Cognitive radio technology is used to improve spectrum efficiency by having the cognitive radios act as secondary users to access primary frequency bands when they are not currently being used. In general conditions, cognitive secondary users are mobile nodes powered by battery and consuming power is one of the most important problem that facing cognitive networks; therefore, the power consumption is considered as a main constraint. In this paper, we study the performance of cognitive radio networks considering the sensing parameters as well as power constraint. The power constraint is integrated into the objective function named power efficiency which is a combination of the main system parameters of the cognitive network. We prove the exi

The article examines metaphors as one of the fundamental means used by D. Rubina when writing the novel “Parsley Syndrome” to form images of dolls as equal heroes of the work. The author of the article continues research related to the work of Dina Ilinichna Rubina, a representative of modern Russian prose.

Static Synchronous Series Compensator (SSSC) is a well known device for effectively regulating the active power flow in a power system. In this paper, the SSSC linearized power flow equations are incorporated into Newton-Raphson algorithm in a MATLAB written program to investigate the control of active poweer flow and the transient stability of a five bus and a thirty bus IEEE test systems, during abnormal conduction (three phase fault near buses). A comparison of the results obtained for the base case without SSSC and with it to investigate the effectiveness of the device on both of the active power flow and the transient stability.

The present study was invistigated to show the bioaccumulation of some heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) by use Aquatic plant Myriophyllum verticilatum growing in Euphrates river between Spring 2004 to Winter 2005, and these heavy maters was studied in Dissolved and particulat phase of water and exchangable and residual phase of sediment. Heavy metals accumulated according the system water-sediment-aquatic plant, and recorded bioaccumulation factor 1.010, 0.005, 0.009, 0.011, 0.012, 0.010, 0.010, 0.010, 0.011, respectively.

The aim of the research is to identify the role of university education management in achieving sustainable environmental development.

The Iraqi outfit is characterized by special features and identity that are closely related to the traditions, customs, religious and social beliefs and other references of the Iraqi environment and its factors affecting the individual and society. Every place in Iraq has its own uniform, which differs in terms of its artistic, aesthetic and functional components from place to place.

The abaya, especially worn by women, is especially distinct in terms of the design of the uniform, the nature of the cloth made of it, as well as the color of the abaya, which is dominated by black in most designs. The Dar Al-Taros Center and Textile Research initiated the construction of theoretical and practical bases in the design of contemporary

This work aims to study the exploding copper wire plasma parameters by optical emission spectroscopy. The emission spectra of the copper plasma have been recorded and analyzed The plasma electron temperature (Te), was calculated by Boltzmann plot, and the electron density (ne) calculated by using Stark broadening method for different copper wire diameter (0.18, 0.24 and 0.3 mm) and current
of 75A in distilled water. The hydrogen (Hα line) 656.279 nm was used to calculate the electron density for different wire diameters by Stark broadening. It was found that the electron density ne decrease from 22.4×1016 cm-3 to 17×1016 cm-3 with increasing wire diameter from 0.18 mm to 0.3 mm while the electron temperatures increase from 0.741 to

The large number of failure in electrical power plant leads to the sudden stopping of work. In some cases, the necessary reserve materials are not available for maintenance which leads to interrupt of power generation in the electrical power plant unit. The present study, deals with the determination of availability aspects of generator in unit 5 of Al-Dourra electric power plant. In order to evaluate this generator's availability performance, a wide range of studies have been conducted to gather accurate information at the level of detail considered suitable to achieve the availability analysis aim. The Weibull Distribution is used to perform the reliability analysis via Minitab 17, and Artificial Neural Networks (ANNs) by approaching o

 Investigating the heavy metals in soil is important to the life of humans and living organisms. Diyala River Lower Reaches was chosen due to the changes in environmental characteristics that took place in recent years. Twelve sediment samples were collected from four different sites. The physical, and chemical properties and the concentrations of nine heavy metals were indicated. The results showed that the average concentrations of arsenic, copper, chromium, cobalt, iron, manganese, nickel, lead, and zinc are 8.5, 45.7, 538.5, 12.2, 5.07, 991.7, 183.5, 16.07, 136.5 ppm, respectively. They reflect contamination with arsenic, chromium, and nickel, while they are free of lead, and zinc contamination, according to the Environmental P