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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
Sat Apr 09 2016
Journal Name
Photonic Sensors
Parametric Analysis of NO2 Gas Sensor Based on Carbon Nanotubes
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Publication Date
Fri Jun 30 2017
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Study the Performance of Nanozeolite NaA on CO2 Gas Uptake
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The adsorption isotherms and kinetic uptakes of CO2 were measured. Adsorption isotherms were measured at two temperatures 309 K and 333 K and over a pressure range of 1 to 7 bar. Experimental data of CO2 adsorption isotherms were modeled using Langmuir, Freundlich and Temkin. Based on coefficient of correlation it was found that Langmuir isotherm model was well suited with the experimental data of CO2 adsorption isotherms.  In addition, Adsorption kinetic of CO2 mixture with N2 containing 10 % by volume CO2 and 90 % by volume N2 were determined in a temperature 36 °C and under the atmospheric pressure .When the flow rate was increased from

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Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
Employment of Titanium dioxide thin film on NO2 gas sensing
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Abstract<p>TiO<sub>2</sub> thin films were deposited by Spray Pyrolysis with thickness ((350±25) nm) onto glass substrates at (350°C), and the film was annealed at temperatures (400 and 500)°C. The structural and morphological properties of the thin films (TiO<sub>2</sub>) were investigated by X-ray diffraction, Field emission scanning electron microscopy and atomic force microscope. The gas sensor fabricated by evaporating aluminum electrodes using the annealed TiO<sub>2</sub> thin films as an active material. The sensitivity of the sensors was determined by change the electrical resistance towards NO<sub>2</sub> at different working temperatures (200 </p> ... Show More
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Publication Date
Mon Jun 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Effect of Operating Cconditions on Hydrodesulfurization of Vacuum Gas Oil
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This study was conducted according to contract with the North Refineries Company-Baiji and deals with the hydrodesulphurization of vacuum gas oil of Kirkuk crude oil, boiling range 611-833 K. A trickle bed reactor packed with a commercial cobalt-molybdenum on alumina catalyst was used. The operating conditions were: temperature range 583-643 K, liquid hourly space velocity range 1.50-3.75 1/h, hydrogen to oil ratio about 250 l/l and pressure kept constant at 3.5MPa.
The results showed that the aromatic content decreased and sulfur removal increased with increasing temperature and decreasing space velocity. The properties (viscosity, density, flash point and carbon residue) of the products decrease with temperature increasing, but the

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Publication Date
Sun Feb 03 2019
Journal Name
Iraqi Journal Of Physics
Enhanced hydrogen gas sensitivity employing sputtered deposited NiO thin films
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Publication Date
Tue Mar 20 2018
Journal Name
Offshore Technology Conference Asia
Prediction of Hydrate Phase Equilibrium Conditions for Different Gas Mixtures
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Abstract<p>Gas hydrate formation poses a significant threat to the production, processing, and transportation of natural gas. Accurate predictions of gas hydrate equilibrium conditions are essential for designing the gas production systems at safe operating conditions and mitigating the problems caused by hydrates formation. A new hydrate correlation for predicting gas hydrate equilibrium conditions was obtained for different gas mixtures containing methane, nitrogen and carbon dioxide. The new correlation is proposed for a pressure range of 1.7-330 MPa, a temperature range of 273-320 K, and for gas mixtures with specific gravity range of 0.553 to 1. The nonlinear regression technique was applie</p> ... Show More
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Publication Date
Wed Feb 20 2019
Journal Name
Iraqi Journal Of Physics
The effect of volume fraction on the fatigue strength of unsaturated polyester / glass fiber composite
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 In this work polymeric composites were done from unsaturated polyester as a matrix reinforced with glass fiber type (E-glass) with two different volume fraction 20% & 40%. Fatigue tests showed that the number of fatigue cycles to failure limit for samples reinforced with uniform (woven Roving 0-90°) E-glass fiber and random (continuous fibers) with volume fraction 40% more than that for the same samples with volume fraction 20%. Also the fatigue results showed that the uniform samples failed with fatigue cycles more than that of random.

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Publication Date
Mon Mar 27 2023
Journal Name
8th Engineering And 2nd International Conference For College Of Engineering – University Of Baghdad: Coec8-2021 Proceedings
Experimental study of natural convection heat transfer on an enclosure partially filled porous medium heated from below by constant heat flux
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This study reports on natural convection heat transfer in a square enclosure of length (L=20 cm) with a saturated porous medium (solid glass beads) having same fluid (air) at lower horizontal layer and free air fill in the rest of the cavity's space. The experimental work has been performed under the effects of heating from bottom by constant heat flux q=150,300,450,600 W/m2 for four porous layers thickness Hp (2.5,5,7.5,1) cm and three heaters length δ(20,14,7) cm. The top enclosure wall was good insulated and the two side walls were symmetrically cooled at constant temperature. Four layers of porous media with small porosity, Rayleigh number range (60.354 - 241.41) and (Da) 3.025x10-8 has been investigated. The obtained data of temperatu

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Publication Date
Fri Jan 01 2021
Journal Name
Materials Today: Proceedings
Structural performance of fiber-reinforced lightweight concrete slabs with expanded clay aggregate
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Publication Date
Thu Dec 13 2018
Journal Name
International Journal Of Engineering &amp; Technology
Effect of Steel Fiber on Properties of High Performance No-Fine Concrete
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No-fine concrete (NFC) is cellular concrete and it’s light weight concrete produced with the exclusion of sand from the concrete. This study includes the mechanical properties of lightweight reinforced by steel fiber, containing different proportions of steel fiber. This study was done using number of tests. These tests were density, compressive strength, flexural strength and absorption. These tests of the molds at different curing time. The results of tests that implication of fiber to No. fine concrete did not affect significantly on the compressive strength, While the flexural strength were gets better. Results explained that, the flexural strength of (1%) fiber No- fine concrete molds are four times that of the reference mold

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