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jih-2857
Simulation and Evaluation of a Variable Effective Focal Length of Refractive Binocular Telescope
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The telescope works to magnify images of distant objects in general, but it needs special optical elements to complete the task to the fullest. The telescope needs optimal balance values of the optical parameters used to produce the best image, such as the effective focal length and the diameter of the pupil aperture, which are combined in a single concept called the focal number. The ground-based binary telescope relies on special lenses and an exceptional prism to achieve a hybrid design that produces clear images of relatively distant terrestrial objects. The pupil diameter of the telescope is relatively large to ensure that the largest possible amount of light is received, and as a result, a good image is obtained.

In this work, an achromatic objective lens and a Porro prism has been used to reduce the length of the telescope and change the path of the rays to the eyepiece, in addition to the presence of a flat convex lens behind the prism to collect the rays coming from it to reach the eyepiece. The effective focal length of the optical system was changed to illustrate the effect of this factor on the performance of a telescope and as a result of its effect on the image quality.

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Publication Date
Mon Jan 02 2017
Journal Name
Al-academy
The semiology of culture and the sign variable in a theatre performance: Iraqi theatre as an example
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The culture of theatre performance has a vital role in the process of reading the linguistic and visual signs of the performance. And the process of transforming a theatre performance from its original context into a new hosting cultural context starts from the actual reading of the text. Directors derives their new signs out of his personal culture, depending on the society where they lives and the culture that forms the social conventions, traditions and beliefs. The text is usually written within its own historical and temporal culture. The process of its production usually takes it away from its original culture, when it interprets the codes of the original writer and their visual and linguistic signs and instils new alternative sign

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Publication Date
Thu Oct 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Evaluating the Optical Properties of the Schmidt Cassegrain Spider Obscuration Telescope Using Zemax Program
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Schmidt Cassegrain spider obscuration telescope (SCT) is one of the types of observations operating with a concave mirror. It combines several lenses and mirrors working together as an optical system. The light rays fall into the tube from the main mirror and gather on another smaller mirror called a secondary mirror. Unlike the formation of Newton's telescope, no light is made from the secondary mirror out the side of the tube but is directed to the middle of the main mirror. There is an opening in the middle of the main mirror so the light beam can go out and direct the vision lens system. The secondary mirror is located in the middle of a glass slice and is installed by thin carriers. The function of this board is to correct the portr

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Publication Date
Wed Apr 03 2024
Journal Name
International Journal Of Economics And Finance Studies
THE IMPACT OF ARTIFICIAL INTELLIGENCE ON ACCOUNTING PERFORMANCE: SUSTAINABLE DEVELOPMENT AS A MEDIATING VARIABLE
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The UN plans to achieve several development objectives by 2030. These objectives address global warming, a major issue. This method aims to improve sustainable accounting performance (AP). In this circumstance, AI is being applied in various fields, notably in economic, social, and environmental (ESE) domains. This research investigates how sustainable development (SD) influences AI methodologies and AP improvement. The research examined a sample of Iraqi banks listed on the Iraq Stock Exchange from 2014 to 2022. AI was measured by ATM and POS prevalence. A three-dimensional approach examined economic, social, and environmental (ESE) sustainability. Meanwhile, the performance of sustainable accounting was measured through the return on asse

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Scopus
Publication Date
Fri Dec 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Relationship Study Between Total Length with Otolith Length and Thickness in Two Fish Species: Coptodon zillii (Gervais,1848) and Cyprinus carpio” (Linnaeus,1758)
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Abstract<p>This study aimed new indications that may clarify the relationships between the total and standard lengths, and the length of the otolith, as well as the thickness and weight of these bones compared to the body weights of two different species of invasive fish in the Iraqi aquatic environment, the common carp <italic>Cyprinus carpio</italic> of the Cyprinidae family, and the common Tilapia. <italic>Coptodon zillii</italic>, from the Cichlidae family. The results showed that the otolith were not related to some of the vital characteristics of the studied fish, and there were differences in the correlation coefficient between some vital measurements with high signifi</p> ... Show More
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Publication Date
Thu Apr 18 2019
Journal Name
Al-kindy College Medical Journal
Clinical and Refractive Outcomes of Toric Phakic Implantable Collamer lens Implantat for correction of myopic astigmatism
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Background: Currently there are four general approaches to correct refractive errors: refractive corneal surgery, crystalline lens surgery and implantation of an intraocular lens in anterior or posterior chamber.

Objective: To evaluate the predictability, safety and stability of toric phakic implantable collamer lens implantation to correct moderate to high myopic astigmatism. in  Eye Specialty Private Hospital, Baghdad, Iraq.

Type of the Study: a prospective non randomize intervention study.

Methods: 60 eyes of 40 patients underwent implantation of a toric implantable collamer lens (V4c design).Mean spherical refraction was ₋11.32 diopter

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Publication Date
Thu Dec 16 2021
Journal Name
Kufa Medical Journal
Clinical and Refractive Outcomes of Toric Phakic Implantable Collamer Lens Implantation for correction of myopic astigmatism
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Background: Currently there are four general approaches to correct refractive errors: refractive corneal surgery, crystalline lens surgery and implantation of an intraocular lens in anterior or posterior chamber. Aim: To evaluate the predictability, safety and stability of toric phakic implantable collamer lens implantation to correct moderate to high myopic astigmatism. Methods: Sixty eyes of 40 patients underwent implantation of a toric implantable collamer lens (V4c design) in the Eye Specialty Private Hospital, Baghdad, Iraq were studied. The mean spherical refraction was -11.32±3.17 diopter (D) with a range of -6.00 to -18.00 D and a mean cylinder of -2.61±1.16 with range of -1.00 to -5.50 D. The outcome measures that evaluat

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Publication Date
Fri Feb 08 2019
Journal Name
Iraqi Journal Of Laser
Refractive Index Scaling in Hollow Core Photonic Crystal Fiber
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In this paper, simulation study of the frequency shift of photonic bandgaps due to refractive index scaling using liquids filled hollow-core photonic crystal fibers is presented. Different liquids (distilled water, n-hexane, methanol, ethanol and acetone) are used to fill the cladding of 2 types of hollow core photonic crystal fibers (HC19-1060, HC7-1060). These liquids are used to change the effective index scaling and index contrast of the cladding. The effect of increasing temperature of the liquid (20-100 0C for water and 20-70 0C for other liquids ) infiltrated hollow core fiber on the bandgap width and transmission properties has been computed. The maximum photonic bandgap width at 0.0243 has appeared with filling HC7-1060 PCF with

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Publication Date
Sun Jun 30 2024
Journal Name
Iraqi Journal Of Science
Telescope Mirror Cleaning Using Atmospheric Pressure Multi-Channel Radio Frequency Plasma Jet
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     In this work, the surface of the telescope’s mirror is cleaned using an atmospheric-pressure radio frequency plasma jet (APRFPJ), which is generated by Argon gas between two coaxial metal electrodes. The RF power supply is set to 2 MHz frequencies with three different power levels: 20, 50, and 80 W. Carbon, that has adhered to the surface, can be effectively removed using the plasma cleaning technique, which also modifies any residual bonds. The cleaned surface was clearly distinguished using an optical emission spectroscopy (OES) technique and a water contact angle (WCA) analyzer for the activation property on their surfaces. The sample showed a super hydrophilic surface at an angle of 1° after 2.5 minutes of plasma tre

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Publication Date
Sat Jan 01 2022
Journal Name
Journal Of Engineering
A Five Variable Refined Plate Theory For Thermal Buckling Analysis Uniform And Nonuniform Of Cross-Ply Laminated Plates
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This research is devoted to investigating the thermal buckling analysis behaviour of laminated composite plates subjected to uniform and non-uniform temperature fields by applying an analytical model based on a refined plate theory (RPT) with five unknown independent variables. The theory accounts for the parabolic distribution of the transverse shear strains through the plate thickness and satisfies the zero-traction boundary condition on the surface without using shear correction factors; hence a shear correction factor is not required. The governing differential equations and associated boundary conditions are derived by using the virtual work principle and solved via Navier-type analytical procedure to obtain critica

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Publication Date
Thu Aug 01 2019
Journal Name
مجلة العلوم الاقتصادية والإدارية
Improving" Jackknife Instrumental Variable Estimation method" using A class of immun algorithm with practical application
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Improving" Jackknife Instrumental Variable Estimation method" using A class of immun algorithm with practical application