Preferred Language
Articles
/
alkej-293
Thermal Behaviour of Paraffin Wax/Poly Vinyl Alcohol Composite Material
...Show More Authors

Polymer additives binder system provides many properties useful in thermal energy storage (TES) then developed the efficient energy storage materials and green strength bodies system.

This paper studies the thermal energy storage property for polyvinyl alcohol (PVOH) / paraffin wax (WPw) blends. To enhance paraffin wax thermal conductivity, PVOH as a material which high conductivity was employed. A fixed weight of Paraffin wax was dispersed with PVOH heterogeneously at different additive weights ratios of PVOH/Pw (50/50, 67/33, 75/25, and 80/20) wt. ratio respectively. The composite material was prepared using wetted pressing method.

Both base materials (polyvinyl alcohol and paraffin wax) were scanned using differential scanning calorimeter (DSC) under non-isothermal conditions, the result was analysed to determine the thermal transition temperature of PVOH and paraffin wax base material. The thermal decomposition of PVOH and waste paraffin wax proved that high transition temperature (TG) for PVOH reached 209ᴼc rather than wax of 60ᴼc respectively. This result shows that PVOH suppress the thermal stability of PVOH/waste paraffin wax composites. Afterward examines the thermal conductivity enhancement using Lee- disk techniques. Composite materials PVOH/paraffin wax have a high thermal conductivity which increases thermal conductivity of waste paraffin wax as a heat storage media and  this allows to apply change in phase with wide range of temperatures, and the highest decreased ratio of phase-change heat is very low, compared to that of paraffin only. Therefore, PVOH, added to paraffin which has significant potential for enhancing the thermal storage characteristics of paraffin.

A wax/PVOH system acts as strength body resistance to sever contact of both air and moisture then a moisture absorbance percent was achieved by use both Fourier transform infrared spectroscopy (FTIR) techniques and moisture solutions (100% H2O) for all pure and composite material system Pw/PVOH, the results shows high resistance to ambient conditions (air/ moisture) for composite system rather than pure materials (PVOH and Pw). 

                                              

View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Dec 19 2018
Journal Name
Arab Science Heritage Journal
فصول فصول من تاريخ يوحنا النيقي فتح مصر
...Show More Authors

These Chapters are concerning a lot of information about Islamic conquest of Egypt . The important chapters are the following :- Chapter 111 :- Concerning the first encounter of Amru with the Romans at the city of Heliopolis . Chapter 112:- How all the Jews assembled in the city of manuf owing to their fear of the Muslim . the Jews left the gates of Misr open and fled to Alexandria .

View Publication Preview PDF
Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
A solution to the Lifely Disobedience and its Effect to Stop Divorce
...Show More Authors

Allah legislated marriage and made it dwelling, fellowship and mercy between
the two couples, Prophet Moh'd (peace of Allah and blessing be upon him) ordered a
husband to look after his wife, treat her with full charity and make love with here
every kindly. On the other hand, he ordered a wife to obey her husband and respect
him deeply, nevertheless, some obstacles may sometimes be appeared within the life
of their marriage, this may be caused by either a husband or a wife. This problem is
called lifely disobedience (AL-Noshooz).
In the other words, this means that a wife begins to hate her husband, refuse his orders
and not obey him.
In brief, they hate each other which leads to some marks appear in their
m

... Show More
View Publication Preview PDF
Publication Date
Wed Dec 30 2015
Journal Name
College Of Islamic Sciences
Trees and their impact on humans And the environment from a Qur'anic perspective
...Show More Authors

Show the greatness of Allah Almighty when contemplating the benefits of trees and plants in
Life in general and trees mentioned in the Koran in particular, do not have to meditate that
He acknowledges the greatness of the Almighty Creator, and his preference over man, that he is prepared for his livelihood
And give him what he can do in this life to the fullest.
  The study also stressed the need to urge people to this great blessing trees
By preserving them and wasteful wastefulness.
  The study also pointed to the need to guide people towards the aesthetics and improvements of
Look through and enjoy the beauty of trees, flowers, greenery and fruits ..

View Publication Preview PDF
Publication Date
Sun Apr 28 2019
Journal Name
Arab Science Heritage Journal
تحقيق تحقيق القسم الثاني من مخطوطة خبرة الفقهاء
...Show More Authors

In fact, the main idea of ​​the manuscript is to deal with  subdivision science of Islamic jurisprudence, it has a touch of ambiguity that attract all knowledge men , many students like to study it according to its ambiguity and trying to solve

View Publication Preview PDF
Publication Date
Sun Apr 28 2019
Journal Name
Arab Science Heritage Journal
موقف موقف البغداديين من الأقليات الدينية/البهائية أنموذجاً
...Show More Authors

       this study examined the various incidents of heritage and documentary dimension in relation with the contemporary history of Baghdad and the presence of religious minorities and ethnicities. The Baha'i came to Iraq in the late  century and the list of religious minorities is still not recognized. In this research study

View Publication Preview PDF
Publication Date
Sun Jun 18 2023
Journal Name
Arab Science Heritage Journal
تحقيق القسم السادس من مخطوطة خبرة الفقهاء للفرغاني
...Show More Authors

    In fact, the main idea of ​​the manuscript is to take note of a branch of Islamic jurisprudence, which is the science of jurisprudential and this manuscript in its title and subject to the men of knowledge of jurisprudence because of its ambiguity calls for thinking, and the brainstorming mood to test the intelligence of jurisprudence, Of students of knowledge jurisprudence. This section contains (25) questions starting with the question (101) and ending with (125) .

View Publication Preview PDF
Publication Date
Fri Aug 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Sub–Nyquist Frequency Efficient Audio Compression
...Show More Authors

This paper presents the application of a framework of fast and efficient compressive sampling based on the concept of random sampling of sparse Audio signal. It provides four important features. (i) It is universal with a variety of sparse signals. (ii) The number of measurements required for exact reconstruction is nearly optimal and much less then the sampling frequency and below the Nyquist frequency. (iii) It has very low complexity and fast computation. (iv) It is developed on the provable mathematical model from which we are able to quantify trade-offs among streaming capability, computation/memory requirement and quality of reconstruction of the audio signal. Compressed sensing CS is an attractive compression scheme due to its uni

... Show More
View Publication Preview PDF
Publication Date
Wed Mar 02 2022
Journal Name
Journal Of Educational And Psychological Researches
Training Needs for Teachers from the Educational Professional Development Center
...Show More Authors

The research aims to characterize the strategic plan of the Educational Professional Development Center, to reveal the most important training needs for teachers from this center, to reveal the extent to which this center meets those needs, and to identify the differences between teacher responses about the degree of importance, availability of those needs according to variables of sex, specialization, and years of experience. This descriptive study adopted a questionnaire applied to (256) teachers in the K.S.A. The results of the study showed that all training needs ranged in the degree of importance from large to very large and that the most important were the skills associated with communicating with members of the learning community.

... Show More
View Publication Preview PDF
Publication Date
Mon Jan 23 2023
Journal Name
Arab Science Heritage Journal
التجارة في البحرين من خلال كتب الرحالة والبلدانيين
...Show More Authors

Economic life in any of the countries depends mainly on economic activity due to its great role in meeting the needs and expenditures of the state . therefore ، Bahrain played a major role in commercial exchange operation ،  whether at home or abroad . whatever the matter

View Publication Preview PDF
Publication Date
Sun Jan 13 2019
Journal Name
Arab Science Heritage Journal
استخلاص وتنقية أنزيم الكايتنيز من خميرة Saccharomyces cerevisiae
...Show More Authors

تم التحري عن انتاج انزيم الكايتنيز من خميرة Saccharomyces cerevisiae  حيث زرعت هذه الخميره في وسط سائل يحتوي على الكايتين ومواد نتروجينية مختلفة . اجريت غربلة لسلالات الخميرة المستعملة لتعين السلالة الاعلى انتاجا للانزيم . بينت النتائج ان السلالة S2 اعطت اعلى فعالية نوعية بلغت 3.5 وحدة /ملغم بروتين .

View Publication Preview PDF