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.
Fire is the most sever environmental condition affecting on concrete structures, thus investigating for fire safet, IJSR, Call for Papers, Online Journal
In Iraq, water shortages and drought, especially during the hot summer months, necessitates that municipal authorities adopt water reuse projects like reusing treated domestic wastewater for crop irrigation. This work gives the conceptual and basic design elements for the necessary steps of filtration, UV irradiation and chlorination to make such a wastewater fit for agricultural use. A typical rural community of 50,000 people is considered as an example case for which functionality and relative simplicity of the proposed designs are prime factors. The objectives are 1) to show what is required and 2) that the presented information may be utilized to embark on the following phases of detailed design and execution of such projects.
Indium oxide In2O3 thin films fabricated using thermal evaporation of indium metal in vacuum on a glass substrate at 25oC using array mask, after deposition the indium films have been subjected to thermal oxidation at temperature 400 °C for 1h. The results of prepared Indium oxide reveal the oxidation method as a strong effect on the morphology and optical properties of the samples as fabricated. The band gap (Eg) of In2O3 films at 400 °C is 2.7 eV. Then, SEM and XRD measurements are also used to investigate the morphology and structure of the indium oxide In2O3 thin films. The antimicrobial activity of indium oxide In2O3 thin films was assessed against gram-negative bacterium using inhibition zone of bacteria which improved higher ina
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Problem of the research:
The studies and researches have noticed the aggravation of violence practice in all educational means using different and innovated styles against children in the school and house in order to upbringing by the parents or the school .
It is a training method for the person to participate in the society and prepare him to be an effective member.
The current research confines the children in age (6-12) years old representing the primary stage who face different kind of violence during the familiar or school education.
The current research aims to:
1 – The kinds of violence which happens to the children in the primary
... Show MoreMany of the signs that the global energy system indicate the start of a period of transition from total dependence on fossil energy sources, especially oil, into a new era in which alternative energy sources play an important role in meeting the growing needs of energy demand, so sought many of the developed countries through research the studies carried out to try to bring renewable energy sources and non-renewable (shale oil, oil sands, solar energy, wind energy .... etc) replace traditional fossil energy sources (oil, gas, coal) and despite the recent availability dramatically and spread throughout the the world, but they are going to dry up in the foreseeable future. So many countries, especially the developed sought to find
... Show MoreThe loose sand is subject to large settlement when it is exposed to high stresses. This settlement is due to the nature of the high drainage of sand, which displays foundations and constructions to a large danger. The densification of loose sandy soils is required to provide sufficient bearing capacity for the structures. Thus soil stabilization is used to avoid failure in the facilities. Traditional methods of stabilized sandy soil such as fly ash, bituminous, and cement often require an extended curing period. The use of polymers to stabilize sandy soils is more extensive nowadays because it does not require a long curing time in addition to being chemically stable. In this study, the effect of adding different percent
... Show MoreThis research aims to test the effect of strategic cohesion with its dimensions (organizational excitement, organizational casting, organizational synergy) as an independent variable on administrative excellence as a dependent variable in the Ministry of Planning, and through surveying several employees (general managers, heads of departments, and units managers). As a research community, and based on the importance of the research topic in the aforementioned research community. The researchers have adopted the descriptive-analytical using the questionnaire as the main data collection. 155 questionnaires were distributed, yet,114 of them were retrieved and 110 were used for final statistical analysis. The researchers used the relev
... Show MoreThe internationalization of the Libyan crisis and its accompanying militarization of the conflict have played a vital role in hindering to reach a comprehensive political settlement solution in Libya. The increasing international greediness in the Libyan energy resources and the geopolitical importance of the Libyan State led to the involvement of many international and regional powers in this crisis and transformed the Libyan crisis into “proxy war”. Moreover, the Turkish direct military intervention in the Libyan crisis is considered as one of the main constraints facing the international and regional efforts to settle the Libyan crisis as a result of the Turkish insistence on its military existence in Libya to preserve i
... Show MoreThe higher education has become an enterprise integrate system that described as knowledge society, the essential part in its electronic and virtual format in the shadow of globalization challenges with its various dimensions . Until the logical ryles aboat a strategic partnership between the Iraqi higher education establishments and their international equivalent ones Strategic windows should be invested for the purpose of enhancing the quality of higher education in a sustainable way. This forms a challenge before the international education leaders on the social, operational and establishment's level to determinte knowledge gap, observing, diagnosing and processing in the present and future, e
... Show MoreIncreasing world demand for renewable energy resources as wind energy was one of the goals behind research optimization of energy production from wind farms. Wake is one of the important phenomena in this field. This paper focuses on understanding the effect of angle of attack (α) on wake characteristics behind single horizontal axis wind turbines (HAWT). This was done by design three rotors different from each other in value of α used in the rotor design process. Values of α were (4.8˚,9.5˚,19˚). The numerical simulations were conducted using Ansys Workbench 19- Fluent code; the used turbulence model was (k-ω SST). The results showed that best value for extracted wind energy was at α=19˚, spread distance of wak
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