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bsj-2538
Comparison between Direct and Coherent Optical Communication System
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The work in this paper focuses on the system quality of direct and coherent communication system for two computers. A system quality is represented by Signal to Noise ratio (SNR) and Bit Error Rate (BER). First part of the work includes implementation of direct optical fiber communication system and measure the system quality .The second part of the work include implementation both the( homodyne and heterodyne)coherent optical fiber communication system and measure the system quality . Laser diode 1310 nm wavelength with its drive circuit used in the transmitter circuit . A single mode of 62.11 km optical fiber is selected as transmission medium . A PIN photo detector is used in the receiver circuit. The optical D-coupler was used to combine the optical signal that come from transmitter laser source with optical signal of laser local oscillator at 1310/1550 nm to obtain coherent detection . Results show that for direct detection the SNR and the BER (28.5 dB, 9.64x10-8,) respectively, while for homodyne and heterodyne coherent detection , the SNR(94.36,97.71)dB and the BER are (1.32x10-22,2.43x10-23) at maximum optical fiber length at 62.11 km. Results show that the homodyne and heterodyne detection are better than direct detection because the large output SNR and low BER of the received signal.

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Publication Date
Wed Sep 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Prediction of the Scale Removal Rate in Heat Exchanger Piping System Using the Analogies between Mass and Momentum Transfer
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The possibility of predicting the mass transfer controlled CaCO3 scale removal   rate has been investigated.

Experiments were carried out using chelating agents as a cleaning solution at different time and Reynolds’s number. The results of CaCO3 scale removal or (mass transfer rate) (as it is the controlling process) are compared with proposed model of prandtl’s and Taylor particularly based on the concept of analogy among momentum and mass transfer.

Correlation for the variation of Sherwood number ( or mass transfer rate ) with Reynolds’s number have been obtained .

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Publication Date
Thu Feb 18 2021
Journal Name
Journal Of Optical Communications
Theoretical investigation of multiple input–multiple output (MIMO) technique for line of sight (LoS) underwater wireless optical communications system
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Abstract<p>In this paper, a theoretical investigation was suggested to study underwater wireless optical communication (UWOC) system based on multiple input–multiple output (MIMO) technique. The modulation schemes such as RZ-OOK, NRZ-OOK, 32-PPM and 4-QAM applied under different coastal water types. MIMO technique enabled the system to transmit data rate with longer distance link. The performance of the proposed system examined by BER and data rate as a metrics. Several impairments such as the types of water by the attenuation of coastal water and the distance link were taken into account for the transmission of the optical signal to appreciate the reliability of the MIMO technique. The theore</p> ... Show More
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Publication Date
Sun Nov 01 2020
Journal Name
Journal Of Engineering
A Signal Amplification-based Transceiver for Visible Light Communication
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Visible light communication (VLC) is an upcoming wireless technology for next-generation communication for high-speed data transmission. It has the potential for capacity enhancement due to its characteristic large bandwidth. Concerning signal processing and suitable transceiver design for the VLC application, an amplification-based optical transceiver is proposed in this article. The transmitter consists of a driver and laser diode as the light source, while the receiver contains a photodiode and signal amplifying circuit. The design model is proposed for its simplicity in replacing the trans-impedance and transconductance circuits of the conventional modules by a simple amplification circuit and interface converter. Th

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Publication Date
Sun Dec 10 2017
Journal Name
Al-academy
The speech communication btween the shape and content in commercial advertising
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The Main think that be kept by the speech communication as a concept traditionally being expressed on the subject or a certain idea of ​​a goal came on as needed functional addressed to recipients of benefits or likely to benefit from those rhetorical message through a speech importance and priority of the effect of not less than the effect of that letter, in science content role ends once you absorb it mentally, either in the art of design Valamadmon intellectual embodied through its interaction with the overall shape of the finished design, and often content is associated in the mind of the receiver through a letter communicative linked to the sense or the goal that meant the designer, and try to identify and explain. And meaning i

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Publication Date
Tue Oct 06 2020
Journal Name
College Of Islamic Sciences
Distress Tolerance among the Employees in Media and Communication in Baghdad.
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Abstract: The aim of this study was to identify the Distress Tolerance among the Employees in  Media and Communication in Baghdad.and to identify the significance of the differences between sex ,scientific specialization ,age,and marital status. and the researcher used the Distrees  Tolerance measure for Simon &Gahar 2005.  The sample of the study consisted of(37)Employees.The Scale of Distrees Tolerance were used as the study tools after being checked for their Validity and Reliability. The research results indicated that employees have high scores on the scale of stress tolerance and that there are statistically significant differences between the age groups and between married and unmarried people a

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Publication Date
Sat Dec 17 2022
Journal Name
Journal Of Al-ma'moon College
Simulation and Implementation of SNR Measurement processor for Adaptive Communication Systems
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Publication Date
Thu Sep 15 2022
Journal Name
Al-academy
The philosophy of physical and sensory communication in the dramatic show
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Modern critical theories revealed polemical views about the reality of the existence of communication - as a necessity for building a deliberative discourse - in the theater or not. To the theory of communication with all the conditions it imposes on thinking, interaction, and emancipation of selves in different contexts.
Therefore, the current research included four chapters, the first chapter dealt with the research problem, which was represented in (the philosophy of sensory and physical communication in theatrical performance), and the first chapter included the importance of the research, its goal and its limits, and ended with defining the terminology, and the second chapter included (theoretical framework) the first topic (ph

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Publication Date
Thu Mar 30 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Determination of Cefalexin by Direct (UV- Vis) Spectrophotometer and Indirect(Flame Atomic Absorption) Technique
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         A new method for the determination of the drug cefalexin in some Pharmaceuticals using (UV-Vis) and  indirect Flame Atomic Absorption Spectrophotometer (FAAS) , Fe III should forms a chelating complex with cefalexin (CEX –Fe III) at pH (1-8) and the best pH for the formation of (CEX –Fe III) chelating complex was (2) .The complex extracted with Methanol  and  Dimethy-Sulphoxide .The mole-ratio method has been used to determine the structure of chelate (CEX - Fe III) and found to be 2:1 LM ( Ligand : Metal.) .

Keywords : Cefalexin , chelating complex.

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Publication Date
Sun Mar 01 2015
Journal Name
Baghdad Science Journal
Removal of Direct 50 Dyes from Aqueous Solution Using Natural Clay and Organoclay Adsorbents
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In this study, hexadecyltrimethylammonium bromide (HDMAB) - bentonite was synthesized by placing alkylammonium cation onto bentonite. Adsorption of textile dye such as direct Yellow 50 on natural bentonite and HDMAB -bentonite was investigated. The effects of pH, contact time,dosage clay and temperature were investigated experimentally .The Langmuir and Freundlish isotherms equations were applied to the data and values of parameters of these isotherm equations were evaluated. The study indicated that using 0.2 g of HDMAB (hexadecyltrimethylammonium bromide) lead to increase the percentage removal(R%) from 78% for pure bentonite to 99 %. The optimum pH value for the adsorption experiments was found to be pH=3 and therefore all the experim

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Catalyzed and Promoted Direct Reaction of Ethyl Chloride with Silicon Using Stirred-Bed Reactor
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In this paper a stirred-bed performed of the copper catalyzed synthesis of ethylchlorosilanes from silicon and ethyl chloride was described. A Si-catalyst mixture prepared by reaction of CuCl and Si was employed. The compositions of products were mainly ethyltrichlorosilane, diethyldichlorosilane, and ethyldichlorosilane and mainly depended on the extent of Cu in the mixture and the reaction temperature. A promoting effect on the extent of adsorption was observed on the addition of certain additives. The kinetic data revealed the direct depended of the reaction rate on C2H5Cl pressure.

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