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

The effect of the concentration of the colloidal nanomaterial on their optical limiting behavior is reported in this paper. The colloids of sliver nanoparticles in deionized water were chemically prepared for the two concentrations (31 ppm and 11ppm). Two cw lasers (473 nm Blue DPSS laser and 532 nm Nd:YAG laser) are used to compare the optical limiting performance for the samples. UV–visible spectrophotometer, transmission electron microscope (TEM) and Fourier Transformation Infrared Spectrometer (FTIR) were used to obtain the characteristics of the sample. The nonlinear refractive index was calculated to be in the order of 10-9 cm2/W. The results demonstrate that the observed limiting response is significant for 532nm. In addition, t

the research was exposed to a study the importance of the role of the supportive entities in providing the useful information to the tax administration and their ability to extend the level of the tax base of taxpayers, through the improvement of the tax payers determination and their tax settle for the purpose of increasing the tax revenue, and shed light on the legal evidence through which these entities become officially assigned to perform a supplementary task to the General Committee for Taxes GCT, to help it to perform its task efficiently, and to study the reasons of the weak cooperation of the supportive entities and their reluctance to provide useful information which leads to limiting the tax base.

The research data hav

Self control is the perception of the individual of his duty at, the capacity of self testing in systematic durations and the ability of individuate to control his behavior, The control will be spontaneous when the individual will have a special ideas about the correct or incorrect behavior and choosing his way according it.
The present study airs at:
1- building and measuring self control and balancing among means among university students according to gender and specialization.
To achieve the above mention aim, the two researchers built a scale of self control depending on some theories and applying it on a sample consists of (400) male and female students in Baghdad university studying in scientific and human fields. The two

The aimes of this study is to investigate Optimism and Pessimism among university undergraduates including the first and fourth stage students ,the sample of this stoudy contained (326) students ,(166) male and (160) female, The researcher adopted a scale of Dember et al (1889) translated and adjusted  to arabic version by Al-Dosoke (2001). The results have shown that   students have  optimism including the first and fourth stage and no significant difference between the students  as far as ncluding the first and fourth  study stage and gender, Implications of the results and recommendations for further research are discussed.

Clothes are considered a means of aesthetic and artistic expression that help to hide the flaws of the body and highlight its merits , it has importance in people's lives as it reflects the individual's idea of himself and his personality. Whereas  the appreciation  in clothing  is a reflection of a person's sense of artistic components and the application of this sense to the clothes of his choice. Regarding the differences in clothing tastes by the university students according to the following variables (gender, specialization, stage of study,  age, monthly income), the current research is considered quantitative descriptive research that is concerned with studying a phenomenon that exists in reality, measuring it

على الرغم من التقدم العلمي والتكنولوجي للمعلومات فما زالت الذاكرة تقوم بالدور الاساس بغض النظر عن الامكانيات العلمية في العصر الحديث من حيث ان الكثير من مفرادات الثقافة الانسانية ينقل من جيل الى اخر بواستطتها, ومن الصعب تصور حياة نفسية مقصورة على الحافز فقط, اننا لو اقتصرنا على الحافز لكان التفكير غير ممكن لان الذاكرة هي التي تصل الحافز بالماضي وابسط صورها هي الذاكرة الاولية . فلولا الذاكرة لما تكونت ال

The current research was aimed at the following:
1. Measurement of   Boldness among the students of  university.

2. Identify the differences in Boldness between university students according to variable of Sex (male / female) and variable of Specialization (scientific / literary).

To achieve this aims of the research, the researcher set up the instrument is scale of the Boldness that consistent (34) item, and the researcher applying this scale on the sample amounted to (200) student of  University. Then   after data processing statistically, the researcher reached the following results:

The research seeks to measure stigma on the children of kindergarten and get to know the differences between males and females and between kindergarten and preschool in social fear. Has been verified by the researcher was true scale of social fear after the drafting of paragraphs (43) items, and display it on a group of experts , has proven its validity after some amendments , bringing the number of paragraphs in its final form (29) items . was statistical analysis of the paragraphs of the brokered power-discriminatory , it is clear that all paragraphs distinct and statistically significant, as well as to find a relationship degree of para-class items consistency . was to ensure the stability of the scale in a re-test , as the stability

Historical concepts are among the concepts that are difficult to present to the pre-school child except by using modern techniques, as well as the difficulty of making visits to all historical monuments and going back to antiquity and the lack of studies in this area, therefore, we need an attractive medium that children love which is able to convey some abstract concepts that are difficult to teach to children using traditional methods, and among these activities that the kindergarten provides to children are the stories through which they develop their linguistic wealth, consolidate their religious and spiritual inclinations, refine their correct morals, and form their proper attitudes, knowledge and life concepts.

The