This work deals with kinetics and chemical equilibrium studies of esterification reaction of ethanol with acetic acid. The esterification reaction was catalyzed by an acidic ion exchange resin (Amberlyst- 15) using a batch stirred tank reactor. The pseudo-homogenous and Eley-Rideal models were successfully fitted with experimental data. At first, Eley-Rideal model was examined for heterogeneous esterification of acetic acid and ethanol. The pseudo-homogenous model was investigated with a power-law model. The apparent reaction order was determined to be (0.88) for Ethanol and (0.92) for acetic acid with a correlation coefficient (R2) of 0.981 and 0.988, respectively. The reaction order was determined to be 4.1087x10-3 L0.8/(mol0.8.min) with R2 of 0.954. The adsorption constants of acetic acid and ethanol were calculated as 0.023 and 0.044 L/mol, respectively and the lumped reaction constant were determined to be 5*10-4 L2/gcat.mol.min. The results of the reaction kinetic study show that the high acetic acid/ethanol molar ratio was favored. The maximum conversion of 70 % was obtained at 70°C for acetic acid/ethanol molar ratio of 4.
One technique used to prepare nanoparticles material is Pulsed Laser Ablation in Liquid (PLAL), Silver Oxide nanoparticles (AgO) were prepared by using this technique, where silver target was submerged in ultra-pure water (UPW) at room temperature after that Nd:Yag laser which characteristics by 1064 nm wavelength, Q-switched, and 6ns pulse duration was used to irradiated silver target. This preparation method was used to study the effects of laser irradiation on Nanoparticles synthesized by used varying laser pulse energy 1000 mJ, 500 mJ, and 100 mJ, with 500 pulses each time on the particle size. Nanoparticles are characterized using XRD, SEM, AFM, and UV-Visible spectroscopy. All the structural peaks determined by the XRD
... Show Moreهدفت الدراسة الحالية الى التعرف ما اذا كان هناك تقبل اجتماعي للتلاميذ بطيئي من قبل اقرانهم العاديين؟ وكذلك معرفة ما اذا كان هناك فروق ذات دلالة في التقبل الاجتماعي بين افراد عينة الدراسة على وفق المتغيرات الاتية:
أ- العمر (9-13)
ب- الجنس (ذكور –اناث)
ج- المرحلة الدراسية
د- الحالة الاقتصادية (جيدة –متوسطة –جيدة جدا)
ولغرض تحقيق اه
... Show MoreA piezoelectric cantilever beam with a tip mass at its free end is a common energy harvester configuration. This article introduces a new principle of designing such a harvester that increases the generated power without changing the resonance frequency of the harvester: the attraction force between two permanent magnets is used to add stiffness to the system. This magnetic stiffening counters the effect of the tip mass on the efficient operation frequency. Five set-ups incorporating piezoelectric bimorph cantilevers of the same type in different mechanical configurations are compared theoretically and experimentally to investigate the feasibility of this principle: theoretical and experimental results show that magnetically stiffened harve
... Show MoreRemoval of direct blue dye by electrocoagulation method has been investigated using aluminum electrode in a bench-scale electrochemical system. Current density, NaCl concentration, electrocoagulation time, and dye concentration has been studied as effecting parameters in color removal efficiency. Increasing of current density will increase the color removal efficiency and energy consumption as well. While increasing NaCl concentration increase the color removal efficiency but it decrease energy consumption. High dye concentration is needed for extra electrocaogolation time to reach the same efficiency that obtained with low dye concentration .With current applied 0.35 amps. and NaCl concentration of 2 g/l more
... Show MoreIn the present study, gold nanoparticles (AuNPs) were prepared using a simple low cost method synthesized cold plasma at different exposure time . The nanoparticles were characterized using UV-Visible spectra, X-ray diffraction (XRD). The prepared AuNPs showed surface Plasmon resonance centered at 530, 540,and 533 nm. The XRD pattern showed that the strong intense peaks indicate crystalline nature and face centered cubic structure of gold nanoparticles for all samples were prepared .The average crystallite size of the AuNPs was 20-40 nm. Morphology of the AuNPs were carried out using FESEM. Observations show that the AuNPs synthesized we well dispersed with and particle sizes ranging from 9 to 31 nm with spherical shapes which are cle
... Show MoreOily carwash wastewater is a high organic and chemical wastewater. This paper targeted to investigate a treatment to decrease the water consumption and contaminants in car-washing stations. Electrocoagulation combined with ultrasonic energy (Sono-Electrocoagulation) was suggested so that the carwash wastewater is treated to be reused. The effect of both the voltage and time of treatment on the removal of COD, turbidity, conductivity, and total dissolved solids (TDS) were studied at constant initial pH 7 and electrode distance 2 cm. The results showed the best results of removal COD, turbidity, TDS, and reduce electrical conductivity is when the voltage was 30 V and a treatment time of 90 minutes.
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... Show MoreThe condition of Islam and Muslims and what their political, social, cultural and educational status, and even religious and faith status, has led to whoever feels his belonging to this great religion and that middle nation, to try as much as he can to fix what has been corrupted as much as he can, and perhaps in diagnosing illness and illness as It was said half the way to treatment, and from this standpoint I liked to occupy thought, work consideration and harness part of the youth’s life in order to reach what contributes to reforming the situation and the safety of generations, and this is only in seeking knowledge and learning it by following the guidance of the Messenger (r) and his companions ( y) Therefore, the subject of my re
... Show MoreThe deposition process and investigation of the physical properties of tungsten trioxide (WO3) thin films before and after gamma irradiation are presented in this paper. The WO3 thin films were deposited, using the pulse laser deposition technique, on glass substrates at laser energies of 600mJ and 800mJ. After deposition, the samples were gamma irradiated with Co60. The structural and optical properties of polycrystalline WO3 thin films are presented and discussed before and after 5kGy gamma irradiation at the two laser energies. X-ray diffraction spectra revealed that all the films consisted of WO3 crystallized in the triclinic form; the dislocation density and lattice strain increased with the absorbed dosage of gamma
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