Abstract: The increased interest in developing new photonic devices that can support high data rates, high sensitivity and fast processing capabilities for all optical communications, motivates a pre stage pulse compressor research. The pre-stage research was based on cascading single mode fiber and polarization maintaining fiber to get pulse compression with compression factor of 1.105. The demand for obtaining more précised photonic devices; this work experimentally studied the behavior of Polarization maintaining fiber PMF that is sandwiched between two cascaded singe mode fiber SMF and fiber Bragg gratings FBG. Therefore; the introduced interferometer performed hybrid interference of both Mach-Zehnder and Fabry-Perot interferometers. The hybrid interference is resulted from the interference of the forward, backward and X,Y polarization components of the propagating light along the cascaded fibers. In conclusion spectral pulse compression with maximum compression factor in range of 3-6 was obtained by tuning applied stress on the shortest etched PMF segment of the interferometer (i.e. 8cm length). Such interferometer can support fine tunable all optical band pass filter
Abstract
Theoretical and experimental methodologies were assessed to test curved beam made of layered composite material. The maximum stress and maximum deflection were computed for each layer and the effect of radius of curvature and curve shape on them. Because of the increase of the use of composite materials in aircraft structures and the renewed interest in these types of problems, the presented theoretical assessment was made using three different approaches: curved beam theory and an approximate 2D strength of material equations and finite element method (FEM) analysis by ANSYS 14.5 program for twelve cases of multi-layered cylindrical shell panel differs in fibe
... Show MoreNanoparticles of copper sulfide have been prepared by simple reaction between using copper nitrate with different concentrations ratio 0.1, 0.3, and 0.5 mM, thiourea by a simple chemical route. The prepared Nano powders have been deposited onto glass substrates by casting method at 60°C. The structure of the product Nano- films has been studied by x-ray diffraction, where the patterns showed that all the samples have a hexagonal structure of covellite copper sulfide with the average crystalline sizes 14.07- 16.51 nm. The morphology has been examined by atomic force microscopy, and field emission scan electron microscopy. The AFM images showed particles with almost spherical and rod shapes with average diameter sizes of 49.11- 90.64 nm.
... Show MoreA novel design and implementation of a cognitive methodology for the on-line auto-tuning robust PID controller in a real heating system is presented in this paper. The aim of the proposed work is to construct a cognitive control methodology that gives optimal control signal to the heating system, which achieve the following objectives: fast and precise search efficiency in finding the on- line optimal PID controller parameters in order to find the optimal output temperature response for the heating system. The cognitive methodology (CM) consists of three engines: breeding engine based Routh-Hurwitz criterion stability, search engine based particle
swarm optimization (PSO) and aggregation knowledge engine based cultural algorithm (CA)
This research study experimentally the effect of air flow rate on humidification process
parameters. Experimental data are obtained from air conditioning study unit T110D. Results obtained
from experimental test, calculations and psychometrics software are discussed. The effect of air flow rate
on steam humidification process parameters as a part of air-conditioning processes can be explained
according to obtained results. Results of the steam humidification processes (1,2) with and without
preheating with 5A and 7.5A shows decreasing in dry bulb temperature, humidity ratio, and heat add to
moist air with increasing air flow rate, but humidification load, and total energy of moist air increase with
increasing air flo
The impact of applying the K-W-L self-scheduling technique on first-year intermediate students' learning of basic volleyball skills, Ayad Ali Hussein*, Israa Fouad Salih
هدف هذا البحث إلى قياس الإجهاد الرقمي لدى طلبة جامعة بغداد، والكشف عن الفروق في الإجهاد الرقمي بناءً على متغيرات الجنس (ذكر - أنثى)، والمرحلة الدراسية (أولى - رابعة)، والاختصاص (علمي - إنساني). تألفت عينة البحث من (200) طالبًا وطالبة من جامعة بغداد، وتم تطبيق مقياس" الإجهاد الرقمي "الذي تم إعداده من قبل الباحثة خصيصًا لهذا البحث. وتم اعتماد المنهج الوصفي التحليلي وبعد تطبيق مقياس البحث وتحليل النتائج بالوسائل الإحص
... Show MoreMental stress occurs due to the effect of time that passes at an accelerated pace and doing business imposed by the speed of the match with his speed in light of the vast amount of audio and visual information through scientific progress and media workers, as well as the impact of physical factors associated with doing business, such as noise and congestion .... . etc.. The relationship of the individual to take a negative surroundings have devastating effects on the cognitive process as a whole dimension. This creates a sense of helplessness with the depletion voltage to a state of mental stress, so The problems from the standpoint of Aljhtalt scientists are basically cognitive problems appear to exist when it happens to the ind
... Show MoreThe research aims to identify the effect of teaching-learning design based on the constructivism theory on the life skills of middle stage students. The sample consisted of (60) students from one of the middle schools in Baghdad's governorate. The experimental group and control group consisted of 30 students for each group, the research tool was the life skills scale composed of (78) items. The scale proved its validity and reliability, which was found to be (0.85). The results showed a statistically significant difference in life skills between the two groups of research in favor of the experimental group, which studied the educational design according to models of constructivism theory compared to the usual method of teaching.