A low speed open circuit wind tunnel has been designed, manufactured and constructed at the
Mechanical Engineering Department at Baghdad University - College of Engineering. The work is one of
the pioneer projects adapted by the R & D Office at the Iraqi MOHESR. The present paper describes the
first part of the work; that is the design calculations, simulation and construction. It will be followed by a
second part that describes testing and calibration of the tunnel. The proposed wind tunnel has a test
section with cross sectional area of (0.7 x 0.7 m2) and length of (1.5 m). The maximum speed is about (70
m/s) with empty test section. The contraction ratio is (8.16). Three screens are used to minimize flow
disturbances in the test section. The design philosophy is discussed and methods for wind tunnel
calculation are outlined. Simulation of wind tunnel using ANSYS shows no separation of flow along
wind tunnel. Construction steps are also included in present work.
The figure of personality modes determines its privileged style in the use of modern and advanced technological tools in the process of changing and developing in order to keep up with that. The proses of selection and choosing administrators in the appropriate places are the most important functions of senior management because it is easy to adopt factory buildings or establishments But this is a human world as that of machines world. So it is required to have people in the process of changing those who have a time, Knowledge, skill, ability and strong administrative personal skills, those people (leaders) should to put a clear vision for the selection and application of the change efforts and to create the necessary climate and
... Show MoreThis research deals with the effects of welding variables using MIG/MAG spot by using Argon (Ar) gas and CO2 to show their effect on the mechanical characteristics and microstructure of low alloy steel type DIN15Mo3 and determine the optimum condition for the process of welding ; current & time. The results show the possibility of using CO2 and also Ar in low alloy steel welding with a little decrease in the shear force of not more than 13% for 4mm thickness and time 2sec. The shear force increased when using Ar instead of CO2 to be , The shear force reach 36KN when using Ar at 2mm thickness time of 8 sec and current of 220 Amp. , when used CO2 instead of Ar d
... Show Morethis work, a simple method was used to prepare the MnO2 nanoparticles. These nanoparticles then were characterized by several techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and atomic force microscope (AFM). The results showed that the diffraction peak of MnO2 nanoparticles was similar to that of standard data. The images of AFM and SEM indicated that the MnO2 nanorods were growing from the MnO2 nano spherical shape. PVA-pentaerythritol/MnO2 nanocomposite films were fabricated by evaporating casting method. The dielectric constant and loss tangent of P-Ery/MnO2 films were measured between 10 kHz and 1 MHz using LCR. As the content of MnO2 increased, the dielectric constant
... Show MoreIn this research, main types of optical coatings are presented which are used as covers for solar cells, these coatings are reflect the infrared (heat) from the solar cell to increase the efficiency of the cell (because the cell’s efficiency is inversely proportional to the heat), then the theoretical and mathematical description of these optical coatings are presented, and an optical design is designed to meet this objective, its optical transmittance was calculated using (MATLAB R2008a) and (Open Filters 1.0.2) programs
Despite recent attempts to improve safety in the construction sector, this sector is considered dangerous and unsafe. Iraq is one of the emerging nations that suffers from a lack of construction safety management. In 2018, the construction sector in Iraq was responsible for 38% of all industrial accidents. Creating a safety program minimizes this problem by making safety an intrinsic part of construction projects. As a result, this article aims to identify the crucial safety factors that affect the safety performance in Iraqi construction projects. After conducting a critical literature review of the related literature, a list of 35 sub-factors classified into nine categories of main factors was chosen to rank each facto
... Show MoreThe effective insulation design of the stress grading (SG) system in form-wound stator coils is essential for preventing partial discharges and excessive heat generation under pulse-width modulation excitation. This paper proposes a method to find the optimal insulation design of the SG system aimed at reducing the dielectric and thermal stresses in the machine coil. The non-uniform transmission line model is used to predict the voltage propagation along the overhang, SG, and slot regions considering the variation in the physical properties of the insulation layers. The machine coil parameters for different insulation materials are calculated by using the finite element method. Two optimization algorithms, fmincon and particle swarm optimiz
... Show MoreBackground: Molar Incisor hypomineralisation (MIH) is one of the biggest challenges with great clinical interest. Currently, the etiology of MIH remains unclear. There is no previous study concerning school children aged 7 – 9 years in Al-Najaf governorate in order to estimate the prevalence and severity of molar incisor hypomineralisation and the possible associated risk factors. This study aimed to estimate the prevalence, severity and the possible associated etiological factors of molar incisor hypomineralisation and also to study the correlation between body mass index and molar incisor hypomineralisation. Material and Methods: Across sectional study conducted at Al-Najaf Governorate. A total of 600 children were enrolled those
... Show MoreDifferent Arabic and Islamic societies are free of evil instincts. Therefore, certain provisions of legitimacy came to stress the importance of the intentions of sharia to achieve the interests of all people that involve several aspects, including the five fundamental things: religion, oneself, offspring, mind and money. Almighty Allah has specified certain punishments on those who violate these things by imposing punishments on the part of the criminal to preserve souls. He imposes the penalty of theft to preserve property, the Hadd punishment for adultery to preserve the symptoms, the punishment on the drunk to preserve the mind, and the Hadd punishment for the apostate to preserve the religion. By the adherence to these punishments li
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