Preferred Language
Articles
/
alkej-534
Hydrodynamics, Mass and Heat Transfer in Reactive Distillation
...Show More Authors

      The ethyl acetate synthesis via heterogeneous reactive distillation is studied experimentally using ethanol and acetic acid. Three types of cation exchanging resins were used as catalysts: Zerolit 225, Zerolit 226 and Ambylite 400. Experiments were carried out in two units of the same dimensions. Each unit consisted of three sections: rectifying, reactive and stripping sections of heights (60+25+20) cm respectively and 2.5cm column diameter. The first unit (column-A-) was a fractionation type and the second unit (column-B-) was packed column. The packing type was hollow glass cylinders with 10 mm height, and 4, 5 mm inner and outer diameter respectively.

      The experiments were carried out by using two operation modes. The semi-batch and continuous operation mode. In the first part of present investigation, the semi-batch mode was used to evaluate the catalyst type and to evaluate the performance of reactive distillation unit configuration (Fractionation and packed column). Results show that, the column-B- gave higher conversion rates than column-A-. This is attributed to the high surface area available for liquid vapour contact in packed type column, which leads to increasing mass transfer rates.  On the other hand, Ambylite 400 catalyst showed higher activity for esterification reaction than other two types of catalysts.

      The second part of work continued with column -B- only. It is well known that, the esterification process is regarded one of exothermic reactions. Therefore, the monitoring of the temperature distribution along column axial for all three types of catalysts showed that the temperature distribution was essentially the same due to steady state operation in continuous operation mode. On the other hand, the effect of reflux ratio on temperature distribution was clearly noted, that is as the reflux ratio increased the temperature distribution along the column was reduced for each type of catalysts.

      On the other hand, the experimental results point that, as a reflux ratio increases the conversion rates of acetic acid is increased too because such increasing is related to high mass transfer rates between  vapour and liquid along reactive distillation column.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Mar 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
International business particularly that centered on foreign direct investment
...Show More Authors

:  

While practicing of International business particularly that centered on foreign direct investment, let on one side, to achieving objectives of transnational corporations specially that represented in continuous pursue to improving its cash flows and maximization of stockholders wealth which is considered the most important objective to the transnational corporations, but in the same time its lead, on other side, to increasing the foreign exchange risk exposuring these corporations. So, the transnational corporations (TNCs) struggling to make strategies which are dealing in smart way, with this risk and its management in way that enable to avoiding risk comple

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Nov 28 2018
Journal Name
Arab Science Heritage Journal
العالم العالم ابن خلدون ( ت 808 هـ ) (نظريته في السياسة والعصبية)
...Show More Authors

Ibn Khaldun is one of the best Arab Muslims scientists who participated in establishing Arabic Muslims heritage in all different disciplines & directions specially in sociology, neurological & his political theories which showed the development of Arabic philosophy in all scientific disciplines specially his introduction

View Publication Preview PDF
Publication Date
Sun Jun 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
تحليل – الكلفة – الحجم – الربح – في ظل نظام الكلفة على أساس الأنشطة
...Show More Authors

Recent advancement in production technologist of manufacturing processes have left an important effects upon cost structure. Moreover the problem for providing necessary and adequate information for managerial decision making.

Therefore the cost – volume – profit analysis under the new activity based costing has replace the old method for Analysing the relation between C.V.P with respect to profit planning and control.

In brief the C.V.P object is to discuss the effect of changes on profit resulting from changes in sales volume, cost of manufacturing and selling price.

This study consists of four chapters:

The first chapter dea

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jan 06 2023
Journal Name
مجلة الباحث الاعلامي
مواقع الويب ودورها في بناء الصورة الذهنية للمنظمات الرياضية \ دراسة مسحية
...Show More Authors

Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
مفھوم الامانة في التراث الأدبي للامام علي ( علیھ السلام ) - دراسة تحلیلیة
...Show More Authors

the boot of honesty in the dictionary the term linguistic and religious
heritage, literary and Islamic Sufi thought, and concept in the literature of Imam
Ali, peace is upon him. And studied the summary first concerns its presence in the
literature and implications and directions, either the second part, has cared for the
analytical study has found research that safe weight was the counterpart of the
personality of the Imam accompanied the character most prominent in his
character, namely, (courage), it has struggled to deliver a impact of humanity in his
time and after the word and deed, It was based on the imagination in the formation
of images sensual and intellectual, to his persuasion of the evidence and argu

... Show More
View Publication Preview PDF
Publication Date
Mon Oct 22 2018
Journal Name
Arab Science Heritage Journal
نحو نحو نظام لغوي عربي متوازن في المساواة بين الرجل والمرأة
...Show More Authors

     Human Rights The word of graduation in the Arabic language to many meanings may be the most appropriate of what Al-Ragheb Al-Isfahani said in the right: is the coming of the thing from saying or doing at the time it must and in the form that must be, so the term human rights includes the following:First: A party has the right and another duty to.

View Publication Preview PDF
Publication Date
Mon Feb 04 2019
Journal Name
Journal Of The College Of Education For Women
ملامح دلالية في موشحات صدر الدين ابن الوكيل 665-716 هـ
...Show More Authors

0

View Publication Preview PDF
Publication Date
Mon May 11 2020
Journal Name
Baghdad Science Journal
The Jacobson Radical of the Endomorphism Semiring of P.Q.- Principal Injective Semimodules
...Show More Authors

 

 In this work, we introduced the Jacobson radical (shortly Rad (Ș)) of the endomorphism semiring Ș =  ( ), provided that  is principal P.Q.- injective semimodule and some related concepts, we studied some properties and added conditions that we needed. The most prominent result is obtained in section three

-If   is a principal self-generator semimodule, then (ȘȘ) = W(Ș).

Subject Classification: 16y60

View Publication Preview PDF
Scopus (2)
Scopus Clarivate Crossref
Publication Date
Wed Jun 29 2022
Journal Name
Journal Of The College Of Education For Women
Factors Affecting the Students' Choice of a Major at King Abdulaziz University
...Show More Authors

The present study aimed at examining the factors that affect the choice of A major among a sample of BA fe(male) students at the levels 3-8 in King Abdulaziz University (KAU), in Jeddah, Saudi Arabia. To meet this objective, a descriptive survey method was used together with a questionnaire that consisted of 4 axes to answer the central question: What are the factors affecting the choice of a major at the university? Results have shown that the item that measured the students’ ability to choose the major ranked (First); it was concerned with the effect on the students' choice of his/her major in the university. On the last position and with respect to this effect came the professional tendencies and desires. Results have also shown tha

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Mar 22 2023
Journal Name
مجلة الجامعة العراقي ة
اتجاهات معاصرة في ط ا رئق التدريس التعلم النشط أنموذج ا
...Show More Authors

يعد التعلم النشطعملية نشطة ذهنية يبذٌل بها العقل الجهد الكافي لإِكتشاف المعرفة فالمعلمليس ناقلاً فيه للمعرفة ،) وانما مرشداً وموجهاً والمتعلم محور العملية التدريسية فيه،إِي عمليةإِبداع يختار منها المعلمما يستطيع الابداع فيه وتركيبه)حارص، 2015:6 والتعلم النشط طريقة تعاونية يشترك فيها جميع المتعلمين بالأنشطة والواجبات المتنوعة التي تسمح لهم بالأصغاء الإِيجابي والتحليل السليم للمادة والتفكي ا رلابداعي اذ تت

... Show More
Preview PDF