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Performance Analysis of FSO under Turbulent Channel Using OSTBC
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Free Space Optics (FSO) plays a vital role in modern wireless communications due to its advantages over fiber optics and RF techniques where a transmission of huge bandwidth and access to remote places become possible. The specific aim of this research is to analyze the Bit-Error Rate (BER) for FSO communication system when the signal is sent the over medium of turbulence channel, where the fading channel is described by the Gamma-Gamma model. The signal quality is improved by using Optical Space-Time Block- Code (OSTBC) and then the BER will be reduced. Optical 2×2 Alamouti scheme required 14 dB bit energy to noise ratio (Eb/N0) at 10-5 bit error rate (BER) which gives 3.5 dB gain as compared to no diversity scheme. The results show that using Multiple-Input-Multiple-Output (MIMO) technique represented by Alamouti scheme gives the improved BER performance as compared with no diversity (Single-Input-Single-Output (SISO)) technique.

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Publication Date
Tue Jun 03 2014
Journal Name
Heat Transfer - Asian Research
CFD Simulation of Heat Transfer Augmentation in a Circular Tube fitted with Alternative Axis Twisted Tape in Laminar Flow under the Constant Heat Flux
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Publication Date
Thu Oct 03 2013
Journal Name
Heat Transfer-asian Research
CFD Simulation of Heat Transfer Augmentation in a Circular Tube Fitted with Alternative Axis Twisted Tape in Laminar Flow under a Constant Heat Flux
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Publication Date
Sat Jan 01 2022
Journal Name
Journal Of The Mechanical Behavior Of Materials
The slenderness ratio effect on the response of closed-end pipe piles in liquefied and non-liquefied soil layers under coupled static-seismic loading
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Abstract<p>This study presents the findings of a 3D finite element modeling on the performance of a single pile under various slenderness ratios (25, 50, 75, 100). These percentages were assigned to cover the most commonly configuration used in such kind of piles. The effect of the soil condition (dry and saturated) on the pile response was also investigated. The pile was modeled as a linear elastic, the surrounded dry soil layers were simulated by adopting a modified Mohr-Coulomb model, and the saturated soil layers were simulated by the modified UBCSAND model. The soil-pile interaction was represented by interface elements with a reduction factor (R) of 0.6 in the loose sand layer and 0.7 in t</p> ... Show More
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Publication Date
Sun Jan 21 2024
Journal Name
International Development Planning Review
THE ROLE OF ACADEMIC COACHES IN HANDBALL SKILL PERFORMANCE FROM THE POINT OF VIEW OF THEIR PLAYERS
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The aim of the study is to prepare a measure of the role of academic coaches in handball skill performance from the point of view of the researchers. The researchers used the descriptive approach in the research procedures as it is an appropriate approach in achieving the research objectives. The next question is: To what extent will the players benefit from the academic coach in developing their skill performance? This is the measure of the role of academic coaches. From 16 items, the research community included players (Al-Karkh Club - Al-Hashd Sports Club) and the number of players was (Al-Karkh 14 - Al-Hashd 14). The research sample was intentional and represented (the research community 100% The researchers concluded that measuring the

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Publication Date
Tue Jun 15 2021
Journal Name
Al-academy
Forms of post-modernism in performance of Iraqi theatre "dream of Baghdad exam": عمار عبد سلمان محمد
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  The effects of postmodernism on theatrical form was managed by the director (Anas Abdul Samad) to be employed in the Iraqi play (Dream in Baghdad) and the researcher sought to study this problem and divided it into four chapters dealt with in the first chapter the problem of research and its need, the importance of research, As well as the definition of terminology, either Chapter II theoretical framework divided by the researcher to the first two is the postmodernism in the theater is the most prominent reference references and the second most important postmodern applications in the world play and then the researcher concluded the second chapter of the most important indicators. In the third chapter, the researcher identified th

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Publication Date
Sun Dec 01 2024
Journal Name
Al-qadisiyah Journal For Agriculture Sciences
Effect of Holes Diameter and Speed of Die on the Performance of Machine and Feed Pellet Quality
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The aim of this study to evaluate the effects of die holes diameter and speed of die on the performance of machine and feed pellet quality. Machine productivity (Kg.h-1), consumed power (kW), pellet durability (%) and pellet bulk density (g.cm-3) was studied. The study factors consisted of three diameter of die holes (3, 4, and 5 mm), and three speeds die (280, 300, and 320 rpm). Results showed with increasing of die holes diameter from 3 to 4 and to 5 mm give a significant increase in machine productivity, while consumed power, pellet durability and pellet bulk density a significant decreased. By increasing the die speed, from 280 to 300 then to 320 rpm, the machine productivity increased significantly, while consumed power, pellet durabil

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Publication Date
Thu May 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Study of Effect of Diesel Fuel Energy Rate in Duel Fuel on Performance of Compression Ignition Engine
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The aim of this work is to study the effect of diesel fuel percentage on the combustion processes in compression ignition engine using dual – fuel (diesel and LPG).

 The brake thermal efficiency increased with the increase of diesel fuel rate at low loads, and decreased when load increased. To get sufficient operation in engine fueled with dual fuel, it required sufficient flow rate of diesel fuel, if the engine fueled with insufficient diesel fuel erratic operation with miss fire cycles presented.

Dual-fuel operation at part load showed higher specific fuel consumption than straight diesl operation. At full loads, brake specific fuel consumption of duel fuel engine approaches that for diesel fuel values.

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Publication Date
Thu Apr 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The impact of the of Six Sigma to improve the performance of dentists in albaladeat specialized Dental
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The research aims at introducing the principles of six sigma and if it had any effect of the dimensions of six sigma to improve the performance of the dentists and the availability of an appropriate environment in the center Specialist respondent to the application of six sigma principles and how to adopt Specialized Center under the dimensions of the six sigma and if there informed enough with the management methodology six sigma, and if you can adopt six sigma as one of the entrances to reduce medical errors. So  Search creating six sigma five dimensions and are (the commitment and support of senior management, the focus  on the patient, continuous improvement, training and civil, and infrastructure) as a variable int

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Publication Date
Thu Jun 15 2023
Journal Name
Bionatura
Effect of aqueous extracts of the sprouted seeds on the quantitative and qualitative yield of the coral lettuce cultured under the modified nutrient solution film NFT system
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The study was conducted at the fields of the Dept. of Horticulture and Garden Engineering, College of the Agricultural Engineering Sciences, Jadriyah in the fall season of 2020-2021 aiming to culture the coral lettuce with green and red leaves under the hydroponics system using the modified nutrient solution film NFT and study the effect of aqueous extracts of alfalfa and berseem sprouted seeds on the quantitative and qualitative yield of the lettuce crop. The research was conducted as an experiment of split plots within the Randomized Complete Block Design (RCBD) of three replicates. The seedlings of the green coral lettuce, Locarno RZ, and red coral lettuce, Locarno RZ, symbolized by A and B respectively, were transferred to the c

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Publication Date
Thu Jun 15 2023
Journal Name
Journal Of Population Therapeutics And Clinical Pharmacology
Detection the Phylogenetic groups of E. coli that isolated from diarrheal in children under five years and study their relationship of common serotypes in Baghdad hospitals.
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