Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 2 )

2019 ( 446 )

2018 ( 510 )

2017 ( 503 )

Custom range...

Search Results: 1 - 10 of 211041 matches for " Mona N. El Hazek "
All listed articles are free for downloading (OA Articles)
Page 1 /211041
Display every page Item
Dissolution of Manganese from Polymetallic Material Using Sulfuric-Oxalic Acid Medium  [PDF]
Mona N. El Hazek, Azza A. Gabr
American Journal of Analytical Chemistry (AJAC) , 2016, DOI: 10.4236/ajac.2016.75044
Abstract: Sedimentary rocks have been found to host several Mn minerals in addition to some economic metal values. Besides recoverable Al occurring as gibbsite mineral, the latter include Cu, Zn, Co, Ni, U as well as rare earth elements. In this work, the ore material was subjected to sulfuric acid leaching in the presence of oxalic acid as a reductant to maximize the extraction of Mn. The optimum leaching conditions to achieve almost complete leaching efficiency of Mn with Fe dissolution not exceeding 13% involved 0.5 M sulfuric acid and 0.25 M oxalic acid in a solid/liquid ratio of 1/15 at 85°C for 105 min using an ore size of -150 μm. The leaching behavior of the associated interesting metal values (Al, Cu and Zn) has also been investigated.
Potash Breakdown of Poly-Mineralized Niobium-Tantalum-Lanthanides Ore Material  [PDF]
Mona N. El Hazek, Nawal H. Mohamed, Azza A. Gabr
American Journal of Analytical Chemistry (AJAC) , 2019, DOI: 10.4236/ajac.2019.103009
Abstract: The potentiality of the alkali breakdown of the poly mineralized ore material south Gabal El-A’urf area, central Eastern Desert, Egypt is investigated. It includes the multiple oxide mineral tanteuxenite, monazite, bastnasite, anatase, as well as zircon. This ore material assaying lanthanides (RE2O3 1.9%), niobium (Nb2O5 1.25%) as well as titanium and zirconium (TiO2 and ZrO2 1.23% and 1.12%) respectively besides tantalum (Ta2O5 0.13%), were used for the present work. This sample has thus been subjected to two alkali breakdown techniques using potash; namely agitation leaching and fusion. The latter technique was found to be preferred as it gives higher leaching efficiency. The optimum leaching conditions are weight ratio of the ore/potassium hydroxide 1/2 at 400°C for 1 h. The realized leaching efficiencies attained 95.0% and 93.7% for Nb and Ta respectively as well as 96% for lanthanides and 75% for Ti while that for Zr did not exceed 10%.
Diabetic cystopathy in children and adolescents with Type 1 diabetes mellitus  [PDF]
Mona A. K. Salem, Safinaz A. El Habashy, Dalia N. Toaima, Hassan S. Shaker, Osama M. A. H. Hetta, Jonair H. A. El Kafy
Journal of Diabetes Mellitus (JDM) , 2014, DOI: 10.4236/jdm.2014.41004

Background: Urinary bladder dysfunction is a major complication of diabetes mellitus and its mechanism has been attributed to autonomic and/or peripheral neuropathy. Objectives: Evaluation of diabetes mellitus and neuropathy effect on the urinary bladder dynamics in children and adolescents with Type 1 diabetes mellitus. Patients and Methods: The study included 80 children and adolescents with Type 1 diabetes for at least 5 years; 60 patients were with manifestations of autonomic and/or peripheral neuropathy and 20 patients were free of either. We assessed both groups for presence of cystopathy by means of uroflowmetry and cystometry. Results: All patients with diabetic neuropathy had abnormal urodynamic test results of variable types and degrees with bladder hypercompliance as the most frequent abnormality. Other urodynamic abnormalities were found in both diabetic patients’ groups with no significant difference in frequency. Conclusions: Diabetic neuropathy might be strongly related to urodynamic abnormalities particularly the bladder hypercompliance. Some diabetic patients may have cystopathy in absence of evident neuropathy. This may be due to undetected neuropathy or diabetes induced myopathy of the detrusor muscle.

An Efficient Technique for Finding the Eigenvalues of Fourth-Order Sturm-Liouville Problems  [PDF]
Mohamed El-Gamel, Mona Sameeh
Applied Mathematics (AM) , 2012, DOI: 10.4236/am.2012.38137
Abstract: In this work, we present a computational method for solving eigenvalue problems of fourth-order ordinary differential equations which based on the use of Chebychev method. The efficiency of the method is demonstrated by three numerical examples. Comparison results with others will be presented.
Modeling of Water Flow and Nitrate Transport to Subsurface Drains  [PDF]
Alaa El-Sadek, Mona Radwan
Journal of Agricultural Chemistry and Environment (JACEN) , 2018, DOI: 10.4236/jacen.2018.71005
Abstract: In this study,?the water flow and nitrate transport to a subsurface drain, using a simplified and detailed model, are simulated for the specific hydro-geological conditions of Elverdinge and Assenede, Belgium. Previously, the DRAINMOD-N model proved to be able to simulate nitrate concentrations and drainage well for an?in-situleaching experiment, the?Hooibeekhoeve?in the community of Geel (north-eastern part of Belgium), conducted in 1992-1995. In this study, the calibrated model is used to simulate the nitrate leaching for the winter period 2000-2001 in Elverdinge and Assenede and is compared to a model with a simplified nitrate transport description. The comparative analysis between both model approaches reveals that the simplified model is able to predict sufficiently accurate the observed nitrate leaching. The detailed approach however has the advantage of giving?a more accurate estimate of the nitrogen mineralization, N deposition and denitrification, resulting in a more precise modeling of the nitrate leaching to surface waters and groundwater.
Adsorptive stripping voltammetry determination of the hormone therapy Raloxifene HCl in formulation and human serum
Ghoneim, Mohamed M.;Hassanein, Amera. M.;Salahuddin, Nehal A.;El-Desoky, Hanaa S.;Elfiky, Mona N.;
Journal of the Brazilian Chemical Society , 2012, DOI: 10.1590/S0103-50532012005000016
Abstract: raloxifene hcl (rlx) was found to strongly adsorb onto surface of the mercury electrode in a monolayer surface coverage of 5.724 × 10-10 mol cm-2. two precise, rapid and extraction-free linear sweep and square wave adsorptive cathodic stripping voltammetry (ls-adcsv and sw-adcsv, respectively) methods are described for trace quantitation of rlx in bulk form, commercial formulation and human serum. limits of quantification (loq) of 2.0 × 10-9 and 5.0 × 10-11 mol l-1 rlx in bulk form and 4.0 × 10-9 and 1.0 × 10-10 mol l-1 rlx in spiked human serum were achieved by the described ls-adcsv and sw-adcsv methods, respectively. insignificant interferences from some common excipients, metal ions and co-administrated drugs were obtained. loq achieved by the methods are low as well as they offer good possibilities for determination of drug in low-dosage pharmaceutical preparations. however, the sw-adcsv method described is sensitive enough to assay the drug also in human serum.
Properties of buffalo Mozzarella cheese as affected by type of coagulante
Nawal S. Ahmed,Mona A.M. Abd El-Gawad,M.M. El-Abd,N.S. Abd-Rabou
Acta Scientiarum Polonorum : Technologia Alimentaria , 2011,
Abstract: Background. Mozzarella is one of several pasta filata or stretched curd cheeses that originated in Italy. The name pasta filata refers to a unique plasticizing and texturing treatments of the fresh curd in hot water that imparts to the finished cheese its characteristic fibrous structure and melting properties. Mozzarella cheese made from standardized buffalo milk with 3 and 1.5% fat. The effect of coagulant types (calf rennet, chymosin and Mucor miehei rennet) on the cheese properties was carried out. Material and methods. Fresh raw buffalo milk and starter cultures of Streptococcus salvarius ssp. thermophilus and Lactobacillus delbrueckii ssp. bulgaricus were used. The coagulants were calf rennet powder (HA-LA), microbial rennet powder (formase ISOTL from Mucor miehei) and chymosin derived by fermentation (CDF). Milk, curd, whey,kneading water and cheese were analysed. The slab gel electrophoresis patterns of Mozzarella cheese were also applied. Statistical analyses were also applied on the obtained data. Results. Recovery of DM of both curd and cheese decreased in case of using Mucor miehei rennet while the recovery of TP and fat content in both curd and cheese and their loss to whey and kneading water were nearly the same. Soluble nitrogen and soluble tyrosine and tryptophan contents elevated with increasing the storage period. Increasing rate of the soluble nitrogen in case of using Mucor miehei rennet was higher compared to that made with the other types of coagulant. TVFA content increased with advancing the storage period, also increased with increasing the fat content of the original milk fat used. No effect can be seen due to the coagulant types. The meltability increased with storage period progress. While the effect of the type of coagulant enzyme hade neglect effect on meltability fat leakage and oiling off. Mozzarella cheese made with Mucor miehei rennet obtained the highest firmness compared with those made using calf rennet, or chymosin. Both scores of the flavour and body and texture improved with progressing of storage period, and were higher in case of using Mucor miehei rennet, while the appearance score of the cheeses decreased with increasing the storage period at 4°C. Conclusion. Using Mucor miehei rennet increased the rate of proteolysis during storage period more than the other 2 types of coagulant. They also, showed the higher sensory evaluation.
The Value of High Antistreptolysin O Titre as an Indicator of Tonsillectomy in Upper Egypt  [PDF]
Essam A. Abo El-magd, Mona Abdel Meguid, Abd El Rahman El Tahan
International Journal of Otolaryngology and Head & Neck Surgery (IJOHNS) , 2016, DOI: 10.4236/ijohns.2016.51001
Abstract: Background: In this study, we aimed to evaluate the benefit of performing of tonsillectomy in patients with raised serum ASO titre only in absence or presence of group A beta heamolytic streptococci (GABHS) in throat swab. Materials and methods: In this prospective cohort study, 196 patients below the age of 14 were suffering from non-specific streptococcal infections, without fulfilling the clinical parameters used for the diagnosis of chronic tonsillitis 156 patients had a raised ASO titre above 200 iu/ml. Throat swab culture was performed in all patients. Results: The results showed that out of the 156 patients, 52 had positive throat swab for GABHS. All of the patients underwent tonsillectomy. Follow-up of the patients for one year after the operation, 88% of the first group with high ASO titre and positive throat swab showed improvement of symptoms; 25% of the second group with high ASO titre and negative throat swab showed improvement of symptoms. Conclusion: Our study shows that isolation of GABHS from the patients tonsils by throat swab along with high ASO titre may be an indication of tonsillectomy in absence of any other indications.
HER-2/Neu Status in Gastric Carcinomas in a Series of Egyptian Patients and Its Relation to Ki-67 Expression  [PDF]
Saba El-Gendi, Iman Talaat, Mona Abdel-Hadi
Open Journal of Pathology (OJPathology) , 2015, DOI: 10.4236/ojpathology.2015.54014
Abstract: Objective: HER-2/neu status in gastric carcinomas (GCs) has not been studied before in the Egyptian population. Materials and Methods: Seventy-three GCs were evaluated for the expression of HER-2/neu and Ki-67 using immunohistochemistry (IHC). Fluorescence in situ Hybridization (FISH) was done for HER2/neu IHC score 2+ cases. Results: Out of the 73 gastric carcinomas, 23 (31.5%) were score 0, 17 (23.3%) were score 1+, 23 (31.5%) were score 2+, and 10 (13.7%) were score 3+. FISH analysis revealed that the HER-2/neu gene was amplified in 11 out of the 23 cases (47.8%) scored 2+ by IHC. Therefore, the overall HER-2/neu positivity rate was 28.8% and it was significantly associated with higher T-stage and lymphovascular invasion (LVI). The Ki-67 expression rate ranged between 10% and 100%, with 84.9% of the cases (n = 62) featuring high Ki-67 scores. High Ki-67 score was significantly associated with male sex, tumor grade, and number of positive nodes. HER-2/neu protein expression correlated significantly with Ki-67 score. Twenty tumors showed combined HER-2/neu positivity and high Ki-67 score and were significantly associated with higher T-stage and occurrence of LVI, implying a more aggressive behavior. Conclusions: The rate of HER-2/neu positive GCs in our series simulates universal rates, thereby mandating routine evaluation of HER-2/neu status in all GCs submitted to our laboratory to benefit from trastuzumab therapy. Further studies on a larger number of GCs are required to prove that the concurrent HER-2/neu positivity and high Ki-67 score are markers of worse prognosis.
The Formation of Fringes of Equal Chromatic Order across Double Clad Fiber in the Presence of High Power Lasers  [PDF]
Mona F. Omar, Rania H. Abd El-Maksoud
Optics and Photonics Journal (OPJ) , 2016, DOI: 10.4236/opj.2016.62005
Abstract: Multiple-beam fringes of equal chromatic order interferometry is a powerful technique to extract optical properties over a continuous range of spectrum. In this paper we develop a theory for the spectral shape of the fringes of equal chromatic order (FECO) that are formed across a double-clad fiber. The modified single term Sellmeier dispersion formula is used to construct the refractive index dispersion curves for the liquid, claddings, and core. Expressions for the paraxial optical path length for several rays passing through the fiber and the liquid are developed. The condition of bright fringe is applied to get an analytical expression for the spectral shape of the FECO across a double-clad fiber with an elliptical/circular inner cladding. A potential application of this theory is to determine the dispersion of Kerr constant of the claddings and the core of the fiber. To illustrate the theory and its application, simulation examples are provided and discussed.
Page 1 /211041
Display every page Item

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