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 increasing use of polymeric materials in the daily life, leads to challenges in the processing industry to deliver high performance materials with affordable terms. However, new processing techniques lead to high costs. In order to reduce processing costs it is necessary to understand the non-Newtonian behavior of the polymers in their molten state to be able to simulate the processes before the construction of the plants starts. Here the shear thinning behavior of the viscosity of polymeric melts is essential. Thus, this paper deals with the experimental investigation of the thermo-rheological behavior of the viscosity of one of the most used polymers (Polypropylene) over a wide range of temperatures and shear rates.  Furthermo

This study is concerned with revealing the semiotics of thresholds, and its role in building textual coherence at the form and semantic level in Sunset Garden Diwan of the Saudi poet Ghazi Al-Qasaibi. This research aims to spotlight on the semiotic theme of the title threshold and its relation to other thresholds. As the death phenomenon and absence dominated the poetic achievement space through intertwined semiotic relationships that lead to each other through the parallel text semiotics.This study is based on the semiotic method which concerns with searching for the interpretive connotations and revealing the profound symbols in the threshold structure and its role in the whole formation of the Diwan. Among the most prominent conclusio

The infrastructure is one of the basic components of the tourism industry in Iraq in general and in Najaf in particular, in spite of there are obstacles and problems that which are hindered the development of tourism in Iraq, some of them are related to the  tourism industry itself, some are related to the security and political situation, and some are related to poor management of tourism. However, the infrastructure is considered the cornerstone of the success of the tourism industry in Iraq and other countries, if it is available, it can be a potential indicator of success, and on the contrary, it is a hindrance to go forward. The aim of this research is to shed light on the availability of requirements for the s

      Edward Albee, as a playwright, indicates that art should be useful and have a message. Therefore, his work foregrounds and critically examines issues concerning the Neurosis of Blackness and psychological trauma. Albee uses cruelty of racism in reflecting psychological trauma and emotional abuse of American black identity in his plays. Race, social inequality, and gender still sustain to engender controversy audience consciously. Racial discrimination is one of the major issues that affect the American Society. Albee challenges and exposes the presumptive dreams of equality of American society and institutional racism. Therefore, one of the main problems of the twentieth century in America is skin color. It

In order to study the effect of inoculation with mycorrhiza and fertilization with plant residues on the growth of plants, we used two factors: the first two levels of mycorrhiza inoculation, Glumus mossea (0 and 10 g.pot^-1) and the second factor, four levels of plant residues (10 g.pot^-1) celery plant residues, 10 g pot^-1 mint residues, and 10 g pot^-1 black bean seed residues. Mychorrizal treatment (10 g pot^-1) increased the number of mycorrhiza spores and the infection percentage of mycorrhizal by 917.44% and 13088.23%, respectively; celery treatment (10 g.pot^-1) increased the chlorophyll index in the leaves and height of the chard plant by 31.34% and 94.04%, re

Thin films of pure polycarbonate (PC) with anthracene doping PC films for different doping ratios (10, 20, 30, 40, 50 and 60 ml) were prepared by using a casting method. The influence of anthracene doping ratio on photo-fries rearrangement of polycarbonate was systematic investigated. Furthermore, pure PC and anthracene doping PC films were irradiated via UV light at a wavelength (254 nm) for different periods (5, 240, 288, and 360 hrs). The photo-fries rearrangement occurring in pure PC and anthracene doping PC films were monitored using UV and FTIR spectroscopies. The photo-fries rearrangement leads to scission the carbonate linkage and formation phenylsalicylate and dihydroxybenzophenes. The result of the UV spectrum confirms disappea

The main aim of this research is to: 1) identify the Transformational Leadership of the Managers of higher School in ALkut district and its relationship with organizational Loyalty. 2) Clarify the relationship between Transformational Leadership and organizational Loyalty. Regarding the research methodology, the researcher used the descriptive method because it meets this research. The two research tools were a questionnaire and the statistical program (spss). The results revealed that there is a strong positive relationship between Transformational Leadership and organizational Loyalty, which means that when the managers have a Transformational Leadership leads to having organizational loyalty.