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
Fri Dec 31 2021
Journal Name
Political Sciences Journal
Moderation in Omani External political behavior (1970-2020)
...Show More Authors

Receipt date:08/26/2020 accepted date:9/8/2020 Publication date:12/31/2021

Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 International License.

        The research entitled (Moderation in Omani External Political Behavior 1970-2020. contained introduction and two sections conclusion and recommendations. The introduction included a general overview of the topic, and the importance of the political behavior o

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Jan 01 2008
Journal Name
Journal Of Educational And Psychological Researches
اثرالتعلم باللعب في السلوك العدواني لدى اطفال الروضه
...Show More Authors

يستهدف البحث التعرف على اهمية التعلم باللعب لاطفال رياض الاطفال وانعكاساتها على تعديل سلوكهم، حيث ان اللعب هو دنيا الطفل المليئة بالمتعة والاستطلاع والاستكشاف، كما ان اللعب بالنسبة للاطفال يمثل لهم الحياة بكل ما فيها من معنى.

وفي الوقت نفسه اللعب هو وسيلة من وسائل الضبط والتوجيه للتعامل مع سلوك الاطفال، فمن خلال اللعب نستكشف النبوغ والتفوق منذ وقت مبكر، حيث ان التعلم باللعب يمثل حاجة حيو

... Show More
View Publication Preview PDF
Publication Date
Fri Jul 01 2022
Journal Name
Humanitarian And Natural Sciences Journal
الـوزير محمد بن علي بن خلف ابو غالب الملقب بـ ( فـــخـر الــمـلك ) ( ت 407 هـ - 1016 م ) دراسة تأريخية
...Show More Authors

ــد ً الوزيرالـــوزيــرمحمد بن علي بن خلف ابو غالب الملقب بـ (فـــخـر الــمـلك )(407هـ-1016م)من الشخصيات المهمة،ية البويهية ، المثيراء الامارواعظم وزرالجدل ، وهذا ما سنوضحهفي البحث .ي كون والده ِ كان صيرفيا ً فلادة ونشأة الوزير فخر الملك في بيئة عنيت بالجانب الأدارأسهمت وٌي ديوان مدينة واسط ، أثرِاتهفي صقل قدرالإالع ِ دارية ، فضلا ً عن صفاتهقلية ،ة البويهية علىاء الأماروالشخصية التي جعلته ُ يكون رمز وزرلكل ةارال

... Show More
View Publication
Publication Date
Mon Sep 01 2014
Journal Name
Al-khwarizmi Engineering Journal
Numerical Investigation of Transient Heat Conduction through a Thermal Insulation of Temperature Dependant Thermal Properties
...Show More Authors

The two-dimensional transient heat conduction through a thermal insulation of temperature dependent thermal properties is investigated numerically using the FVM. It is assumed that this insulating material is initially at a uniform temperature. Then, it is suddenly subjected at its inner surface with a step change in temperature and subjected at its outer surface with a natural convection boundary condition associated with a periodic change in ambient temperature and heat flux of solar radiation. Two thermal insulation materials were selected. The fully implicit time scheme is selected to represent the time discretization. The arithmetic mean thermal conductivity is chosen to be the value of the approximated thermal conductivity at the i

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 01 2013
Journal Name
Journal Of International Academic Research For Multidisciplinary
SYNTHESIS AND LIQUID CRYSTALLINE BEHAVIOUR OF NEW SERIES CONTAINING 1, 3-OXAZEPINE AND 1, 3-THIAZOLE RINGS
...Show More Authors

The synthesis and properties of two new series of compounds having 1,3-Oxazepineand 1,3-thiazole rings connected through azo linkage are reported. These compounds weresynthesized by the reaction of phthalic anhydride with Schiff bases. The molecular structuresof these compounds were verified by elemental analysis, FTIR and 1HNMR spectroscopy.The mesomorphic behaviors of these compounds were studied by optical polarizedmicroscopy (OPM) and differential scanning calorimetry (DSC). All compounds of the twoseries show liquid crystalline properties. The influence of the central oxazepine and thiazolerings and the terminal substituents on the type and temperature range of the mesomorphousproperties of these compounds has been elucidated

Publication Date
Thu Jan 19 2023
Journal Name
Plos One
Knowledge sharing behaviour among head nurses in online health communities: The moderating role of knowledge self-efficacy
...Show More Authors
Background

Head nurses are vital in understanding and encouraging knowledge sharing among their followers. However, few empirical studies have highlighted their contribution to knowledge-sharing behaviour in Online Health Communities (OHCs). In addition, scant literature has examined the moderating role of knowledge self-efficacy in this regard.

Purposes

This study examines the moderating role of self-efficacy between the association of four selected individual factors of head nurses (i.e., Trust, Reciprocity, Reputation, and Ability to Share) and their knowledge-sharing behaviour in OHCs in Jordan.

<
... Show More
View Publication
Scopus (10)
Crossref (11)
Scopus Clarivate Crossref
Publication Date
Thu May 31 2012
Journal Name
Al-khwarizmi Engineering Journal
An Experimental Study on the Effect of Shape and Location of Vortex Generators Ahead of a Heat Exchanger
...Show More Authors

An experimental study is carried out on the effect of vortex generators (Circular and square) on the flow and heat transfer at variable locations at (X = 0.5, 1.5, 2.5 cm) ahead of a heat exchanger with Reynolds number ranging from 62000< Re < 125000 and heat flux from 3000 ≤ q ≤ 8000 W/m2 .

In the experimental investigation, an apparatus is set up to measure the velocity and temperatures around the heat exchanger.                     

The results show that there is an effect for using vortex generators on heat transfer. Also, heat transfer depends on the shape and location. The circular is found t

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 02 2011
Journal Name
Journal Of Educational And Psychological Researches
الطرائق والأساليب الشائعة في تدريس مادة التربية الإسلامية في المرحلة المتوسطة من وجهة نظر مدرسي مادة التربية الإسلامية ومدرساتها والمشرفين الاختصاص
...Show More Authors

The problem of the current research has been crystallized through the study of the current reality of teaching Islamic Education in the intermediate schools. In order to get realistic results and to built on them the recommendations and suggestion that might help in improving teaching Islamic Education with more effective styles in the intermediate and secondary schools, this research has been formulated with the following question:

What are the common methods and styles used in teaching Islamic Education in the intermediate schools?

The importance of the research can be summarized as follows:

  1. The importance of the Islamic Education according to its

... Show More
View Publication Preview PDF
Publication Date
Mon Apr 24 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Thermal Degradation Kinetics of Polyamide 6,6 Cable Ties by Thermogravimetric Analysis
...Show More Authors

  The thermal degradation of cable ties of polyamide (PA6,6) neat and UV stabilized was investigated by thermogravimetry (TG) and its derivative (DTG) at several heating rates between 5 and 80 oC min-1  in helium atmosphere. High heating rates signal novel peaks in the DTG curves that indicate melting temperature of PA6,6. The kinetic parameters calculated via isoconversion and nonisothermal data using the Flynn-Wall-Ozawa, Kissinger and CoatsRedfern methods showed comparable activation energy values. Exposure of the ties to outdoor environment causes pre-mature stress cracking and brittle failure due to prevalence of crosslinking reaction occurring in the polymer chains

View Publication Preview PDF
Publication Date
Tue May 01 2018
Journal Name
Journal Of Physics: Conference Series
Chaotic behaviour of the Rossler model and its analysis by using bifurcations of limit cycles and chaotic attractors
...Show More Authors

The behaviour of certain dynamical nonlinear systems are described in term as chaos, i.e., systems' variables change with the time, displaying very sensitivity to initial conditions of chaotic dynamics. In this paper, we study archetype systems of ordinary differential equations in two-dimensional phase spaces of the Rössler model. A system displays continuous time chaos and is explained by three coupled nonlinear differential equations. We study its characteristics and determine the control parameters that lead to different behavior of the system output, periodic, quasi-periodic and chaos. The time series, attractor, Fast Fourier Transformation and bifurcation diagram for different values have been described.

View Publication
Scopus (37)
Crossref (25)
Scopus Clarivate Crossref