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.

In this paper, we study the incorporation of the commensalism interaction and harvesting on the Lotka–Volterra food chain model. The system provides one commensal prey, one harvested prey, and two predators. A set of preliminary results in local bifurcation analysis around each equilibrium point for the proposed model is discussed, such as saddle-node, transcritical and pitchfork. Some numerical analysis to confirm the accruing of local bifurcation is illustrated. To back up the conclusions of the mathematical study, a numerical simulation of the model is carried out with the help of the MATLAB program. It can be concluded that the system's coexistence can be achieved as long as the harvesting rate on the second prey population is

This study had succeeded in producing a new graphical representation of James abacus called nested chain abacus. Nested chain abacus provides a unique mathematical expression to encode each tile (image) using a partition theory where each form or shape of tile will be associated with exactly one partition.Furthermore, an algorithm of nested chain abacus movement will be constructed, which can be applied in tiling theory.

Asthma is a chronic respiratory disorder of airways characterized by inflammation, hyperresponsiveness, inflammatory cell infiltration, mucous secretion, and remodelling. Ammi majus is medicinal plant belong to family of Apiaceous which has anti-inflammatory and antioxidant activities. This study designed to investigate of anti-asthmatic activity of alcoholic extract of Ammi majus in improvement of asthma. Forty-eight healthy female mice divided to six groups Group I:  the negative control group (distal water only), Group II: Positive control group (ovalbumin group), Group III: Ammi majus (64 mg/kg/day) with sensitization, Group IV:Ammi majus  (128 mg/kg/day) with sensitization, Group V: Ammi majus (64 mg/kg/day) without sensitiza

The origin of this technique lies in the analysis of François Kenai (1694-1774), the leader of the School of Naturalists, presented in Tableau Economique. This method was developed by Karl Marx in his analysis of the Departmental Relationships and the nature of these relations in the models of " "He said. The current picture of this type of economic analysis is credited to the Russian economist Vasily Leontif. This analytical model is commonly used in developing economic plans in developing countries (p. 1, p. 86). There are several types of input and output models, such as static model, mobile model, regional models, and so on. However, this research will be confined to the open-ended model, which found areas in practical application.

Inflammatory bowel disease (IBD) is a common chronic inflammatory disease of the gastrointestinal tract, including ulcerative colitis and Crohn's disease. ulcerative colitis (UC)  disease is characterized by chronic, persistent, recurrent, and nonspecific intestinal ulcers and mucosal inflammation. This study investigated the protective effects of cinnamic acid on dextran sodium sulfate (DSS) induced ulcerative colitis in mice. Forty adult male mice were collected and randomly divided into five groups, group Ӏ received a suspension of distill water and poloxamer, and group ӀӀ received 3% DSS in drinking water for 7 consecutive days. Two treatment groups received an oral suspension of cinnamic acid 50 and 25 mg/kg respectively an

This study aims to identify the degree of Arabic language teachers at the secondary stage possessing the teaching competencies necessary to develop the skills of literary savor among their students from the perception of educational leaders in Bisha Province. To achieve the objectives of the study, the descriptive approach was used by adopting a comprehensive survey method. The study sample consisted of (48) school principals and Arabic language supervisors in Bisha Province who supervise the teaching of Arabic language at the secondary level in Bisha Province. The necessary data was collected using a questionnaire. The results of the study revealed that the evaluation of the study sample for the degree to which Arabic language teachers

Braces in straight bridge systems improve the lateral-torsional buckling resistance of the girders by reducing the unbraced length, while in horizontally curved and skew bridges, the braces are primary structural elements for controlling deformations by engaging adjacent girders to act as a system to resist the potentially large forces and torques caused by the curved or skewed geometry of the bridge. The cross-frames are usually designed as torsional braces, which increase the overall strength and stiffness of the individual girders by creating a girder system that translates and rotates as a unit along the bracing lines. However, when they transmit the truck’s live load forces, they can produce fatigue cracks at their connection