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).
Image fusion is one of the most important techniques in digital image processing, includes the development of software to make the integration of multiple sets of data for the same location; It is one of the new fields adopted in solve the problems of the digital image, and produce high-quality images contains on more information for the purposes of interpretation, classification, segmentation and compression, etc. In this research, there is a solution of problems faced by different digital images such as multi focus images through a simulation process using the camera to the work of the fuse of various digital images based on previously adopted fusion techniques such as arithmetic techniques (BT, CNT and MLT), statistical techniques (LMM,
... Show MoreThe problem of noise in the Baghdad airport has been examined in this study; and noise measurement and survey studies have been carried out at four high noise level (operation, training and development, quality system, and information and technology) zones located in this region. Noise exposure is a common hazard to workforce in general although at varying degrees depending on the occupation, as many workers are exposed for long periods of time to potentially hazardous noise. A questionnaire was completed by 122 workers during this study in order to determine the physical, physiological, and psycho-social impacts of the noise on workers and to specify what kind of measurements have been taken both by the employers and workers for protection
... Show MoreThe problem of noise in the Baghdad airport has been examined in this study; and noise measurement and survey studies have been carried out at four high noise level (operation, training and development, quality system, and information and technology) zones located in this region. Noise exposure is a common hazard to workforce in general although at varying degrees depending on the occupation, as many workers are exposed for long periods of time to potentially hazardous noise. A questionnaire was completed by 122 workers during this study in order to determine the physical, physiological, and psycho-social impacts of the noise on workers and to specify what kind of measurements have been taken both by the employers and workers for protection
... Show MoreStarting from bis (4,4'-diamino phenoxy) ethan(1), a variety of phenolicschiff bases (methylolic, etheric, epoxy) derivatives have been synthesized. All proposed structure were supported by FTIR, 1H-NMR, 13C-NMR Elemental analysis, some derivatives evaluated by thermal analysis (TGA).
This paper focuses on the concept of cognition and its clarification in the light of Islamic epistemology. Knowledge passes through two essential parts: conception and assent. Conception explains simple knowledge, while assent explains knowledge involving a judgment. The paper proceeded with the identification of the problem of relationship blurring between cognition and knowledge. The external and inner senses have explained the relationship between the stages of knowledge and cognition. The external senses receive stimuli and form primary conceptions. These conceptions transfer to the first part of the inner senses, which is common sense; it collects the sensations and transmits them to pictorial power. Secondary conceptions are f
... Show MoreThis study aimed at identifying the effect of violence on speech disorders concerning Arab Broadcasting . Language is a pot of thought and a mirror of human civilization and communication tool, but the Arabic language is suffering a lot of extraneous terms them, particularly through the media. This study attempts to answer the following question: Is the phenomenon of linguistic duality in the Media reflected negatively on the rules of the classical language? The study deals with the explanation and interpretation of the phenomenon that has become slang exist in our Media More. And the study suggests re- consideration of the value in the Media ,hence the problem will be resolved.
A new generalizations of coretractable modules are introduced where a module is called t-essentially (weakly t-essentially) coretractable if for all proper submodule of , there exists f End( ), f( )=0 and Imf tes (Im f + tes ). Some basic properties are studied and many relationships between these classes and other related one are presented.
Short fiction, documentary and animation films constitute an outlet for many young filmmakers, who find in them a fulfillment of their ambitions. Therefore, this expansion in the cinematic movement witnessed by the cultural scene, despite the differences in levels, has produced films and names of promising young directors. In spreading cultural and artistic awareness and developing aesthetic taste. The research problem was represented in the following question (What are the characteristics of the short film and how its directive treatments are).
The theoretical framework included three sections: the first topic is the short film, its nature and features, the second topic is the elements of construction, and the third topic is Iraqi
The Arab Islamic Manuscripts in the science libraries humanly global heritage in different types of knowledge and science, as they were not confined to a particular flag but extended to include all kinds of science, and to facilitate the knowledge of these types of manuscripts has been necessary to operate them indexed in most libraries , because it is important in determining the size of those manuscripts and set them up and facilitate the work of the investigators, as well as the significance of indexing to know printed manuscripts in order to avoid repetition of the publication of the manuscript more than once, especially if the deployment is to be characterized by accurate scientific integrity and following the origins of the scienti
... Show MoreSituational regret and its relation to the vitality of conscience among university students The research seeks to identify situational regret and its relation to the vitality of conscience among university students, identify the significant differences in regard with students’ gender, and identify if there is a correlation between situational regret and the vitality of conscience. To do this, two scales were adopted; one to measure situational regret consisted of (31) items, which was designed by (Al-badrani, 2006), besides, costa and macrys’ (1992) scale that translated in Arabic language by (Al-qaisy, 2013). It composed of (35) items. Total of (120) male and female students were collected from three-different colleges (science, art
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