The result of a developed mathematical model for predicting the design
parameters of the fiber Raman amplifier (FRA) are demonstrated. The amplification
parameters are tested at different pump power with different fiber length. Recently,
the FRA employed in optical communication system to increase the repeater distance
as will as the capacity of the communication systems. The output results show, that
high Raman gain can be achieved by high pumping power, long effective area that
need to be small for high Raman gain. High-stimulated Raman gain coefficient is
recommended for high Raman amplifier gain, the low attenuation of the pump and the
transmitted signal in the fiber lead to high Raman gain.

En el contexto iraquí, el análisis de las dificultades léxicas de los estudiantes de ELE es fundamental para poder llevar a cabo prácticas que respondan dos necesidades concretas. Por un lado, ofrecer experiencias de aula que garanticen el desarrollo de competencias comunicativas que optimicen el uso adecuado de la lengua española (L2); por otro, atender a las exigencias que se hacen desde el PCIC y el MCER para tener unos parámetros claros de evaluación. Así las cosas, en este artículo se propone la caracterización de la competencia léxica como parte de las competencias lingüísticas desde la perspectiva del MCER, para señalar cuál es el alcance de su optimización para los estudiantes arabófonos en general y los ira

Recent phosphorus (P) pollution in the United States, mainly in Maine, has raised some severe concerns over the use of P fertilizer application rates in agriculture. Phosphorus is the second most limiting nutrient after nitrogen and has damaging impacts on crop yield if found to be deficient. Therefore, farmers tend to apply more P than is required to satisfy any P loss after its application at planting. Several important questions were raised in this study to improve P efficiency and reduce its pollution. The objective of this study was to find potential reasons for P pollution in water bodies despite a decrease in potato acreage. Historically, the potato was found to be responsible for P water contamination due to its high P sensitivity a

A study of the singlet and triplet states of two electron systems in the first excited state was performed using a simple quantum mechanical model, which assigns the 1s,and 2s orbital with two different variational parameters. Our results agree with a high level calculation used by Snow and Bills.

The wave functions of the coherent states of the charged oscillator in magnetic field are obtained via a canonical transformation. The numerical calculations of these functions are made and then the space and time plots are obtained. It was shown that these states are Gaussians distributions of widths vary periodically in an opposite way with their peaks. We interpret that is due to the mutual actions of the spreading effect of the wave packet and the reaction of the magnetic field.

The city of Ghana is one of the important commercial cities in the country of Sudan, as it was a major source of commercial exchanges, and a commercial mediator across the countries of the Maghreb and the metropolises of the countries of Sudan. Many, and most of them take the desert road,    Which traders had to endure the hardships of these roads from the insecurity, high winds and dust that sometimes destroyed the trade convoys, in order to obtain gold, which is one of the most important minerals that Ghana traded with various countries, in addition to the different goods that the merchants carried In particular, salt and its trade with Ghana, and also taxes, which were an important financial resource imposed by some gov

Localization is an essential demand in wireless sensor networks (WSNs). It relies on several types of measurements. This paper focuses on positioning in 3-D space using time-of-arrival- (TOA-) based distance measurements between the target node and a number of anchor nodes. Central localization is assumed and either RF, acoustic or UWB signals are used for distance measurements. This problem is treated by using iterative gradient descent (GD), and an iterative GD-based algorithm for localization of moving sensors in a WSN has been proposed. To localize a node in 3-D space, at least four anchors are needed. In this work, however, five anchors are used to get better accuracy. In GD localization of a moving sensor, the algo

The transverse electron scattering form factors have been studied for low –lying excited states of 7Li nucleus. These states are specified by J? T= (0.478MeV), (4.63MeV) and (6.68MeV). The transitions to these states are taking place by both isoscalar and isovector components. These form factors have been analyzed in the framework of the multi-nucleon configuration mixing of harmonic oscillator shell model with size parameter brms=1.74fm. The universal two-body of Cohen-Kurath is used to generate the 1p-shell wave functions. The core polarization effects are included in the calculations through effective g-factors and resolved many discrepancies with experiments. A higher configuration effect outside the 1p-shell model space, such

The study aimed to identify the perceptions of social studies teachers in the Governorate of Muscat about the importance of employing the skills of the twenty-first century in teaching. The study employed a qualitative approach. The two researchers used an analytical approach based on the Grounded Theory, the data was gathered through semi-structured interviews with (15) male and female teachers. The results indicated that social studies teachers relate the twenty-first-century skills more to improving students’ achievement level in the subject, while they see that these skills have less influence in developing students’ communication skills and cooperation with their peers. In light of the results of the study, the two researchers r

This study is one of the descriptive studies, where the researcher used the survey method, which seeks to provide an accurate and appropriate description of the main and sub-categories of the content of the research for television documentaries on the Iraqi satellite channel, relying on the research questions and objectives to analyze the content of the documentaries according to the approach referred to above. The objectives of the research were summarized to identify the function of the documentary programs in Al-Iraqiya channel to detect the crimes of the former regime, to know the frameworks highlighted by the documentary programs in Al-Iraqiya channel to reveal the crimes of the former regime, to identify the extent of the circ