Abstract

    In order to enhance the efficiency of flat plate solar water collectors without changing in its original shape and with low additional cost, twisted strips are inserted inside its riser pipes. Three flat plate collectors are used for test. Family of twisted strips are inserted inside each collector risers with different twisted ratios (T_R=3,4,5). The collectors are connected in parallel mode (Z-Configuration) and are exposed to the same conditions (solar radiation and ambient temperature) .The experimental results show that, the highest heat transfer rate occurs at twisted ratio (3) .Consequently, for the same twisted ratio the daily efficiencies for the solar collector at d

Sensitive information of any multimedia must be encrypted before transmission. The dual chaotic algorithm is a good option to encrypt sensitive information by using different parameters and different initial conditions for two chaotic maps. A dual chaotic framework creates a complex chaotic trajectory to prevent the illegal use of information from eavesdroppers. Limited precisions of a single chaotic map cause a degradation in the dynamical behavior of the communication system. To overcome this degradation issue in, a novel form of dual chaos map algorithm is analyzed. To maintain the stability of the dynamical system, the Lyapunov Exponent (LE) is determined for the single and dual maps. In this paper, the LE of the single and dual maps

The problem of the current paper is embodied in the weakness of the female students
of the department of the Quran sciences in the college of Education for Women in the
University of Baghdad in the subject of reciting and memorizing the Holy Quran. This is what
the professors and the scientific and educational supervisors stress equally through their visits
to the students applicants during the period of their practical application of teaching in the
schools; especially that the subject is thought for four years during their study in the college.
That weakness is so explicit with a quite large number of the students-applicants, who are
supposed to be the future teachers in the subject of the Holy Quran and Islamic Ed

This research aims to identify the level of Voluntary work among university students, and explore the statistical differences of voluntary work among students due the gender and major. A total of (400) male and female student from morning study were selected as a sample to achieve the research's objectives. Al-Malaki (2010) scale was adopted to collect the required data. The results revealed that men take massive part in voluntary work than women, and students of human sciences showed significant differences than those of other majors.   

ان الغرض من الدراسة الحالية هو التعرف على سمة القلق لدى طالبات كلية التربية للبنات. ولقد استعمل مقياس سبيلبيرجر الذي تكون من (20) فقرة على عينة مقدارها (135) طالبة من كلية التربية للبنات في جامعة بغداد. واظهرت النتائج ان سمة القلق عند الطالبات عالية و فسرت هذه النتيجة بناءً على نظرية سبيلبيرجر ونظرية التحليل النفسي  وقد اتفقت هذه وبعض  ماجاءت به الدراسات السابقة, وقدمت الدراسة الحالية جملة من  التوصي

The research is based on the most important pillars: 1 - constructive towards the Arabic language, functions, and branch into synthetic functions and deliberative functions and internal functions and external functions.
2. Expression, rank, sentence, and patterns (association sentences and compound sentences)
3 - linguistic heritage and modern functional lesson and is based on 1 - heritage and the optimal theory. 2. Heritage function. 3. Theory of optimal theory. 4. Heritage as a reference, history, and source.
4 - discourse: patterns and characteristics - stereotyping discourse - a structure of the discourse - components of discourse.
The first pillars of the use of language start from the fact that the language is a set of

“El bilingüismo como fenómeno mundial”
Desde el ámbito lingüístico que define : ―Las lenguas son sistemas de símbolos diseñados para comunicación” ( 1 ) . Aparece la competencia lingüística ,es decir el bilingüismo es la capacidad de utilizar dos lenguas o más de forma alternativa y las personas implicadas se denominará bilingües, este fenómeno se extiende para comprender las comunidades lingüísticas, por eso la mayoría de los países del mundo son oficialmente bilingües o multilingües , en el sentido tiene dos o mάs lenguas nacionales o regionales oficialmente reconocidas .Algunos países forman ejemplos más destacados del bilingüismo como Άfrica ,Asia,Europa,Oceanía ( 2 )
,America. El propósito d