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 paper presents a highly accurate power flow solution, reducing the possibility of ending at local minima, by using Real-Coded Genetic Algorithm (RCGA) with system reduction and restoration. The proposed method (RCGA) is modified to reduce the total computing time by reducing the system in size to that of the generator buses, which, for any realistic system, will be smaller in number, and the load buses are eliminated. Then solving the power flow problem for the generator buses only by real-coded GA to calculate the voltage phase angles, whereas the voltage magnitudes are specified resulted in reduced computation time for the solution. Then the system is restored by calculating the voltages of the load buses in terms
... Show MoreMedical Ultrasound (US) has many features that make it widely used in the world. These features are safety, availability and low cost. However, despite these features, the ultrasound suffers from problems. These problems are speckle noise and artifacts. In this paper, a new method is proposed to improve US images by removing speckle noise and reducing artifacts to enhance the contrast of the image. The proposed method involves algorithms for image preprocessing and segmentation. A median filter is used to smooth the image in the pre-processing. Additionally, to obtain best results, applying median filter with different kernel values. We take the better output of the median filter and feed it into the Gaussian filter, which then
... Show MoreThe current research aims to determine the extent of the impact of the strategic direction to the business process reengineering, in the Office of the Ministry of Oil To reach that goal was a sample of community research study consisted (50) members of the senior leadership represent the problem in organization researched in the ambiguity of the strategic direction of knowledge of the compatibility of the strategic direction with Business Process Reengineering and used questionnaire, interview and observation to obtain the information needed to search was addressing data by the statistical system spss percentage and the arithmetic mean, standard deviation and coefficient of variation .
... Show MoreAbstract:
This research to monitor the features of the historical method in the
thought of a linguistic scientist is known (ibin genieD. 392 AH by offering a
range of grammatical rules presented in his book (the properties and the
nature of their treatment on the basis of the historical method in accordance
with These are an important milestone in facilitating the grammatical rules and
display image "makes it more suitable for the social reality
The research aims to know the reverberation of the the electronica news bulletin of the ministry of higher education and scientific research in the newspapers of: (AL-Taakhi, AL-Zaman, ALAdala,AL-Sabah and Baghdad) for period from 2nd October 2011 to 1st November 2011 to explain its activity and advantage for the other newspapers and to show the importance which the newspapers showed for the study of the news subject in the bulletin, as well as,to show the proportional differences in which the newspapers interested in the subjects of the published news, and to reach to the results which lead us to good conclusions for the service of decision owner and open new horizons for the researchers to expanding in the s
... Show MoreIn this research we prepared shiff bases unilateral claw( benzyl imine aniline ) and Bilateral claw ( benzayal-2-imine phenol ) in high purity reach to 98% , which it's prepared from aromatic amine with aldehydes, it's solid,thermosetting, not dissolved in water in general. Diagnosed prepared article by using infra red spectroscopy (IR) which shows azomethen grop at 1640cm-1 At this diagnosis we suggest tetra headral mechanism in this Circumstances For a reaction.
Bedsore (pressure ulcers)is a major nurse-careoutcome. There are many influences that can contribute to the progress of pressure ulcers, but the final common pathway to ulceration is tissue ischemia. This study aimed to detect some etiological factors that predispose to bedsore. The study was conducted on patients attending intensive care departments. Out of 82 inpatients who suffered from pressure ulcer, 54were males and 28were females. Specimens were collected during the period of September, 2019 –February, 2020 from different Hospitals (Alkadhimiya Teaching Hospital, General Hospital of AlshaheedAl-Sadr, and Medical City/ Ghazi Al-Hariri hospital) in Baghdad, Iraq. Simultaneously, other 20 specimens were collected as control fromin
... Show MoreBackground: Spirometry is an important test performed in patients expect to have airway obstruction, assessment of intense reaction to inhalers (the trial of reversibility of airway blockade) is a normally utilized technique in clinical and academic studies. The consequences of this test are utilized to make choices on treatment, consideration, exclusion from diagnosis and other research think about, and for analytic marking [asthma versus chronic obstructive airway disease (COPD)]. Usually, the (FEV1) or (FVC) standards before and after giving of the bronchodilator are compared and the adjustment is processed to distinguish variations from the norm in lung volumes and air flow.
Objective: The aim of