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Effect of Design Parameters and Support Conditions on Natural Frequency of Pipe Excited by a Turbulent Internal Flow
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In this study, the effect of design parameters such as pipe diameter, pipe wall thickness, pipe material and the effect of fluid velocity on the natural frequency of fluid-structure interaction in straight pipe conveying fully developed turbulent flow were investigate numerically,analytically and experimentally. Also the effect of support conditions, simply-simply and clamped-clamped was investigated. Experimentally, pipe vibrations were characterized by accelerometer mounted on the pipe wall. The natural frequencies of vibration were analyzed by using Fast Fourier Transformer (FFT). Five test sections of two different pipe diameters of 76.2
mm and 50.8 mm with two pipe thicknesses of 3.7 mm and 2.4 mm and two pipe materials,stainless steel and polyvinyl chloride PVC in the range of Reynolds numbers from 4*104 to 5*105 were studied. Mathematically, the governing continuity and momentum equations were solved numerically by using the finite volume method to compute the characteristics of two dimensional turbulent flow. The dynamics of a pipe conveying fluid was described by the Transfer Matrix Method (TMM) which is provides a numerical technique for solving the equations of pipe vibrations for simply-simply and clamped supports. The results showed that,the natural frequencies increase with pipe diameter increase and the natural frequencies slightly increases with pipe wall thickness increase. Also, the natural frequencies in clamped-clamped supported pipe are higher than those in simply-simply supported pipe.

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Publication Date
Mon Jun 17 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of Two Antigen Preparations From Group A Streptococcus on Phagocytosis and Cellular Counts of Neutrophils and Monocytes in Albino Mice
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The phagocytic activity of peritoneal and blood cells counts with neutrophils and monocytes were evaluated in albino mice treated wtth two antigen preparations (A and B) from group A streptococci (GAS). Antigen A included water bathed bacteria at 70 °C for 60 minutes, while in Antigen B the bacteria was autoclaved at 121° C for 15 minutes. The animals were treated with 12 intraperitoneal doses of the antigens with intervals of three days (36 days). The 12th dose was a challenge dose (live bacteria). The first three doses of Antigen A increased the phagocytic index (PI) to a range of 76.46-78.69%, then a gradual decreased percentage was observed, especially at the challenge dose (PI=6.42%). The count of neutrophils and monocytes fol

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Publication Date
Tue Jun 01 2021
Journal Name
Iop Conference Series: Materials Science And Engineering
An Experimental Research on Design and Development Diversified Controllers for Tri-copter Stability Comparison
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Abstract<p>The drones have become the focus of researchers’ attention because they enter into many details of life. The Tri-copter was chosen because it combines the advantages of the quadcopter in stability and manoeuvrability quickly. In this paper, the nonlinear Tri-copter model is entirely derived and applied three controllers; Proportional-Integral-Derivative (PID), Fractional Order PID (FOPID), and Nonlinear PID (NLPID). The tuning process for the controllers’ parameters had been tuned by using the Grey Wolf Optimization (GWO) algorithm. Then the results obtained had been compared. Where the improvement rate for the Tri-copter model of the nonlinear controller (NLPID) if compared with </p> ... Show More
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Publication Date
Sat Oct 01 2022
Journal Name
Baghdad Science Journal
Effect of Alstonia Boonei Stem Bark Extracts on the Activity of Liver Maker Enzymes in Rats Induced by Ccl4
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This study investigated the outcome of Alstonia boonei stem bark on liver enzymes after inducing the Wistar albino rats with carbon tetrachloride (CCl4). This effect of plant extract was compared with silymarin – a drug commonly used for the treatment of chronic hepatocyte disorder. The plant sample was extracted with ethanol; acute toxicity study of the extract was performed on eighteen Wistar mice, while 30 rats were sacrificed for liver enzymes assay. The rats were divided into six clusters: each cluster has five rats, culster 1 served as control and was given 2 mL/kg b.w - distilled water; clusters 2 – 6 were CCl4 induced. Cluster 2 was untreated but served as the negative control while cluster 3 wa

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Publication Date
Thu Dec 29 2016
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Treatment Effect of Larval Stages by Ecdysone Agonist Hormone (Methoxyfenozide) on The Biology of Cotton Leafworm Spodoptera littoralis (Boisd.)
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       Studies were conducted to evaluate the biological effects of the non-steroidal ecdysone agonist (Methoxyfenozide), on different developmental larval stages of cotton leafworm Spodoptera littoralis (Boisd.) in the laboratory. The results showed that the early larval stages were the most  susceptible to Methoxyfenozide which caused 100% mortality within 4-6 days after treatment at all used concentrations, while such percentage of mortality was achieved within 6 days after treatment for late larval stages when the highest concentration was used (0.2)g (ai) /L. Several morphological deformations were noticed on pupal stage, the results showed that the highest percentage of deformations was 1

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Publication Date
Thu Dec 02 2021
Journal Name
Iraqi Journal Of Science
Effect of the Magnetic Field on the Characteristics of the Dusty Plasma FeO by Using the Direct Current System
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In the present work, the effect of isolated dust particles (FeO) with radius of the grain 0.1μm - 0.5μm of main plasma characteristics are investigated experimentally in direct current system by using magnetic field. The present of dust particle in the air plasma did effect on Paschen minimum and on the plasma properties in low pressure region. The effect of dust particles on discharge voltage, discharge current, plasma potential, floating potential, electron density, electron temperature and Debye length was investigation by using magnetic field. The measurements of parameters are taken by four cylindrical Langmuir probes. The results show the present of dust causes decreasing in discharge voltage with increase pressure while the disc

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Publication Date
Tue Feb 28 2023
Journal Name
Iraqi Journal Of Science
The Effect of Temporal Resolution of Climatic Factors on Agriculture Degradation in Southern Baghdad by Applying Remote Sensing Data
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       The climate changes had been recognized as one of the major factors responsible for land degradation, which has a significant impact on diverse aspects. The present study aims to estimate how the climate change can influence land degradation in the south areas of Baghdad province (Al-Rasheed, Al-Mahmudiyah, Al-Yusufiyah, Al-Madaen, and Al-Latifiyah). The Satellite Landsat-8 OLI and satellite Landsat-5 TM sensor imagery were used to extent land degradation for the period (2010-2019). ArcGIS V.10.4 was applied to manage and analysis the satellite image dataset, including the use of climate factors data from the European Center for Climate Forecasts (ECMWF) by reanalyzes and extraction datasets. To achieve work objectives, many

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Publication Date
Sat Jan 01 2022
Journal Name
Results In Chemistry
Effect of Polyeugenol coating on surface treatment of grade 23 titanium alloy by micro arc technique for dental application
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Titanium alloy (Ti-6Al-4V or Gr.23) was widely used as a dental alloy. In the current study, polymerization of eugenol (PE) on Gr.23 titanium alloys was conducted by an electrochemical process before and after being treated by Micro Arc Oxidation (MAO). The formed films were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion behavior of Gr.23 alloy in an artificial saliva environment at a temperature range of 293–323 K has been studied and assessed by means of electrochemical polarization and impedance spectroscopy techniques. Three cases are taken into consideration; bare Gr.23, Gr.23 coated by PE, and Gr.23 coated by PE after MAO treatment. The maxi

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Publication Date
Wed Dec 01 2010
Journal Name
Iraqi Journal Of Physics
The effect of anode temperature on the Optical characteristic of Se films prepared by direct current planar magnetron sputtering
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This work describes, selenium (Se) films were deposited on clean glass substrates by dc planar magnetron sputtering technique.The dependence of sputtering deposition rate of Se film deposited on pressure and DC power has been studied. The optimum argon pressure has range (4x10-1 -8x10-2 )mbar. The optical properties such as absorption coefficient (α) was determined using the absorbance and transmission measurement from UnicoUV-2102 PC spectrophotometer, at normal incidence of light in the wavelength range of 200-850 nm. And also we calculated optical constants(refractive index (n), dielectric constant (εi,r), and Extinction coefficient (κ) for selenium films.

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Publication Date
Sun Feb 10 2019
Journal Name
Iraqi Journal Of Physics
A study of the effect of acid immersion on some physical properties of ( Epoxy – MgO) composites
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In this study a polymeric composite material was prepared by hand
lay-up technique from epoxy resin as a matrix and magnesium oxide
(MgO) as a reinforcement with different weight fraction (5,10,15,
and 20)% to resin. Then the prepared samples were immersed under
normal condition in H2So4(1 M) solution, for periods ranging up to
10 weeks. The result revealed that the diffusion coefficient
decreasing as the concentration of MgO increase. Also we studied
Hardness for the prepared samples before and after immersion. The
result revealed that the hardness values increase as the concentration
of MgO increase, while the hardness for the samples after immersion
in H2SO4 dec

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Publication Date
Sun Apr 30 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Study Of Optimum Conditions For The Removal Of Ruthenium And Cerium Using Freshly Prepared Manganese Dioxide
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 The adsorption of Ru and Ce were carried out using manganese dioxide as adsorbent. The Optimization of the adsorption conditions were studied as a function of shaking time, nitric acid, metal ions, concentrations and temperature effects.      A rapid initial adsorption on MnO2 is followed by a steady and slow increase of metal uptake. The equilibration time is reached after four hours shaking for Ru and Ce and    the adsorption is much better from one molar acidic solution and 90°C.

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