A pioneering idea for increasing the thermal performance of heat transfer fluids was to use ultrafine solid particles suspended in the base fluid. Nanofluids, synthesized by mixing solid nanometer sized particles at low concentrations with the base fluid, were used as a new heat transfer fluid and developed a remarkable effect on the thermophysical properties and heat transfer coefficient. For any nanofluid to be usable in heat transfer applications, the main concern is its long-term stability. The aim of this research is to investigate the effect of using four different surfactants (sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTAB), and gum Arabic (GA)), each with three different concentrations, and five ultrasonication times (15, 30, 60, 90, and 120 min) on the stability of water-based graphene nanoplatelets (GNPs) nanofluids. In addition, the viscosity and thermal conductivity of the highest stability samples were measured at different temperatures. For this aim, nineteen different nanofluids with 0.1 wt% concentration of GNPs were prepared via the two-step method. An ultrasonication probe was utilized to disperse the GNPs in distilled water. UV–vis spectrometry, zeta potential, average particle size, and Transmission Electron Microscopy (TEM) were helpful in evaluating the stability and characterizing the prepared nanofluids. TEM and zeta potential results were in agreement with the UV–vis measurements. The highest nanofluid stability was obtained at 60-min ultrasonication time. The prepared water-based pristine GNPs nanofluids were not stable, and the stability was improved with the addition of surfactants. The presence of SDBS, SDS, and CTAB surfactants in the nanofluids resulted in excessive foam. The best water-based GNPs nanofluid was selected in terms of better stability, higher thermal conductivity, and lower viscosity. From all the samples that were prepared in this research, the (1–1) SDBS–GNPs sample with 60-min ultrasonication showed the highest stability (82% relative concentration after 60 days), the second better enhancement in the thermal conductivity of the base fluid (8.36%), and nearly the lowest viscosity (7.4% higher than distilled water).
Praise be to God, Lord of the Worlds, and prayers and peace be upon our Master Muhammad and upon all his family and companions:
And then: What most concerns rational people and reformers in the modern era is the moral deviation and delinquency that dominates childhood, due to family disintegration and the lack of discipline of most societies according to the religious and moral motives called for by the heavenly messages, especially Islam, which is the final message and guarantees the reform of people in life. Every time and place.
Islam has drawn attention to this issue (childhood) and made it the focus of its consideration, considering that the child is the nucleus of society and the preparation for the future, so it ordered that
The research aims to identify the educational plan for the private and public kindergartens. The researchers selected a sample consisted of (59) female teachers for the private kindergartens and (150) female teachers for the public kindergartens in the city of Baghdad. As for the research tool, the two researchers designed a questionnaire to measure the educational plan for the private and public kindergartens. The results revealed that private kindergartens have educational plans that contribute considerably to classroom interaction, the public kindergartens lack for educational plans. In light of the findings of the research, the researchers recommend the following: the need to set up a unified educational plan for the priv
... Show MoreThe concept of tolerance is gaining its importance in the midst of an international society suffering from violence, wars and internal and international crises. It is practiced by extremist and extremist forces and movements acting in the name of religion to exclude the different Muslim and non-Muslim people according to the unethical practices and methodologies of Islamic law and reality. , Cultural, civilization .. that distinguish our world today. The society today is suffering from the ideas of the intellectual and aesthetic views of the different ideologically, ethnically, culturally and religiously in the world of the South. This is what the end-of-history thesis of Fukuyama and the clash of civilizations represented to Huntington.
... Show MoreThis paper aims to give an overview of acculturation in the literature by means of its explicit definitions, main characteristics, and categorical process. It also foreshadows the significance of acquiring novice culture with particular connection to second language acquisition. Schumann and John Berry underscored acculturation each with its own model of acculturation. In the case of this review, you will realize that Schumann's two main aspects are firmly rooted in berry's model of acculturation as an exclusive description in relation to second language acquisition. Steven Krashen outlined acquiring language from the intellectual and linguistic view of learning, whereas Micheal Long demanded for communication in social perspective. It has
... Show MoreToday, the architecture field is witnessing a noticeable evolution regarding the used tools that the designer should invest in a peculiar way that is made available in architecture through the concept of synergy generally and algorithmic synergy specifically. The synergy is meant to study and analyze the cooperative behavior of complex systems and self-organizing systems that leads to different outputs referred to by the synergy as the (whole), which is bigger than the sum of parts and in architecture, it's translated as the architectural form. This point resulted in a need of a specific study regarding the concept of synergy that focuses on the cooperative, synergistic relations within the trilogy of (form, structure, and material) and
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First: the problem of research and its importance
The teacher's success in facilitating the students' learning and growth according to the educational and educational goals set out, he must identify the problems of discipline of students in the classroom in terms of sources and reasons and types and methods of prevention and treatment and the teacher to remember that success in his teaching and instruction is not completed more fully once he has the information And knowledge of the subject of the lesson, but must understand the dynamics of the group (class group) and master the skills of classroom management, su
... Show Moreعند إطلالتنا على هذا البلد العربي لابد من التقصي ولو بعجاله عن اقتصاده وهو الاهم باعتبار ان الاقتصاد هو شريان الحياة لأي أمة فلا غنى ولا تهاون في نفس الوقت عن هذا الجانب المهم الذي يرتبط مدى تطوره بتطور البلد وهذا الاخير مرتبط بما متوفر لديه من موارد بشريه ومادية وان تفاوتت النسبة بينها فلا ضير في ذلك فالاهم هو وجود الموجه والمخطط بالاتجاه الصحيح نحو الاستغلال الامثل لهذه الموارد
(وان قلّتْ) وبالتالي
The problem of this paper is identified by knowing the role of the economic television media in shaping the audience's attitudes. It seeks to understand the type of relationship between the dependence of the economic elite audience on news bulletins and its cognitive implications. The categories of Iraqi society, namely, the economic elite category. This paper adopted the descriptive survey method for the period from 3/1/2022 - 6/31/2022. The sample was extracted according to the relative stratified sampling method in the city of Baghdad. A set of results has been concluded, the most prominent of which is the public's heavy reliance on economic news bulletins to obtain news and information, as indicated by (63%) of the respondents partic
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