The fouling depositions of crude oil stream were studied theoretically in a shell and tube heat exchanger to investigate the effect of depositions on the heat transfer process. The employed heat exchanger was with steam flowing in the inner tubes and crude oil in the shell at different velocities and bulk temperatures. It is assumed that fouling occurs only on the heated stream side (crude oil). The analysis was carried out for turbulent flow heat transfer conditions with wide range of Reynolds number, bulk temperature and time. Many previously proposed models for fouling resistance were employed to estimate a new model for fouling rate. It is found that the fouling rate and consequently the heat transfer coefficient were affected by Reynolds number, Prandtls number, film temperature, activation energy, and time.
The results obtained showed that fouling resistance decreased with the increasing of Reynolds number and Prandtls number, and increased with the increasing of film temperature and time. The analyses of results were compared with some experimental work and a reasonable agreement is attained.
Background: The rhizome of ginger is used in cooking and for medicinal purposes such as anti-bacterial, anti-fungal, anti-inflammatory and antioxidant. The aims of the study were to test the effect of ethanolic extract of ginger on growth, adherence and acidogenicity of mutans streptococci in comparison to chlorhexidine gluconate 0.2% and de-ionized water. Materials and methods: From saliva often volunteers (dental students 20-22 years); mutans streptococci was isolated, purified and diagnosed according to morphological characteristic and biochemical tests. Ginger was powdered and extracted, different concentrations of ginger extract were prepared. Chlorhexidine gluconate 0.2% used as a control positive; while de-ionized water was used as a
... Show MoreBackground: Wound healing is a complicated, interactive, integrative process involving cellular and chemotactic activity, the release of chemical mediators and associated vascular response which includes number of phases: inflammatory phase, proliferative phase and remodeling phase. Low level laser therapy can be more effective in the three overlapping phases of wound healing. Biostimulation appears to have an effect on the cellular level, by increasing cellular function and stimulating various cells. The aim of present study was to evaluate histologically the effect of 780-805 diode laser the intensity of inflammation and pattern of epithelization in mice model. Material and methods: The experimental study was performed on ninety six white
... Show MoreThe purpose of this research was to examine the impact of varying doses of ginger powder on broiler productivity. There were 180 commercial strain Ross 308 day old chicks utilized in the experiment, and each chick was weighed and allocated randomly among four treatments. Three different treatments were tested, each with a replication of 15 chicks. The diet was supplemented with 0.5, 1.0 and 2.0g/kg of ginger powder, respectively, as a control. As compared to the other treatments, the control group had considerably higher body weights, weight growth, feed intake, and feed conversion ratio. Ginger powder use was shown to have a detrimental impact on growth in this investigation.
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This study was set out to investigate factors affecting labor productivity on construction in the north of Iraq (Kurdistan) and to rank all the factors based on engineers, contractors, and designer’s opinions. 76 factors were analyzed based on previous literature and a pilot study. Next, by using online Google Form, a questionnaire form was created and sent to people who have experience in the construction industry. Afterward, the questionnaire form was sent to targeted people by email and social media apps. Factors were divided into nine groups “Management, Technical and Technology, Human and Workforce, Leadership, Motivation, Safety, Time, Material and Equipment, and External”. However, 202 respondents participated in this study,
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From a health standpoint, fluoride (F) is a vital element for humans. It had harmful effects on numerous organs when consumed in high dosages. Fluoride poisoning has been linked to liver damage. The purpose of this study was to see how sodium fluoride (Naf) affected liver function and the glycemic index in adult male albino rats. Fourteen (14) adult male Wistar albino rats were randomly and evenly divided into two groups and given the following treatments for thirty (30) days: G1 Group (Control group), were given distilled water and fed a balanced diet, G2 rats were administered water that contained 100 ppm Naf. The animals were fasted for 8-12 hours before being anesthetized and blood samples were taken by heart puncture technique
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Endometriosis is a common women health disorder that occurs when Endometrial-like tissue grows outside the uterus. This may lead to irregular bleeding , pelvic pain, infertility and other complications. Metformin, because of its activity to improve insulin sensitivity, it is used for the treatment of diabetes; it also has a modulatory effect on ovarian steroid production and has anti-inflammatory properties, all may suggest its possible effect in treatment of endometriosis. This study was planned to determine the effect of metformin on serum levels of&nbs
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Background: This research describes the methodology used for the preparation of selenium nanoparticles from Pseudomonas aeruginosa and their administration to lambs for lipid profile checking, administration of selenium nanoparticles as a medication in lambs results in hypolipidemia. Aim: The study aimed to investigate the potential of selenium nanoparticles in improving lipid profiles in lambs. Methods: Healthy lambs (n=10) of similar age and weight were selected for the study. The animals were housed in individual pens with free access to water and a standard diet. The lambs were randomly divided into two groups: the control group (n=5) and the treatment group (n=5). The control group received a standard diet, while the treatme
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The present research aims at recognizing the difficulties and problems which hamper teachers and educators alike when using the internet for educational purposes.It discusses the benefits of the internet as a source of information or publication and as a communicative tool.Arandom sample of (30) teachers working at schools in Baghdad / Second Risafa,was selected.Three of the sample members use the internet for student project plans via internet centers, whereas 16 of them use it for chatting, emailing and research purposes.The rest of the sample have limited knowledge of the internet. The researcher used the interviewing method to gather data from
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We refer in this research into linguistic binaries, try rounding of simiaei news analysis. It is known that there are branches of Linguistics called social Linguistics, divided into communicative Linguistics and media. Perhaps the best justification for the inclusion of a new curriculum in media studies is a semiotic analysis of the news. I›ve turned the speech, language and communication studies in relation to different disciplines, many research projects, and returned only old curriculum, speed shift in thought, proportional to the revolution in information and communication technology, for reality imposed on the entire world, researchers are the first affected by this enormous humanitarian Almanza. Alsimiaaeon still shy away from an
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