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).
The importance of the research lies in developing flexibility exercises (positive and negative) that help improve the level of physical and skill performance, address some weak points, and develop factors that work to implement skills with a wider range of motion, accuracy, and high strength. This is what makes the game of badminton more developed and successful. Performing (dimensions) strokes And the forward projection) by not using the wrist and the correct movement of the striking arm. This makes the player’s performance ineffective, which requires her to practice flexibility and movement flow to address this weakness. The study aims to prepare exercises using flexibility (positive and negative) and to know the e
... Show MoreBlood and urine samples were collected from 203 patients to study the relationship between Diabetes mellitus and urinary tract infections (UTI). Blood and urine specimens were subjected for estimation of random blood sugar, in addition to detection of the most pathogen bacteria which cause urinary tract infection in diabetic patients. The study included the detection of bacterial sensitivity to some antibiotics used in treating urinary tract infections, and also included the study of genetic basis which cause both types of diabetes mellitus. The results can be summarized as follows: The incidence of type ? diabetes in males was (35.8%), and (45.9%) in females . and type 2 diabetes in males was (49.6%), while in females was (40.16%).The inc
... Show MoreDry gas is considered one of the most environmentally friendly sources of energy. As a result, developing an efficient strategy for storing this gas has become essential. In this work, MOF-199 was synthesized and characterized in order to investigate the MOF-199 in dry gas adsorption using a built-in volumetric system (methane, ethane, and propane from Basrah gas company). The MOF-199 (metal organic framework) was synthesized using the solvothermal method at 373K for 24h, and then it was characterized. The dry gas adsorption on MOF-199 was studied under various conditions (adsorbent dosage, contact time, temperature, and pressure). The isothermal adsorption of the dry gas had been studied on MOF-199 using two types of mo
... Show MoreDeception is defined as a linguistic and non-linguistic behavior that is used in interaction in order to make the addressees believe what is believed to be false or lack evidence. McCornack (1992) classifies deception into four manipulative strategies (i.e., fabrication, distortion, equivocation and concealment), other scholars argue that deception encompasses the strategies of “fabrication (outright lying), equivocation (being vague and ambiguous), or concealment (with holding relevant information) Thus, the present study investigates the deception strategies and motives that are used by Johnny Depp and Amber Heard during their defamation trials. Qualitative and quantitative methods are employed when analyzing the data in question. Th
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Abstract
What the research come to:
1- The presentation of the image of the proud person in this
mortal life appeared in several styles such as (conversation)
arousing the insert once and convincing in other time,
(confirmation) in all its types، (argument) scolding with the
gradual progress of time of the discourse .Interview and
parallelism are two of these styles with the presences of the
repetition style especially in the topics that has a reference to
the theme of (pride) being implied not directly stated. The
Koran discourse varied in its reference to the theme of pride
according to the context which is mentioned directly
(eighteen times) which formed one third of the number of
Aim: The purpose of this study was to analyze the patterns of facial fractures in children and to compare them between preschool- and school-aged children. Materials and methods: This retrospective observational study included 57 children with facial fractures. The variables analyzed were the age of the patients—divided into a preschool-aged group (0–5 years) and a school-aged group (6–12 years)—gender, cause of trauma, the facial bones involved, the pattern of fracture, the modality of treatment used, the time between injury and treatment, and the postoperative complications. Results: The incidence of facial fractures in children ≤12 years was 30.2%. The patients consisted of 40 (70.2%) males and 17 (29.8%) females, and most pati
... Show MoreSolid waste is a major issue in today's world. Which can be a contributing factor to pollution and the spread of vector-borne diseases. Because of its complicated nonlinear processes, this problem is difficult to model and optimize using traditional methods. In this study, a mathematical model was developed to optimize the cost of solid waste recycling and management. In the optimization phase, the salp swarm algorithm (SSA) is utilized to determine the level of discarded solid waste and reclaimed solid waste. An optimization technique SSA is a new method of finding the ideal solution for a mathematical relationship based on leaders and followers. It takes a lot of random solutions, as well as their outward or inward fluctuations, t
... Show MoreBoth of the species Typha domengensis and Phragmites communis among the most important plant endemic in flora of Iraq from monocotyledon. Due to the similarity of the two species with each other in many morphological characteristics such as the environment where they live and the form of leaves and type of leaf venation and type of stomata….ets, also both of species belong to monocots plant therefore this research work was conducted find anatomical differences that have the same as taxonomic value to help distinguishing between both species under study. Through this research, we found great importance to the anatomical characteristics which we reached by studying the roots, stems and leaves sections f
... Show MoreBackground: Helicobacter pylorus is one of the most harmful human pathogens & carcinogen. Of the world's population, more than 50% has H. pylori in their upper gastrointestinal tracts. It has been linked to a variety of extra gastric disorders. In correlation to hepatobiliary diseases; recently, the bacterium has been implicated as a risk factor for various diseases ranging from chronic cholecystitis and primary biliary sclerosing cholangitis to gall bladder cancer and primary hepatic carcinomas. However, the association between Helicobacter pylori (H. pylori) and gallbladder diseases is still vague and is controversial.
Aim of study: To elucidate the association of H pylori and gallbladder diseases (calculu
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