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.
Summary: The study focused on the role of the educational counselor in schools, as an integral part of the educational system that faces multiple challenges and difficulties. In this context, the counselor’s role becomes crucial in attempting to reduce or eliminate such difficulties, in addition to guiding students in an appropriate manner. Methodes: The study employed a descriptive field approach, using interviews and direct observation as tools to examine the actual role performed by school counselors. Results: The study concluded with several key findings, most notably the numerous challenges faced by counselors, including students’ negative behaviors, school dropouts, and the limited administrative support for counselors’ work. Fu
... Show MoreThis research aims to find out "the effectiveness of the self-questioning strategy in the achievement of students Phase III institutes of teacher preparation and decision-making in chemistry." The researcher follows approach quasi-experimental with a post-test, and the sample consisted of (27) from " Teachers Training Institute-AL-Byaa "in Directorate of Education Baghdad Karkh / 2 students divided into two unequal groups: experimental its number (14) students studied using reciprocal teaching strategy and control its number (13) students have studied in the usual way.The two groups were equivalent extraneous variables.
The researcher was prepare achievement test consist of 40 items was the adoption of a measure of decision-makin
... Show MoreThe present paper focuses on examining the style of both the civilized dialogue of Prophet Hud (PBUH) in the Glorious Qur'an, and the debated dialogue of Aad’s people. The study consists of an introduction which shows the importance of the civilized dialogue and its significant impact on containing, accepting, and persuading the other in peaceful ways without intolerance and violence. Then, the conditions and techniques of the civilized dialogue and its types have been mentioned. This is followed by the practical side of the study, which involves examining stylistically the techniques used in Hud’s (PBUH) civilized dialogue to be invested later in people’s future conversations. It is also concerned with investigating stylistically
... Show MoreThe occurrence of two species of the genus Myxobolus Bütschli, 1882 (Myxozoa: Myxosporea) for the first time in Iraq from freshwater fishes.
Is a high degree of economic freedom an important part in the development of the economies of developing countries in the last decade of the twentieth century and the beginning of the twentieth century and the atheist. This is because a test subject (deltoid analysis of the relationship between the degree of economic freedom and foreign trade of selected developing countries for the period
( 1990 -2005) to determine the degree of economic freedom in foreign trade promotion in Singapore and Turkey. The research recommends a number of recommendations, the most important is the responsibility of the Ministry of Planning in Iraq that is providing the necessary data for the Fraser Institute, the aim of increasing cooperation
Abstract
quality issue is the only issue the interesting in recent years of the last century, but also came out of sync with the other issue is the issue of environment, Where they have become represent two sides of one currency, challenges faced by the world and raised by the environmental problems have made industrial organizations pay great attention to the environment by improving their environmental performance, and that's where the oil industry is one of the most dangerous industries, influential and damaging to the environment due to the organizations move away from oil for adoption The application of EMS then a tool to improve environmental performance has been chosen sam
... Show MoreThe present study discusses one of the most relevant and required topics in the recent period during globalization, the modern Russian system of terms for the oil and gas industry as a whole acquired a complete form in the second half of the twentieth century. The period of the late XX - early XXI centuries. marked by cardinal transformations in all areas of the political, economic, social and cultural life of Russia. These changes could not but affect industrial production. Transition to a new vector of development of the Russian economy based on the development of commercial trade, on the change and improvement of the development of industrial enterprises in the context of the implementation of national projects and the introduction
... Show MoreThe study consisted in the development and use of a practical method to detect and
monitor, analyze and produce maps of changes in land use and land cover in the district of
Mahmudiya in Baghdad during the period 1990-2007 using the applications of remote sensing
techniques and with the assisstant of geographic information systems (GIS),as a valuable
contribution to land degradation studies.
This study is based maiuly on the processing on two subsets of landsat5 TM images picked up
in August 1990 and 2007 respectively in order to facilitate comparision and were thengeometrically and radiometrcally calibrated ,to used for digital classification purposes using
maximum liklihoods classification or six spectral bands of
Citizenship education is the effective educational tool in building a citizen who is able to participate in building his country. This can only come through the educational efforts that teachers make in the classroom. Such a step requires teachers to have knowledge of citizenship education, its principles, and the foundations for its development. Thus, the study aims to examine the degree of social studies teachers' knowledge of the dimensions of citizenship education at the basic education schools in the Sultanate of Oman. It also aims to examine its relationship with a set of variables. The researchers used the quantitative descriptive approach to achieve the objectives of the study. It further adopted a test tool, which consisted in i
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