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.
Background: Gasoline constituents and its derivatives had many hazardous effects on the general health of humans. Thus, gasoline stations workers may be affected by different types of related diseases.This study was conducted to assess selected salivary elements and their relation with dental caries, oral hygiene status and periodontal diseases among gasoline stations workers in comparison with individuals have no regular exposure to gasoline. Materials and methods: The study group consists of thirty male subjects with an age range (33-39) years who worked in different gasoline stations in different areas of Baghdad city and thirty persons that matching in age and gender and not exposed to gasoline were selected as a control group. Dental c
... Show MoreThe study aims to identify the educational research obstacles as perceived by the faculty members at the universities of south in the west bank. As for study population, it included all (60) faculty-member in the colleges of education (bait lahem, alahliyah, al-khalil, and al-Quds almaftoha). To collect study data, the researcher used a questionnaire that consisted of (43) item; it has categorized into seven-domains: academic working conditions, academic management, resources and information, faculty members, publication, planning, and funding educational research. The findings revealed that Educational research obstacles were high with an average of (4, 39), no significant differences among sample averages and stander deviations on the
... Show MoreThis work describes the enhancement of phenol red decolorization through immobilizing of laccase in chitosan and enzyme recycling. Commercial laccase from white rot fungus, Trametesversicolor (Tvlac), was immobilizedin to freshly prepared chitosan beads by using glutaraldehyde as a cross linker. Characterization of prepared chitosan was confirmed by FTIR and scanning electron microscope (SEM). Tvlac (46.2 U/mL) immobilized into chitosan beads at 0.8 % glutaraldehyde (v/v) within 24 hrs. Synthetic (HBT) and natural (vanillin) mediators were used to enhance dye decolorizoation. It was found that 89 % of phenol red was decolorized by chitosan beads within 180 min. in the absence of enzyme and mediator, while decolorization percenta
... Show MoreIn this study, the photodegradation of Congo red dye (CR) in aqueous solution was investigated using Au-Pd/TiO2 as photocatalyst. The concentration of dye, dosage of photocatalyst, amount of H2O2, pH of the medium and temperature were examined to find the optimum values of these parameters. It has been found that 28 ppm was the best dye concentration. The optimum amount of photocatalyst was 0.09 g/75 mL of dye solution when the degradation percent was ~ 96 % after irradiation time of 12 hours, while the best amount of hydrogen peroxide was 7μl/75 mL of dye solution at degradation percent ~97 % after irradiation time of 10 hours, whereas pH 5 was the best value to carry out the reaction at the highest deg
... Show MoreAn experimental study is conducted on the utilization of the inlet ethanol injection technique in order to evaluate its impact on the performance of a two-shaft T200D mini-gas turbine engine. The maximum degradation recorded in power output was 32.8% at the climate temperature of 45oC. Nevertheless, at that temperature, adding ethanol with Eth/LPG ratio of 20% by volume brought an enhancement in power output of 19.2% compared to normal LPG run. SFC of the dual-fuel engine ranked a level of 22% higher than that with pure LPG consumption. The overall efficiency suffered a maximum reduction of 14.4% with Eth/LPG fuel ratio of 20%, but when the loading was raised beyond 70% of the engine full load; the efficiency of dual-fuel engi
... Show MoreBackground: Since the periodontal disease Index of Ramfjord (Ramfjord index) can potentially shorten the examination time by almost half, many studies evaluated Ramfjord teeth in predicting full-mouth periodontal status of an adult population. The aim of this study was to evaluate the benefit of Ramfjord teeth in predicting the full-mouth clinical attachment level of an adult population in patients attending the college of dentistry- Baghdad University. Materials and methods: The study participants were 100 patients with age range from 30-60 years old which represent group zero. The patients were divided into three main groups according to the age of the patients. Group I and group II each of them composed of 30 patients while group III co
... Show MoreRock type identification is very important task in Reservoir characterization in order to constrict robust reservoir models. There are several approaches have been introduced to define the rock type in reservoirs and each approach should relate the geological and petrophysical properties, such that each rock type is proportional to a unique hydraulic flow unit. A hydraulic flow unit is a reservoir zone that is laterally and vertically has similar flow and bedding characteristics. According to effect of rock type in reservoir performance, many empirical and statistical approaches introduced. In this paper Cluster Analysis technique is used to identify the rock groups in tertiary reservoir for Khabaz oil field by analyses variation o
... Show MoreReduce the required time for measuring the permeability of clayey soils by using new manufactured cell
Nearly a century and a half has passed since Sarah Orne Jewett published her much anthologized short story “A White Heron” (1886), but commentators on the tale missed one of the most important points in the text. It is the story’s similarity to the traditional Euro-centric fairy tale of “Little Red Riding Hood”. As an author, writing at the end of the ninetieth century, a time that witnessed the demise of the Romantic movement in America and the beginning of the age of Realism, Jewett did not romanticize her characters, despite the idyllic landscape in which “A White Heron” is set. Her story can be analyzed as a text that aims at disseminating ecological awareness among her young readers. This study focuses on Jewett
... Show MoreThe culturalization of gender action occupies a wide range in culture, thoughts and modern studies as well as in fine arts and the ways of expressing them.
Theater, as one of these arts, plays roles in establishing the fundamental concepts that aims at stating the uncontrollable deed of the social community. It remains one of the most effective and suitable means to confine the uncivilized practices to overcome a certain crisis after gender and cyborg in societies.
The research concentrates on studying the culturalization of gender action in the Iraqi theatrical address because of the effect it has on the modernizing thought in arts and theater literature. It consists of chapter one which deals w
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