In this experimental study, which was carried out in photonics laboratory at Strathclyde University, UK, dynamics of a multi-Quantum well semiconductor active medium laser, was studied. This is in order to study its emission stability and pulse shape development under the influence of strong optical feedback level with different deriving currents, in the free space transmission medium. An external stable resonator was constructed by inserting high reflectivity dielectric mirror outside the laser output, 20 cm apart from it, which is an extralarge external cavity. Controlling the reflected back optical power was done by using a nonpolarized (50:50) beam splitter. The external resonator supported by focusing (plano-convex) lens in order to make it stable. Laser translated from stable emission when it was solitary, to quasi-static, and low fluctuated, behaves, to be coherence collapse. This is due to the strong (50%) level of optical feedback.
The esterification of oleic acid with 2-ethylhexanol in presence of sulfuric acid as homogeneous catalyst was investigated in this work to produce 2-ethylhexyl oleate (biodiesel) by using semi batch reactive distillation. The effect of reaction temperature (100 to 130°C), 2-ethylhexanol:oleic acid molar ratio (1:1 to 1:3) and catalysts concentration (0.2 to 1wt%) were studied. Higher conversion of 97% was achieved with operating conditions of reaction temperature of 130°C, molar ratio of free fatty acid to alcohol of 1:2 and catalyst concentration of 1wt%. A simulation was adopted from basic principles of the reactive distillation using MATLAB to describe the process. Good agreement was achieved.
External Morphological study of Sympetrum decoloratum Selys of family : Libellulidae from suborder Anisoptera of the order Odonata which were collected from Baghdad Governorate 2011. Such study was included : Detailed description of most body parts (Head, Thorax ,Abdomen and their appendages), with special regard to male genitalia.
Feedback on students’ assignments can be done in many different ways. Nowadays, the growing number of students at universities has increased the burden on the instructors to give feedback on students’ writings quickly and efficiently. As such, new methods of modern online automated feedback tools, such as Hemingway app and ecree,are used to assist and help instructors. Hence, this research is an explanatory study to examine the effect of using the online automated feedback on some Iraqi EFL learners’ writings at the university level. The study comprised 60 students enrolled in an English language course at the University of Anbar. They were divided randomly into two groups, experi
... Show MoreWhite and black chia seeds were used in some food products, such us gluten –free biscuits processing by using rice flour and chia seeds (white and black) with these amonths 112.5, 74.25, 56.25, 27.5 g with 27.5g of quinoa seeds for treatments 1, 2, 3 and 4 respectively, and comparison sensitively with the control treatment which has no additions including the appearance and homogenization of the product, surface cracks, softness, taste and flavor, core color and the specific volume, some microbiological tests were performed for biscuit product after storage for 4 months at 30 and 50°C including bacterial total count and fungal and yeast count, results showed that there weren’t any observation of bacteria or yeast or fungal growth at
... Show MoreThe purpose of this paper is to give the definition of projective 3-space PG(3,q) over Galois field GF(q), q = pm for some prime number p and some integer m.
Also, the definition of the plane in PG(3,q) is given and state the principle of duality.
Moreover some theorems in PG(3,q) are proved.
This paper deals with the F-compact operator defined on probabilistic Hilbert space and gives some of its main properties.
Most of the propositions, after the Arabic letter reached a position of integrity and proficiency, the calligrapher turned to the production of calligraphic formations in various aesthetic and expressive forms, investing the spiritual energies in what these calligraphic compositions show in artistic paintings. It carries a lot of meanings that are embodied in linear formations, and in order to reach these expressions and know the effective positions of space, this research is concerned with studying these technical treatments. The first chapter included the research problem, which included a question about the effectiveness of space in the linear painting, the importance of research and the temporal and spatial boundaries. As for the s
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