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Search Results: 1 - 10 of 117942 matches for " Nesrine T. Lamie "
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Amr M Badawy,Abd El-Aziz B Abd El-Aleem,Nesrine T Lamie*
Pharmacie Globale : International Journal of Comprehensive Pharmacy , 2011,
Abstract: Three stability-indicating methods were developed for the determination of Sildenafil Citrate (SLDC) in the presence of its degradation product. The First method depends on the quantitative densitometric evaluation of thin layer chromatogram of sildenafil citrate in the presence of its degradation product without any interference. Chloroform : methanol : ammonia (9: 1: 0.01 by volume) was used as a mobile phase and the chromatogram was scanned at 292 nm. This method determines SLDC in the concentration range 1.2-3.6 μg/spot with mean percentage recovery 99.80±0.928%. The second method is based on the high performance liquid chromatographic separation on Phenomenex10μ ODS (150 mm ×3.9 mm I.D), particle size (10μm), with a mobile phase consisting of acetonitrile: methanol: 0.05 M potassium dihydrogen phosphate (pH: 5.8) (50: 20: 30 v/v/v followed by UV detection at 290nm. Calibration graph is linear in the concentration range 8-40μg/ml with mean percentage recovery of 100.23±1.188 %. The third method depends on application of bivariate calibration algorithm to the spectrophotometric determination of SLDC in the concentration range 10-60 μg/ml with mean percentage recovery100.05±1.181%. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical preparations. The methods retained their accuracy and precision when the standard addition technique was applied. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the reference method.
Amr M Badawey,Abd El-Aziz B Abd El-Aleem,Nesrine T Lamie*
Pharmacie Globale : International Journal of Comprehensive Pharmacy , 2011,
Abstract: The construction and electrochemical response characteristics of polyvinyl chloride (PVC) membrane sensors for determination of terazosin hydrochloride dihydrate (THD) in presence of its degradation product are described. The sensors are based on the ion association complexes of THD cation with sodium tetraphenyl borate (THD-TPB) [sensor 1] or ammonium reineckate (THD-RNC) [sensor 2] counter anions as ion exchange sites in PVC matrix. The performance characteristics, sensitivity and selectivity of these electrodes in presence of THD alkaline degradation product were evaluated according to IUPAC recommendations. It reveals a fast, stable and linear response for THD over the concentration range 10-5-10-2 M with cationic slopes of -30.90and -31.16 mV per concentration decade with sensors 1 and 2, respectively. These sensors exhibit fast response time (15-30sec), low quantitation limit (5.6x10-6 and 5.2x10-6M, respectively), and good stability (30-45 days). The direct potentiometric determination of THD using the proposed sensors gave average recoveries of 100.03±1.052 and 99.97±0.927 for sensor 1 and sensor 2, respectively. The sensors are used for determination of THD, in pure form, in presence of its degradation product and in tablets. Validation of the method shows suitability of the proposed sensors for use in the quality control assessment of THD and for routine analysis as stability indicating method. The developed method was found to be simple, accurate and precise when compared with a reference HPLC method.
Amr M Badawy,Nadia M Mostafa,Abd El-Aziz B Abd El-Aleem,Nesrine T Lamie*
Pharmacie Globale : International Journal of Comprehensive Pharmacy , 2011,
Abstract: Stability-indicative determination of bambuterol hydrochloride (BH) in the presence of its degradation product (terbutaline), which is also the metabolite, is investigated. The degradation product has been isolated, via aciddegradation, characterized and elucidated. Selective quantification of BH, singly in bulk form, pharmaceutical formulations and/or in the presence of its major degradation product is demonstrated. The indication of stability has been undertaken under conditions likely to be expected at normal storage conditions. Among the spectrophotometric methods adopted for quantification are second derivative (2D), first derivative of ratio spectra (1DD), ratio subtraction and bivariate analysis.
Stability-indicating methods for the determination of rosuvastatin calcium in the presence of its oxidative degradation products
Nadia M. Mostafa,Amr M. Badawey,Nesrine T. Lamie,Abd El-Aziz B. Abd El-Aleem
International Journal of Pharmacy and Biomedical Sciences , 2012,
Abstract: Four different accurate, sensitive and reproducible stability-indicating methods for the determination of rosuvastatin calcium in the presence of its oxidative degradation products are presented. The first method is second-derivative (2D) method at 243.6nm in a concentration range of 5-30μg/mL with mean percentage recovery of 99.94±1.171. The second method is based on ratio-spectra 1st derivative (1DD) spectrophotometry of the drug at 240nm, over a concentration range of 5-35μg/mL with mean percentage recovery of 99.77±0.974. The third method utilizes quantitative densitometric evaluation of thin-layer chromatography of rosuvastatin calcium in the presence of its oxidative degradation products, using ethyl acetate: methanol: ammonia (7:3:0.01, v/v/v) as a mobile phase. Chromatograms are scanned at 245 nm. This method analyses rosuvastatin calcium in a concentration range of 0.6–3.4μg/spot with mean percentage recovery of 99.78±1.419. The fourth method is an HPLC method for the simultaneous determination of rosuvastatin calcium in the presence of its oxidative degradation products. The mobile phase consists of water: acetonitrile: methanol (40:40:20 v/v/v).The standard curve of rosuvastatin calcium shows a good linearity over a concentration range of 10-60μg/mL with mean percentage recovery of 100.22±0.859. These methods were successfully applied to the determination of rosuvastatin calcium in bulk powder, laboratory-prepared mixtures containing different percentages of the degradation products and pharmaceutical dosage forms. The validity of results was assessed by applying standard addition technique. The results obtained were found to agree statistically with those obtained by a reported method, showing no significant difference with respect to accuracy and precision.
Fast Hybrid PSO and Tabu Search Approach for Optimization of a Fuzzy Controller
Nesrine Talbi
International Journal of Computer Science Issues , 2011,
Abstract: In this paper, a fuzzy controller type Takagi_Sugeno zero order is optimized by the method of hybrid Particle Swarm Optimization (PSO) and Tabu Search (TS). The algorithm automatically adjusts the membership functions of fuzzy controller inputs and the conclusions of fuzzy rules. At each iteration of PSO, we calculate the best solution and we seek the best neighbor by Tabu search, this operation minimizes the number of iterations and computation time while maintaining accuracy and minimum response time. We apply this algorithm to optimize a fuzzy controller for a simple inverted pendulum with three rules.
Interval Type-2 Fuzzy Logic Control of Mobile Robots  [PDF]
Nesrine Baklouti, Robert John, Adel M. Alimi
Journal of Intelligent Learning Systems and Applications (JILSA) , 2012, DOI: 10.4236/jilsa.2012.44031
Abstract: Navigation of autonomous mobile robots in dynamic and unknown environments needs to take into account different kinds of uncertainties. Type-1 fuzzy logic research has been largely used in the control of mobile robots. However, type-1 fuzzy control presents limitations in handling those uncertainties as it uses precise fuzzy sets. Indeed type-1 fuzzy sets cannot deal with linguistic and numerical uncertainties associated with either the mechanical aspect of robots, or with dynamic changing environment or with knowledge used in the phase of conception of a fuzzy system. Recently many researchers have applied type-2 fuzzy logic to improve performance. As control using type-2 fuzzy sets represents a new generation of fuzzy controllers in mobile robotic issue, it is interesting to present the performances that can offer type-2 fuzzy sets by regards to type-1 fuzzy sets. The paper presented deep and new comparisons between the two sides of fuzzy logic and demonstrated the great interest in controlling mobile robot using type-2 fuzzy logic. We deal with the design of new controllers for mobile robots using type-2 fuzzy logic in the navigation process in unknown and dynamic environments. The dynamicity of the environment is depicted by the presence of other dynamic robots. The performances of the proposed controllers are represented by both simulations and experimental results, and discussed over graphical paths and numerical analysis.
Aging Effect on Characteristics of Oil Impregnated Insulation Paper for Power Transformers  [PDF]
Loai S. Nasrat, Nesrine Kassem, Nadia Shukry
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.51001

This paper deals with experimental investigations of the electrical and physical properties of oil impregnated insulation paper for power transformers at different temperatures. The ac breakdown voltage, tensile strength and water content of insulation papers impregnated in mineral oil for different time periods were investigated. The effect of insulation paper thickness on the electrical and mechanical properties has also been studied. The results showed that the breakdown voltage and the tensile strength decreased with increasing the time of immersion of insulation paper in oil at room temperature, at 5 and at -12. Also, the thermal aging effect on the characteristic of insulation paper has been studied. It was found that high temperatures affect the breakdown voltage and the tensile strength to a great extent.

Approaches for Detailed Modelling of Ultra-Precision Positioning Systems  [PDF]
Dominik Dahlmann, Nesrine Sassi, Berend Denkena
Modern Mechanical Engineering (MME) , 2016, DOI: 10.4236/mme.2016.61005
Abstract: Nowadays, the productivity of ultra-precision machining is fundamentally limited by low feed rates because of the required accuracies in the nanometre range. An increase in motion dynamics leads to disturbances that affect the toolpath’s accuracy. Existing control concepts are not able to reliably detect and compensate the deviations caused by increased dynamics. This paper compares modelling approaches for ultra-precision positioning systems aiming to predict and compensate occurring deviations.
Hepatitis C virus (HCV) status in newborns born to HCV positive women performing intracytoplasmic sperm injection
F Nesrine, H Saleh
African Health Sciences , 2012,
Abstract: Background: A low risk of HCV vertical transmission has been reported especially in those born to women with viraemia. Intracytoplasmic sperm injection (ICSI) being an assisted reproduction technique includes procedures that may increase risk of transmission. Objective: To determine the rate of vertical transmission of HCV to newborns born to HCV positive mothers in ICSI cycles. Methods: In a cross-sectional observational study, serum samples have werecollected within the first week after birth from newborns of two groups of ICSI cycles females. Group one: 30 women HCV antibody (Ab) positive/HCV RNA negative. Group two: 30 women HCV Ab positive/ HCV RNA positive. Newborn sera were subjected to HCV antibody testing, and detection of HCV viral RNA by PCR. Results: None of the newborns born to PCR negative females undergoing ICSI cycles showed positive results neither for HCV antibody, or for HCV RNA. Only one out of the 30 newborns born to PCR positive females was positive for HCV antibody and HCV RNA. Conclusion: HCV vertical transmission in ICSI cycles seemed to be of low incidence in PCR positive women, while in the case of HCV PCR negative/sero-positive women, it appeared to be completely absent. This observation could have an impact on the clinicians’ counseling for HCV positive females seeking ICSI.
Quand les jeunes s’expriment : appropriation symbolique de l’espace bougiote à travers rap et graffiti
Lydia Benbelaid,Nesrine Mahrouche
Synergies Algerie , 2012,
Abstract: Dans cette présente recherche, nous avons tenté de rendre compte de certaines pratiques langagières, bien particulières, inhérentes aux jeunes. Pour cela, nous nous sommes intéressées à deux types de pratiques, à savoir : le rap et le graffiti. Ces formes d’inscriptions s’inscrivent dans la culture Hip Hop (urbaine), et si nous y avons accordé un intérêt certain, c’est parce qu’il s’agit de moyens qui permettent aux jeunes d’exprimer leur mal-vivre social, d’asseoir leur identité, de s’approprier leur espace, de marquer leur territoire et d’ériger des barrières virtuelles. A travers quelques photographies de graffitis, entretien avec un leader de groupe de rap et des textes de rap, nous avons essayé de répondre au questionnement suivant : quelles sont les spécificités des pratiques dites jeunes et comment tendent-elles à l’appropriation de l’espace ?
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