Preferred Language
Articles
/
joe-2020
Experimental and Theoretical Investigation of Noise Effect in Centrifugal Fan Impeller
...Show More Authors

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 .

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Sep 27 2019
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of ageing on selected salivary chemical compositions and dental caries experience among group of adults
...Show More Authors

Background: Ageing is a continuous accumulative ordinary physiological phenomena occurs upon all organs and body structures including saliva by its constituents which can influence the caries process, for that this study was conducted to determine the impact of ageing on selected chemical composition of saliva and their effects on dental caries experience characteristics at different age groups among apparently healthy men. Materials and method: A descriptive comparative study was conducted to compare between three study samples (young, middle and old age adults), thirty male in each study insert, aged (20 years, 40 years and 60 years) respectively. They were selected from private health center in Baghdad - Iraq, from the mid of November

... Show More
View Publication Preview PDF
Scopus (1)
Crossref (2)
Scopus Crossref
Publication Date
Fri Jan 01 2016
Journal Name
World Scientific News
Effect of annealing temperature on the structural and optical properties of CdSe: 1% Ag thin films
...Show More Authors

Publication Date
Mon Jan 08 2018
Journal Name
International Journal Of Science And Research
effect of steel fiber type on compressive strength and modules of rupture on reactive powder concrete
...Show More Authors

Publication Date
Tue Jun 14 2022
Journal Name
Vi.international Scientific Congress Of Pure,applied And Technological Sciences Vi.uluslararası Fen,uygulamalı Ve Teknolojik Araştırmalarkongresi
THE EFFECT OF IRRIGATION INTERVAL AND SPRAYING WITH NANOFERTILIZER ON THE FLOWERING LIFE OF TOMATO PLANTS
...Show More Authors

This experiment was carried out in one of the fields (A) affiliated to the College of Agricultural Engineering Sciences / University of Baghdad, for the spring season 2021, On hybrid tomato plants (Mayai Mayai) to test flower viability, using two factors, the first was three levels of irrigation interval (2, 4, 6) days, and the second factor three concentrations of compound Nano fertilizer with concentrations (0, 1.5, 2.5) gm liter-1, so that the number of treatments is 9 treatments and three replications, the number of experimental units is 27 experimental units distributed randomly according to the random drawing method to ensure reducing experimental error and obtaining the most accurate results. A factorial experiment 3 x 3 x 3 was carr

... Show More
Publication Date
Sat Jul 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Effect of High Salt Concentrations on some Growth Characteristics and Feed Intake Rate of Ctenopharyngodon idella
...Show More Authors
Abstract<p>Grass carp at a weight of 34.68 + 2 g were gradually exposed to four saline concentrations: tap water (0.1), 3, 6, 9, and 12 gm/litter, and the first concentration represented a control treatment. Fish were fed on a diet with a protein content of 30% for ten weeks. Results of the growth experiment showed that the feed conversion rate was 2.46, 3.58, 4.84, 6.77, and -8.56 in the first to fifth treatments, respectively, and the rate feed conversion efficiency was 40.65, 27. 93, 20.66, 14.77 and 11.68 %, while the protein intake was 22.38, 20.44, 18.86, 17.47 and 16.56 g in salt concentrations of 0.1, 3, 6, 9 and 12 g/L, respectively. In another experiment to study the effect of salt acc</p> ... Show More
View Publication
Scopus (1)
Scopus Crossref
Publication Date
Sun Jun 04 2017
Journal Name
Baghdad Science Journal
Effect of Ferocene Concentration on the Percent Conversion and Molecular Weight of Poly(Methyl Methacrylate) Homopolymers
...Show More Authors

This research is addressing the effect of different ferrocene concentration (0.00, 2.15x10-3, 4.30x10-3, 8.60x10-3, and 12.9x10-3) on the bulk free radical polymerization of methyl methacrylate monomer in benzene using benzoyl peroxide as initiator. The polymerization was conducted at 60º C under free oxygen atmosphere. The resulting polymers were characterized by FTIR. The results were compared with the presence and absence of ferrocene at 10% conversion. The %conversion was 3.04% with no ferrocene present in the polymerization medium and its increase to 9.06 with a first lowest ferrocene concentration added, i.e. 2.15 x10-3mol/l. This was positively reflected on the poly(methyl methacrylate) molecular weight measured by viscosity techniq

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Dec 06 2009
Journal Name
Baghdad Science Journal
Effect of Different Conditions on Viability and Antagonistic Activity of Saccharomyces boulardii on Enteric Pathogenic Bacteria
...Show More Authors

In this part of programme , different bacterial isolates mainly Salmonella spp, Shigella spp and Escherichia coli were used for antagonism with Saccharomyces boulardii under different conditions . S.boulardii was grown under aerobic conditions and antagonized with young overnight nutrient broth cultures of test bacterial isolates and other kept in refrigerator for a week after full growth . Young cultures were more susceptible to antagonistic effect of yeast compared to old cultures and on isolates grown on solid medium for 24 hr. S.boulardii grown under aerobic and microaerobic conditions and antagonized with overnight broth cultures of test bacterial isolates , The results revealed that aerobic cultures of yeast had more inhibito

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Feb 03 2019
Journal Name
Iraqi Journal Of Physics
Effect of indium content on X- ray diffraction and optical constants of InxSe1-x thin films
...Show More Authors

Alloys of InxSe1-x were prepared by quenching technique with
different In content (x=10, 20, 30, and 40). Thin films of these alloys
were prepared using thermal evaporation technique under vacuum of
10-5 mbar on glass, at room temperature R.T with different
thicknesses (t=300, 500 and 700 nm). The X–ray diffraction
measurement for bulk InxSe1-x showed that all alloys have
polycrystalline structures and the peaks for x=10 identical with Se,
while for x=20, 30 and 40 were identical with the Se and InSe
standard peaks. The diffraction patterns of InxSe1-x thin film show
that with low In content (x=10, and 20) samples have semi
crystalline structure, The increase of indium content to x=30
decreases degree o

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Effect of gas flow rate on plasma temperature and electron density of atmospheric argon plasma jet
...Show More Authors

In this study, method for experimentally determining the electron density (ne) and the electron temperature (Te) in the atmospheric Argon plasma jet is used; it is based on optical emission spectroscopy (OES). Boltzmann plot method used to calculate these parameters measured for different values of gas flow rate. The results show that the electron temperature decreasing with the increase of gas flow rate also indicates an increasing in the electron density of plasma jet with increasing of gas flow rate.

View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Sun May 07 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of Silica Sio2 on the Dielectric and Physical Properties of Mn –Ni Ferrite
...Show More Authors

The effect of SiO 2 ) Silica) on the dielectric and physical properties of Mnx-Ni1 -xFe2O4 ،، X=0.5 is studies. The samples are prepared by the conventional manufacturing
method. We found that the physical and dielectric properties of Mn-Ni ferrite change
considerably with the substituent samples .the variation of dielectric constant as a function of
frequency of ferrite system decrease with frequency increases and increase with the increase
the concentration of SiO 2 . It was found that the increase of SiO 2 concentration of all our
samples produce an increase in mass density and decrease with porosities

View Publication Preview PDF