This paper presents a comparison study on thermal performance conic cut twist tape inserts in laminar flow of nanofluids through a constant heat fluxed tube. Three tape configurations, namely, quadrant cut twisted tape (QCT), parabolic half cut twisted tape (PCT), and triangular cut twisted (VCT) of twist ratio= 2.93 and cut depth= 0.5 cm were used with 1% and 2% volume concentration of SiO2/water and TiO2/water nanofluids. Typical twist tape with twist ratio of= 2.93 was used for comparison. The results show that the heat transfer was enhanced by increasing of Reynolds number and nanoparticles concentration of nanofluid. The results have also revealed that the use of twist tape enhanced the heat transfer coefficient significantly and maximum heat transfer enhancement was achieved by the presence of triangular cut twist tape insert with 2% volume concentration of SiO2nanofluid. Over the range investigated, the maximum thermal performance factor of 5.13 is found with the simultaneous use of the SiO2nanofluid at 2% volume concentration VCT at Reynolds number of 220. Furthermore, new empirical correlations for Nusselt number, friction factor, and thermal performance factor are developed and reported.
Sustainable human development means meeting the basic needs of society and striving for continuous improvement in quality, as it seeks to increase economic well-being while providing adequate housing and nutrition, as well as providing electricity, water, health and education services . Ten centuries ago, Islam highlighted the importance of the development effort and the necessity of its sustainability before the West took it in the 1970s. There are a number of challenges that greatly affect the reality of achieving and ensuring Millennium Development Goals. The research recommends the importance of fighting administrative and financial corruption, as this is one of the biggest challenges facing the possibility of advancing the economy and
... Show MoreThe current research aims at extracting the standard characteristics of the emotional balance of the university students according to the response theory. This was accomplished by following accredited scientific steps, to achieve this goal, the researcher followed scientific steps in the procedures of the analysis of the scale. She translated the scale from English to Arabic and then made a reverse translation. it was presented to a committee of experts in English to ensure and verify the validity of the paragraphs logically and prove the face validity of the scale, which consists of (30) paragraphs, it was presented to (6) experts who are specialists in the educational and psychological sciences and in the light of their observations ha
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The study aims to identify the level of health services provided in private suites to government hospitals from the perspective of the recipi
... Show MoreBiotreatment using immobilized cells (IC) technology has proved to be the most promising and most economical approach for the removal of many toxic organic pollutants found in petroleum-refinery wastewater (PRW) such as phenol. This study was undertaken to evaluate the degradation of phenol by Pseudomonas cells individually immobilized in two different bio-carrier matrices including polyvinyl alcohol-guar gum (PVA-GG) and polyvinyl alcohol-agar agar (PVA-AA). Results of batch experiments revealed that complete removal of phenol was attained in the first cycle after 150 min using immobilized cells (IC) in both PVA-GG and PVA-AA. Additional cycles were confirmed to evaluate the validity of recycling beads of immob
... Show MoreMarshlands environment in southern Iraq is unique and is considered a habitat of thousands of migratory birds as shelter and a source of livelihood for thousands of people living there. Its environment is characterized by a fragile ecosystem that requires great care and effort to achieve the greatest possible balance and parallelism of development, which necessarily require careful environmental planning that accurately regulates the resources of the environment and therefore, planned the best way to use them. The idea of research for creating the spatial organization of the development of the human settlements and taking into account the environmental aspect by thinking for the plann
The research aims to study the importance of applying lean accounting techniques and the tools and methods they contain, the most important of which is the “value path costs” technique and its impact on rationalizing and controlling costs, as well as reducing production costs in general and reducing quality costs in a way Special by reducing or eliminating waste and waste in both time and resources and meeting customer requirements. In order to achieve this goal, the researcher relied on the application of lean accounting tools by obtaining data related to the mill, in addition to that, the information obtained as a result of field coexistence in the mill and being able to view the records of the mill in the research sample. From the
... Show MoreThis study identified the genus Coelastrella Chodat, 1922 which was isolated from a sediment sample taken from the Tigris river in Baghdad Governorate, Iraq. The alga was isolated and cultured in modified Chu 10 media and the morphological features of the isolated algae were observed in light microscopy (LM); it showed some characteristic features of this genus, such as its ellipsoidal or lemon- shaped cells, a visible pyrenoid and the chloroplast parietal. To ensure correct identification of the isolated alga, a molecular analysis using 18S rRNA gene and DNA sequencing revealed a match with C. terrestris (Reisigl) Hedewald & N. Hanagata 2002. This species is a new record in Iraq
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