The esterification reaction of ethyl alcohol and acetic acid catalyzed by the ion exchange resin, Amberlyst 15, was investigated. The experimental study was implemented in an isothermal batch reactor. Catalyst loading, initial molar ratio, mixing time and temperature as being the most effective parameters, were extensively studied and discussed. A maximum final conversion of 75% was obtained at 70°C, acid to ethyl alcohol mole ratio of 1/2 and 10 g catalyst loading. Kinetic of the reaction was correlated with Langmuir-Hanshelwood model (LHM). The total rate constant and the adsorption equilibrium of water as a function of the temperature was calculated. The activation energies were found to be as 113876.9 and -49474.95 KJ per Kmol of acetic acid for the esterification reaction and the heat of adsorption of water. These results agreed well with the previous published data.
Background: Dyslipidemia is a major cause of
cardiovascular disease, which in turn, is the most
common cause of female morbidity and mortality.
Postmenopausal women (natural and surgical) are at
higher risk of developing cardiovascular disease,
especially coronary artery atherosclerosis.
Objective: To observe the relationship between blood
lipids: total cholesterol (TC), high density lipoproteincholesterol (HDL-C), low density lipoproteincholesterol (LDL-C), triglycerides (TGs), and very low
density lipoprotein- cholesterol (VLDL-C), LDL-C/
HDL-C ratio (atherogenic index) and menopausal
status, and to determine the co-factors that may explain
this relationship
Methods: A prospective, cross-sectional st
In dealing with media management phenomenon, concept and elements, we have tried, as much as possible, to build an abstract concept that can be analyzed and measured by analyzing the elements and components of the concept mentioned and explain it.
Before further consideration of the management of media campaigns, it is necessary to restore some points of media management so as not to understand the subject of campaign management as if it is independent of the concept of media management and the objectives that we seek to ensure its achievement. As we have noted that the concept of media management frames the administration mentioned as:
- Authority to manage the media institution.
- Operations supervised by the me
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This research dealt with the modern dengue living in its linguistic meaning and where this dengue will be, and its cause and treatment, then concluded the talk about the search with the results envisaged from this research, has been shown that the main reason in living dengue: is after the slave of the book of God and the Sunnah of the Prophet peace be upon him Him.
This research aims to deal with contemporary knowledge methodology to correlate between operations strategy and technological change or modernization in productive paths for industrial organizations depend on practical indicators for competitive priorities that is objectives of operations performance.
The research is based on main hypothesis, concentrates on determination of technological change which is decided by the level of technology deterioration in current operations path compared with the competitors leaders-technology leaders.
We apply these concepts on hypothetical case to two similar companies in their production nature and te
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The unbalanced distribution of investments in the economic fields of the 1950s had a negative impact on the overall economic life of the country in that period and subsequent periods. Since the 1960s, the planning agencies have tried to reduce the negative impact of imbalance in regional development and the emergence of disparities in development between the regions of the country and to identify disparities in levels of spatial development. At the planning level, there have been many studies and mathematical and statistical models to analyze variance and clarify its dimensions and to measure the degree of developmental disparity between Regions and means of narrowing this problem and the development of policies and strategies for develo
... Show MoreSlurring Phenomenon And Throat Voices
It is no secret to anyone the lofty classifications and wonderful investigations made by Muslim scholars in various eras, with which they removed the dust of ignorance from the nation, clarified the argument, and illuminated the path of education, especially in the legal sciences, which are the foundation of religion.
It is the life of hearts and the path of grammarians in this world and the hereafter.
Among those scientific classifications are the investigations they have written in the science of the principles of legislation, which have established the general evidence and the original rules to which practical legal rulings are referred. And as you know, it is the basis of Islamic jurisprudence, a means of knowing its
... Show MoreBackground: Gingival recession is defined as the apical migration of the gingival margin below the cementoenamel junction (CEJ), resulting in exposure of the root surface and it is one of the main esthetic complaints of patients. The management of gingival recession and its sequelae is based on a thorough assessment of the etiological factors and the degree of tissue involvement.
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S Khalifa E, N Adil A, S Husam Ali, H Nibras A…, 2009