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Hybrid compensation of polarization-multiplexed QPSK optical format for high bit rate networks
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<span lang="EN-GB">Transmitting the highest capacity throughput over the longest possible distance without any regeneration stage is an important goal of any long-haul optical network system. Accordingly, Polarization-Multiplexed Quadrature Phase-Shift-Keying (PM-QPSK) was introduced lately to achieve high bit-rate with relatively high spectral efficiency. Unfortunately, the required broad bandwidth of PM-QPSK increases the linear and nonlinear impairments in the physical layer of the optical fiber network. Increased attention has been spent to compensate for these impairments in the last years. In this paper, Single Mode Fiber (SMF), single channel, PM-QPSK transceiver was simulated, with a mix of optical and electrical (Digital Signal Processing (DSP)) compensation stages to minimize the impairments. The behaviour of the proposed system was investigated under four conditions: without compensation, with only optical compensator, with only DSP compensator and finally with both compensators. An evidence improvement was noticed in the case of hybrid compensation, where the transmission distance was multiplied from (720 km) to more than (3000 km) at 40 Gb/s.</span>

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Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Engineering
Wear Rate and Hardness of Boride Low Carbon Steel
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There are no single materials which can withstand all the extreme operating conditions in modern technology.  Protection of the metals from hostile environments has therefore become a technical and economic necessity.  

In this work, for enhancing their wear-resistance, boride layers were deposited on the surface of low carbon steel by a pack cementation method at 850 °C for (2, 4, and 6) h using vacuum furnace. The boronizing process was achieved using different concentration of boron source (20, 25, and 30) % wt. into coating mixture to optimize the best conditions which ensure the higher properties with lower time. The coating was characteristic by X ray diffraction (XRD), and it is confirmed t

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Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Design of a Kinematic Neural Controller for Mobile Robots based on Enhanced Hybrid Firefly-Artificial Bee Colony Algorithm
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The paper present design of a control structure that enables integration of a Kinematic neural controller for trajectory tracking of a nonholonomic differential two wheeled mobile robot, then  proposes a Kinematic neural controller to direct a National Instrument mobile robot (NI Mobile Robot). The controller is to make the actual velocity of the wheeled mobile robot close the required velocity by guarantees that the trajectory tracking mean squire error converges at minimum tracking error. The proposed tracking control system consists of two layers; The first layer is a multi-layer perceptron neural network system that controls the mobile robot to track the required path , The second layer is an optimization layer ,which is impleme

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Publication Date
Thu May 24 2018
Journal Name
Aip Conference Proceedings
The study effect of weight fraction on thermal and electrical conductivity for unsaturated polyester composite alone and hybrid
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In this research prepared two composite materials , the first prepared from unsaturated polyester resin (UP) , which is a matrix , and aluminum oxide (Al2O3) , and the second prepared from unsaturated polyester resin and aluminum oxide and copper oxide (CuO) , the two composites materials (Alone and Hybrid) of percentage weight (5,10,15)% . All samples were prepared by hand layup process, and study the electrical and thermal conductivity. The results showed decrease electrical conductivity from (10 - 2.39) ×10-15 for (Up+ Al2O3) and from (10 - 2.06)×10-15 for (Up+ Al2O3+ CuO) .But increase thermal conductivity from( 0.17 - 0.505) for (Up+ Al2O3) and from (0.17 - 0.489) for (Up+ Al2O3+ CuO).

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Publication Date
Sun Jun 12 2022
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Investigation of Lipid Polymer Hybrid Nanocarriers for Oral Felodipine Delivery: Formulation, Method, In-vitro and Ex-vivo Evaluation
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Publication Date
Sat Jun 01 2019
Journal Name
Agricultural Engineering
Comparing Nozzles with Different Wear Rate and Working with the Same Application Rate of Different Plant Protection Products in Aspect of Plants Condition
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Abstract<p>Three different types of nozzles (different wear rate) were used in this study. They are classified depending on the severity of their wear to three groups: new, worn and damaged nozzles. Those nozzles were spraying with the same application rate (303 l/ha) on two-year field trials; this was achieved by changing the spraying pressure for each group of nozzles in order to get the same application rate. This practice is usually done by operators of sprayers, who calibrate the sprayers on the same application rate every year without changing the nozzles, so they tend to reduce the spraying pressure in order to compensate the flow rate increase due to the nozzles yearly wear. Two types of</p> ... Show More
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Publication Date
Thu Oct 25 2018
Journal Name
Journal Of Optical Communications
320 Gbps Free Space Optic Communication System Deploying Ultra Dense Wavelength Division Multiplexing and Polarization Mode Division Multiplexing
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Abstract<p>This work aims to investigate the integrated ultra-dense wavelength division multiplexing (UDWDM) and polarization division multiplexing (PDM) schemes incorporated in the free space optic (FSO) communication system. Erbium-doped fiber amplifiers (EDFAs) are used as post and pre-amplifiers in the proposed UDWDM–PDM–FSO system to boost the transmission power for increasing the distance. Thirty-two channels are transported over the FSO link to realize the total data transmission of 160 and 320 Gbps with 0.08 and 0.1 nm channel spacing, respectively. Results are also reported with non-return to zero modulation schemes. The performance of the proposed UDWDM–PDM–FSO transmission sys</p> ... Show More
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Publication Date
Mon Apr 03 2023
Journal Name
Journal Of Electronics,computer Networking And Applied Mathematics
Comparison of Some Estimator Methods of Regression Mixed Model for the Multilinearity Problem and High – Dimensional Data
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In order to obtain a mixed model with high significance and accurate alertness, it is necessary to search for the method that performs the task of selecting the most important variables to be included in the model, especially when the data under study suffers from the problem of multicollinearity as well as the problem of high dimensions. The research aims to compare some methods of choosing the explanatory variables and the estimation of the parameters of the regression model, which are Bayesian Ridge Regression (unbiased) and the adaptive Lasso regression model, using simulation. MSE was used to compare the methods.

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Publication Date
Sun Dec 01 2019
Journal Name
Al-khwarizmi Engineering Journal
An Experimental Study on Electrochemical Grinding Parameters on Hardness and Material Removal Rate for Stainless Steel 316
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Electrochemical Grinding (ECG) process is a mechanically assisted electrochemical process for material processing. The process is able to successfully machine electrically conducting harder materials at faster rate with improved surface finish and dimensional control. This research studies the effect of applied current, electrolyte concentration, spindle speed and the gap between workpiece and tool on hardness and material removal rate during electrochemical grinding for stainless steel 316. The characteristic features of the electrochemical grinding process are explored through Taguchi-design-based experimental studies. The better hardness can be obtained at 10 A of the current, 150 g/l of the electrolyte concentration, 0.3 mm of gap an

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Publication Date
Fri Aug 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
The Causal Relationship Between Money Supply , Inflation and Exchange Rate in Iraq for the Period ( 1990-2011)
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   The paper aims to measure the impact of monetary policy on price stability , by testing the causal relationship between the money supply,  inflation rate and the exchange rate , In order to prove that the  inflation is a monetary phenomenon in the Iraqi economy , and that the exchange rate is controlled in the money supply , the money supply as an endogenous  variable continued we found by using the standard tests to the existence of a single co-integration  between the money supply and the rate of inflation and the money supply and the parallel exchange rate, This confirms the existence of a long-term relationship between the variables , It also confirmed the results of the vector error correctio

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Publication Date
Mon Apr 01 2024
Journal Name
Iraqi Journal Of Oil And Gas Research (ijogr)
Comparative study of electrochemical oxidation system hybrid with photocatalytic system for the treatment of Al-Najaf petroleum refinery wastewater
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