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Thermochromic and opacity behaviors in vanadium dioxide nanofilms: a theoretical study
Abstract<p>Vanadium dioxide nanofilms are one of the most essential materials in electronic applications like smart windows. Therefore, studying and understanding the optical properties of such films is crucial to modify the parameters that control these properties. To this end, this work focuses on investigating the opacity as a function of the energy directed at the nanofilms with different thicknesses (1–100) nm. Effective mediator theories (EMTs), which are considered as the application of Bruggeman’s formalism and the Looyenga mixing rule, have been used to estimate the dielectric constant of VO<sub>2</sub> nanofilms. The results show different opacity behaviors at different wavelength ranges (ultraviolet, visible, and infrared). The results depict that the highest opacity of the insulating phase is achieved at the ultraviolet region and it reduces for the metal phase. Besides, the results demonstrate that the opacity possesses a redshift during the changes at the three phases. Regarding the infrared region, the lowest opacity value is achieved at the insulator phase and it increases to the highest value at the metal phase. In the visible region, the opacity behavior remains similar in the three phases. It is worth noting that the lowest opacity is found for thinner nanofilm. Since both the refractive index and the extinction index are among the most essential optical constants, hence, both of them were compared with the experiment results, and an excellent agreement is achieved between them.</p>
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Publication Date
Tue Jan 02 2007
Journal Name
Journal Of The Faculty Of Medicine Baghdad
DNA content of Spermatozoa with respect to Seminal Sperm Concentration using a Microchemical Spectrophotometric Method

Background: To determine the DNA content in subfertile patients and to correlate it with seminal sperm concentration.
Design: Prospective observational study.
Setting: College of Medicine, Dept. of Physiological chemistry and Institute for embryo Research and infertility treatment-University of Baghdad.The study was conducted
through years 2004-2005.
Methods: A random sample of 61 subfertile male patients undergoing semen evaluation and aged from 20-45 years were studied. Semen samples were assessed for seminal sperm
concentration microscopically and were classified into 3 different groups according to count (million/ml).Then sperm D N A content (μg/ml) was estimated using a microchemical
spectropho

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Publication Date
Thu Jun 10 2010
Journal Name
Iraqi Journal Of Laser
Experimental Investigation of a Laser Wireless Video Communication System Using Intensity Modulated /Direct Detection Technique

In this work Laser wireless video communication system using intensity modualtion direct
detection IM/DD over a 1 km range between transmitter and receiver is experimentally investigated and
demonstrated. Beam expander and beam collimeter were implemented to collimete laser beam at the
transmitter and focus this beam at the receiver respectively. The results show that IM/DD communication
sysatem using laser diode is quite attractive for transmitting video signal. In this work signal to noise
ratio (S/N) higher than 20 dB is achieved in this work.

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Publication Date
Thu Aug 20 2020
Journal Name
Arab World English Journal
Investigating the Effectiveness of YouTube as a Learning Tool among EFL Students at Baghdad University

YouTube is not just a platform that individuals share, upload, comment on videos; teachers and educators can utilize it to the best maximum so that students can have benefits. This study aims at investigating how active and influential YouTube can be in the educational process and how it is beneficial for language teachers to enhance the skills of students. The study demonstrates different theoretical frameworks that tackle the employment of technology to enhance the learning/teaching process. It relies on the strategies of Berk (2009) for using multimedia media, video clips in particular to develop the abilities of teachers for using technology in classrooms. To achieve the objective of the study, the researchers develop a questionnair

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Publication Date
Tue Nov 09 2021
Journal Name
Abu Dhabi International Petroleum Exhibition & Conference
Numerical Simulation of Gas Lift Optimization Using Artificial Intelligence for a Middle Eastern Oil Field
Abstract<p>Artificial lift techniques are a highly effective solution to aid the deterioration of the production especially for mature oil fields, gas lift is one of the oldest and most applied artificial lift methods especially for large oil fields, the gas that is required for injection is quite scarce and expensive resource, optimally allocating the injection rate in each well is a high importance task and not easily applicable. Conventional methods faced some major problems in solving this problem in a network with large number of wells, multi-constrains, multi-objectives, and limited amount of gas. This paper focuses on utilizing the Genetic Algorithm (GA) as a gas lift optimization algorit</p> ... Show More
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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
On The Dynamical Behavior of a Prey-Predator Model With The Effect of Periodic Forcing

The dynamical behavior of a two-dimensional continuous time dynamical system describing by a prey predator model is investigated. By means of constructing suitable Lyapunov functional, sufficient condition is derived for the global asymptotic stability of the positive equilibrium of the system. The Hopf bifurcation analysis is carried out. The numerical simulations are used to study the effect of periodic forcing in two different parameters. The results of simulations show that the model under the effects of periodic forcing in two different parameters, with or without phase difference, could exhibit chaotic dynamics for realistic and biologically feasible parametric values.

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Publication Date
Thu Oct 01 2020
Journal Name
Chemical Engineering And Processing - Process Intensification
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Publication Date
Sun Jun 07 2015
Journal Name
Baghdad Science Journal
A Solution of Second Kind Volterra Integral Equations Using Third Order Non-Polynomial Spline Function

In this paper, third order non-polynomial spline function is used to solve 2nd kind Volterra integral equations. Numerical examples are presented to illustrate the applications of this method, and to compare the computed results with other known methods.

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Publication Date
Tue Dec 25 2018
Journal Name
Summaries Of Working Papers, Research And Experiments
Publication Date
Tue Feb 13 2024
Journal Name
Iraqi Journal Of Science
Stability Analysis of A stage Structure Prey-Predator Model with Hollimg Type IV Functional Response

In this paper a stage structure prey-predator model with Hollimg type IV functional response is proposed and analyzed. The local stability analysis of the system is carried out. The occurrence of a simple Hopf bifurcation and local bifurcation are investigated. The global dynamics of the system is investigated with the help of the Lyapunov function. Finally, the analytical obtained results are supported with numerical simulation and the effects of parameters system are discussed. It is observed that, the system has either stable point or periodic dynamics.

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Publication Date
Sat Sep 30 2023
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Removal of Lead Ions from Wastewater by using a Local Adsorbent from Charring Tea Wastes

   Adsorption of lead ions from wastewater by native agricultural waste, precisely tea waste. After the activation and carbonization of tea waste, there was a substantial improvement in surface area and other physical characteristics which include density, bulk density, and porosity. FTIR analysis indicates that the functional groups in tea waste adsorbent are aromatic and carboxylic. It can be concluded that the tea waste could be a good sorbent for the removal of Lead ions from wastewater. Different dosages of the adsorbents were used in the batch studies. A random series of experiments indicated a removal degree efficiency of lead reaching (95 %) at 5 ppm optimum concentration, with adsorbents R2 =97.75% for tea. Three mo

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