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Dispersion in a Gas Filled Hollow Core Photonic Crystal Fiber
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Hollow core photonic bandgap fibers provide a new geometry for the realization and enhancement of many nonlinear optical effects. Such fibers offer novel guidance and dispersion properties that provide an advantage over conventional fibers for various applications. Dispersion, which expresses the variation with wavelength of the guided-mode group velocity, is one of the most important properties of optical fibers. Photonic crystal fibers (PCFs) offer much larger flexibility than conventional fibers with respect to tailoring of the dispersion curve. This is partly due to the large refractive-index contrast available in the silica/air microstructures, and partly due to the possibility of making complex refractive-index structure over the fiber cross section. In this paper the fundamental physical mechanism has been discussed determining the dispersion properties of PCFs, and the dispersion in a gas filled hollow core photonic crystal fiber has been calculated. We calculate the dispersion of air filled hollow core photonic crystal fiber, also calculate the dispersion of N2 gas filled hollow core photonic crystal fiber and finally we calculate the dispersion of He gas filled hollow core photonic crystal fiber.

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Publication Date
Sun Nov 20 2022
Journal Name
Journal Of Optics
Good cleavers for fiber-optic communication technology
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Fiber optics technology has shown immense applications in the areas of medicine, telecommunication, and imaging. For these particular applications, it requires fibers with precise cleaving. In this paper, we will demonstrate a quick, simple and efficient cleaving method that can result in a high-quality fiber surface that works well for many fiber-optic applications. The smooth tip and good surface quality obtained on the cleaved surface of optical fiber is demonstrated by using a microscope imaging system and was flat surface with a 900 angle for perpendicular cleavages. The precision cleaver provides smooth and high-quality cleaves on single-fiber surfaces as opposed to the ruby scribe pen. The defects that may occur during the cleaving p

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Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Characteristics of Zinc Oxide Film Prepared by Chemical Spray Deposition as a Gas Sensor
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Zinc oxide thin films were deposited by chemical spray pyrolysis onto glass substrates which are held at a temperature of 673 K. Some structural, electrical, optical and gas sensing properties of films were studied. The resistance of ZnO thin film exhibits a change of magnitude as the ambient gas is cycled from air to oxygen and nitrogen dioxide

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Publication Date
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
Core competencies and Their Role in Enhancing Organizational flexibility: An Analytical Study of the Views of a Sample of Employees in Presidency University of Mosul
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Abstract

The study aims to identify the levels of core competencies dimensions and types of organizational flexibility in the investigated organization, as well as to determine the nature of the relationship and the impact of core competencies dimensions with the process of organizational flexibility. Thus, a number of research questions were presented to express the research problem as follows:

  • What is the level of the investigated individuals' awareness to core competencies and organizational flexibility across their dimensions and types in the investigated organization?
  • To what extent are core competencies and organizational flexibility available in the Organiz

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Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
The role of knowledge management strategies in building core competenciesAn exploratory study of the views of a sample of managersOffice of Financial Supervision in Iraq
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The strategies of knowledge management have became the basis in the promotion of core competencies. Therefore gained an increasing prominence. This led the administrations of organizations to work to effectiveness of there strategies, which results to build there core competences through teamwork, empowerment and personal effectiveness of employees. From this arises research problem about the  organizations leaders recognize extent of knowledge management strategies which that lead to core competence. In addition the research tray definition the relation and nature of affect between its variables. The research was carried on sample (72) managers from board of supreme audit in Iraq and used statistical tools and methods.

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Publication Date
Fri Oct 19 2018
Journal Name
Journal Of Economics And Administrative Sciences
"The Effect of Organizational Power Top Management Resources in Building Core Competencies: Analytical Research
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The problem of the current research as the Iraqi Drilling Company suffers from the many challenges facing its work as a result of the current conditions in Iraq and the subsequent changes in the policies of the State Which left an impact on its activities and objectives, which created pressure on the importance of an organizational power capable of diagnosing the core competencies and development and maintain them to contribute to the raising and success in the performance of the company. The researchers adopted the method of analytical research and adopted the questionnaire as a main tool in the collection of research data and information . It was distributed to a community of (140) individuals from the low mana

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Publication Date
Sun Apr 30 2023
Journal Name
Al-kindy College Medical Journal
Ultrasound Guided Core Needle Biopsy in The Diagnosis of Suspicious Breast Lesions: Radiologist’s perspectives
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Background: Ultrasound guided core needle biopsy is becoming a gold standard in the work up of suspicious breast lesion. In Iraq, radiologists are not taking the lead in core needle biopsy performance.

Objectives: To evaluate the radiologist performance of core needle biopsy highlighting the precession and accuracy of the procedure, the concordance of ultrasound and histopathology, and identifying challenges facing the radiologist during the procedure.

Subjects and Methods: A prospective study involving a total of 50 patients with ultrasound (US) BIRADS IV or V.  Ultrasound guided core needle biopsy was performed for each patient. Surgical pathol

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Publication Date
Fri Aug 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Types of the Fiber Glass-Mat on Fatigue Characteristic of Composite Materials at Constant Fiber Volume Fraction: Experimental Determination
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The aim of this work is to study the influence of the type of fiber glass –mat on fatigue behavior of composite material which is manufactured from polyester and E-glass (woven roving, chopped strand mat (CSM)) as a laminate with a constant fiber volume fraction (VF) of 33%. The results showed that the laminates reinforced with E-glass (woven roving) [0/90, ±45.0/90] and [0/90, CSM, 0/90] have lower fatigue strength than the laminates reinforced with E-glass [0/90]3,[CSM]3 and [CSM, 0/90, CSM]  although they had different tensile strength; the best laminate was [0/90]3 .

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Publication Date
Fri Mar 31 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Micro encapsulation of Naproxen By Complex Coacervation and Aqueous Colloid Dispersion Part ( 1 )
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Naproxen is a non steroidal anti inflammatory and antipyretic drug which has local irritation effect  on  the  stomach, and  unpleasant taste,  besides bad   flowability and light sensitivity .The drug was prepared as microcapsules by complex coacervation method using acacia-gelatin coating materials , and aqueous colloid polymer dispersion method ( ACPD ), using ethyl cellulose and sodium alginate coating materials . The results indicated that microcapsules prepared by 2:1  core:wall ratio is the best for both methods, with an average encapsulation efficiency (75%) and avarege yield (90%) .

Moreover the drug release was affected mainly by core : ratio ,pH enviroment and method of microenca

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Publication Date
Tue Sep 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Characterization of Metal Dispersion of Some Naphtha Reforming Catalysts by Methylcyclohexane Dehydrogenation Reaction
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The dispersion of supported Pt and Pt–Ir reforming catalysts have been studied, after treatment with oxidative and reducing atmosphere. Methylcyclohexane dehydrogenation reaction in the absence of hydrogen was used as a test reaction. An attempt was made to relate the behavior of the catalysts upon subject to reaction, to the dispersion of the same type of catalysts upon treatment with similar atmosphere and temperatures which appeared in literature. The total conversion of reaction can be explained by a change in metal dispersion. Thus, methylcyclohexane dehydrogenation reaction appears to be a really “structure sensitive” reaction.

      The toluene yield increases as the oxidation temperature i

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Publication Date
Sun Jun 21 2020
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Enhancement of Aqueous Solubility and Dissolution Rate of Etoricoxib by Solid Dispersion Technique
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Etoricoxib (EXB) is a highly selective cox-2 inhibitor which belongs to the non-steroidal anti-inflammatory drug (NSAID). EXB is a class II drug according to the biopharmaceutical classification system (BCS), which possess a very low aqueous solubility in water.  In the present study, many trials were made to improve the aqueous solubility and dissolution rate of EXB by solid dispersion technique.

Eighteenth EXB formulas were formulated as a solid dispersion using a variety of hydrophilic polymers (as carriers)   including poloxamer 407 (PXM 407), poloxamer 188 (PXM 188) and polyethylene glycol 4000 (PEG 4000) at different drug: polymer ratios (1:1, 1:3 and 1:5). These formulas were prepared by two methods; solvent

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