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.
Objective(s): To find out the incidence Rate of abortions in pregnant women Admitted Maternal and pediatric Hospitals at Al-Diwaniyah City and to identify the relationship between the incidence rate of abortion and the associated risk factors that led to the occurrence of abortion.
Methodology: A descriptive study was conducted to identify the Incidence Rate of Abortions and its Associated Factors among Women at AL-Diwaniyah City’s Maternity and pediatric Hospital from 16 September 2020 to 16 March 2021 . The sample study includes (100) pregnant women with abortion out of (3800) pregnant women. The data was collected by means of a questionnaire through a personal intervie
... Show MoreThe bubble columns are widely used as a two or three phase reactor in industrial chemical process such as absorption, biochemical reactions, coal liquefaction, etc. To design such a column, two main parameters should be taken in consideration, the gas hold-up (), and the liquid phase mass transfer coefficient KLa. The study includes the effect of gas velocity and the addition of alcohols on gas hold-up and mass transfer coefficient in bubble column with draught tube when the length of the column is 1.5m and the ratio of the draught tube diameter to the column diameter equals 0.5 and the air dispersion into the base of the draught tube using a multi hole tuyere is equivalent to a diameter of 0.15 mm and
... Show MoreThe study aims to investigate the effect of the Six Thinking Hats Strategy on the achievement of essay writing skills among third-year students in Arabic Language and Literature who are Persian speakers enrolled in the course of Essay Writing (III) at Shiraz University for the academic year 2019-2020. The sample of the study consisted of (15) male and female students who were taught according to the pre-posttest, using the quasi-experimental approach. After applying the statistical analysis on the scores of the post-test, the results showed that there are statistically significant differences in the average of students' achievement in the skills of essay writing in terms of using the Six Thinking Hats Strategy. The results also proved th
... Show MoreA new heterocyclic Schiff bases ligand (HL) derived from condensation of 2-Amino-4-methylbenzothiazole with 4-Diethylaminosalicylaldehyde have been synthesized and characterized by (FTIR & UV.Vis) spectroscopies, (1H & 13C)NMR spectra, mass spectrum, elemental microanalysis (C,H,N,S). Metal complexes with Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions have been also synthesized and characterized by (FTIR & UV.Vis) spectroscopies, flame atomic absorption, molar conductivity measurements and magnetic susceptibility. These studies indicate that the mole ratio (L:M) is (2:1) for Co(II) complex and (1:1) for other complexes. The spectral results indicate that the ligand coordinates with met
... Show MoreThe change in the optical band gap and optical activation energy have been investigated for pure Poly (vinyl alcohol)and Poly (vinyl alcohol) doped with Aluminum sulphate to proper films from their optical absorption spectra. The absorption spectra were measured in the wave range from (200-700) nm at temperature range (25-140) 0C. The optical band gap (Eg) for allowed direct transition decrease with increase the concentration of Aluminum sulphate. The optical activation energy for allowed direct transition band gap was evaluated using Urbach- edges method. It was found that ?E increases with increasing the concentration of Al2 (SO4)3 and decreases when temperature increases.
Many of the key stream generators which are used in practice are LFSR-based in the sense that they produce the key stream according to a rule y = C(L(x)), where L(x) denotes an internal linear bit stream, produced by small number of parallel linear feedback shift registers (LFSRs), and C denotes some nonlinear compression function. In this paper we combine between the output sequences from the linear feedback shift registers with the sequences out from non linear key generator to get the final very strong key sequence
Le professeur Taranne et La non-Communication
In the present work, a Z-scan technique was used to study the nonlinear optical properties, represented by the nonlinear refractive index and nonlinear absorption coefficients of the Ag nanoparticles. In this technique, a pulsed second harmonic Nd :YAG laser at wavelength 532 nm was used. The results show that the nonlinear refractive index and nonlinear absorption coefficients of the Ag nanoparticles are found to be dependent on the size these nanoparticles.