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 chang

The research aims to identify the meaning of drug addiction, which being one of the behavioral-deviation signs. It largely seems similar to alcohol-addiction. World health organization has defined drug addiction as a sporadic or chronic-state of intoxication emerges of recurrent-consumption of drugs that impact harmfully on individual and society. The second aim is to study the psychological and health implications on drugs’ users and thirdly to design a psychological-program for those who take drugs.     

This study aimed at analyzing and studying the strategic and geopolitical importance of the Sahel region, which increased the regional competition for the resources of the region, especially the energy resources that have been and continue to be one of the axes of conflict and competition between these forces.
The researcher tried to review the competition between the international force, France, the United States of America, China, Algeria and Libya, and the African coast. We note that there is a positive correlation between the severity of the conflict and the intensity of the competition of the major powers to control the countries of the region and the extent of political and economic stability These countries are directly affecte

This Study Aimed to Recognize the Self-Efficacy Level Among Musically Talented Students the sample of this study consisted of (85) Musically smart students male and female students in Irbid governorate, of the analytical descriptive method ، and the Self-Efficacy scale were used, and the results indicated the following:
-The Self-Efficacy level among Musically smart students was high.
-There are no statistically significant differences (α ≥ 0.05)due to the impact of gender in a the total degree .
-There are no statistically significant differences (α=0.05) due to the impact of stage in a the total degree.

The Iranian-Sudanese relations during the era of the transitional government (1985-1986), and the era of the third democratic government, has seen a marked improvement, particularly since the transitional government, which was formed in Sudan following a popular uprising that toppled former President Jaafar Nimeiri followed based on balancing policy in international relations, which is the same policy adopted by the government of Sadiq al-Mahdi that, especially that Mr. Sadiq al-Mahdi had enjoyed close ties with the government in Tehran before he took office, and on the basis of the policy of diplomatic representation between the two countries returned since the time of the transitional government after relations were severed due to the

Abstract

      In this study, we compare between the autoregressive approximations (Yule-Walker equations, Least Squares , Least Squares ( forward- backword ) and Burg’s (Geometric and Harmonic ) methods, to determine the optimal approximation to the time series generated from the first - order moving Average non-invertible process, and fractionally - integrated noise process, with several values for d (d=0.15,0.25,0.35,0.45) for different sample sizes (small,median,large)for two processes . We depend on figure of merit function which proposed by author Shibata in 1980, to determine the theoretical optimal order according to min

Assume that G is a finite group and X = tG where t is non-identity element with t3 = 1. The simple graph with node set being X such that a, b ∈ X, are adjacent if ab-1 is an involution element, is called the A4-graph, and designated by A4(G, X). In this article, the construction of A4(G, X) is analyzed for G is the twisted group of Lie type 3D4(3).