In this study, the kinetics for the reaction of tert-butanol esterification with acetic acid in the presence of Dowex 50Wx8 catalyst was investigated. The reaction kinetic experiments were conducted in 1000 milliliter vessel at temperatures ranged from 50 - 80 oC, catalyst loading 25-50 g/L, and the molar ratios of acetic acid to tert-butanol from 1/3 – 3/1. The reaction rate was found to increase with increasing temperature and catalyst loading. It was also found the conversion of the tert-butanol increases as the molar ratio of acid to alcohol increases from 1/3 – 3/1. The Non-ideality of the liquid phase was taken into account by using activities instead of molar fractions. The activity coefficients were calculated according to the group contribution UNIFAC method. The results show that the activation energy of tert-butanol esterification with acetic acid was found to be 1.09 kJ/mol.
A series of heterogeneous basic catalysts of CaO, MgO and CaMgO2 at different calcination temperature were synthesized via solution combustion method. Different characterization techniques have been carried out to investigate the structure of the produced catalysts i.e. X-ray diffraction (XRD), particle size analyzer, morphology by atomic force microscope (AFM) and reflection using UV-VIS diffuse reflectance spectra. The particles size analyzer revealed that the mixed oxide catalysts calcined at different calcination temperature possess smaller nano size particles compared to pure CaO. Moreover, the energy band gap was calculated based on the results of diffuse reflectance spectra. The energy band gap was redu
... Show MoreThe study aimed to recommend a new spectrophotometric-kinetic method for determination of carbamazepine (CABZ) in its pure form and pharmaceutical forms. The proposed procedure based on the coupling of CABZ with diazotized sulfanilic acid in basic medium to yield a colored azo dye. Factors affecting the reaction yield were studied and the conditions were optimized. The colored product was followed spectrophotometrically via monitoring its absorbance at 396 nm. Under the optimized conditions, two method (the initial rate and fixed time (10 minute)) were applied for constructing the calibration graphs. The graphs were linear in concentration ranges 2.0 to 18.0 µg.mL-1 for both methods. The proposed was applied successfully in
... Show MoreTwo arylenedisuccinamic acids, namely 1,4-phenylene-disuccinamic acid and 4,4'biphenyl-disuccinamic acid were prepared from the reaction of two moles of succinic anhydride with one mole of 1,4-phenylenediamine dihydrochloride and beinzidine respectively.Dehydration of arylenedisuccinamic acid in the pressence of polyvinyl alcohol (PVA) and catalytic amount of concentrated.H2SO4,gives N,N'-arylenedisuccinimidesPVAcomposite polymers. Dehydration of arylenedisuccinamic acid (without PVA) in the pressence of catalytic amount of conc. H2SO4 gives N,N'-arylenedisuccinimides. Arylenedisuccinamic acid and arylenedisuccinimides characterized by CHN-analysis,FT.IR and 1H,C13-NMR.Spectral analysis
In this paper, we study flow of photons rate production in a quark-gluon QG plasma. General theory of this study is based on the field theory for hard interaction. The kinetic of photons production from hard interaction in charm with anti-top to production photons with gluon due to plasma phase at high temperatures (150, 200,250,300 and 350 MeV) .It has been investigated and studied using the postulate of quantum chromodynamic theory QCD .The photons production rate of hard photons with( GeV) are insensitive to strength coupling and depend mainly on the temperature of system T . Despite the different critical temperature (150 and 190MeV) comes, we ï¬nd that same order of flow rate photons magnitude in both cases. In both cases, the f
... Show MoreA rapid and sensitive method for the determination of amoxicillin trihydrate (AMXT) based on the diazo-coupling reaction was studied. Sulphanilic acid diazotizes with nitrite ion in acidic medium to produce a water soluble, colorless diazonium ion, which subsequently coupled with AMXT to form a colored azo dye in the alkaline medium, having maximum absorption at 455 nm. The calibration graph showed that Beer's law is obeyed over the concentration range of 0.3 – 30.0 μg/mL of AMXT, with the detection limit of 0.15 μg/mL and molar absorptivity was 2.3 × 104 L/mol.cm. The accuracy and the precision were acceptable depending upon the values of error percentage and relative standard deviation. The influence of common interfer
... Show MoreBy extracting crystal violate dye (CV) from its aqueous solution, the photocatalytic decolorization performance of ZnO/MWCNT nanocomposite was evaluated. The nanocomposite was prepared by precipitation of ZnO and incorporates on the surface of Multi-Walled Carbon Nanotubes (MWCNT). ZnO nanoparticles were synthesized using the sol gel process with MWCNT acting as a template. They were then analyzed by XRD, SEM, and TEM, which revealed how the shape of the spherical nano ZnO interacts with the point of zero charge (pzc), which allows us to see the physical attributes. In the dipping photoreactor, which included a slurry of dye solution and ZnO/MWCNT nanocomposite, the effectiveness of decolorization was assessed. The photodecolori
... Show MoreThermonuclear reaction rates are calculated for three oxygen isotopes 14,15,16O in CNO cycles reactions occurring in red giant stars. These reactions are:, , , , and . Reaction rates have been calculated using Matlab codes, and related comparisons were made with NACRE II and Reaclib libraries, and the ratios of production to the destruction of 15,16O isotopes were found. Present reaction rate results were close to most of the selected reactions, and in some cases larger with a factor of 1-3. 15,16O production to destruction ratios indicated a special tendency to saturate at temperatures higher than ~ 2 GK, and these ratios were in general larger than 1 indicating an excess of producing such isotopes in re
... Show MoreA spectrophotometric method is proposed for the determination of some drugs containing amino group such as mesalazine, metoclopramide and dopamine in pharmaceutical formulations. It was simple, precise, accurate, rapid, and based on the oxidation of each drug with chromate as an oxidizing agent in the presence of 1N hydrochloric acid. Then indigo carmine is reacted with residual chromate in the presence of a catalysis factor (sodium oxalate). Increasing in absorbance's value of the color system is proportional to the amount of the three drugs which is measured at the selected wavelength of 610 nm.
The proposed method is obeying Beer's law in the ranges of (1-40, 2-44 and 2-52) ppm for the concentration of
... Show MoreDue to the importance of the extraction process in many engineering and medical industries, in addition to great interest in medicinal plants, in this research, microwave-assisted extraction has been applied to extract some active compounds from Rosmarinus officinalis leaves. The optimal extraction conditions were then determined by calculating the ratio and extraction efficiency. The process has also been described through kinetic study by applying five kinetic models, the Hyperbolic diffusion model, Power low model, the First order reaction model, Elovich's model, and Fick's second law diffusion model and determining their compatibility with the studies operation, and determining the kinetic constants for each model. The result
... Show MoreThe corrosion behavior and corrosion inhibition of α-brass (65.3% Cu, 34.4% Zn and others 0.3%) in 0.6 mol.dm-3 NaCl solution have been investigated using potentiostatic polarization technique, the main results obtained were expressed in terms of corrosion (Ec) and corrosion current (ic). The research was performed in neutral and slightly acidic media [pH=7 and pH=4] over the temperature range (288-318)K. It was found that the rate of corrosion increases with the increase of acidity and the increase of temperature. The rate of corrosion increased with the increase of temperature in conformity with Arrhenius equation. Values of activation energy (Ea*), pre-exponential factor (A) and entropy of activation (∆S*) have been derived f
... Show More