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Designing Cassegrain Telescope System with Best Obscuration Ratio of Secondary Mirror
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     A computer simulation was conducted using Optics Software for Layout and Optimization (OSLO) to design a Cassegrain telescope system for on-axis rays. In order to establish such a telescope, the two mirrors of the optical system were designed as spherical surfaces: a concave mirror and a convex mirror. The obscuration ratios of the Cassegrain telescope's secondary mirror were examined using different values, which ranged between 0.1 and 0.3, to determine the best obscuration ratio. This work adopted three criteria to decide which obscuration ratio is the best for the Cassegrain telescope. The first criterion was the number of rays that reached the final image. The second criterion was calculating the modulation transfer function (MTF). The third criterion was calculating the point spread function (PSF) and Strehl ratio (SR). Finally, the result showed that the best obscuration ratio of the telescope’s secondary mirror was found at D2/D1=0.116-0.166, where D1=0.76 m for the primary mirror and D2=0.09 – 0.125m for the secondary mirror.

 

 

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Publication Date
Sun Aug 13 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Designing A Computer Program to Determine the Points and Planes in 3-Dimensional Projective Space
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  The purpose of this work is to determine the points and planes of 3-dimensional projective space PG(3,2) over Galois field GF(q), q=2,3 and 5 by designing a computer program.

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Publication Date
Wed Mar 15 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Lethal Effect of Secondary Metabolites of Metarhizium anisopliae (Metschnikoff) Sorokin Against Chrysomya albiceps (Wiedeman, 1819) (Dipetra: Calliphoridae)
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This was study conducted to evaluate the efficacy of the secondary metabolites from produced Metarhizium anisopliae  in potato sucrose broth, rice broth and wheat broth, against larvae and adults of Chysomya albiceps.  Results showed that filtrate of potato broth was better in mortality rates occurrence when second instar larvae were treated, the mortality rate was 46.67%. While the treatment of the larvae using the filter of rice and wheat broth gave total accumulated mortality rate (larvae and pupae) of 36.67 and 40.00 respectively. While it was 66.76 when treated with potato broth adults food with filtrate recorded high mortality rate reached to 90.00% after one week. 

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Publication Date
Wed Jun 14 2023
Journal Name
Al-academy
Social Graphic Design and its Reflections on The Practices of The Saudi Designer in Designing Awareness Posters
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The concept of social graphic design is one of the most critical areas that highlight the designer's knowledge of social responsibility by employing design skills in community awareness. This study focused on defining social graphic design, the meaning, practices, and strategies for designing awareness posters. This study reviewed two examples of awareness posters that reflect the Saudi designer's practices. The results summarized that social graphic design is a concept not taught directly but gained from permanent practice in designing awareness posters that interact with community issues. The designer's understanding of his social events and their sensing in the visual form of a poster reflects the designer's social awareness. Social g

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Publication Date
Thu Jan 14 2021
Journal Name
Iraqi Journal Of Science
VoIP Speech Encryption System Using Stream Cipher with Chaotic Key Generator
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Recently, with the development multimedia technologies and wireless telecommunication, Voice over Internet Protocol, becomes widely used in communication between connecting people, VoIP allows people that are connected to the local network or the Internet to make voice calls using digital connection instead of based on the analog traditional telephone network. The technologies of Internet doesn’t give any security mechanism and there is no way to guarntee that the voice streams will be transmitted over Internet or network have not been intercepted in between. In this paper, VoIP is developed using stream cipher algorithm and the chaotic cryptography for key generator. It is based on the chaotic maps for generating a one-time rando

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Publication Date
Sun Jan 30 2022
Journal Name
Iraqi Journal Of Science
Role of Glycine-to-Nitrate Ratio in Physical and Magnetic Properties of Zn-Ferrite Powder
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     We report  the influence of different glycine-to-nitrate ratios on the physical and magnetic properties for synthesized zinc-ferrite by  microwave-assisted combustion route. Phase impurity and surface morphology investigated with XRD analysis and field emission- scanning electron microscopy, indicated that  spinel structure  were  formed.Average particles size increased  with the decrease of glycine to nitrate ratio. Magnetic measurement  results indicated that  high values of saturation magnetization  were produced with low  glycine/nitrate ratio. Optical properties of  the investigated ferrites exhibited photo absorption from UV to visible region with 

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Publication Date
Thu Jun 02 2016
Journal Name
Ashrae Transactions
Melting of PCM with nanoparticles in a triplex-tube thermal energy storage system
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Publication Date
Thu Sep 01 2016
Journal Name
Applied Thermal Engineering
Solidification of a PCM with nanoparticles in triplex-tube thermal energy storage system
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Publication Date
Thu Sep 01 2016
Journal Name
Applied Thermal Engineering
Solidification of a PCM with nanoparticles in triplex-tube thermal energy storage system
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Publication Date
Sun Feb 10 2019
Journal Name
Journal Of The College Of Education For Women
Brain Dominance Learning Styles for Secondary School Students Distinguished and Ordinary
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The current research aims at detecting Brain Dominance Learning Styles distinguished
and ordinary secondary school students (males and females).The researcher adopted Torrance
measure, known as ‘the style of your learning and thinking to measure Brain Dominance
Learning Styles’, the codified version of Joseph Qitami (1986); picture (a). The researcher
verified the standard properties of tool. The final application sample was 352 distinguished
and ordinary students; 176 distinguished male and female students and 176 ordinary male and
female students at the scientific fifth level of secondary school from schools in the province of
Baghdad, AL- KarKh Education Directorates in the First and Second . and who have been

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Publication Date
Mon Feb 14 2022
Journal Name
Journal Of Educational And Psychological Researches
Educational value Implied in Secondary School Principals' weekly Speeches at Baghdad
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The research falls in to three sections: the first section has two parts; the first one includes a general description of the research: its   problem, aim, limitations, methodology, and the terminological definition. The second part presents historical background of the weekly school speeches in Iraq and their types. Section Two has two parts: the first is about the principles of writing weekly speeches, their elements, and principals, their conditions. As for the second part, it is about introducing four samples of weekly school speeches distributed as two taken from Al-karkh sector and two taken from Al-rusafa'a sector. The third section: analyzing the content of the sample and giving a short historical background abo

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