Preserving and saving energy have never been more important, thus the requirement for more effective and efficient heat exchangers has never been more important. However, in order to pave the way for the proposal of a truly efficient technique, there is a need to understand the shortcomings and strengths of various aspects of heat transfer techniques. This review aims to systematically identify these characteristics two of the most popular passive heat transfer techniques: nanofluids and helically coiled tubes. The review indicated that nanoparticles improve thermal conductivity of base fluid and that the nanoparticle size, as well as the concentrations of the nanoparticles plays a major role in the effectiveness of the nanofluids.

This current study aims at recognizing the feelings of Baghdad University students towards life quality. The research variables are: gender (male, female), the academic specialization (science, humanities), the academic stage (2^nd, 4^th). To achieve the research aims, the researcher adopted Life Quality Scale of (Mensi and Kadhim 2006) which is consist of (56) items in its final figure in five alternatives. The researcher tested the psychometric features of the scale represented by validity and reliability. The scale has been applied on a sample of Baghdad University students that is contained of (240) students equally distributed in the Colleges of Engineering, Science, Arts, and Political sciences.

أهمية البحث والحاجة إليه:

تبدو لنا المسؤولية الاجتماعية بأنها أحدى الخصائص التي يكتسبها الفرد من بيئته الاجتماعية, بتأثير مجموعة القيم التي تحكم سلوك الأفراد في ذلك المجتمع فتبدأ المسؤولية الاجتماعية بأولى صورها على شكل إدراك الفرد لمتطلبات المجتمع وإدراكه لدوره في المساهمة في أنجاز تلك المتطلبات, وفي الواقع إن الإدراك لوحده لا يكفي لان يمارس الفرد مسؤوليته داخل المجتمع, فيظهر المستوى الأخر و

The aim of this study is to understand the effect of addition carbon types on aluminum electrical conductivity which used three fillers of carbon reinforced aluminum at different weight fractions. The experimental results showed that electrical conductivity of aluminum was decreased by the addition all carbon types, also at low weight fraction of carbon black; it reached (4.53S/cm), whereas it was appeared highly increasing for each carbon fiber and synthetic graphite. At (45%) weight fraction the electrical conductivity was decreased to (4.36Scm) and (4.27Scm) for each carbon fiber and synthetic graphite, respectively. While it was reached to maximum value with carbon black. Hybrid composites were investigated also; the results exhibit tha

Electrical properties were studied for Pectin/PVA graphene composites films and the effect of aqueous interaction on their properties. The conductivity and the dielectric constant of this composite are important because Polysaccharide like pectin is increasingly being used in biomedical applications and as nanoparticles coating materials. The Dielectric and conductivity of composite films were compared in dry and wet condition the differences in the results were attributed to the water molecules and the hydrogen bond which connect the three composite compounds (Pectin, PVA and Graphene) together. These connections were allowed the hydrogen and hydroxyl group’s migrations in the composite super molecules. On the other hand, graphene was pr

The electrical properties of the AlNiCo thin films with thickness (1000oA) deposited on glass substrates using Ion – Beam sputtering (IBS) technique under vacuum <10-6 torr have been studied . Also it studied the effect of annealing temperature from this films , It is found that the effective energy decrease with increase of temperature and the conductivity decrease with increase temperature 323oK but after this degree the conductivity increasing .