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jih-3276
Comparison of the Optical Efficiency of Two Designs of the Maksutov–Cassegrain Telescope
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The research aims to develop the best possible design for the widely used Cassegrain telescope. The system consists of two models of different designs: (a) the telescope consists of a Maksutov lens, a spherical primary mirror, and a secondary mirror attached to the lens; (b) it consists of a Maksutov lens and a spherical primary mirror, plus a non-lens attached secondary mirror located between the lens and the primary mirror. The image was evaluated and analyzed using the analysis tools in Zemax software. The results of the two designs showed that the telescope whose secondary mirrors are not adjacent to the Maksutov lens produces high quality image that is almost free from aberration, and then comes the telescope whose secondary mirrors are adjacent to the Maksutov lens in terms of image quality. In the first design, the tangential and sagittal axes in the MTF function of the remaining angles (0.1, 0.2, 0.3, 0.4, and 0.5) contain two curves, which show how the loss of symmetry has changed the value of the function for the two axes. In the second design, the sagittal and tangential axes are identical in the angles of incidence (0, 0.1, and 0.2), and the transverse and sagittal axes of the remaining angles (0.3, 0.4, and 0.5) contain two curves. In PSF for the first design, there are several pretty high peaks on the surface of the image at the angle of incidence (0, 0.1). Since the shape is regular, the point spread function indicates that there isn't an aberration, but in terms of the angles (0.2, 0.3, 0.4, 0.5), we observe a gradual loss in intensity and the appearance of elevations on both sides of the picture. In the second design, at the angles (0, 0.1, 0.2, 0.3), we observe in Figure 5 that there are several high peaks free from aberration.

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Publication Date
Mon Sep 13 2021
Journal Name
Eureka: Physics And Engineering
A numerical study to improve the position and angle of the producer gas injector inside the intake manifold to minimize emissions and efficiency enhancement of a bi engine
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To develop a petrol engine so that it works under the bi-engine pattern (producer gas-petrol) without any additional engine modifications, a single-point injection method inside the intake manifold is a simple and inexpensive method. Still, it leads to poor mixing performance between the air and producer gas. This deficiency can cause unsatisfactory engine performance and high exhaust emissions. In order to improve the mixing inside the intake manifold, nine separate cases were modelled to evaluate the impact of the position and angle orientation inside the intake manifold on the uniformity and spread of the mixture under AFR=2.07. A petrol engine (1.6 L), the maximum engine speed (8000 rpm), and bi-engine mode (petrol-producer ga

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Publication Date
Sat Mar 31 2018
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
A Comparison between the Product-Refill and the Equalization Oxygen Pressure Swing Adsorption Processes
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This work presents a design for a pressure swing adsorption process (PSA) to separate oxygen from air with approximately 95% purity, suitable for different numbers of columns and arrangements. The product refill PSA process was found to perform 33% better (weight of zeolite required or productivity) than the pressure equalization process. The design is based on the adsorption equilibrium of a binary mixture of O2 and N2 for two of the most commonly used adsorbents, 5A & 13X, and extension from a single column approach. Zeolite 13X was found to perform 6% better than zeolite 5A. The most effective variables were determined to be the adsorption step time and the operational pressure. Increasing the adsorption step

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Publication Date
Mon May 14 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Comparison Between Different Approaches to Overcome the Multicollinearity Problem in Linear Regression Models
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    In the presence of multi-collinearity problem, the parameter estimation method based on the ordinary least squares procedure is unsatisfactory. In 1970, Hoerl and Kennard insert analternative method labeled as estimator of ridge regression.

In such estimator, ridge parameter plays an important role in estimation. Various methods were proposed by many statisticians to select the biasing constant (ridge parameter). Another popular method that is used to deal with the multi-collinearity problem is the principal component method. In this paper,we employ the simulation technique to compare the performance of principal component estimator with some types of ordinary ridge regression estimators based on the value of t

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Publication Date
Thu Dec 31 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Application of data content analysis (DEA) technology to evaluate performance efficiency: applied research in the General Tax Authority
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The aim of the research is to use the data content analysis technique (DEA) in evaluating the efficiency of the performance of the eight branches of the General Tax Authority, located in Baghdad, represented by Karrada, Karkh parties, Karkh Center, Dora, Bayaa, Kadhimiya, New Baghdad, Rusafa according to the determination of the inputs represented by the number of non-accountable taxpayers and according to the categories professions and commercial business, deduction, transfer of property ownership, real estate and tenders, In addition to determining the outputs according to the checklist that contains nine dimensions to assess the efficiency of the performance of the investigated branches by investing their available resources T

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Publication Date
Wed Aug 28 2019
Journal Name
Journal Of Engineering
Subsurface Water Retention a Technology for Increasing the Field Use Efficiency and Water Saving Values of Cucumber Plant
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The technology of subsurface soil water retention (SWRT) uses a polyethylene ‎trough that is fixed under the root zone of the plant. It is a modern technology to increase the values of water ‎use efficiency, plant productivity and saving irrigation water by applying as little irrigation water ‎as possible. This study work aims at improving the crop yield and water use efficiency of a cucumber plant with less applied irrigation water by installing membrane trough below the soil surface. The field experiment was conducted in the Hawr Rajab District of ‎Baghdad Governorate in Winter 2018 for testing various trickle irrigation ‎systems. Two agricultural ‎treatment plots were utilized in a greenhouse for the compa

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Publication Date
Thu Sep 05 2019
Journal Name
Journal Of Engineering / University Of Baghdad
Subsurface Water Retention a Technology for Increasing the Field Use Efficiency and Water Saving Values of Cucumber Plant
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The technology of subsurface soil water retention (SWRT) uses a polyethylene trough that is fixed under the root zone of the plant. It is a modern technology to increase the values of water use efficiency, plant productivity and saving irrigation water by applying as little irrigation water as possible. This study work aims at improving the crop yield and water use efficiency of a cucumber plant with less applied irrigation water by installing membrane trough below the soil surface. The field experiment was conducted in the Hawr Rajab District of Baghdad Governorate in Winter 2018 for testing various trickle irrigation systems. Two agricultural treatment plots were utilized in a greenhouse for the comparison. Plot T1 has used a subsurface t

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Publication Date
Wed Nov 02 2022
Journal Name
Polymers
Ameliorating the Mechanical Parameters, Thermal Stability, and Wettability of Acrylic Polymer by Cement Filling for High-Efficiency Waterproofing
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Acrylic polymer/cement nanocomposites in dark and light colors have been developed for coating floors and swimming pools. This work aims to emphasize the effect of cement filling on the mechanical parameters, thermal stability, and wettability of acrylic polymer. The preparation was carried out using the casting method from acrylic polymer coating solution, which was added to cement nanoparticles (65 nm) with weight concentrations of (0, 1, 2, 4, and 8 wt%) to achieve high-quality specifications and good adhesion. Maximum impact strength and Hardness shore A were observed at cement ratios of 2 wt% and 4 wt%, respectively. Changing the filling ratio has a significant effect on the strain of the nanocomposites. The contact angle was i

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Publication Date
Thu Jun 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Efficiency of public investment spending and its impact on economic growth in Iraq For the period 2003- 2013
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Occupy public investment spending, a great deal of attention since the thirties of the last century, to play important role in economic and social development process and therefore most of the countries are trying different degree of economic development to the completion of the largest amount of public investment, especially in infrastructure, which is one of the pillars essential to economic development, and in order to maximize utilization of the completion of public investment should focus on achieving efficiency in completion.
    The current reality of public projects in Iraq, indicating the absence of several key characteristics that must be provided if these proje

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Publication Date
Thu Oct 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Study the Efficiency of Poly Nicotine Amide as Anticorrosion Coating on Stainless Steel and Study Its Biological Activity
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Using an electrochemical polymerization technique at room temperature, poly nicotine amide (PNA) was produced from the monomer nicotine amide (NA) in aqueous solution. The structure of polymer layer generated on the stainless steel surface (316 L) (working electrode) is investigated by Fourier Transmission Infrared Region (FT-IR). The anti-corrosion activity of polymer coating on the stainless steel (SS 316 L) is investigated by electrochemical polarization in 0.20M solution of HCl at 293-323K. The graphene -modified polymer film-coated SS had greater protection efficiency (PE percent) when compared to Nano ZnO -modified polymer film-coated SS. For the corrosion process of SS 316 L, kinetic and thermo-dynamic parameters of activation are

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Publication Date
Mon Jun 16 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of the effectiveness of coenzyme Q10 gel in management of patients with chronic periodontitis (I intra group comparison)
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Background: Periodontal pathogens can induce free radicals over-formation and thus may cause collagen and periodontal destruction. Anti-oxidants are used as supplements to counteract the over production of free radicals in periodontal disease, that can reduce of collagen destruction. Coenzyme Q10 serves as an endogenous antioxidant, regenerates other antioxidants, stimulates cell growth, and inhibits cell death. Because it is an antioxidant, coenzyme Q10 has received much research attention associated with periodontal diseases. Perio Q gel may possibly be effective as a topical agent and as an adjunct to scaling& root planing in treatment of gingivitis and chronic periodontitis. Aim of study:Determine the periodontal health status in a foll

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