Experimental and numerical investigations of the centrifugal pump performance at non-cavitating and cavitating flow conditions were carried out in the present study. Experiments were performed by applying a vacuum to a closed-loop system to investigate the effects of the net positive suction head available (NPSHa), flow rate, water temperature and pump speed on the centrifugal pump performance. Accordingly, many of the important parameters concerning cavitation phenomenon were calculated. Also, the noise which is accompanied by cavitation was measured. Numerical analysis was implemented for two phase flow (the water and its vapor) using a 2-D simulation by ANSYS FLUENT software to investigate the internal flow of centrifugal pump under cavitating conditions. It was observed that with decreasing NPSHa, the values of the pump head, flow rate and efficiency initially remain constant, but with further reduction in NPSHa these parameters will decrease. Also, it was found that at 3% head drop the percentage drop of the flow rate is less than 2% whereas the percentage drop of the efficiency is greater than 3%. Numerically, it was noticed that the cavitation regions appear at the leading edge of suction side of the impeller blades which represents the lowest pressure area inside the computational domain of the centrifugal pump.
In the present investigation, new polymers of Poly [ N - acryl - N - sulfonic acid - N\ yL - 2 - substitute - 4 - oxo - thiazolidine ] Maleic and Succinic diimide were synthesized by seven steps; first step includes esterification of different cyclic anhydride, using one mole of absolute methanol in the presence few drops of conc. H2SO4, yielded mono group ester [I] , which was reaction with thionyl chloride to give ester acid chloride [II] .Then reacted with sulfanilic acid to product compound [III] , which was condensation with hydrazine hydrate to give acid hydrazide [IV] . The new different Schiff bases [V-VIII] were synthesized by reaction of acid hydraizide with different (aliphatic and aromatic) aldehyedes and ketones in the prese
... Show MoreTitanium dioxide nanorods have been prepared by sol-gel template
method. The structural and surface morphology of the TiO2 nanorods was
investigated by X-ray diffraction (XRD) and atomic force microscopy
(AFM), it was found that the nanorods produced were anatase TiO2 phase.
The photocatalytic activity of the TiO2 nanorods was evaluated by the
photo degradation of methyl orange (MO). The relatively higher
degradation efficiency for MO (D%=78.2) was obtained after 6h of exposed
to UV irradiation.
This study aims to track and analysis Hitler's personality by explaining the impact of the social environment in shaping his behavior and addressing the defeat of Germany in the World War 1 and its impact on building his political personality and included his political activism and his policy to get rid of the terms of the Versailles Military Treaty in the light of his plans in his book ( Kifahi) The nature of the study had to be divided into an introduction and two topics followed by the conclusion of the most important results, in addition to a list of references and a summary in English and from God the Good luck.
4-[(2-Amino-4-phenylazo)-methyl]-cyclo hexane carboxylic acid, a new Azo (LH2) ligand, was synthesized by reaction of the diazonium salt of trans-4-(amino-methyl) cyclo hexane carboxylic acid with 3-amino phenol. The azo ligand was characterized by micro elemental analysis (C.H.N.O.) and TGA as well as spectroscopic techniques (UV-Vis, FTIR, 1H-NMR, and LC-Mass). Atomic absorption, elemental analysis, infrared, LC-Mass, TGA, and UV-Vis spectral methods, as well as conductivity and magnetic susceptibility, were used to characterize the complexes of Ni (II), Pd (II), and Pt (IV). The following general formula has been given for the produced compounds based on the results obtained, which are as followi
... Show MoreThe selection of proper field survey parameters of electrical resistivity can significantly provide efficient results within a reasonable time and cost. Four electrode arrays of 2D Electric Resistivity Imaging (ERI) surveys were applied to characterize and detect subsurface archaeological bodies and to determine the appropriate array type that should be applied in the field survey. This research is to identify the subsurface features of the Borsippa archaeological site, Babylon Governorate, Middle Iraq. Synthetic modeling studies were conducted to determine the proper array and parameters for imaging the shallow subsurface features or targets. The efficiency of many array types has been tested for the detection the buried archaeolog
... Show MoreComputer simulations were carried out to investigate the dependence of the main perturbation parameters (Sun and Moon attractions, solar radiation pressure, atmosphere drag, and geopotential of Earth) on the orbital behavior of satellite. In this simulation, the Cowell method for accelerations technique was adopted, the equation of motion with perturbation was solved by 4th order Runge-Kutta method with step (1/50000) of period to obtain the state vectors for position and velocity. The results of this simulation have been compared with data that available on TLEs (NORD data in two line elements). The results of state vectors for satellites (Cartosat-2B, Gsat-14 an
This research aims to know the effectiveness of teaching with a proposed strategy according to the common Knowledge construction modelin mathematical proficiency among students of the second middle class. The researchers adopted the method of the experimental approach, as the experimental design was used for two independent and equal groups with a post-test. The experiment was applied to a sample consisting of (83) students divided into two groups: an experimental comprising (42) students and a control group, the second comprising (41) students., from Badr Shaker Al-Sayyab Intermediate School for Boys, for the first semester of the academic year (2021-2022), the two groups were rewarded in four variables: (chronological age calculated in mo
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