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 .
The research aims to highlight the role of accounting disclosure in raising the quality of tax settling accounts so as to enhance confidence between taxpayers (corporates) and tax authority, standing over companies commitment to take care of their financial statements which are prepared to the appropriate accounting disclosure of tax authority. It has been noticed that a good disclosure about the results of the activity leads to the acceptance of the tax authority to the results which are stated by the financial statements and the tax is linked on its bases. The researcher depends on the deductive approach which based on Arabic and foreign references, books, researches, previous studies, scientific &nb
... Show MoreThe present research deals with the spatial variance analysis in Jwartadistrict and conducting a comparison on the spatial and seasonal changes of the vegetation cover between (2007-2013) in order to deduce the relationship between the vegetation density and the areas which are exposed to the risk of water erosion by using Plant Variation Index NDVI) C (coefficient and by using Satellite images of Landsat satellite which are taken in 2/7/2007 and Satellite images of Landsat satellite taken in 11/1/ 2013, the programs of remote sensitivity and the Geographic Information Systems.
The study reveals that there is a variance in the density of vegetation cover of the area under study betwee 2007 and 2013. Howev
... Show MoreInterested in many scholars and reseachers the subject of the media and means varied his roleinfluential in the definition of the public of issues and political, cultural, social and because of its spread wide and ability to address the people of all levels effect them in the formation consciousness of those issues and types of this awareness is an awareness of the tax, contribute to media formation consciousness tax through the definition of people what tax and importance of the role of its revenues to supplement the state budget by posting tax laws and regulations of applied and all what respect process account tax, to be in charge of the tax familiar enough about this, which avoid being cheated taxmisleading when rev
... Show MoreThe research aims to identify the elements of performance supervisory good and effective and availability in the Governmental council through examination and analysis of the reality and practice of censorship in this Council through study and evaluate the characteristics of the regulatory effective upon which the Governmental council in the performance of his work and knowledge of their adequacy by comparing the established criteria , and determine the effect of characteristics supervisory the performance standards for the Governmental council, Based search to two assumptions key to check the level of the relationship and the influence of the dimensions of the con
... Show MoreThe aim of this study is to investigate the relationship between microRNA 378 and BMP15 gene expression levels in blood samples collected from 50 healthy fertile females as controls and 50 hyperprolactinemia infertile females by quantitative real-time polymerase chain reaction (RT-qPCR). Specific primers were designed for this purpose based on the sequences of microRNA 378 and BMP15 retrieved from NCBI and designed by primer 3 software. The result assessing the expression level of BMP15 in hyperprolactinemia (HPL) was 0.220, while the control group's fold change value was 1.000. The HPL group showed downregulation in the expression of the BMP15 gene. While the fold expression values of the miRNA378 gene in the hyperprolactinemia
... Show MoreThe current research seeks to identify the role of the marketing intelligence system in its dimensions (customer intelligence, market intelligence, competitor intelligence, insurance product intelligence, sales representatives) and its reflection on improving the quality of the insurance service provided by the National Insurance Company represented in its dimensions (reliability, response, tangibility, Safety, the spirit of empathy, communication) adopted in the current research, and based on that, the research came as an attempt to find out the extent to which the research sample company can apply the approach of the marketing intelligence system and its impact on improving the quality of the insurance service provided to custo
... Show MoreThe aim of the research is to identify the extent of the ability to ensure the integrated reports by the auditor in verifying the credibility of these reports, and their implications for the benefit of all parties dealing with the economic unit, as well as measuring the impact of the assurance procedures followed by the auditors and their role in confirming these reports.
The research methodology was designed after studying the previous literature related to the research variables, and then the relationship between these variables was tested, through the use of a questionnaire list. A questionnaire targeting the community of auditors in the local environment, and the results of the study wer
... Show MoreThis paper performance for preparation and identification of six new complexes of a number of transition metals Cr (lII), Mn (I1), Fe (l), Co (II), Ni (I1), Cu (Il) with: N - (3,4,5-Trimethoxy phenyl-N - benzoyl Thiourea (TMPBT) as a bidentet ligand. The prepared complexes have been characterized, identified on the basis of elemental analysis (C.H.N), atomic absorption, molar conductivity, molar-ratio ,pH effect study, I. Rand UV spectra studies. The complexes have the structural formula ML2X3 for Cr (III), Fe (III), and ML2X2 for Mn (II), Ni (II), and MLX2 for Co (Il) , Cu (Il).
The sun which is all energy sources, in today's society, hot water is used for various purposes starting from household to power production. People are adopting various ways to accomplish these goals, such as firewood heat and electrical power, so solar energy is an alternative to the dwindling resources of fossil fuels. Conversion of solar radiation into heat is one of the simplest and most direct applications of this energy, it can be used to heat water systems. A widely used flat-plate solar collector. In this study we have come to heat water using solar energy. This research presents the design and experimental analysis for using Spiral Flow Solar Water Heater (SFSWH) to enhance the thermal efficiency of a flat plate solar collector.
... Show MoreThis study calculated the surface roughness length (Zo), zero-displacement length (Zd) and height of the roughness elements (ZH) using GIS applications. The practical benefit of this study is to classify the development of Baghdad, choose the appropriate places for installing wind turbines, improve urban planning, find rates of turbulence, pollution and others. The surface roughness length (Zo) of Baghdad city was estimated based on the data of the wind speed obtained from an automatic weather station installed at Al-Mustansiriyah University, the data of the satellite images digital elevation model (DEM), and the digital surface model (DSM), utilizing Remote Sensing Techniques. The study area w
... Show More