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.
Physiological status and litter size can indeed have a significant impact on ewes' hematological parameters, which are essential indicators of their health. Therefore, this study examined the hematological profiles of ewes during pregnancy with single and twins in the Awassi ewes. The present study involved 232 ewes in good health and at sexual maturity. Among them, 123 ewes had single pregnancies, while 109 ewes had twin pregnancies. The age range of the ewes included in the study was between 3.5 and 4.5 years. Hematological tests were conducted on the sheep's blood samples promptly following collection. The findings demonstrated variations in hematological parameters among pregnant
... Show MoreCurrent Thesis has aimed to identify : The Psychological barriers for university students , Differences in psychological barriers depending on the variable sex (Males – Females) , Adjustment to College life for university students, Differences in Adjustment to College at university life depending on the variable sex (Males – Females), and finally, The correlation between psychological barriers and Adjustment to College life. The researcher has prepared a sample consisted of (100) male and female students who were randomly selected from university students, The researcher has adopted a measure of (2002) to measure the psychological barriers, also the researcher adjustment scale with university life.
The results showed that universi
The current research deals with spatial relations as a tool to link urban landmarks in a homogeneous composition with monumental sculptures, by identifying these landmarks and the extent of their impact on them, which constitutes an urgent need to evaluate the appropriate place and its effects on them, so that this analytical study is a critical approach adopted in artistic studies of monumental models in Arabcapitals .The current research came in four chapters, the first chapter of which dealt with the research problem, its importance and the need for it, then its objectives that were determined in revealing the spatial relations and their impact on
... Show MoreBackground: Vibration decreases the viscosity of composite, making it flow and readily fit the walls of the cavity. This study is initiated to see how this improved adaptation of the composite resin to the cavity walls will affect microleakage using different curing modes
Materials and methods: Standard Class V cavities were prepared on the buccal surface of sixty extracted premolars. Teeth were randomly assigned into two groups (n=30) according to the composite condensation (vibration and conventional) technique, then subdivided into three subgroups (n=10) according to light curing modes (LED-Ramp, LED-Fast and Halogen Continuous modes). Cavities were etched and bonded with Single Bond Universal
... Show MoreAbstract:The optimum design of the magnetic deflector with the lowest values of the radial and spiral distortion aberration coefficients was computed. The optimized calculations were made using three models, Glaser bell-shaped, Grivet-lenz and exponential models. By using the optimum axial field distribution, the pole pieces shape which gave rise to those field distributions was found by using the reconstruction method. The calculations show that the results of the three models coincide at the lower values of the excitation parameter. In general the Glaser- bell shaped model gives the optimum results at the whole range of the excitation parameter under investigation.The negative values of the spiral distortion aberration coefficient appears
... Show MoreThirty five samples were collected from patients (1-30) years old, suffered from, infected skin , rushes, boils , oral thrush, anal & vaginal itches. Candida albicans 57.3% (20 isolates) and Candida tropicalis 22.5% (8 isolates) Aspergillus fumegatus 11.5% (4 isolates) Aspergillus nigar 8.7%(3 isolates) , were isolated & identified from these samples. Alcoholic & water hot extracts of the punica granatum (Pomegranate) peels as well as the dried powder were prepared. The anti-fungal activity of the extracts was evaluated by means of the agar-well diffusion assay. The extract exhibited potent activity against yeast. The Minimum inhibitory concentra
... Show MoreThis study included the Zakhikhah area in the Al- Anbar desert, which it bounded on the north, east, and west by the Euphrates River and on the south by the Ramadi-Qaim road. Several exploratory field trips were taken to the study area. During this time, a semi-detailed area survey was carried out based on satellite imagery captured by American Land sat-7, topographic maps, and natural vegetation variance. All necessary field tools, including a digital camera and GPS device, were brought to determine the soil type and collect plant samples. All of these visits are planned to cover the entire state of Zakhikhah. All vegetation cover observations, identifying sampling sites and attempting to inventory and collect medicinal plants in t
... Show MoreAim: To evaluate the commercial pure titanium disks that structuring by laser in two design (dot and groove) each one with three different laser scan (5, 15 and 25) and comparing with titanium surface that not subjected to any surface structuring (control) through measuring the wettability test and surface roughness test. Materials and methods: Structuring on the surface of the commercial pure titanium (CP Ti) disks was performed via using fiber laser CNC machine in two design (dot and groove) in three different laser scans (5, 15 and 25), then the structuring disks analyzed with the control group by atomic force microscope and water contact angle test. Results: The results of this study showed that the surface roughness and the wettability
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