As the bit rate of fiber optic transmission systems is increased to more than , the system will suffer from an important random phenomena, which is called polarization mode dispersion. This phenomenon contributes effectively to: increasing pulse width, power decreasing, time jittering, and shape distortion. The time jittering means that the pulse center will shift to left or right. So that, time jittering leads to interference between neighboring pulses. On the other hand, increasing bit period will prevent the possibility of sending high rates. In this paper, an accurate mathematical analysis to increase the rates of transmission, which contain all physical random variables that contribute to determine the transmission rates, is presented. Thereafter, new mathematical expressions for: pulse power, peak power, time jittering, pulse width, and power penalty are derived. On the basis of these formulas, one can choose a certain operating values to reduce or prevent the effects of polarization mode dispersion.
A Factorial Study for separation anxiety in students, of Baghdad City
Background: The first and second choice for vascular access in patients with end stage renal disease (ESRD) is radio cephalic and brachio cephalic arteriovenous fistula (AVF).In patients with failed previous AVF e or poorly visualized or impalpable cephalic veins, the basilic vein can be mobilized and superficialized to create an AVF with the brachial artery.Objective: The aim of this study is to report our experience at the Vascular Surgery Department/ Surgical Specialty Hospital in brachio-basilic (BB) vascular access for hemodialysis.Methods: From January 2006 to December 2009, 31 patients with ESRD whose cephalic veins were thrombosed or impalpable or had previous unsuccessful vascular access procedures were referred to the Vascular
... Show MoreThe aim of this research was to evaluate the level of ball control in basketball. There was a great weakness in ball control that affected the mastery of many skills that affect the success of the team. The researcher also found a lack in training programs concerning ball control. The researchers used (9) special tests for ball control out of (41) test applied on young basketball players were (86). The researchers concluded that: 1. Criteria were set for test results of ball control. 2. A level of criteria was set for test results of ball control.
content Analysis for Some Type of Pillows used in Iraqi houses
Building a geological model is an essential and primary step for studying the reservoir’s hydrocarbon content and future performance. A three-dimensional geological model of the Asmari reservoir in Abu- Ghirab oil field including structure, stratigraphy, and reservoir petrophysical properties, has been constructed in the present work. As to underlying Formations, striking slip faults developed at the flank and interlayer normal. Abu Ghirab oilfields are located on the eastern anticlinal band, which has steadily plunged southward. 3D seismic interpretation results are utilized to build the fault model for 43 faults of the Asmari Formation in Abu Ghirab Oilfield. A geographic facies model with six different rock facies types
... Show MoreSuggestion Plan for the Reclassification of U.N Publications in Central Library
The present work aims to study forward osmosis process using different kinds of draw solutions and membranes. Three types of draw solutions (sodium chloride, sodium formate, and sodium acetate) were used in forward osmosis process to evaluate their effectiveness with respect to water flux and reverse salt flux. Experiments conducted in a laboratory-scale forward osmosis (FO) unit in cross flow flat sheet membrane cell. Three types of membranes (Thin film composite (TFC), Cellulose acetate (CA), and Cellulose triacetate (CTA)) were used to determine the water flux under osmotic pressure as a driving force. The effect of temperature, draw solution concentration, feed and draw solution flow rate, and membrane types, were studied with
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