The Esterification kinetics of acetic acid with ethanol in the presence of sulfuric acid as a homogenous catalyst was studied with isothermal batch experiments at 50-60°C and at a different molar ratio of ethanol to acetic acid [EtOH/Ac]. Investigation of kinetics of the reaction indicated that the low of [EtOH/Ac] molar ratio is favored for esterification reaction, this is due to the reaction is catalyzed by acid. The maximum conversion, approximately 80% was obtained at 60°C for molar ratio of 10 EtOH/Ac. It was found that increasing temperature of the reaction, increases the rate constant and conversion at a certain mole ratio, that is due to the esterification is exothermic. Activity coefficients were calculated using UNIFAC program. Results showed deviation in activation energy in the non-ideal system of about 20% this is due to the polarities of water and ethanol compared to the non-polar ethyl acetate this dissimilarity leading to strong non- ideal behavior. The homogenous reaction has been described with simple power-law model. The chemical equilibrium combustion calculated form the kinetic model in agreement with the measured chemical equilibrium.
The syntheses, characterizations and structures of three novel dichloro(bis{2-[1-(4-methoxyphenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})metal(II), [M(L)2Cl2], complexes (metal = Mn, Co and Ni) are presented. In the solid state the molecules are arranged in infinite hydrogen-bonded 3D supramolecular structures, further stabilized by weak intermolecular π…π interactions. The DFT results for all the different spin states and isomers of dichloro(bis{2-[1-phenyl-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})metal(II) complexes, [M(L1)2Cl2], support experimental measurements, namely that (i) d5 [Mn(L1)2Cl2] is high spin with S = 5/2; (ii) d7 [Co(L1)2Cl2] has a spin state of S = 3/2, (iii) d8 [Ni(L1)2Cl2] has a spin state of S =
... Show MoreIn two commercial broiler breeds (Cobb 500 and Hubbard F-15), the polymorphisms of the chicken insulin-like growth factor 2 (IGF2) gene were studied. A total of three hundred avian blood samples were obtained. Using a fast salt-extraction technique, genomic DNA was isolated. Using polymerase chain reaction, 1146 bp fragments of the gene were amplified (PCR). The amplified fragments were subjected to restriction enzyme digestion using HinfI endonuclease enzyme, and the digested products were separated on a 2% agarose gel. The findings indicated two alleles T and C for the target locus, with respective frequencies of 73.3% and 26.7%. Three distinct genotype variations, TT, TC, and CC, were found, with genotype frequencies of 59.1 percent, 28.
... Show Morenew six mixed ligand complexes of some transition metal ions Manganese (II), Cobalt(II), Iron (II), Nickel (II) , and non transition metal ion zinc (II) And Cadmium(II) with L-valine (Val H ) as a primary ligand and Saccharin (HSac) as a secondary ligands have been prepared. All the prepared complexes have been characterized by molar conductance, magnetic susceptibility infrared, electronic spectral, Elemental microanalysis (C.H.N) and AA . The complexes with the formulas [M(Val)2(HSac)2] M= Mn (II) , Fe (II) , Co(II) ,Ni(II), Cu (II),Zn(II) and Cd(II) L- Val H= (C5H11NO2) , C7H5NO3S The study shows that these complexes have octahedral geometry; The metal complexes have been screened for their in microbiological activities against bacteria.
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Взгляд на пол как на комплексное социальное отношение означает,что роль женщины в истории следует рассматривать не просто как новый для исторической науки предмет исследования, а как обойденный вниманием ученых вопрос об отношениях между людьми или группами людей.
Женщина играет особую и важную роль в обществе , даже скажут ,что она половина нашего общества ,поэтому она яв
... Show MoreThis study deals with examining UCAS students’ attitudes in Gaza towards learning Arabic grammar online during the Corona pandemic. The researcher has adopted a descriptive approach and used a questionnaire as a tool for data collection. The results of the study have statistically shown significant differences at the level of "0.01" between the average scores of students in favor of the students of the humanities specializations. It has also been found that the students’ attitudes at the Department of Humanities and Media towards learning Arabic grammar online are positive. Additionally, the results revealed no statistical significant differences due to the variable of UCAS students’ scientific qualifications. The results stressed
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Vorwort:
Die Übersetzung gilt in der Vergangenheit als Brücke zwischen verschiedenen Gesellschaften. Sie spielt eine große Rolle im Bereich Kulturaustausch der Länder. Die Araber haben das früh betrachtet, und die Übersetzung als Wissenschaft wird eine der wichtigsten Lehren. Viele griechische Wissenschaften waren durch Übersetzung in den arabischen Ländern bekannt.
In dieser Forschung findet man einen Überblick über die Wichtigkeit der Sprichwörterübersetzung und welche Rolle spielt diese Übersetzung im Z
... Show MoreArts acts to reduce and exclude everything that is not necessary in the delivery of meaning, especially representative performance, which is based on the intensification of the physical and vocal actions, and in drawing the dimensions of the character. And because that, the artistic staff, among others in the ministry of education, are considered the cornerstone, in the development of theatrical activities in schools, this research came to find out the extent to which teachers in primary schools, in secondary schools and artistic supervisors rely on shorthand mechanisms in the representative performance.
The current research relied on the descriptive approach, in analyzing his sample, which was deliberately chosen, Among the most imp
This study was for searching for Cholera Bacteria serotype which causes epidemiology Cholera in the 2007 in a fast method which contains (Rapid Visual Test) (Crystal V.C.) which was used for the first time in Iraq to diagnosis of Cholera Bacteria & compared with the traditional bacteriology method. The Cholera disease is one of the most dangerous epidemiological diseases which lead to death with a percentage of (50 – 70) % in the severe cases for untreated patients . For this purpose, 100 samples of stool from the patients from a (13) hospitals in Baghdad Governorate in the period from August to the end of December. The Cholera was diagnosis in two methods, 1st method was the fast method using the nitrocellulose which is coated with anti-
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The spherical double pole-piece electron lens i§ depend on some
fact0rs : the- minimum va}ue-of projector fo·cal length (Fp)i:J,Iill • the
maximum value of magnetic flux density (Bm) , the total hal[ width
,(W) o'f asyriunetrical clln'e of magnetic field distribution [because there are differe_nt values of bore diameter (D1) • i. &
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