Femtosecond laser pulse propagation in monomode optical fibers is demonstrated and investigated numerically (by simulations) and experimentally in this paper. A passively mode locked Nd:glass laser giving a pulse duration of about 200 fsec at 1053 nm wavelength and 120 mW average optical power with 100 MHz repetition rate is used in the experimental work. Numerical simulations are done by solving the nonlinear Schrödinger equation with the aid of Matlab program. The results show that self phase modulation (SPM) leads to compression of the spectral width from 5 nm to 2.1 nm after propagation of different optical powers (34, 43, 86 and 120 mW) in fibers of different length (5, 15, 35 m). The varying optical powers produced a varying phase shift. The output spectral width also changed with the fiber length at a given peak power.
The basic concept of diversity; where two or more inputs at the receiver are used to get uncorrelated signals. The aim of this paper is an attempt to compare some possible combinations of diversity reception and MLSE detection techniques. Various diversity combining techniques can be distinguished: Equal Gain Combining (EGC), Maximal Ratio Combining (MRC), Selection Combining and Selection Switching Combining (SS).The simulation results shows that the MRC give better performance than the other types of combining (about 1 dB compare with EGC and 2.5~3 dB compare with selection and selection switching combining).
This paper deals with the description of the system of formation and derivation of words in the Russian language. In this work, we will present recent trends in the study of the Russian language that deal with vocabulary formation. The lexical system of the Russian language is associated with a common (or opposite) meaning; similar (or opposite) in stylistic characteristics; united by a common type of word formation; related to a common descent and belonging to a vocabulary of much or little use, etc. The results of the most prominent linguists and specialists who dealt with this topic will be presented, in addition to presenting their different views on word formation. The words of the Russian language consist of mor vimat that participate
... Show MoreThe present study was included the isolation of Keratinophilic fungi from water samples taken from 19 indoor public swimming pools in Baghdad during four season (summer ,fall ,spring ,and winter). Isolation period was September 2011and September 2012 . Samples were collected from different places in swimming pool . Sixteen keratinophilic fungal species, belonging to twenty –one genera were isolated using Surface Dilution Plating (SDP) and Hair Bait Technique (HBT) . Aspergillus genus was the most frequent and occurrence (19.84%), followed by Trichophyton (11.60%) and Fusarium (7.59% ) . The most common fungal infection occurred in summer season (42.16%) , and the most frequent month manifestation of species occurred in August
... Show MoreThe aim of the current study is to identify the morphological description of the tongue in mongoose (Herpestes javanicus) and its relation to the feeding pattern. For this purpose the (5) samples of tongues were dissected from the head of mongoosecaught from different areas of Al-Najaf province, cleaned in normal saline and examined under the dissecting microscope. The results showed the absence of the middle groove in the lingual apex area. As well as the absence of lingual prominence in the body area. The dorsal surface is characterized by the presence of four types from lingual papillae (filiform, cylindrical, fungiform, circumvallate), while the ventral surface is free of lingual papillae. The filiform papillae spread throughout the dor
... Show MoreLevels of primary education are varying in Sulaimaniyah Province, which defines as a lower stage of education process and seems to be found in most settlements to save the individual and community from illiteracy in its traditional notion which means the individuals, potentiality for reading and writing if he/she graduated from this stage successfully. The research can put the priority for goodness of primary education service within Sulaimaniyah Province that includes Sulaimaniyah city as a dominance based on statistical indicator which called the standardized score (z). The indicator (z) calculated for the basic items of primary education to diagnosis the range of developing that service in Sulaimaniyah city especially and put
... Show MoreThe world of Muwaffaq Khidr Al-Qasasi has a clear and realistic orientation. This trend is in full harmony with his philosophy and vision of life and things. Through self-awareness is nothing but an expression of an imbalance in the interaction between self and reality, and it remains lacking in credibility.
Osteoarthritis is a degenerative disease affecting joints that is chronic and disables the movement of patients with increasing pain and decreasing their quality of life with age. Available treatments are only symptomatic with no cure. Recent methods for managing osteoarthritis involve using pharmacological, non-pharmacological treatments or both for improving physical function in patients and alleviating pain. Clinical trials were conducted to reveal the extent of benefits obtained from different nutraceuticals and food supplements, such as collagen with growing use and fairly good results in the treatment of osteoarthritis. The goal of this study is to review the current information about the rational use of collagen in osteoarthritisKeyw
... Show MoreA total of 722 algal taxa are recorded in Diyala River by different authors. Most of the identification algae belong to three Divisions: Bacillariophyceae (367, 50.8%), Chlorophyceae (179, 24.8%), and Cyanophyceae (126, 17.5%).
Iraq has witnessed development in many fields and the electricity production sector is one of the most important of these fields. This is attributed to the State’s philosophy in supporting this sector through the development of economic development projects to serve and raise the level of the Iraqi individual. Electricity production in Iraq is affected by many variables such as load growth, economic and financial conditions, planning, etc. All these led to a disparity in the production of electric power to cover the demand for energy. The paper deals with the electricity generation sector overview in Iraq, Analysis of the effects of variables on the implementation of power generatio