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Experimental and Theoretical Investigation of Noise Effect in Centrifugal Fan Impeller
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In this work a study was made in centrifugal fan blower to investigate the effect of impeller blade design on sound pressure level (SPL). Shroud and unshroud impeller of nine blades are used. The sound generation from flow inside the test rig at different positions was displayed by using spectral analyzer. The experiments were carried out in anechoic chamber with small holes in its walls, under ambient condition about (25-27) C ° to avoid the effect of temperature on the sound pressure level. The results showed that (SPL) decreased with the increase of distance from the source about (3-4)dB when distance varied about (0.8-1.06)m, and the (SPL) decreased with the decrease of velocity about (8-12)dB when velocity varied between (13000-2600) r.p.m., and when the velocity remain constant (SPL) increased with the increased of pressure about (7-15)dB when the pressure varied between (36-8)mbar. For the purpose of comparison, two types of impellers were tested under same conditions, the results showed that (SPL) increased when shroud used on the impeller. The mathematical results show good agreement with the experimental results. The study also concluded a spectral analysis of the noise generated using 1/3 octave band filter. The analysis showed that (SPL) increased with frequency range of (0.8-400) Hz. The maximum sound pressure level was appeared clearly in the frequency range between 200 – 400 Hz .

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Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
The effect of the repurchase policy in stock tradingIn financial markets - case study
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The research dealt with the case stock repurchase policy of Emaar Real Estate Company one of listed companies in Dubai Stock exchange. The research has launched from the cognitive dimensions of repurchasing policy which took great concern in the literatures of financial management, and also this policy became as substitute for distributing the monitory profit in the last three decades in the international financial markets, but it did not get any importance in the Arab Markets such as that of the Arab Gulf in addition to the Iraqi Stock Exchange.

The research summarized a set of conclusions, the most important one was the consistence of analysis result with the test of the major two hypotheses (The first

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Publication Date
Wed Aug 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of Some Lean Production Tools in selecting a Mass Customization Strategy
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   The research aims to indicate the relationship between lean production tools included seven {constant improvement , and Just in time (JIT), and the production smoothing , and quality at the source, and standardized work, Visual management, and activities 5S }  and  Mass Customization strategy for the model (Pine & Gilomer, 1997) {collaborative, adaptive, cosmetic, transparent}, as well as providing a conceptual framework and applied for variables search to clarify how they will choose a Mass Customization strategy through the lean production tools, , and recognize the reality of the practices of Iraqi industries in such a field. Moreover, aims to highlight the positive aspects that accrue to companies a

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Publication Date
Fri Jun 16 2023
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
The Possible Protective Effect of Cinnamic Acid on Ovalbumin-Induced Asthma in Mice
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Asthma is a chronic respiratory disorder in which immunological and structural cells play a role. The limits of conventional medicines necessitate the development of innovative therapeutic techniques for asthma. In the present study, we investigated the possible protective effect of cinnamic acid (CA) on ovalbumin-induced asthma in a mouse model. Sixty albino male mice BALB/c type weighing (20-30) grams were chosen at random and divided into five groups each one contains 12 animal: Group I: PBS/liquid paraffin control. Group II: asthma model group. Group III: cinnamic acid control group; mice received cinnamic acid (50 mg/kg) in liquid paraffin orally by gavage. Group IV: asthma model / group of (25 mg / kg) cinnamic acid; mice received

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Publication Date
Tue Sep 01 2015
Journal Name
Journal Of Engineering
Effect of Recirculation Ratio on the Uniformity Flow in a High Area Ratio of Outlets Pipe at Different Entrance flow rates
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The uniform flow distrbiution in the multi-outlets pipe highly depends on the several parameters act togather. Therefor, there is no general method to achieve this goal. The  goal of this study is to investigate the proposed approach that can provide significant relief of the maldistribution. The method is based on re-circulating portion of flow from the end of the header to reduce pressure at this region . The physical model consists of main manifold with uniform longitudinal section having diameter of 152.4 mm (6 in), five laterals with diameter of 76.2 mm (3 in), and spacing of 300 mm. At first, The experiment is carried out with conventional manifold, which is a closed-end. Then, small amount of water is allowed

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Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
The Effect of CdCl2 and annealing treatments on structural properties of CdS/CdTe heterojunction
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CdS and CdTe thin films were thermally deposited onto glass substrate. The CdCl2 layer was deposited onto CdS surface. These followed by annealing for different duration times to modify the surface and interface of the junction. The diffraction patterns showed that the intensity of the peaks increased with the CdCl2/annealed treatment, and the grain sizes are increased after CdCl2/annealed treatment

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Publication Date
Tue Dec 01 2009
Journal Name
Iraqi Journal Of Physics
Study of the Electronic Properties and Hall Effect of Amorphous Si1-xGex:H Thin Films
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The electronic properties and Hall effect of thin amorphous Si1-xGex:H films of thickness (350 nm) have been studied such as dc conductivity, activation energy, Hall coefficient under magnetic field (0.257 Tesla) for measuring carrier density of electrons and holes and Hall mobility as a function of germanium content (x = 0–1), deposition temperature (303-503) K and dopant concentration for Al and As in the range (0-3.5)%. The composition of the alloys and films were determined by using energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS).
This study showed that dc conductivity of a-Si1-xGex:H thin films is found to increase with increasing Ge content and dopant concentration, whereas conductivity activati

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Publication Date
Sun Dec 04 2011
Journal Name
Baghdad Science Journal
Effect of Insecticide Dichlorvos on Ovaries of Mosquito Fish Gambusia affinis (Baird and Girard)
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The toxicity of insecticide dichlorvos (90%) was tested in ovaries of mosquito fish using three sublethal concentrations (0.3, 0.6, 0.8 µg/L) and studied their effects on the means of body and ovary weights, gonadosomatic index, ovum size and ova number. Results showed that there was a significant (P<0.05) decrease in body and ovary weights, ovum size and ova count. However, there was no significant (P<0.05) difference in gonadosomatic index in treated groups with the three concentrations of dichlorvos compared with the control group. This study was added evidence on the ovular toxicity of dichlorvos concerning its effect on fish production as well as reduction in the means of productive offspring and their survival.

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Publication Date
Thu Feb 28 2019
Journal Name
Journal Of Biodiversity And Environmental Sciences
Estimation of blood lead level and its effect on hormonal responses of exposed men
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Publication Date
Sat Apr 20 2024
Journal Name
Int J Eng Res Technol
Effect of irrigation levels and organic matter on water use efficiency of chilli pepper
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Publication Date
Tue Jan 01 2019
Journal Name
Journal Of Southwest Jiaotong University
Effect of Saturation Levels on Shear Strength and Bearing Capacity Properties of Soil Types
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This study presents a comprehensive set of laboratory works for the examined soil layers extracted from Baghdad city (specifically from Alkadhimya, Alaitaifiya, and Alhurriya) to illustrate their engineering properties. The researchers have adopted the unified soil classification system for soil classification purposes. Also, the direct shear test was performed for soil samples with various degrees of saturation (0%, 25%, 50%, 75%, and 100%). The test results have shown a significant reduction in cohesion property with higher moisture content within soil samples. Also, a noticeable reduction in angle of internal friction value has occurred with such changes. Furthermore, it has been found that the bearing capacity of unsaturated soi

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