Bending effects on the transmission of optical signal are investigated on a single mode
optical fiber (SMOF) of 10 m length, core radius of 5 μm and optical refractive index difference
0.003. The bending radii (R) were between 0.08 and 0.0015 m. A great decrease in the amplitude is
shown for radii below 0.01 m. Sudden break down occurs for radii less than 0.0015 m. Birefringence
(B) is difficult to measure for long fibers. Meanwhile, B was found by comparing with calibrated
fiber of the same properties but of length of 0.075 m. The results show an increase in propagation
constant (Δβ) and the decrease in beat length (Lb), and show that bending decreases the critical radius
of curvature (Rc) related to B. The changes induced on the initial phase of the signal are shown for
bending curvatures of radii 0.06, 0.03 and 0.005 m. The linear phase retardation is found to increase
more rapidly for bends of R< 0.05 m. The degree of polarization decreases smoothly for bends of
R>0.01m. Below this curvature, the fluctuation and great instability in the polarization- state of the
output signal are easily detected. All these features are very important in using SMOF in sensitive
optical devices especially in long distance fiber communications.
Abstract
The research aims to investigate the private sector attitudes toward operational contracting in special education schools. The research adopted the qualitative approach by using personal interviews with a sample of (45) private school owners and managers in Oman. The results of the research revealed that there is an agreement among the majority of respondents on the ability of the private sector to manage special education schools, the advantages of the partnership, as well as the need for guarantees to support this partnership. The government should fully assume it. The role of the private sector remains to raise the operational efficiency of schools. Opinions vary about the level of powers granted to t
... Show MoreAbstract. In this research, the uranium concentration in (16) water samples collected from some agricultural areas surrounded with AlTuwitha nuclear site in Baghdad-Iraq was measured by using a CR-39 detector. The concentration of uranium in this study was from (0.6 ± 0.33mg/l) to (2.51 ± 0.49 mg/l), and the weighted average for the concentrations (1.262 ± 0.402 mg/l). The results showed it is a concentration of uranium level in water samples studied is higher than the allowed limit recommended by WHO and ICRP.
"The aim of the research is to identify the availability of the dimensions of the research variables represented by organizational symmetry and the quality of work-life at the University of Information and Communications Technology, which is one of the formations of the Ministry of Higher Education and Scientific Research in Baghdad, in addition to knowing the relationship and influence between them. The research relied on the descriptive analytical approach based on peer description. The research was analyzed and the research sample consisted of (148) individuals, the sample was chosen using the comprehensive inventory method, data was obtained by relying on the questionnaire which was prepared from ready-made m
... Show MoreIn this research, radon concentrations in some types of healthy drinking water samples available in Iraq's market were measured using a technique called Durridge RAD-7-H2O with closed loop. Then the rate of annual effective dose in human taken this water is determined.
It was found that, radon concentrations in studied samples ranged between 1.2 Bq.m-3 to 142 Bq.m-3. The results of the radon concentrations and the rate of annual effective dose for drinking water samples were significantly lower than the USEPA and WHO recommended limits that equal 500 Bq/m3 and 1 mSv/y resp
... Show MoreThis research aimed to diagnose the perception based on Telecommunications of Iraq to the importance of activating knowledge management marketing in possession, as well as Indication of impediments to activate the management of marketing knowledge in the researched companies, also aimed to show the extent of the existence of significant differences in perception based on Telecommunications Iraqi importance of activating the management marketing knowledge in possession. To achieve the objectives of this research, the questionnaire was developed and distributed to a sample of telecommunications companies in the city of Sulaimaniya, was selected on the criterion according to the company's life in terms of seniority in the telecommunication
... Show MoreThe study aims to identify the uses and the impact of social networking applications and websites on stock markets and their role in defining the details of dealing with stock movement and trading. The study also aims to highlight the role of these networks by increasing confidence in stock markets and companies as well as encouraging and inciting young people to invest in these markets, the study belongs to the descriptive analytical approach, the study population consisted of all current and potential investors in the stock and financial markets in the United Arab Emirates. The study used a questionnaire that was distributed to a number of followers of social networking pages and websites that deal with trading
... Show Morekindergarten teacher is one of the fundamental pillars upon which the kindergarten environment so that exposure to a number of problems that could affect its functioning in addition to any deficiencies in this environment leads to deprive a child of some activities and acquisition of concepts so the researcher studying the problems of working in kindergartens from the perspective of the parameters, so the researcher based measuring instrument for labour problems of (30) search sample was paragraph (50) parameter that was chosen at random and have been extracted Sincerity and strength tool researcher used statistical methods and discriminatory (Pearson correlation coefficient, t
... Show MoreAbraham son of Izra, the poet, the philosopher, the grammarian, and the Turah exegesis, is considered one of the famous poets in the era of Islamic reign in Spain which is called the "Golden Era". He was taught all types of teaching which was rich in Jewish literary products. He learned Arabic and studied Arabic language and literature. He travelled a lot, and made tours within Spanish places, and even reached the North of Africa. He preferred living with Muslim rulers in the south of Spain, like the rest of the Jews who emigrated from the north of Spain to the South in search for freedom and to participate in higher positions of the Islamic Palace. He was influenced by Arabic culture, and even translated "Th
... Show MoreTourist business organizations face a challenging and the risks dynamic environment reflected its impact on the community and generate extra under pressure in the responsibilities and burdens of exceptional and affected much of factors, accidents and risks as a result of the actions and attitudes of disasters variety may exceed the geography of States border, which requires the absorption of risks facing the tourism and how to manage and deal with them scientific and reasonable grounds for the diagnosis and treatment of risk and how to reduce the aggravation and the different kinds.
As risks affecting the most important and vital to organizations as a tourist aspects of the market share and styles tourist
... Show MoreThe current study aims to identify:The meta-motivation and Uniqueness seeking of the study sample. The correlated relationship among them. The present study sample consists of (400) students from the colleges of engineering, University of Baghdad, and the University of Technology in the academic year (2019-2020), and the researcher has adopted the Chen Scale (1995)to measure the meta-motivation after its translation into Arabic by(Al-Samawi,2011).The scale includes six dimensions. The researcher has also adopted the Snyder&Fromkin scale (1980) to measure the uniqueness seeking after translating and adapting it into the Arabic environment. The scale consists of three dimensions. The results show that students of the Facult
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