Preferred Language
Articles
/
W4avU4YBIXToZYALbILl
Stability and thermophysical properties of non-covalently functionalized graphene nanoplatelets nanofluids
...Show More Authors

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).

Crossref
Publication Date
Sat Apr 01 2023
Journal Name
Fluid Phase Equilibria
Prediction of solubility of vitamins in the mixed solvents using equation of state
...Show More Authors

View Publication
Scopus (1)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Thu Mar 31 2022
Journal Name
Journal Of The College Of Education For Women
Spatial Variation of the Manifestations of Visual Pollution in the Municipality of Shula
...Show More Authors

The research deals with the problem of visual pollution, as it is one of the most important urban problems that cities suffer from. The concept of visual pollution has recently emerged to describe the deformation and degradation of the urban environment. Visual pollution is defined as any component of the surrounding environment that is inconsistent and not homogeneous with its natural and human components. The volume of visual pollution has doubled due to the non-compliance with the laws, regulations and controls set by the Municipality of Baghdad by the citizens, and to the weak municipal role that the municipality plays in implementing these laws. Therefore, it has become necessary to know the manifestations of visual pollution and th

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sat Nov 11 2023
Journal Name
مجلة كلية الامام الاعظم
Provisions for inheritance of agricultural lands (transfer of the right to dispose of)
...Show More Authors

Agricultural lands have great importance in people's lives, and their exploitation has a great impact on strengthening the national economy. Therefore, countries have given great importance to this sector, and because of the importance of this sector, the state has given large areas of these lands to the farmers to invest in agriculture, and among these farmers are those who died and left behind children who took up crafts. Agriculture, for fear that these agricultural lands would be abandoned and turned into waste lands, a land system was introduced called (regular distribu- tion), which corresponds to (legitimate inheritance). Under this system, these lands were trans- ferred to the children of farmers who died so that the process of inve

... Show More
Preview PDF
Publication Date
Tue Jan 01 2013
Journal Name
Journal Of Genetic And Environmental Resources Conservation
The study of food preference of Callosobruchus maculatus to five types of fabaceae
...Show More Authors

Publication Date
Thu Nov 01 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Assessment of the psychological domain of the quality of life for infertile men
...Show More Authors

Abstract A descriptive correlation study which was utilizing an assessment approach, was carried out from November 19th, 2002 through April 30, 2004 in order to assess the psychosocial domain of the quality of life for the infertile men. A purposive sample of (200) men with infertility was selected from the High Institute for Embryo Research and Infertility Treatment and Alsamaraee Hospital in Baghdad city. A questionnaire was adoapted and developed of the World Health Organization quality of life scale for the purpose of the study. The questionnaire (WHOQOL) (1998) Reliability and validity of the questionnair

... Show More
View Publication Preview PDF
Publication Date
Wed May 10 2023
Journal Name
Journal Of Engineering
EFFECT OF CHANGE IN THE COEFFICIENT OF PERMEABILITY ON CONSOLIDATION CHARACTERISTICS OF CLAYS
...Show More Authors

The settlement rate and pore water pressure dissipation rate are mainly controlled by the permeability of soil. Both laboratory and field tests show that the permeability is varied during the loading and consolidation process. It is known that consolidation process is accompanied by decrease in void ratio which leads to decrease in the coefficient of permeability. The importance of the decrease of the coefficient of permeability on the time rate of settlement and pore water pressure needs to be investigated.
This paper takes into account the change in coefficient of permeability during consolidation and studies its effect on consolidation characteristics of a clay layer. The finite element method is used in the analysis and the packag

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Mar 31 2016
Journal Name
Al-khwarizmi Engineering Journal
Enhancement of Buckling Resistance of Aluminized Long Columns of Stainless Steel AISI 303
...Show More Authors

This paper has investigated experimentally the dynamic buckling behavior of AISI 303 stainless steel Aluminized and as received long columns. These columns, hot-dip aluminized and as received, are tested under dynamic buckling, 22 specimens, without aluminizing (type 1), and 50 specimens, with hot-dip aluminizing at different aluminizing conditions of dipping temperature and dipping time (type 2), are tested under dynamic compression loading and under dynamic combined loading (compression and bending) by using a rotating buckling test machine. The experimental results are compared with Perry Robertson interaction formula that used for long columns. Greenhill formula is used to get a mathematical model that descripts the buckling behavior

... Show More
View Publication Preview PDF
Publication Date
Thu Oct 18 2018
Journal Name
Journal Of Economics And Administrative Sciences
Effect of Attitudes in the ethics of the public job of the individual
...Show More Authors

Attitude is an important subject that has attracted researchers and thinkers in organizational theory and organizational behavior because of its great importance in various field studies. Field evidence suggests that individuals in their daily lives or careers respond to specific events through a set of internal tendencies Internal tendencies are negative or positive and systematic. These trends tend to be invisible, not limited to certain boundaries, and involve a significant number of individuals within organizations or society.

 The research aims to identify the impact of trends in the ethics of public service workers for individuals, through a sample of (72) doctors and (60) administrative staff

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Sep 07 2014
Journal Name
Baghdad Science Journal
Analytical Study of near Mobility Edge Density of States of Hydrogenated Amorphous Silicon
...Show More Authors

Experimental results for the density of states of hydrogenated amorphous silicon due to Jackson et al near the valence and conduction band edges were analyzed using Levenberg-Marquardt nonlinear fitting method. It is found that the density of states of the valence band and the conduction band can be fitted to a simple power law, with a power index 0.60 near the valence band edge, and 0.55 near the conduction band edge. These results indicate a modest but noticeable deviation from the square root law (power index=0.5) which is found in crystalline semiconductors. Analysis of Jackson et al density of states integral J(E) data over about (1.4 eV) of photon energy range, showed a significant fit to a simple power law with a power index of 2.11

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Oct 01 2010
Journal Name
Iraqi Journal Of Physics
Investigation of plasma characteristics of center region of post cylindrical magnetron sputtering device
...Show More Authors

A d.c. magnetron sputtering system was designed and fabricated. The chamber of this system is consisted from two copper coaxial cylinders. The inner one used as the cathode and the outer one used as anode with magnetic coil located on the outer cylinder (anode). The axial behavior of the magnetic field strength along the cathode surface for various coil current (from 2A to 14A) are shown. The results of this work are investigated by three cylindrical Langmuir probes that have different diameters that are 2.2mm, 1mm, and 0.45mm. The results of these probes show that, there are two Maxwellian electron groups appear in the central region. As well as, the density of electron and ion decreases with increases of magnetic field strengths.

View Publication Preview PDF