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joe-2070
Evaluation of Convective Heat Transfer and Natural Circulation in an Evacuated Tube Solar Collector
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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.

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Publication Date
Sun Apr 25 2021
Journal Name
Egyptian Journal Of Chemistry
Indirect spectrophotometric determination of Mebendazole using n-bromosuccinimide as an oxidant and tartarazine dye as analytical reagent
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Publication Date
Sat Dec 15 2018
Journal Name
Journal Of Baghdad College Of Dentistry
The impact of an Oral Health Education (OHE) program by teachers and mothers on adolescents' oral health
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Background: Adolescence is one of the most dynamic stages of human development. However, Oral health is an integral part of public health, significantly impacts on the quality of life. OHE program is an important issue that should be given to them. The aim of this study was to evaluate oral health outcomes on adolescents' oral health by teachers and mothers Materials and Methods: The study was carried out in seven schools of Diyala - Baquba city. This 14-weeks duration study assessed the effectiveness of school OHE program on oral hygiene status, gingival health, and halitosis assessment of 80, 12 year-old, both genders of school adolescents. From the selected schools, one group was supervised by the teachers and the other was supervised

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Publication Date
Tue Oct 24 2023
Journal Name
Environmental Engineering Research
Exploring electromembrane extraction and liquid membrane for efficient removal of heavy metals from aqueous solutions: An overview
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Environmental pollution is experiencing an alarming surge within the global ecosystem, warranting urgent attention. Among the significant challenges that demand immediate resolution, effective treatment of industrial pollutants stands out prominently, which for decades has been the focus of most researchers for sustainable industrial development aiming to remove those pollutants and recover some of them. The liquid membrane (LM) method, specifically electromembrane extraction (EME), offers promise. EME deploys an electric field, reducing extraction time and energy use while staying eco-friendly. However, there's a crucial knowledge gap. Despite strides in understanding and applying EME, optimizing it for diverse industrial pollutant

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Publication Date
Mon May 22 2023
Journal Name
Journal Of Applied Business And Technology
Toxic Workplace, Mental Health and Employee Well-being, the Moderator Role of Paternalistic Leadership, an Empirical Study
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Based on previous research results that recognized the role of paternalistic leadership in promoting a positive work climate, this study explored the impact of a toxic work environment on the mental health and well-being of employees. We used the quantitative methodology to collect and analyze data. A sample of 108 participants from Iraqi internet service provider (ISPs) companies represented the purposive study sample. We targeted employees who experienced the COVID-19 pandemic. All data was collected through an electronic questionnaire (Google and Microsoft Forms). The research model was tested using structural equation modeling (SEM). The results showed a negative effect of the toxic workplace on the mental health of employees. T

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Publication Date
Sat Jul 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Evaluation the Effect of some Plant Extracts in Controlling the Oriental Hornet vespa orientalis Linnaeus, 1771 Near the Apiaries
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Abstract<p>A significant amount of apiaries is destroyed in most areas of Iraq by attacking of the hornet<italic>Vespa orientalis</italic>Linnaeus, 1771, as well as the deterioration of European honey bees’ Apis mellifera Linnaeus, 1758 productivity recently because the environmental changes and pollutions; this effect was evident in the economy and plant production, because the bees as the most popular species of pollinator of crops globally. There is no effective and environmentally safe method yet; Therefore, this study suggested to use essential oils of Mediterranean cypress<italic>Cupressus sempervirens</italic>L., 1753 (Pinales: Cupressaceae), and testing as a repellant substance. In</p> ... Show More
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Publication Date
Tue Jul 22 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of Propolis from Kurdistan region as a new resinous sealer in root canal obturation-part I biocompatibility study
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Background: Many materials were proposed as root canal obturating materials but the biocompatibility issue remains to be a critical one. Propolis has been used as a therapeutic agent since the time of Hippocrates. It is known that propolis exhibits some pharmacological activities, such as antibacterial, antiviral, antifungal and anti inflammatory activity. Materials and methods: Eighteen albino rats were used in the study and divided randomly into three groups of 6 animals for each group. Each group was scheduled to be sacrificed at different time periods, which were three days, one week and three weeks. Propolis and ZOE sealer implants of 4mm in diameter and 0.5 gm in weight were implanted in the dorsal side of the rats. At the end of the

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Publication Date
Tue Mar 01 2016
Journal Name
Journal Of Pharmaceutical Sciences
Development and Evaluation of Biodegradable Particles Coloaded With Antigen and the Toll-Like Receptor Agonist, Pentaerythritol Lipid A, as a Cancer Vaccine
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Publication Date
Sat Jun 04 2022
Journal Name
Al–bahith Al–a'alami
Digital public relations and its role in prioritizing the masses: An analytical study of the United Nations website : (A paper extracted from a PhD dissertation)
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This paper aims to identify how the United Nations works through its website in prioritizing audiences towards international issues، by identifying the digital PR mechanisms used in digital PR contents in prioritizing audiences towards the international issues they deal with. To achieve the objectives of this paper, the researcher used the survey method and content analysis tool with a view to identifying the ranking of international issues on the website of health، peace and security، humanitarian assistance، human rights، women، migrants، refugees and displaced persons، economic development، United Nations affairs، culture and education، environment and climate، sustainable development, and law and crime prevention. One of

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Publication Date
Sun Jun 30 2024
Journal Name
Modern Sport
The effect of an educational curriculum using virtual reality glasses in improving some kinetic abilities and learning freestyle swimming for first-year primary school students
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هدفت الدراسة الى الاهتمام واستغلال ماهو جديد من تقنيات واجهزة حديثة في تعليم السباحة الحرة عن طريق توجيه الاطفال على تطوير مداركهم واستيعابهم بالتطور التكنولوجي الذي يتناوله العالم ،قامت الباحثتان باعداد منهج تعليمي باستخدام نظارة الواقع الافتراضي وذالك بتوفير بيئة مشابهة للبيئة الحقيقية تحاكي مدارك عقول الاطفال في عالم افتراضي لتتكون صورة كاملة عن مهارات السباحة الحرة ،ومن هنا اتت المشكلة نتيجة تعل

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Publication Date
Tue Jul 22 2025
Journal Name
Journal Of Baghdad College Of Dentistry
A Comparison between the Horizontal Condylar and Bennett Angles of Iraqi Full Mouth Rehabilitation Patients by Using Two Different Articulator Systems (An In-Vivo Study)
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Background: Errors of horizontal condylar inclinations and Bennett angles had largely affected the articulation of teeth and the pathways of cusps. The aim of this study was to estimate and compare between the horizontal condylar (protrusive) angles and Bennett angles of full mouth rehabilitation patients using two different articulator systems. Materials and Methods: Protrusive angles and Bennett angles of 50 adult males and females Iraqi TMD-free full mouth rehabilitation patients were estimated by using two different articulator systems. Arbitrary hinge axis location followed by protrusive angles and Bennett angles, estimation was done by a semiadjustable articulator system. A fully adjustable articulator system was utilized to locate th

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