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Effects of internal Acoustic Excitation on the Improvement of Airfoil Performance
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The effect of internal acoustic excitation on the leading-edge, separated boundary layers and the aerodynamic performance of NACA23015 cross section airfoil are examined as a function of excitation location with ranging frequency range (50-400) Hz of the introduced acoustic. Tests are separately conducted in two sections, open type wind tunnels at the Reynolds number of 3.3x105 for measurement at angle of attack (0, 3, 6, 9 &12) deg. and 3x104 for the visualization at angle of attack (12) deg. based on the airfoil chord. Results indicated that the excitation frequency and the excitation location are the key parameters to alter the flow properties and thus to improve the aerodynamic performance. The most effective excitation frequency is found to be equal to the shear layer instability frequency and on excitation location close to the separation point. Moreover, the lift is increased and drag reduced dramatically. The corresponding boundary layers are visualized to be reattached to the surface. 

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Publication Date
Sat Jan 01 2022
Journal Name
Ieee Transactions On Power Delivery
Optimal Dielectric Design of Medium Voltage Toroidal Transformer with Electrostatic Shield under Fast Front Excitation
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Accurate calculation of transient overvoltages and dielectric stresses from fast-front excitations is required to obtain an optimal dielectric design of power components subjected to these conditions, which are commonly due to switching and lightning, as well as utilization of power-electronic devices. Toroidal transformers are generally used at the low voltage level. However, recent investigations and developments have explored their use at the medium voltage level. This paper analyzes the model-based improvement of the insulation design of medium voltage toroidal transformers. Lumped and distributed parameter models are used and compared to predict the transient response and dielectric stress along the transformer winding. The parameters

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Publication Date
Tue Jun 01 2021
Journal Name
Electric Power Systems Research
Electromagnetic transient modeling of form-wound stator coils with stress grading system under PWM excitation
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The insulation system of a machine coil includes several layers made of materials with different characteristics. The effective insulation design of machine coils, especially in the machine end winding, depends upon an accurate model of the stress grading system. This paper proposes a modeling approach to predict the transient overvoltage, electric field, and heat generation in machine coils with a stress grading system, considering the variation of physical properties in the insulation layers. A non-uniform line model is used to divide the coil in different segments based on material properties and lengths: overhang, stress grading and slot. The cascaded connection of chain matrices is used to connect segments for the representation of the

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Publication Date
Sat Feb 09 2019
Journal Name
Journal Of The College Of Education For Women
The Infertility problems HS Effects on human development
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  • The problem of infertility considers one of the chronic problem a which faced the
    individual & families equally . This problem causes a negative effects in psychological ,
    social and development fields. The infertility contributes in weakening the human
    development, when the human development has become as a centre point which centered
    about individual preparing , rehabilitation, training and knowledge toreach to the required
    excellence.
    We think that , the infertility destroys the socially development; therefore the socially and
    scientific institutions are working hard to find successful solution to resolve the problem
    infertility through sophisticated and scientific methods. This problem
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Publication Date
Wed Sep 30 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Reflection of the audit of contracts according to "related services" on the report of the auditor: applied research in Palestine International Hotel Company / shareholding company
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The issue of auditing contracts according to the related services is one of the important topics It has also become necessary to develop traditional procedures and auditing according to international standards to improve the profession of accounting and auditing. From this standpoint, the research aims to indicate the reflection of the contracting audit in accordance with the related services on the auditor's report. in line with the new directions regarding the need to adopt international standards in the Iraqi environment as the research problem focused on the non-comprehensiveness of the audit programs that deal with auditing contracts according to assurance commitments to contribute obtaining Governing evidence, The research

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Publication Date
Thu Dec 31 2020
Journal Name
College Of Islamic Sciences
: Islamic law; perfection The rule of perfection in Islamic law and its impact on the creative construction of the individual and society: The rule of perfection in Islamic law and its impact on the creative construction of the individual and society
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This research explains to us the role of the Islamic religion in the issue of accuracy in speech and work, and how it is closely related to human production in his life, and Islam affirms that his idea is mainly reflected in his production, and how it affects the perception of the meaning of creativity. Therefore, our Islam affirmed the accuracy in every word or work we do to build a society in which people enjoy high quality in ethics and dedication in their work so that the Islamic system depends on humanity to preserve our rights on the other hand the research discusses the deliberate default and how it reflects on our production and how it makes it less good.

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Publication Date
Tue Oct 30 2018
Journal Name
Risalat Al-huquq Journal
Legal Protection for Producers of Sound Recordings under Iraqi Law
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Piracy on phonograms is now, rightly, the crime of the electronic age. Despite the protection sought by States to provide for such registrations, whether at the level of national legislation or international agreements and conventions, but piracy has been and continues to pose a significant threat to the rights of the producers of those recordings, especially as it is a profitable way for hackers to get a lot of money in a way Illegal, which is contrary to the rules of legitimate competition. Hence, this research highlights the legal protection of producers of phonograms in light of the Iraqi Copyright Protection Act No. (3) of 1971, as amended.

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Publication Date
Sat Dec 01 2018
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Survey theopinions professional and academics on building the strategy of internal audit function and the possibility of keeping abreast of developments
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The research problem is clearly deficient suffered by the internal audit function in all institutions of Iraq, as a result of the lack of sponsor organizations for this profession and there is no law or local legislation determine its powers and its responsibilities and scope of work As well as the lack of interest of senior management in economic units that function, as it focuses its work on the scope of financial and accounting matters only So required to rebuild this function in line with the current developments as well as the lack of a framework that defines the strategy of this function, and it came the idea of research to find out how to create a regulatory method for re-strategic construction of the internal audit function depen

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
The Limnological Effects of River Lesser-Zab on Tigris River, Iraq
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The present study included the physico-chemical parameters of Lesser-Zab river and its effects on Tigris river. Monthly water samples were taken from the two rivers during January to October 1999.There were no signifcant difference in water temperatures. Both rivers were fresh to oligohalin, alkaline and very hard. Close values were determined in total suspended solids in both rivers with little increasing during rainfall period and high discharge. Water was well areated and over saturation was recorded in several occasions. Dissolved oxygen values of Tigris river were influenced by Lesser-Zab. Cations were more dominant than anions in both rivers. In Lesser-Zab, the anions were increased during spring season and declined in summer which t

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Publication Date
Tue May 23 2023
Journal Name
Journal Of Engineering
Injection Temperature Effects on the Properties of High Density Polyethylene Crates
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This study was undertaken to provide more insight on the optimum injection temperature used for the production of PE crates, thereby saving time and money, and improving part quality. The work included processing trails of HDPE crates in an injection
molding machine at five temperatures ranged from 220 to 300°C. Both Rheological and mechanical characterization was conducted in order to understand the effect of injection temperature on the properties of crates. Oven aging was also applied for (4 weeks) to evaluate the long-term thermal stability. The results revealed that producing the crates at a temperature range of (260-280 °C) gives the best rheological and mechanical result. The lowest drop in thermal stability has been observed

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Publication Date
Mon Apr 13 2020
Journal Name
International Journal Of Research Inpharmaceutical Sciences
The UV light effects on pectinase production of Pantoea sp. bacteria
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