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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
Sun Nov 01 2020
Journal Name
Iraqi Journal Of Laser
Treatment of facial acne scar using Fractional Er: YAG laser
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Background: Acne is a common disorder experienced by adolescents and persists into adulthood in approximately 12%–14% of cases with psychological and social implications of high gravity. Fractional resurfacing employs a unique mechanism of action that repairs a fraction of skin at a time. The untreated healthy skin remains intact and actually aids the repair process, promoting rapid healing with only a day or two of downtime. Aims: This study, was designed to evaluate the safety and effectiveness of fractional photothermolysis (fractionated Er: YAG laser 2940nm) in treating atrophic acne scars. Methods: 7 females and 3 males with moderate to severe atrophic acne scarring were enrolled in this study that attained private clinic for Derm

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Publication Date
Wed Mar 29 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Anti-bacterial Properties of Melatonin against Mycobacterium Tuberculosis in Vitro
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         57 isolates of Mycobacterium tuberculosis and Mycobacterium bovis were identified; they were isolated from different clinical sources which included sputum, bronchial wash, abscess, pleural fluid, gastric fluid, eye fluid, and CSF, also urine and ear swab. This investigation was carried out on 198 patient attended National Reference Laboratory for T.B during September 2009. Also the study declared that the ratio of separation of this bacterium from male was (67.6%) and it’s higher than the ratio of separation this bacterium from females which was (32.3%). The susceptibility of Mycobacterium tuberculosis to melatonin was evaluated. Many concentrati

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Publication Date
Thu Jan 24 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Impact of Tax knowledge in compliance costs: Applied Research
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This research Sought to Determine the Relationship and  impact  between the tax knowledge in dimensions  of the tax compliance costs (monetary costs, time costs, psychic costs) Since the sample included 81 individuals represented by the Executive directors and Financial  and Accountant working in the Joint-stock company,  A questionnaire was used as a tool for data collection and its analysis.  For the purpose of analyzing the research data the statistical package for social science, SPSS. The most important tools used in the statistical analysis are:(standard deviation, and simple linear regression, percentages,  arithmetic mean, Cronbach's alpha, F-test, T- Test). The research found a weakness attenti

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Publication Date
Thu Feb 24 2022
Journal Name
Journal Of Educational And Psychological Researches
The developmental role of the social worker in child care
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This research discusses the developmental role of the social worker in providing care for children at risk. The research is desicriptive in nature include both the theoretical and field aspects. The theoretical aspect focuses on the characteristics and requirements of these children and what forms and implications are exposed to them by society, what is the developmental role of the social worker in the rehabilitation of this group. As for the field aspect, the study sample took a (40) social workers who working in Aiwa institutions inside Baghdad. A questionnaire of (14) questions was used as tool to collect the needed data.

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Publication Date
Sun Sep 30 2001
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Component of Pattern Materials and Its Influence on Physical Properties
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Publication Date
Sat Jun 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Determination of Volumetric Mass Transfer Coefficient in Fixed Bed Adsorption
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This work was conducted to determine the volumetric mass transfer coefficient (Ky.a) infixed bed adsorption using hexane-benzene mixture by adsorption onto a fixed bed of white silica gel. Benzene concentration was measured by gas chromatography. The effect of feed flow rate and initial concentration of benzene in hexane-benzene mixture on the volumetric mass transfer coefficient and on the adsorption capacity of silica gel was investigated.

In general, the volumetric mass transfer coefficient increases with increasing hexane flow rate, and with increasing initial concentration of benzene in the mixture. The ultimate value of (Ky.a) was at 53 ml/min of hexane flow rate with benzene initial concentration of (6.53 wt. %), and it wa

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Publication Date
Fri Oct 01 2021
Journal Name
Journal Of Engineering
Some Geotechnical Properties of Plastic Soil Enhanced with Cement Dust
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Plastic soil exhibits unfavorited geotechnical properties (when saturation), which causes negative defects to engineering structures. Different attempts (included various materials) were conducted to proffer solutions to such defects by experimenting in practical ways. On one hand, these attempts aimed to improve the engineering characteristics of plastic soil, and on the other hand, to use problematic waste materials as a stabilizer, like cement kiln dust, and to reduce environmental hazards. This paper explored the shrinkage, plasticity, and strength behavior of plastic soil enhanced with cement dust. The cement dust contents were 0%, 5%, 10%, 15% and 20% by dry weight of soil. An experimental series of shrinkage and p

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Publication Date
Sun Jul 02 2017
Journal Name
Journal Of Educational And Psychological Researches
Analysis of third intermediate chemistry book following sustainable development standards
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The current research seeks to Analyze third intermediate chemistry book following sustainable development standards for academic year (2016-2017). To do this, a list of sustainable development standards that should be included in chemistry book was designed based on the previous studies. The first version of the list consisted of (50) sub-case divided into three standards (social, economic, and environmental) which was exposed to group of experts in teaching chemistry and teaching methods. The list has modified to (43) sub-case. The researcher followed the implicit and explicit meaning in his analysis: one for recording and repetition and the other for frequency. The result showed that third intermediate chemistry book has achieved (20)

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Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Engineering
Buckling Analysis of Composite Plates under Thermal and Mechanical Loading
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Buckling analysis of composite laminates for critical thermal (uniform and linear) and mechanical loads is reported here. The objective of this work is to carry out theoretical investigation of buckling analysis of composite plates under thermomechanical loads, and experimental investigation under mechanical loads. The analytical investigation involved certain mathematical preliminaries, a study of equations of orthotropic elasticity for classical laminated plate theory (CLPT), higher order shear deformation plate theory (HSDT) , and numerical analysis (Finite element method), then the equation of motion are derived and solved using Navier method and Levy method for symmetric and anti-symmetric cross-ply and angle-ply laminated plates t

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Publication Date
Sun Jul 01 2018
Journal Name
Journal Of Educational And Psychological Researches
The Use of Discourse Markers by Iraqi Secondary Schools Pupils
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This research aims at investigating pupils’ ability in using discourse markers which are identified in the English textbooks of secondary schools. Four texts are chosen from third intermediate class. The four texts are short stories of different topics.                                                  

        This research hypothesizes that there are no statistical significant differences among Iraqi intermediate pupils’ ability in using textual

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