The evacuated tube solar collector ETC is studied intensively and extensively by experimental and
theoretical works, in order to investigate its performance and enhancement of heat transfer, for Baghdad climate
from April 2011 till the end of March 2012. Experimental work is carried out on a well instrumented collector
consists of 16 evacuated tubes of aspect ratio 38.6 and thermally insulated tank of volume 112L. The relation
between convective heat transfer and natural circulation inside the tube is estimated, collector efficiency, effect of
tube tilt angles, incidence angle modifier, The solar heating system is investigated under different loads pattern (i.e
closed and open flow) to evaluate the heat loss coefficient from tank and tubes, test the collector with various
aspect ratios (32.9 and 27.2). The enhancement in collector performance is studied by using two reflectors (Flat
Plate and Curved Plate) and nanofluid (Water-AL2O3).Theoretical work is run by software (Fluent 6.3), to compute
the velocity and temperature profiles within the tube, for different tube diameters, effect of tube junction angle and
stagnant region in the bottom of the evacuated tube. The experimental results shows that the heat loss coefficient
for tube is W/m2.K and for tank is W/m2.K, the maximum collector temperature is 79°C in winter and
99°C in summer, while that belong to nanofluid collector is 99°C in winter. The best tilted angle (optimum) of
evacuated tube is 41° annually. The collector efficiency increased when using nanofluid of (1, 0.6, 0.3)% volume
fraction as(28.4, 6.8, 0.6)% respectively. The efficiency decreases as (33, 62)% when decreasing tube aspect ratio
from 38.6% to 32.9% and 27.2% respectively. An increase of (16.9 and 7.08)% in collector efficiency is obtained
when using curved and flat plate reflectors respectively. From simulation the best junction angle of the tank is
22.5°. The stagnant region is influenced with changing heat flux, tilted angle and aspect ratio.
The research aims to highlight the significance and composition and the diversity of meanings and the Quranic context in the necessary and transgressive verbs in Surat (Abs).
This research consists of : a preamble , and two studies . The researcher addressed in the preliminary the importance of the phenomenon of necessity and infringement, the signs of the necessary action , the structure and controls of the act , the methods of infringement , its sections and signs.
As for the first topic : The researcher addressed the necessary verbs in Surat Abs , an applied study in terms of grammati
... Show MoreThis research explains to us the role of the Islamic religion in the issue of accuracy in speech and work, and how it is closely related to human production in his life, and Islam affirms that his idea is mainly reflected in his production, and how it affects the perception of the meaning of creativity. Therefore, our Islam affirmed the accuracy in every word or work we do to build a society in which people enjoy high quality in ethics and dedication in their work so that the Islamic system depends on humanity to preserve our rights on the other hand the research discusses the deliberate default and how it reflects on our production and how it makes it less good.
The aim of this message to monitor this phenomenon throught the Quran , which is the constitution of the Islamic nation and Hariatha as well as to express kasalah integrity , justice honesty , patience , abd pacr .
We feel this vocabulary to hight athical values advocated by the Quran and the need to build commitment to the orthodox society free of corruption that leads ta a disorder of the human society .
The outcome of the study the researcher found that faith to a number of results was most notably the advent of righteusness in the Holy Quran meaning of comprehensive RPR spacious field and breadth Maadenh .
Summary First: The importance of the study and the need for it: The society is composed of an integrated unit of groups and institutions that seek to achieve a specific goal within a system of salary, and the family remains the most influential institutions on the individual and the unity of society, with the roles and responsibilities of the individual and society, and through the continuation and strength of other social organizations derive their ability On the other hand, any break-up in the institution of the family is reflected negatively on the cohesion of society and its interdependence, and the causes of this disintegration vary from society to another, but family problems remain the main factor in obtaining it. Second: Study Ob
... Show MoreResearch summary
The Quranic discourse focused on a lot of vocabularies that carry goals that help man to acquire good, according to a methodology relies on adopting lofty ideas and values. The individual towards society, and the responsibility of society towards the individual. In our present age, the Muslim individual lives in a state of confrontation with deviant ideas, which unfortunately possess the means that make their impact great on society. The study concluded that the Holy Quran contains indicators and determinants of misguided and deviant thought, Which must be avoided because of the seriousness of its effects. Religion, in its general sense, represents a culture that transcends the limits of human ins
... Show MoreBackground: The quality of drinking water is directly related to community health. Therefore, improving the quality of drinking reflects positively on the health situation in general. The studies that deal with the quality of drinking water in the city of Baghdad in terms of chemical or microbial content are very scanty. Objective: The current review highlights the most important studies and research articles that concern the quality of drinking water, both bottled water and tap water, in terms of chemical and biological contamination and chemophysical specifications for drinking water. Abstract: Studies have shown that drinking water in the city of Baghdad, especially tap water, contains certain levels of heavy metals,
... Show MoreFaith is a feature of the Mesopotamian population, since the ancient Mesopotamian was a believer and obedient to his God in any case, and this encouraged the emergence of some of the phenomena interpreted by historians as an integral part of the civilization and ancient history of this country, and these phenomena are the phenomena of the deification of kings for themselves, The first phenomenon was a personal endeavor for the uniqueness of power, sometimes to correct some mistakes in societies to balance the state, and civil rule is independent of religious rule, and the second was the result of divination and predictions of omen, in the case of any bad harbinger of the king, such as the occurrence of eclipse To the sun or a lunar eclip
... Show MoreA new spontaneous mutation (dh) is described for Culex quinquefasciatus Say. This
phenotype was observed in the second generation to cause complete coloration of the head
capsule and the siphon of the larvae. This character is mainly detectable in the larval stage
and slightly in the adult stage.
The reciprocal mass matting between mutants from F2 generation and normal wild type
sibs, revealed that the mode of inheritance can be controlled by an autosomal recessive
gene(s). This happened for both sexes with slightly variability in their expression. No
significant larval mortalities were found in all crosses.
Test method was developed radioimmunotherapy to appoint in two groups of patients infected with a uterine tumor Great conditions in tumor tissue benign and malignant Ddh teacher radioactive iodine isotope