Four different spectrophotometric methods are used in this study for the determination of Sulfamethoxazole and sulfanilamide drugs in pharmaceutical compounds, synthetic samples, and in their pure forms. The work comprises four chapters which are shown in the following: Chapter One: Includes a brief for Ultraviolet-Visible (UV-VIS) Absorption spectroscopy, antibacterial drugs and sulfonamides with some methods for their determination. The chapter lists two methods for optimization; univariate method and multivariate method. The later includes different types, two of these were mentioned; simplex method and design of experiment method. Chapter Two: Includes reaction of the two studied drugs with sodium nitrite and hydrochloric acid for diazotization reaction followed by coupling with diphenylamine in acidic medium to form, a blue colored azo dye compound which exhibits maximum absorption (λmax) at 530 nm for sulfamethoxazole complex and 531 nm for sulfanilamide complex against the reagent blank and the concentration of these drugs were determined spectrophotometrically. The optimum reaction conditions and other analytical parameters were evaluated. In addition to classical univariate optimization, modified simplex method has been applied in optimization of the variables affecting the color producing reaction. The results show better optical characteristics for calibration curves and statistical data were obtained under optimum conditions obtained by multi simplex optimization, in comparison with those obtained via univariate method for two studied drugs. Beer’s law obeyed in the concentration range of 0.5-12.0 μg.mL-1, 0.5-7.0 μg.mL-1 for sulfamethoxazole and sulfanilamide respectively with molar absorptivity of 4.9617×104 L.mol-1.cm-1 for sulfamethoxazole and 5.9185×104 L.mol-1.cm-1 for sulfanilamide. The detection limits were 0.036 μg.mL-1 and 0.016 µg.mL-1 for the two complexes respectively by simplex method. No interferences from the studied excipients on the determination of these drugs were found therefore, the proposed methods were applied successfully II for the determination of the sulfamethoxazole and sulfanilamide in pharmaceutical compound and in synthetic samples. Chapter Three: Is based on the formation of condensation complexes of each drug with sodium 1,2-naphthoquinon-4-sulfonate as a chromogenic reagent. The absorbance values, for the formed complexes were measured at 460 nm for sulfamethoxazole and 455 nm for sulfanilamide; against reagent blank. Different variables affecting the completion of reaction have been carefully optimized following the classical univariate sequence and design of experiment (DOE) method and the results were obtained under optimum conditions by (DOE) optimization which shows better optical characteristics for calibration curves and statistical data in comparison with those obtained via univariate method for two studied drugs. The calibration graphs are linear in the ranges of (5.0-50.0) µg.mL-1 for sulfamethoxazole and (5.0-30.0) µg.mL-1 for sulfanilamide with detection limit 0.359 µg.mL-1for sulfamethoxazole complex and 0.536 µg.mL-1 for sulfanilamide complex. The molar absorptivity was found to be (7.0918×104 L.mol-1.cm-1) for sulfamethoxazole and (7.0774×104 L.mol-1.cm-1) for sulfanilamide by the design of experiment (DOE) method. Finally no interferences from the studied excipients on the determination of these drugs were found. The proposed methods have been successfully applied for the determination of sulfamethoxazole and sulfanilamide in their pharmaceutical preparation and synthetic samples. Chapter Four: Includes two parts; Derivative spectrophotometry and partial least-squares (PLS). Derivative spectrophotometry is based on the first and second derivative spectra of absorption which has been applied for simultaneous spectrophotometric determination of sulfamethoxazole and sulfanilamide in their mixture in the ultraviolet region. The method offers an advantage of getting rid of the resulting error in the values of absorption because of the presence of each drug with the presence of interferences from the excipients. It was found that the method is able to accurately estimate sulfamethoxazole in the range of (2.0-50.0) μg.mL-1; in mixtures containing III (2.0-30.0) μg.mL-1 of sulfanilamide, as (interferent). The results obtained, with the first derivative measurements, indicate that when the concentration of sulfanilamide is kept constant and the concentration of sulfamethoxazole varied, the peak amplitudes are measured at peak-to-baseline (223, 254,287 nm), peak to peak height between (223- 254 nm), (254-287nm). Moreover, the height at the zero cross of sulfanilamide at (235.62, 258.72 nm), heightto-height of the two zero crosses between (235.62-258.72 nm) and area under peak between (241.95-267.04 nm), (267.04-330 nm) were found to be in proportion to the sulfamethoxazole concentration therefore they are used for the determination of it. The careful inspection of the second derivative spectra obtained for the mentioned mixtures of sulfamethoxazole and sulfanilamide shows that peak to basline is at (239.5, 263.5, 267.75, 301, 215 nm) , height to basline is at zero cross is at (245.86, 271.28 nm) , peak to peak is between (239.5-264.25 nm), (239.5-267.75 nm), (271.28-301 nm), (215-239.5 nm), height to height is at two zero cross (245.86-271.28 nm) in addition to peak area at the interval between (254.12-281 nm), (286.95- 329.5 nm), (221.75-254.12 nm) measurements at specified wavelength could be used to quantify the exact concentration of sulfamethoxazole in presence of sulfanilamide. Sulfanilamide was determined for the range of (2.0-50.0) μg.mL-1; in a mixture containing (2.0-50.0) μg.mL-1 of sulfamethoxazole as (interferent). The procedure gave good results over the studied range of concentration depending on peak-to-baseline at (224, 246, 271 nm), height at zero cross at (241.95, 267.04 nm), peak to peak between (224-246 nm), (246-271 nm), height to height at two zero cross (241.95-271 nm) and area under the peak at (235.62-258.72 nm) measurements were found to be used for the determination of sulfanilamide in the first derivative technique. On other situation, the wavelengths are at 218 nm, 231 nm, 260 nm and 278 nm (peak to base line measurements), and height at two zero cross at 254 nm and 281 nm, and peak to peak measurements between (218-231 nm), (231-260 nm) and (260-278 nm), and height at zero cross at (254, 281 nm), wavelengths at (210-224 nm) , (224-245.84 nm) and (271.28-330 nm) peak area at the interval measurements were used for the estimation of sulfanilamide on second derivative.
Sansevieriatrifasciata was studied as a potential biosorbent for chromium, copper and nickel removal in batch process from electroplating and tannery effluents. Different parameters influencing the biosorption process such as pH, contact time, and amount of biosorbent were optimized while using the 80 mm sized particles of the biosorbent. As high as 91.3 % Ni and 92.7 % Cu were removed at pH of 6 and 4.5 respectively, while optimum Cr removal of 91.34 % from electroplating and 94.6 % from tannery effluents was found at pH 6.0 and 4.0 respectively. Pseudo second order model was found to best fit the kinetic data for all the metals as evidenced by their greater R2 values. FTIR characterization of biosorbent revealed the presence of carboxyl a
... Show MoreThe limited availability of the two-circle diffractometer to collect intensity measurements down to the monoclinic system has been extended in a novel procedure to collect intensities for the triclinic system. The procedure involves the derivation of matrix elements from graphical representation of the reciprocal lattice. Offset of the origins of the upper layers from that of the zero-layer - characteristic of triclinic system - is determined and the 3 x 3 matrix elements are evaluated accordingly. Details of crystal alignment by X-rays for the triclinic system utilizing the intensities of equivalent reflections is described
This paper presents the Extended State Observer (ESO) based repetitive control (RC) for piezoelectric actuator (PEA) based nano-positioning systems. The system stability is proved using Linear Matrix Inequalities (LMIs), which guarantees the asymptotic stability of the system. The ESObased RC used in this paper has the ability to eliminate periodic disturbances, aperiodic disturbances and model uncertainties. Moreover, ESO can be tuned using only two parameters and the model free approach of ESO-based RC, makes it an ideal solution to overcome the challenges of nano-positioning system control. Different types of periodic and aperiodic disturbances are used in simulation to demonstrate the effectiveness of the algorithm. The comparison studi
... Show MoreThe issue of penalized regression model has received considerable critical attention to variable selection. It plays an essential role in dealing with high dimensional data. Arctangent denoted by the Atan penalty has been used in both estimation and variable selection as an efficient method recently. However, the Atan penalty is very sensitive to outliers in response to variables or heavy-tailed error distribution. While the least absolute deviation is a good method to get robustness in regression estimation. The specific objective of this research is to propose a robust Atan estimator from combining these two ideas at once. Simulation experiments and real data applications show that the proposed LAD-Atan estimator
... Show MoreElastic magnetic M1 electron scattering form factor has been calculated for the ground state J,T=1/2-,1/2 of 13C. The single-particle model is used with harmonic oscillator wave function. The core-polarization effects are calculated in the first-order perturbation theory including excitations up to 5ħω, using the modified surface delta interaction (MSDI) as a residual interaction. No parameters are introduced in this work. The data are reasonably explained up to q~2.5fm-1 .
Machine learning has a significant advantage for many difficulties in the oil and gas industry, especially when it comes to resolving complex challenges in reservoir characterization. Permeability is one of the most difficult petrophysical parameters to predict using conventional logging techniques. Clarifications of the work flow methodology are presented alongside comprehensive models in this study. The purpose of this study is to provide a more robust technique for predicting permeability; previous studies on the Bazirgan field have attempted to do so, but their estimates have been vague, and the methods they give are obsolete and do not make any concessions to the real or rigid in order to solve the permeability computation. To
... Show MoreThe need for optical fibers has emerged for its ability to transmit information with less attenuation and over long distances. In this work, four optical fibers with core radii from 1 μm to 4.75 μm in steps of 1.25 μm and a numerical aperture of 0.17 were studied and their modes properties have been calculated at a wavelength of 633 nm by using RP Fiber Calculator (free version 2022). Also, the effect of increasing the core radius on these properties has been studied. Multimode fibers can be obtained when the radius of the fiber core is large compared to the operating wavelength of the fiber which is less than the cutoff wavelength of the mode. Otherwise, a single-mode fiber is obtained. It has been concluded that all the calculated p
... Show MoreIn this work, the effect of the addition of bright nickel plating and silver carried out by the electroplating method has been studied, on the coating of copper nanoparticles on the copper base metal via the process of thermal evaporation. The improvement of the solar absorber using CuNP in combination with the bright nickel and silver was obtained to be better than copper nanoparticles individually. A bright nickel enhanced the absorbed thermal stability. Also, other optical properties, absorptions, and emissivity slightly decreased from (93% to 87%), while the existence of silver had a slight impact on absorption of about (86.50%). On the other hand, thermal conductivity was evaluated using hot disk analyzer. The results showed a good
... Show MoreA new application of a combined solvent extraction and two-phase biodegradation processes using two-liquid phase partitioning bioreactor (TLPPB) technique was proposed and developed to enhance the cleanup of high concentration of crude oil from aqueous phase using acclimated mixed culture in an anaerobic environment. Silicone oil was used as the organic extractive phase for being a water-immiscible, biocompatible and non-biodegradable. Acclimation, cell growth of mixed cultures, and biodegradation of crude oil in aqueous samples were experimentally studied at 30±2ºC. Anaerobic biodegradation of crude oil was examined at four different initial concentrations of crude oil including 500, 1000, 2000, and 5000 mg/L. Complete removal of crud
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