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.
Objective(s): This study was conducted to deal with the importance and effect of various variables which might
have influence in hydrocephaly occurrence.
Methodology: A retrospective design was performed and continued for 4 months. It included 89 nonrandomized
consecutive samples collected from the Early Detection of Childhood Disabilities Center (E.D.C.D.C.)
Duhok. The population involved was the entire cases of both sexes that attended the centre during the period from
1
st.Jan, 1998 to 30th. Dec. 2008 with final diagnosis of hydrocephaly. Patients’ records from the centre were used to
collect data.
Results: Hydrocephaly has been recognized as a public health problem in Duhok province, Iraqi Kurdistan region,<
In this work, functionally graded materials were synthesized by centrifugal technique at different
volume fractions 0.5, 1, 1.5, and 2% Vf with a rotation speed of 1200 rpm and a constant rotation time, T
= 6 min . The mechanical properties were characterized to study the graded and non-graded nanocomposites
and the pure epoxy material. The mechanical tests showed that graded and non-graded added alumina
(Al2O3) nanoparticles enhanced the effect more than pure epoxy. The maximum difference in impact strength
occurred at (FGM), which was loaded from the rich side of the nano-alumina where the maximum value was
at 1% Vf by 133.33% of the sample epoxy side. The flexural strength and Young modulus of the fu
Thin films of pure tin mono-sulfide SnS and tin mono-sulfide for (1,2,3,4)% fluorine SnS:F with Thicknesses of (0.85 ±0.05) ?m and (0.45±0.05) ?m respectively were prepared by chemical spray pyrolysis technique. the effect of doping of F on structural and optical properties has been studied. X-Ray diffraction analysis showed that the prepared films were polycrystalline with orthorhombic structure. It was found that doping increased the intensity of diffraction peaks. Optical properties of all samples were studied by recording the absorption and transmission spectrum in range of wave lengths (300-900) nm. The optical energy gap for direct forbidden transi
... Show MoreThis paper present a study about effect of the random phase and expansion of the scale sampling factors to improve the monochrome image hologram and compared it with previous produced others. Matlab software is used to synthesize and reconstruction hologram.
The efficient removal of dissolved organic compounds (DOC) from wastewater has become a major environmental concern because of its high toxicity even at low concentrations. Therefore, a technique was needed to reduce these pollutants. Ion exchange technology (IE) was used with AmberliteTM IR120 Na, AmberliteTM IR96RF, and AmberliteTM IR402, firstly by using anion and mixed bed system, where the following variables are investigated for the process of adsorption: The height of the bed in column (8,10 and 14 cm), different concentrations of (DOC) content at constant flow rate. The use of an ion exchanger unit (continuous system) with three columns (cation, anion, and mixed bed) was studied.
... Show MoreThe present study was performed to evaluate the level of some risk factors (biochemical and immunological) in hypothyroid Iraqi patients considering the different thyroid functional states (hypothyroidism and subclinical hypothyroidism).The study includes 82 patients clinically diagnosed with hypothyroidism. Three study groups have been investigated: (47 clinical hypothyroid patients, 12 subclinical hypothyroid patients 23 healthy individuals) of different ages. This study, show that the proportion of females (83.3 %), (87.2%) in subclinical and clinical hypothyroidisim respectively higher than the proportion of males (16.7%),(12.8%) in subclinical and clinical hypothyrodism respectively of the total patients.The majority of subclinical hyp
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