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Optical CDMA Coded STBC Based on Chaotic Technique in FSO Communication Systems
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Free-Space Optical (FSO) can provide high-speed communications when the effect of turbulence is not serious. However, Space-Time-Block-Code (STBC) is a good candidate to mitigate this seriousness. This paper proposes a hybrid of an Optical Code Division Multiple Access (OCDMA) and STBC in FSO communication for last mile solutions, where access to remote areas is complicated. The main weakness effecting a FSO link is the atmospheric turbulence. The feasibility of employing STBC in OCDMA is to mitigate these effects. The current work evaluates the Bit-Error-Rate (BER) performance of OCDMA operating under the scintillation effect, where this effect can be described by the gamma-gamma model. The most obvious finding to emerge from the analysis is that the BER can be enhanced by orders of magnitude for different numbers of users and different values of scintillation effects using a MIMO

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Publication Date
Mon Jun 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Study the Effect Different Radioactive Dose on Mechanical Properties of Composite Material from Novolak Resin Exposure to High – Energy Radiation
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The research involves using phenol – formaldehyde (Novolak) resin as matrix for making composite material, while glass fiber type (E) was used as reinforcing materials. The specimen of the composite material is reinforced with (60%) ratio of glass fiber.

      The impregnation method is used in test sample preparation, using molding by pressure presses.

      All samples were exposure to (Co60) gamma rays of an average energy (2.5)Mev. The total doses were (208, 312 and 728) KGy.

      The mechanical tests (bending, bending strength, shear force, impact strength and surface indentation) were performed on un irradiated and irrad

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Publication Date
Tue Oct 11 2022
Journal Name
College Of Islamic Sciences
The Jurisprudence rule and its impact on Islamic legislation “Forcing does not nullify the rights of others” as a model .
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Research Summary :

         Praise be to God, Lord of the Worlds, and prayers and peace be upon the Master of the Messengers, his family and all his companions, then after:

     This is brief research that contained between its two covers one of the jurisprudence rules derived from Islamic Sharia that guarantees the right of others, in case of forcing to do the prohibited act, and it is a restriction of the rule: “Necessities allow prohibitions” and “Hardship brings facilitation” and support for the rule: “Necessities are valued.” It is an origin in alleviating the taxpayer definitely , and the study has briefly shown some of the jurisprudential appli

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Publication Date
Thu Apr 17 2008
Journal Name
Anbar Journal Of Agricultural Sciences 6 (2)‏
Influence of foliar sprays with Copper and Zinc on the resistance of citrus rootstocks to gumosis caused by Phytophthora citropthora. ‏
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Publication Date
Tue Nov 03 2020
Journal Name
Modern Sport
Effect of using flat hierarchical method on some aspects of muscular strength and straight serve skill for nascent tennis players
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The researcher focused on the importance of the physical abilities of the tennis game, as this game is one of the games that are characterized by its specificity in performance as this game is characterized by continuous movement and dealing with different elements, so this game requires the development of muscle strength, which plays an important role in Performance skills in the game of tennis. There are several methods to develop strength, including flat hierarchical technique, which is one of the most common forms of training in the development of muscle strength.     As for the research problem, the researcher found a method that has an effect on the development of force. Therefore, the researcher tried to diversify a

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Publication Date
Fri Jan 11 2019
Journal Name
Iraqi Journal Of Physics
Effect of low level nozzle height on properties of copper oxide absorption layer prepared by fully computerized spray pyrolysis depositions
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The effect of approaching nozzle jet from the deposition surface
on structural, optical and morphology properties of copper oxide thin
films was studied. The film was prepared by homemade fully
computerized CNC spray pyrolysis deposition technique at
preparations speed (3, 4, 5, and 6 mm/sec). The repeated line mode
was used at deposition temperature equal 450 °C whereas the
spraying time was in the range of (15-30 min) according to the
deposition speed. The film exhibit polycrystalline structure with
preferred orientation along (-111), (022) and (011), (002) at a 2θ
value of (35.63o) and (38.8o) respectively. Optical band gaps were
recorded at these speed shows variance in value from (1.53-2.08 eV).
Fi

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Publication Date
Fri Dec 15 2017
Journal Name
Journal Of The College Of Education For Women
The Effect of Using Authentic Materials on ESP Students’ Achievement at College of Physical Education and Sciences Sport for Women
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Authentic materials are the most important tools that the teacher could use in class in order to make teaching go smoothly and effectively in transmitting the necessary knowledge to all students. This research has investigated experimentally the effect of using authentic materials in teaching English as a foreign Language, because a number of studies point out that the use of authentic materials is regarded a useful means to motivate learners, arouse their interest and expose them to the real language they will face in real life situations.

It is hypothesis that there is no statistical significance difference between the experimental group who taught English as a foreign language by using the authentic materials with those  

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Publication Date
Sun Dec 02 2012
Journal Name
Baghdad Science Journal
Effect of magnetic treatment of irrigation water and seed on some vegetative characteristics and production of black seed "Nigella sativa
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Seeds of Nigella sativa were sown in containers containing 15kg Loamy soil. The seeds were divided before sewing into two groups. The first group was soaked with ordinary tap water end the second group was treated with magnetized water for 24hrs. The irrigation process was completed until 75% of capacity field with two types of water (tap water of magnetized water with three replications).The magnetized water was obtained from special electric device designed for this purposeRecorded measurements (plants height, the number of branches/ plant, dry weight ofplant, number of flowers, 1000 seed weight) during the harvest period.Results indicated that the seed group which was treated with magnetized water was more significant than the one which

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Publication Date
Fri Mar 01 2019
Journal Name
Al-nahrain Journal Of Science
Effect of Active Galactic Nuclei (AGN) on the Photometric and Morphologic Properties of NGC 4414 and NGC 4369 Spiral Galaxies
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The purpose of this work is to clarify the effect of the Active Galactic Nucleus (AGN) on the properties of the galaxy. A photometric study of two galaxies by surface optical measurements techniques and by using'griz filters' was performed. The scientific material that used in this work was obtained from ''SLOAN DIGITAL SKY SURVEY'' (DR7), a fuzzy color, contour maps, photometric parameters, and color indices were studied by using surface photometric technique. The work was done by Ellipse task in IRAF (Image Reduction and Analysis Facility) software from the National Optical Astronomy Observatory (NOAO).

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Publication Date
Fri Dec 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Effect of Adding Kojic Acid and Sodium Alginate to Semen Extender of Buffalo Bulls on some Biological and Bacteriological Parameters
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Abstract<p>This experiment examined the effects of adding sodium alginate and Kojic acid as substitutes for conventional antibiotics to Skim milk extender on the characteristics of cryopreserved and frozen buffalo bull semen, as well as the evaluation of their additions as antibiotics that help lower the microbial load. Following the collection and dilution of the Skim milk extender, the experimental treatments were separated into five groups, as follows: T1: (control-) without adding any antibiotics; T2: (control+) adding the conventional antibiotics Gentamicin 0.4 IU and Tylosin 0.08 IU per 100 ml; T3: adding Kojic acid at (0.06 g/L) T4: adding sodium alginate at (0.6 mg/mL)T5: adding a combin</p> ... Show More
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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Preparation of superposed thin film (CdTe)1-xSex / ZnS and Studying the Effect of Concentration on Some its Electrical Properties.
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Preparation of superposed thin film (CdTe)1-xSex / ZnS) with concentration of (x= 0.1, 0.3, 0.5) at a temperature of substrate (Ts= 80 0C) by using Thermal Vacuum Evaporation System. The measurement of X-ray diffraction shows that the compounds CdTe, ZnS, (CdTe)1-xSex and (CdTe)1-xSex / ZnS have a polycrystalline structure, the C-V characteristic shows that the capacitance degrease by increasing the concentration (x) in reverse bias, while the I-V characteristic shows the current dark (Id) increase in forward and reverse bias by increasing (x) and the photocurrent (Iph) increase in reverse bias by increasing the concentration (x), the values of photocurrent are greater than from the values of the dark current for all concentrations

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