The aim of this research is to study the factors affecting drag coefficient (C d ) in
non-Newtonian fluids which are the rheological properties ,concentrations of non-
Newtonian fluids, particle shape, size and the density difference between particle and
fluid .Also this study shows drag coefficient (C d ) and particle Reynolds' number (Re
P ) relationship and the effect of rheological properties on this relationship.
An experimental apparatus was designed and built, which consists of Perspex pipe
of length of 160 cm. and inside diameter of 7.8 cm. to calculate the settling velocity,
also electronic circuit was designed to calculate the falling time of particles through
fluid.
Two types of solid particles were used; glass spheres and crushed rocks as
irregularly shaped particles with different diameters and compared with each other.
The concept of equivalent spherical diameter (D S ) was used to calculate the
diameters of irregularly shaped particles.
The flow behavior for Non-Newtonian fluids was represented by Power-Law model.
Two types of polymers were used, Carboxy Methyl Cellulose CMC with
concentrations of (3.71, 5, 15 and 17.5) g/l and polyacrylamide with concentrations of
(2, 4 and 6) g/l.
The results showed that the drag coefficient decreased with increasing settling
velocity and particle diameters and sizes; and increased as fluid become far from
Newtonian behavior and concentrations and the density difference between particle
and fluid.
The results also showed that the rheological properties of Non-Newtonian fluids
have a great effect on the drag coefficient and particle Reynolds number relationship,
especially in laminar-slip regime and decreases or vanishes at transition and turbulentslip
regimes.
New correlations were obtained which relates drag coefficient with concentrations
of polymers and with flow behavior indices for spherical and irregular shaped
particles in Carboxy Methyl Cellulose CMC and polyacrylamide solutions.
In this study three inorganic nano additives, namely; CaCO3, Al2O3 and SiO2 were used to prepare nanocomposites of unsaturated polyester in order to modify their mechanical properties, i.e. tensile strength, elongation, impact and hardness. The results indicated that all the three additives were effective to improve the mechanical properties up to 4% by weight. The effectiveness of them follows the order : CaCO3 > Al2O3 > SiO2 This is due to their particle size in which CaCO3 (13nm), Al2O3 (20-30nm) and SiO2 (15-20nm).
Some new cyclic imides are prepared by the reaction of ampicillin drug with different cyclic anhydrides as a first step to form amic acids for ampicillin drug. The second step includes the reaction of prepared amic acids with acetic anhydride and anhydrous sodium acetate with heating in THF as a solvent to give cyclic imide compounds. These compounds are identified by melting points, FT-IR, 1H-NMR, and biological activity
Polymeric hollow fiber membrane is produced by a physical process called wet or dry/wet phase inversion; a technique includes many steps and depends on different factors (starting from selecting materials, end with post-treatment of hollow fiber membrane locally manufactured). This review highlights the most significant factors that affect and control the characterization and structure of ultrafiltration hollow fiber membranes used in different applications.
Three different types of polymers (polysulfone PSF, polyethersulfone PES or polyvinyl chloride PVC) were considered to study morphology change and structure of hollow fiber membranes in this review. These hollow fiber membranes were manufactured with different pro
... Show MoreThis study was conducted on the possibility of manufacturing kids’ foods fortified by legumes. Three raw materials of boiled vegetables (carrots, potatoes and zucchini) were used, one of the pre-boiled legumes was added to the mixture, which included chickpeas, lentils, mung, soybean, fenugreek, by the percentage of 5% and 10%. The results of the chemical analysis showed no statistically significant differences (P <0.05) between the coefficients of moisture, ash and fiber. However, the ash ratio increased from 0.76 to 0.88% and fiber from 0.43 to 0.87%. As for protein and fat, A8 coefficient (add 10% soybean bean) recorded highest ratio of 2.54 and 0.71% respectively, the results of the analysis of mineral elements showed that the A8 coef
... Show MoreBackground׃ Halitosis is a common condition and is most often caused by a buildup of bacteria in the mouth because of gum disease, food, or plaque. It can result in anxiety among those affected, it is also associated with depression and symptoms of obsessive compulsive disorder. The aim of this study isto assess the prevalence of self-reported halitosis and associated factors (dental plaque, gingival condition and dental caries) in 15 years old male students in Karbala city in Iraq. Additionally, we studied adolescents’ concern with their own breath and whether anyone had ever told them that they had halitosis. Methods׃ A cross sectional observational survey was conducted to15 years old high school students from public and p
... Show MorePricing has an important position among the elements of marketing mixture (4ps) as it represents revenues that in turn represent one of the important pillars' for resources affecting on organizations sustainability and development , and the failure in determining prices and their strategies has a dangerous effect on the organizations reality and future as a whole . from this point, this is what from the focus of the research problem,which centered on how to get companies to critical price that satisfies customers and achieve corporate objectives.
... Show MoreThe nucleon momentum distributions (NMD) and elastic electron scattering form factors of the ground state for some 1f-2p-shell nuclei, such as 58Ni, 60Ni, 62Ni, and 64Ni
isotopes have been calculated in the framework of the coherent fluctuation model (CFM) and expressed in terms of the weight function lf(x)l2 . The weight function (fluctuation function) has been related to the nucleon density distribution (NDD) of the nuclei and determined from the theory and experiment. The NDD is derived from a simple method based on the use of the single particle wave functions of the harmonic oscillator potential and the occupation numbers of the states. The feature of the l
Journal of Theoretical and Applied Information Technology is a peer-reviewed electronic research papers & review papers journal with aim of promoting and publishing original high quality research dealing with theoretical and scientific aspects in all disciplines of IT (Informaiton Technology
Background: Varicose vein (VV) is a common problem that mostly occurs in legs. This medical condition can influence the quality of life and working condition of nurses. Aim of the study: To estimate the prevalence of lower limbs varicosity and its associated risk factors among nurses. Methods: This a cross-sectional descriptive study was carried out among 100 nurses working Baghdad Teaching Hospital, Surgical Specialties Hospital, and Al- Kidney Teaching Hospital, Baghdad, Iraq from January 1st to May 10th, 2022. The participants were recruited in the study using systematic random sampling. The Occupational Sitting and Physical Activity and Aberdeen Varicose Vein Questionnaires were used for data gathering. Results: The prevalence o
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