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Stability and thermophysical properties of non-covalently functionalized graphene nanoplatelets nanofluids
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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).

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Publication Date
Sun May 01 2022
Journal Name
World Economics & Finance Bulletin
PLANNING BUDGETS AND THEIR ROLE IN CONTROLLING COSTS ELEMENTS APPLIED RESEARCH IN THE GENERAL COMPANY FOR FOOD PRODUCTS
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Planning budgets are one of the methods used by the administration in controlling the elements of costs represented by (direct material costs, direct wage costs, and indirect manufacturing costs), and their importance lies in that they reflect what the activity of the economic unit should be in the future. In order to achieve the objectives of the economic unit and to solve this problem, the research was based on the following hypothesis (the role of planning budgets in controlling the elements of costs). , and thus the ability to reduce these costs and thus achieve profits by increasing sales and increasing market share, and the need to urge the state to support the company and the manufacturing sector, which helps and contributes

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Publication Date
Sun Sep 06 2009
Journal Name
Baghdad Science Journal
The Morphological Change in Sunflower Plant under Hardening Conditions to Drought Tolerance. II. Leaf Number and Leaf Area
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The study was conducted during the spring season of 2000 and2001. The objective was to study the changes in leaves number of sunflower plants and its leaf area during growth stages under hardening conditions to drought tolerance. Agricultural practices were made according to recommendations.Asplit-split plots design was used with three replications.The main plots included irrigation treatments:irrigation to100%(full irrigation),75and50%of available water.The sub plots were the cultivars Euroflor and Flame.The sub-sub plots represented four seed soaking treatments:Control(unsoaking), soaking in water ,Paclobutrazol solution(250ppm),and Pix solution(500ppm). The soaking continued for 24 hours then seeds were dried at room temperature

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Publication Date
Sat Sep 01 2018
Journal Name
J Of Baghdad College Of Dentistry
Serum Tumor Necrosis Factor Alpha and High Sensitive C-Reactiveprotein as Biomarkersin Periodontitis in Iraqi Patients with Osteoarthritis
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Publication Date
Fri Jan 01 2016
Journal Name
Journal Of College Of Education
An Investigative Study on the Electron Energy Distribution Function and Electron Transport Coefficients in SF6 -- Ne Gas Mixtures
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Publication Date
Tue Jun 01 2021
Journal Name
Gene Reports
Vitamin D receptor rs2228570 and rs1544410 genetic polymorphisms frequency in Iraqi thalassemia patients compared to other ethnic populations
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Background: The genetic polymorphisms of vitamin D receptor (VDR) have an association with thalassemia development, additionally to the environmental elements that elicited the disorder in the genetically predisposed individuals. As well, VDR functions responsible for the regulation of bone metabolism, such its part in immunity. Aim: The sitting study intended to inspect the association between thalassemia disease and the genetic polymorphisms of VDR among the Iraqi population then compared these findings to other findings of thalassemia patients in other different ethnic populations. Materials and methods: The restriction enzymes Bsm-I and Fok-I were applied to determine the genetic polymorphisms frequencies of VDR by a Polymerase Chain Re

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Publication Date
Wed Sep 11 2024
Journal Name
Edelweiss Applied Science And Technology
Learning styles according to Entwistle model and their relationship to mathematical excellence among scientific fifth-grade female students
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The objective of the present study is to determine the nature and direction of the correlation between mathematical excellence and learning styles as defined by the Entwistle, model in fifth-grade scientific female students. The descriptive correlational approach was implemented by the two researchers to accomplish the research objectives. A scale was developed to assess the learning styles of female students in the sample in accordance with the Entwistle, model. : (Knowledge, understanding, application, analysis, synthesis, evaluation, systematic thinking, creativity), and the research community was determined by the female students of the scientific fifth grade in the morning preparatory and secondary schools of the General Direct

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Publication Date
Fri Jul 01 2016
Journal Name
Arabian Journal Of Geosciences
Polymetallic sulfide ores hosted in Late Permian carbonate at the Alanish locality, northern Iraq: petrography and mineral chemistry
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Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Engineering
Synchronous Buck Converter with Perturb and Observe Maximum Power Point Tracking Implemented on a Low-Cost Arduino-microcontroller
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Maximum power point tracking (MPPT) is used in photovoltaic (PV) systems to enhance efficiency and maximize the output power of PV module, regardless the variation of temperature, irradiation, and the electrical characteristics of the load. A new MPPT system has been presented in this research, consisting of a synchronous DC-DC step-down Buck converter controlled by an Arduino microcontroller based unit. The MPPT process with Perturb and Observe method is performed with a DC-DC converter circuit to overcome the problem of voltage mismatch between the PV modules and the loads. The proposing system has high efficiency, lower cost and can be easily modified to handle more energy sources. The test results indicate that the u

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Publication Date
Tue Jan 01 2019
Journal Name
Journal Of International Oral Health
Endothelin-1 is a surrogate biomarker link severe periodontitis and endothelial dysfunction in hypertensive patients: The potential nexus
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Aim and Objectives: The objective of this study was to illustrate the link between periodontitis (PO) and endothelial dysfunction in hypertensive patients. Materials and Methods: This cross‑sectional study involved 53 hypertensive patients with or without PO compared with 28 healthy controls. On the basis of the study protocol, the participants were divided into three groups: Group (1): 24 patients with hypertension only, Group (2): 29 patients with hypertension and PO, and Group (3): 28 healthy controls. Lipid profile, endothelin‑1 (ET‑1), and high‑sensitivity C‑reactive protein (hs‑CRP) were measured. Blood pressure and body mass index (BMI) were evaluated. Diagnostic criteria of severe PO periodontal indices including plaque

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Scopus (19)
Crossref (12)
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Publication Date
Sun Jun 07 2009
Journal Name
Baghdad Science Journal
THE MORPHOLOGICAL CHANGE IN SUNFLOWER PLANT UNDER HARDENING CONDITIONS TO DROUGHT TOLERANCE . I. PLANT HEIGHT AND STEM DIAMETER
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The objective of the work was to study the changes in height and stem diameter of sunflower plants during growth stages under hardening conditions to drought tolerance. Field experiments were carried out during the spring season of 2000 and2001. Agricultural practices were made according to recommendations.Asplit-split plots design was used with three replications.The main plots included irrigation treatments:irrigation to100%(full irrigation),75and50%of available water.The sub plots were the cultivars Euroflor and Flame.The sub-sub plots represented four seed soaking treatments:Control(unsoaking), soaking in water ,Paclobutrazol solution(250ppm),and Pix solution(500ppm). The soaking continued for 24 hours then seeds were dried at room

... Show More
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