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Slot Design Procedure for a NACA 4412 at High Angle of Attack
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The main objective of the present work is to find a method increases the efficiency of the airfoil that is used for blade in wind turbine, wing in aircraft, propeller and helicopter (like NACA 4412). By overcoming the separation of flow at high angle of attacks, a slotted airfoil had been used and solved numerically through connecting the pressure side in the bottom surface with the suction side in the top surface of the airfoil to energize the separated flow. Slot exit, width and slope were considered as a parameters of slot configuration to determine the effective design of consideration. Reynolds number was taken as [1.6 x106 ] and the angle of attacks were ranged from (0o - 20o ). The numerical solution with Ansys Fluent commercial program had been used to solve a fully turbulent N.S. equations with κ-ω SST turbulence model. The method of changing variables with best one among them was adopted to find the design of the slot. The results of flow field and airfoil characteristics for solid and slotted airfoil were described and illustrated in the present work which showed that the airfoil produces higher lift coefficient value and lower drag coefficient as compared with solid airfoil. Moreover, it delays stalling angle of attack to 19o . The slotted airfoil shows an increasing in maximum lift to drag ratio up to 110% at angle of attack 18o . The most effective slot is found at 60% chord, slope 65o and width 1% chord.

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Publication Date
Fri Sep 24 2021
Journal Name
Arab World English Journal
A Pragma- Stylistic Analysis of Formal Congratulatory Letters in English and Arabic
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Politeness strategies are of significant importance to maintain the face of the addressee. Senders of formal congratulatory letters seek to create a positive image in the minds of their addresses by performing particular illocutionary acts and face-saving acts (FSAs) in the form of written texts. To the best knowledge of the researcher, this topic received little attention from linguistic researchers, especially on the pragma-stylistic level. The importance of this study arises from the fact that congratulatory formal letters are an effective tool in the successful performance of foreign relations and thus deserve investigation. The current study investigates the pragmastylistic aspects of illocutionary acts and FSA Politeness Stra

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Publication Date
Wed Jun 03 2020
Journal Name
Political Sciences Journal
The role of the strategic culture variable in negotiations (Brexit a model)
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      Negotiations are distinguished in that they are an easy and simple means between the conflicting parties, and it is an effective means at the same time as the conflicting parties seek understanding on the most effective way to solve their dispute, but negotiations are not always appropriate to resolve international disputes, especially when there is a disparity in power between the negotiating countries, or when it is missing Goodwill, or even when one of the parties is absent or less flexible, and the internal circumstances of one of the conflicting countries may play a negative or positive role in the success of the negotiations, away from the influence of the role of external variables in that, a

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Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Engineering
Study the Dynamic Behavior of Rotor Supported on a Worn Journal Bearings
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In this paper, the effect of wear in the fluid film journal bearings on the dynamic behavior of rotor bearing system has been studied depending on the analytical driven of dynamic stiffness and damping coefficients of worn journal bearing. The finite element method was used to modeling rotor bearing system. The unbalance response, critical speed and natural frequency of rotor bearing system have been studied to determine the changes in these parameters due to wear. MATLAB software was used to find the analytical values of dynamic coefficients of journal bearing. The results of rotor mounted on fluid film journal bearings showed that the wear in journal bearing increases the amplitude of unbalance response and decrease critical speed, sta

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Publication Date
Sun Feb 20 2022
Journal Name
Papers In Physics
Electronic and optical properties of nickel-doped ceria: A computational modelling study
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Cerium oxide CeO2, or ceria, has gained increasing interest owing to its excellent catalytic applications. Under the framework of density functional theory (DFT), this contribution demonstrates the effect that introducing the element nickel (Ni) into the ceria lattice has on its electronic, structural, and optical characteristics. Electronic density of states (DOSs) analysis shows that Ni integration leads to a shrinkage of Ce 4f states and improvement of Ni 3d states in the bottom of the conduction band. Furthermore, the calculated optical absorption spectra of an Ni-doped CeO2 system shifts towards longer visible light and infrared regions. Results indicate that Ni-doping a CeO2 system would result in a decrease of the band gap. Finally,

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Publication Date
Mon Sep 30 2024
Journal Name
Nasaq
A Semiotic Analysis Of Visual-Textual Elements In TobaccoFree Initiative 2021 Advertisements
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The provided research paper offers a thorough analysis of the semiotic analysis present in tobacco-free initiative advertisements from the year 2021. The study delves into the intricate process of decoding the diverse signs, symbols, and visual components integrated into these anti-smoking campaigns. The core aim of this investigation is to comprehend and explore the semiotic tactics that underlie these advertisements, with a particular emphasis on visual communication as a pivotal tool in shaping the public's attitudes and behaviors towards tobacco usage. The research introduces a significant theoretical framework, the "Taxonomy of Image-Text Relations and Functions" theory, as proposed by Emily E. Marsh and Marilyn Dom

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Publication Date
Thu Oct 18 2018
Journal Name
International Journal Of Research In Social Sciences And Humanities
A Linguistic study of Presupposition in Rattigan’s play ‘while the sun shines’
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As a kind of linguistic study, the study of presupposition in drama is one of captivating topic to explore, because of the capability of this topic to make people perceive the presupposition differently. Presupposition is one of the most important concepts in linguistics. It refers to the implicit inferences made in communication between people. These inferences are necessary to understand the utterances correctly. The research particularly endeavors to focus on the linguistic constructions that activate presupposition.

Publication Date
Tue Dec 28 2021
Journal Name
The Iraqi Journal Of Veterinary Medicine
Evaluating Expression of the STAG1 Gene as a Potential Breast Cancer Biomarker
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STAG proteins, which are part of the cohesin complex and encoded by the STAG genes, are known as Irr1/Scc3 in yeast and as SA/STAG/stromalin in mammals. There are more variants as there are alternate splice sites, maybe three open reading frames (ORFs) code for three main proteins, including: SA1 (STAG1), SA2 (STAG2) and SA3 (STAG3). The cohesin protein complex has various essential roles in eukaryotic cell biology. This study compared the expression of the STAG1 gene in four different breast cancer cell lines, including: MCF-7, T-47D, MDA-MB-468, and MDA-MB-231 and normal breast tissue. RNA was extracted from these cell lines and mRNA was converted to cDNA, and then expression of the STAG1 gene was quantified by three sets of specific prim

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Publication Date
Wed Jan 01 2014
Journal Name
Journal Of The College Of Languages (jcl)
The stylistics of expressive structure in Al-Sayyab's attempt- A textual study
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Our research tends to study the poetic attempt of  Badr Shakir Al-Sayyab and examine it stylistically, and we suggested his mature collection '' Rain song'' as a pattern for our textual analysis of the poet's attempt.

   In the beginning , we confirm that branches of applied structures meet to produce poetry such as narration , drama , cinema , mythology , allegory , various religious and historical texts , previous events , and special cumentary events related to work production. If all above-mentioned was complicated and disregarded throughout a single text , the text writer would not secure positive results that might keep open continuity between him and his readers.

   Therefore , this issue w

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Publication Date
Sun Jul 01 2001
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
A new species of Wohlfahrtia Brauer and Bergenstam (Dipetera: Sarcophagidae) from Iraq
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Wohlfahrtia longicorpuris sp. nov., from Iraq described, illustrated and distinguished from related species. The adults were reared from larvae collected from ulcer of a human face. Wohlfahrtia Brauer and Bergenstam is one of most important genus,which contains 19 species (Pape, 1998), some of these produce myiasis in mammals (Verves,1985).Taxonomic revision of this genus has been carried out by the following authors: Rohdendrof (1956), Zumpt (1965) and Pape (1996).

 

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Publication Date
Thu Aug 21 2025
Journal Name
Journal Of Health And Biology
Distribution and Species Diversity of the Dove Genus Streptopelia: A Systematic Review
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Some species, such as the Eurasian Collared-Dove (S. decaocto) are fast expanding around the planet, while others, such as the European Turtle-Dove (S. turtur), are experiencing precipitous population declines. Climate change, habitat loss, greater cultivated areas, and hunting pressure are the major threats to the diversity of Streptopelia. A few species require urgent conservation action. Priority for subsequent research should be to redress outstanding taxonomic uncertainties, ascertain the effect of climate change on distributions, and put in place conservation measures for declining taxa. We provide here a detailed review on how it is possible to understand the diversity of Streptopelia and how such an understanding can con

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