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Confinement factor and carrier recombination of InGaAsP/InP quantum well lasers
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Low-dimensional materials have attracted significant attention in developing and enhancing the performance of quantum well lasers due to their extraordinary unique properties. The optical confinement factor is one of the most effective parameters for evaluating the optimal performance of a semiconductor laser diode when used to measure the optical gain and current threshold. The optical confinement factor and the radiative recombination of single quantum wells (SQW) and multi-quantum wells (MQW) for InGaAsP/InP have been theoretically studied using both radiative and Auger coefficients. Quantum well width, barrier width, and number of quantum wells were all looked at to see how these things changed the optical confinement factor and radiative and non-radiative recombination coefficients for multi-quantum well structures. It was found that the optical confinement factor increases with an increase in the number of wells. The largest value of the optical confinement factor was determined when the number of wells was five at any width. The optical confinement coefficient was 0.23, 0.216, and 0.203 for the number of wells (3, 4, and 5) and well width (27, 19.5, and 15) nm, respectively. In addition, the radiative recombination coefficient increases with the width of the quantum well after 5 nm, and it is much bigger than that of its bulk counterparts.

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Publication Date
Thu Oct 10 2019
Journal Name
Journal Of The College Of Education For Women
Constitutional Review of 1992 and 1996 and the role of the Party of Progress and Socialism
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Constitutional Review of 1992 and 1996 and the role of the Party of Progress and Socialism

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Publication Date
Fri Jun 01 2012
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Phenomena of corruption and money laundering: and causes and risks and their role in the financing of terrorism in Iraq and finding ways of treatment
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Iraq  is Suffering nowadays from the criminal triad represented by the fiscal and administrative corruption, money laundering and terrorism, which are intertwined in a very related relations, as each of them support the other . Since the over growth has been one of its characteristics leaving behind a very dangerous negative effects whether it was social , economic or even political impacts . As a result , this trial is now represents a high risk that threatens the present and the future of Iraq . On the political , economic and social level , it is well to mention that the poor direct investment , the increasing rates of poverty , unemployment , inflation as well as the smuggling of goreign currency an

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Publication Date
Sun Mar 01 2009
Journal Name
Baghdad Science Journal
The structure and optical properties of CdSe:Cu Thin Films
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A polycrystalline CdSe thin films doped with (5wt%) of Cu was fabricated using vacuum evaporation technique in the substrate temperature range(Ts=RT-250)oC on glass substrates of the thickness(0.8?m). The structure of these films are determined by X-ray diffraction (XRD). The X-ray diffraction studies shows that the structure is polycrystalline with hexagonal structure, and there are strong peaks at the direction (200) at (Ts=RT-150) oC, while at higher substrate temperature(Ts=150-250) oC the structure is single crystal. The optical properties as a function of Ts were studied. The absorption, transmission, and reflection has been studied, The optical energy gap (Eg)increases with increase of substrate temperature from (1.65

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Publication Date
Sun Jun 01 2025
Journal Name
Chalcogenide Letters
Fabrication and characterization of Se66S44-xAsx thin films chalcogenide
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In this paper, the effect of sulfur substitution by arsenic on the structural, optical properties of thin films of the trivalent chalcogenide Se66S44-xAsx at different concentrations (where x = 0, 8, 16, and 24 at %) was studied. Thin films with a thickness of (300±10 nm) were prepared using thermal evaporation of bulk samples. Structural examinations were performed using XRD and AFM techniques. All the studied film samples were amorphous in structure and the intensity of the crystalline parts was high in the range of 10-40. Also, in Atomic Force Microscopy (AFM). It was found that increasing the concentration of arsenic affects the structural parameters such as surface roughness, particle density, and average grain size. As the ar

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Publication Date
Sun Sep 04 2016
Journal Name
Baghdad Science Journal
Studying The Optical Properties of CdO and CdO: Bi Thin Films
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Cadmium Oxide and Bi doped Cadmium Oxide thin films are prepared by using the chemical spray pyrolysis technique a glass substrate at a temperature of (400?C) with volumetric concentration (2,4)%. The thickness of all prepared films is about (400±20) nm. Transmittance and Absorbance spectra are recorded in the wave length ranged (400-800) nm. The nature of electronic transitions is determined, it is found out that these films have directly allowed transition with an optical energy gap of (2.37( eV for CdO and ) 2.59, 2.62) eV for (2% ,4%) Bi doped CdO respectively. The optical constants have been evaluated before and after doping.

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Publication Date
Thu Jan 17 2019
Journal Name
Plant Archives
EFFECT OF ANTI-STRESS ON THE GROWTH AND YIELD OF SWEET AND HOT PEPPERS AND ITS CONTENT OF PEROXIDASE AND IAA
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MS Elias, RGM AL-helfy, Plant Archives, 2019

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Scopus
Publication Date
Sun Jun 30 2013
Journal Name
Al-kindy College Medical Journal
Community and Individual Causes of Students Failure in Al Kindy College of Medicine 2012
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Bac kground:
Failure is the state or condition of not meeting a desirable or intended objective, and may be viewed as the opposite of success; students always have a question "Why did I get this grade. On the contrary success leads towards new sources of earning, in fact there are a lot of interacting factors play such extrinsic and extrinsic to reach success.
Objec t i ves :
To explore internal and external factors causing students failure in medical college and to reconnoiter factors improve academic performance.
Methods: A cross-sectional study, conducted in Al Kindy College of Medicine, for the period from November 8th 2012 to May 1st 2013. Formal ethical considerations were obtained about participation and methodology. A

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Publication Date
Tue Mar 01 2022
Journal Name
Iraqi Journal Of Physics
Effect of pH on the Structural and Optical Properties of Cadmium oxide Thin Films Prepared Using the Successive Ionic Layer Adsorption and Reaction (SILAR) Method
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Cadmium oxide (CdO) thin films were deposited using the sequencing ion layer adsorption and reaction (SILAR) method. In this study, the effect of the pH value of an aqueous solution of cadmium acetate at a concentration of 0.2 mol of the cadmium oxide film was determined. The solution source for the cadmium oxide film was cadmium ions and an aqueous ammonia solution. The CdO films were deposited on glass substrates at a temperature of 90 ℃. The cadmium oxide film thickness was determined by the weight difference method at pH values ​​(7.2, 8.2). X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that the size of the crystals increased with the increase in the solution (pH). While the UV-visible spectra of the fil

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Publication Date
Sun Mar 01 2020
Journal Name
Iraqi Journal Of Physics
Synthesis and spectroscopic study of highly fluorescent carbon dots derived from orange juice with Stilbene 420 dye
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Highly-fluorescent Carbon Quantum Dots (CQDs) are synthesized in simple step by hydrothermal carbonization method of natural precursor such as orange juice as a carbon source. Hydrothermal method for synthesized CQDs requires simple and inexpensive equipment and raw materials, thus this method are now common synthesis method. The prepared CQDs have ultrafine size up to few nanometers and   several features such as high solubility in water, low toxicity, high biocompatibility, photo-bleaching resistant, Chemical inertness and ease of functionalization which qualifies it for use in many applications such as bio-imaging, photo-labeling and photo-catalysis.

       This research demonstrates the

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Publication Date
Sun Sep 07 2014
Journal Name
Baghdad Science Journal
Design and study for transmitter system of laser Nd-YAG (1.06 ?m)
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In this research , design and study a (beam expander) for the Nd – YAG laser with (1.06 ?m) Wavelength has been studied at 5X zoom with narrow diversion in the room temperature. by using (ZEMAX) to study the system. Evaluate its performance via (ZEMAX) outputs, as bright Spot Diagram via (RMS), Ray Fan Plot, Geometric Encircled Energy and the value of Focal shift. Then study the effect of field of view on the outputs in the room temperature.

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