only feasible but more accurate under conditions of typical lake water, supporting field survey. The Pearson correlation matrix (R) between the examined water samples/depth and the TOA reflectance values of the worldview-2 (WV-2) satellite data have been investigated and found good correlation. The models developed using the combination of different band pairs also show high accuracy. Cartographical maps were generated depending on the linear correlation coefficient between the measured parameters and the TOA reflectance values of the worldview-2 data. The investigation shows that dissolved oxygen (DO) of the lake water is slight lower than the permissible limit of Saudi standards for lake water. The shallow water has high DO concentration, whereas the deeper shows significantly lower down. Electrical conductivity measurements serve as a useful indicator of the degree of mineralization in the water sample. All the samples which have EC exceed limit. The spatial distribution of EC and TDS inferred that the EC and TDS concentration is the highest at the eastern part of the lake whereas concentration drops down towards the southern side. This study confirms that remote sensing incorporated with GIS and GPS could afford an integrated scheme for mapping water quality and bathometry of the surface water.
3D-Analysis of Soil-Foundation-Structure Interaction in Layered Soil  [PDF]
Mohd Ahmed, Mahmoud H. Mohamed, Javed Mallick, Mohd Abul Hasan
Open Journal of Civil Engineering (OJCE) , 2014, DOI: 10.4236/ojce.2014.44032
Abstract: The analysis of building structure in contact with soil involves an interactive process of stresses and strains developed within the structure and the soil field. The response of Piled-Raft Foundation system to the structure is very challenging because there is an important interplay between the component of building structure and the soil field. Herein, soil-foundation-structure interaction of buildings founded on Piled-Raft Foundation is evaluated through 3D-Nonlinear Finite Element Analyses using PLAXIS3D FOUNDATION code. The soil settlements and forces demand of the high-rise building structures and foundation is computed. The parametric study affecting the soil-foundation-structure response has been carried out. The parameters such as construction phasing, sequential loading, building aspect ratios, soil failure models and thickness proportion of soil field stiff layer, are considered. It is concluded that the interaction of building foundation-soil field and super-structure has remarkable effect on the structure.
Wyllieite-type Ag1.09Mn3.46(AsO4)3
Wafa Frigui,Mohamed Faouzi Zid,Ahmed Driss
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812018843
Abstract: Single crystals of wyllieite-type silver(I) manganese(II) trisorthoarsenate(V), Ag1.09Mn3.46(AsO4)3, were grown by a solid-state reaction. The three-dimensional framework is made up from four Mn2+/Mn3+ cations surrounded octahedrally by O atoms. The MnO6 octahedra are linked through edge- and corner-sharing. Three independent AsO4 tetrahedra are linked to the framework through common corners, delimiting channels along [100] in which two partly occupied Ag+ sites reside, one on an inversion centre and with an occupancy of 0.631 (4), the other on a general site and with an occupancy of 0.774 (3), both within distorted tetrahedral environments. One of the Mn sites is also located on an inversion centre and is partly occupied, with an occupancy of 0.916 (5). Related compounds with alluaudite-type or rosemaryite-type structures are compared and discussed.
Clinical and Genetic Study of Friedreich’s Ataxia and Ataxia with Vitamin E Deficiency in 44 Moroccan Families  [PDF]
Fatima Imounan, Naima Bouslam, El Hachmia Aitbenhaddou, Wafa Regragui, Ahmed Bouhouche, Ali Benomar, Mohammed Yahyaoui
World Journal of Neuroscience (WJNS) , 2014, DOI: 10.4236/wjns.2014.44033

Introduction: Friedreich ataxia (FRDA) is a multi-system autosomal-recessive disease, the most common one of the genetically inherited ataxias. FRDA occurs as a consequence of mutations in the frataxin gene, with an expansion of a GAA trinucleotide. Ataxia with vitamin E deficiency (AVED) is characterized clinically by neurological symptoms with often striking resemblance to those of Friedreich’s ataxia (FA) but serum concentrations of vitamin E are low. Aim of study: To study clinical and genetic features of the Friedreich’s ataxia and AVED patients in 44 Moroccan families. Patients and Methods: Retrospective series of 72 Moroccan patients displaying Friedreich’s ataxia syndrome was recruited over a period of 22 years (1987-2009). All patients had a clinical and ophtalmological examinations, 30 patients underwent electromyography, and CT scan was performed in 29 patients. GAA repeats in the frataxin gene and the 744 del A mutation α-TTP gene were performed in all patients. Results: 17 patients (24% of cases) had the 744 del A mutation in the α-TTP gene responsible of ataxia with vitamin E deficiency (AVED) phenotype. 55 patients  (76% of cases) had GAA expanded allele in the first intron of the frataxin gene. Phenotype-genotype correlation revealed a high frequency of head titubation, decreased visual acuity and slower disease progression in AVED than in Friedreich’s ataxia phenotype (p < 0.05). Conclusion: Our study represents a large series which highlight the clinical and genetic differences between AVED and Friedreich’s ataxia. AVED patients have a better prognosis after alpha-tocopherol treatment.

Uncertainty Principles for the Fourier Transforms in Quantum Calculus
Neji Bettaibi,Ahmed Fitouhi,Wafa Binous
Mathematics , 2006,
Abstract: Some properties of the $q$-Fourier-sine transform are studied and $q$-analogues of the Heisenberg uncertainty principle is derived for the $q$-Fourier-cosine transform studied in \cite{FB} and for the $q$-Fourier-sine transform.
Wavelet Transforms Associated With the Basic Bessel Operator
Ahmed Fitouhi,Neji Bettaibi,Wafa Binous
Mathematics , 2006,
Abstract: This paper aims to study the $q$-wavelet and the $q$-wavelet transforms, associated with the $q$-Bessel operator for a fixed $q\in ]0, 1[$. As an application, an inversion formulas of the $q$-Riemann-Liouville and $q$-Weyl transforms using $q$-wavelets are given. For this purpose, we shall attempt to extend the classical theory by giving their $q$-analogues.
Evaluation of Available Phosphorus by Soil Test Methods in an Acidic Soil Incubated with Different Levels of Lime and Phosphorus  [PDF]
Ashoka Sarker, Md. Abul Kashem, Khan Towhid Osman, Imam Hossain, Farzana Ahmed
Open Journal of Soil Science (OJSS) , 2014, DOI: 10.4236/ojss.2014.43014

An incubation study was conducted in laboratory to determine the effect of lime (L) as CaCO3 and phosphorus (P) as TSP on soil pH and available soil P in an acid soil. Four rates of L equivalent to 0, 1, 2 and 3 ton CaCO3 ha-1 and four rates of P equivalent to 0, 25, 50 and 75 mg P kg-1 were applied in combinations as treatments. The soil was incubated at field capacity for 8 weeks (wk) after which they were extracted using NaHCO3 (Olsen), Mehlich-3, Kelowna and Bray & Kurtz-1 extractants and soil pH was determined. Lime significantly (P < 0.001) increased soil pH. Phosphorus decreased it, though not significantly. Both L and P had significant effects (P < 0.001) on P availability irrespective of extractants used. Two ton CaCO3 plus 75 mg P kg-1 gave the highest available phosphorus. Mehlich-3 method extracted the largest amount of P (14.54 - 67.35 mg·kg-1) while Olsen extracted the smallest amount (3.25 - 32.77 mg·kg-1). The mean extractable P in soils was found to be in the order of Olsen 2 = 0.87 to 0.95).

Arabic Language Teachers in the State of Michigan: Views of Their Professional Needs  [PDF]
Hassan Wafa
Open Journal of Modern Linguistics (OJML) , 2014, DOI: 10.4236/ojml.2014.45053
Abstract: A full-day summer conference directed by this investigator took place in Dearborn city under the umbrella of Western Michigan University for professional development of Arabic teachers serving public, private, and academic charter schools in Michigan. The theoretical framework for conducting the conference was focused on the issue of teaching strategies as well as the needs assessment of teachers for improving their professional development. A group of fifty teachers volunteered to participate in the conference and were asked to complete a twelve-item questionnaire designed to provide their professional profile and their preference in developing professional development. Their professional profile included years of Arabic teaching experience in the United States, teaching level (elementary school, middle school, or high school), teaching certificate, academic credentials, and type of school (public, private, or charter school). The findings indicated that among the ten sub-items related to the professional development skills of the teachers, “Implementing differentiated language instruction” was rated by the participating teachers as the most important components of their professional development skills; followed in order by “Integrating technology and Arabic instruction”; “Using effective learner-centered teaching strategies”; “Using and maintaining Arabic language”; “Implementing a standards-based curriculum”; “Developing curriculum and thematic units”; “Implementing performance assessment methods”; “Conducting constructive action research in Arabic instruction”; “Conducting the Oral Proficiency Interview”; and “Learning how to be a certified Arabic language teacher in Michigan”. In response to the questions regarding the role of Council in supporting Arabic teachers, the participating teachers made a number of constructive suggestions to help improve the quality of teaching Arabic with special focus on facilitating appropriate teaching materials and other instructional tools as a part of curriculum development.
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