Preferred Language
Articles
/
OBdHXZIBVTCNdQwCZa6l
Design and Simulation of Hartley based Multi Orthogonal Band OFDM
...Show More Authors

Recent advances in wireless communication systems have made use of OFDM technique to achieve high data rate transmission. The sensitivity to frequency offset between the carrier frequencies of the transmitter and the receiver is one of the major problems in OFDM systems. This frequency offset introduces inter-carrier interference in the OFDM symbol and then the BER performance reduced. In this paper a Multi-Orthogonal-Band MOB-OFDM system based on the Discrete Hartley Transform (DHT) is proposed to improve the BER performance. The OFDM spectrum is divided into equal sub-bands and the data is divided between these bands to form a local OFDM symbol in each sub-band using DHT. The global OFDM symbol is formed from all sub-bands together using the (IDHT). The BER performance of the proposed system is simulated and compared with the conventional OFDM in different channel conditions to show the gain in SNR achieved by the proposed system.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Dec 01 2009
Journal Name
Iraqi Journal Of Physics
Simulation of an ion Optical Transport and Focusing System
...Show More Authors

A simulated ion/electron optical transport and focusing system has been put forward to
be mounted on high voltage transmission electron microscope for in situ investigations.
The suggested system consists of three axially symmetric electrostatic lenses namely an
einzel lens, an accelerating immersion lens, and a decelerating immersion lens, in addition
to an electrostatic quadrupole doublet lens placed on the image side. The electrodes
profile of these lenses is determined from the proposed axial field distributions. The
optical properties of the whole system have been computed together with the trajectory of
the accelerated charged-particles beam along the optical axis of the system. The computed
dimensions of th

... Show More
View Publication Preview PDF
Publication Date
Thu Mar 14 2019
Journal Name
Al-khwarizmi Engineering Journal
Creeping Gait Analysis and Simulation of a Quadruped Robot
...Show More Authors

A quadruped (four-legged) robot locomotion has the potential ability for using in different applications such as walking over soft and rough terrains and to grantee the mobility and flexibility. In general, quadruped robots have three main periodic gaits:  creeping gait, running gait and galloping gait. The main problem of the quadruped robot during walking is the needing to be statically stable for slow gaits such as creeping gait. The statically stable walking as a condition depends on the stability margins that calculated particularly for this gait. In this paper, the creeping gait sequence analysis of each leg step during the swing and fixed phases has been carried out. The calculation of the minimum stability margins depends up

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Mon Jun 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Simulation of Wiped Film Evaporator
...Show More Authors

A mathematical model and associated computer program were developed to simulate the steady state operation of wiped film evaporators for the concentration of glycerol-water solution. In this model, various assumptions were made to facilitate the mathematical model of the wiped film evaporator. The fundamental phenomena described were: sensible heating of the solution and vaporization of water. Physical property data were coded into the computer program, which performs the calculations of this model. Randomly selected experiments were carried out in a small scale wiped film evaporator from ALVAL COMPANY, using different concentrations of the glycerol solution (10, 30 and 50 Wt. %) for different feed rates (30, 50, 80, 100 and 120 l/h) and

... Show More
View Publication Preview PDF
Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Engineering
SIMULATION OF FLIGHT THROUGH GUST
...Show More Authors

A flight simulation programme has been developed on a personal computer using Microsoft
FORTRAN to simulate flight trajectories of a light aircraft by using Six-Degree-of-Freedom
equation of motion. The simulation has been made realistic through pre-programmed the input to
the control surfaces, atmospheric gust during the flight mode. The programme plays an important
role in the evaluation and validation of the aircraft design process. A light aircraft (Cessna 182T)
has been tested through free flight, gliding flight, flight with gust. The results show good trend and
show that the programme could be dependent as a realistic flight test programme.

View Publication Preview PDF
Crossref
Publication Date
Sun Sep 03 2017
Journal Name
Baghdad Science Journal
Calculation of Lambda Doubling for 7LiH1 molecule Using the System band emission for electronic transmissions
...Show More Authors

The A2?u-X1?g+ emission band system of 7LiH1 molecule has been calculated for Lambda doubling. The relation between wave number ?p , ?Q , ?R conducted the energies of the state of rotation F (J), and (J + 1) with rotational quantum number J, respectively, of 7LiH1 molecule for statehood A2?u using the rotation, fixed vibrational states of both the ground and raised crossovers vibrational against ???= 0 to V ' = 0-4using rotational levels J = 0 to J = 20 have found.

View Publication Preview PDF
Scopus Crossref
Publication Date
Tue Dec 01 2020
Journal Name
Baghdad Science Journal
The Numerical Technique Based on Shifted Jacobi-Gauss-Lobatto Polynomials for Solving Two Dimensional Multi-Space Fractional Bioheat Equations
...Show More Authors

This article deals with the approximate algorithm for two dimensional multi-space fractional bioheat equations (M-SFBHE). The application of the collection method will be expanding for presenting a numerical technique for solving M-SFBHE based on “shifted Jacobi-Gauss-Labatto polynomials” (SJ-GL-Ps) in the matrix form. The Caputo formula has been utilized to approximate the fractional derivative and to demonstrate its usefulness and accuracy, the proposed methodology was applied in two examples. The numerical results revealed that the used approach is very effective and gives high accuracy and good convergence.

View Publication Preview PDF
Scopus (2)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Wed Dec 01 2021
Journal Name
Iraqi Journal Of Physics
Structural and Infrared Spectroscopy of Polyvinylpyrrolidone/Multi-walled Carbon Nanotubes Nanocomposite
...Show More Authors

In this work, polyvinylpyrrolidone (PVP)/ Multi-walled carbon nanotubes (MWCNTs) nanocomposites were prepared with two concentrations of MWCNTs by casting method. Morphological, structural characteristics and electrical properties were investigated. The state of MWCNTs dispersion in a PVP matrix was indicated by Field Effect-Scanning Electron Microscopy (FESEM) which showed a uniform dispersion of MWCNTs within the PVP matrix. X-ray Diffraction (XRD) indicate strong bonding of carbonyl groups of PVP composite chains with MWCNTs. Fourier transfer infrared (FTIR) studies shows characteristics of various stretching and bending vibration bands, as well as shifts in some band locations and intensity changes in others. Hall effect was studied

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Wed Dec 01 2021
Journal Name
Iraqi Journal Of Physics (ijp)
Structural and Infrared Spectroscopy of Polyvinylpyrrolidone/Multi-walled Carbon Nanotubes Nanocomposite
...Show More Authors

In this work, polyvinylpyrrolidone (PVP)/ Multi-walled carbon nanotubes (MWCNTs) nanocomposites were prepared with two concentrations of MWCNTs by casting method. Morphological, structural characteristics and electrical properties were investigated. The state of MWCNTs dispersion in a PVP matrix was indicated by Field Effect-Scanning Electron Microscopy (FESEM) which showed a uniform dispersion of MWCNTs within the PVP matrix. X-ray Diffraction (XRD) indicate strong bonding of carbonyl groups of PVP composite chains with MWCNTs. Fourier transfer infrared (FTIR) studies shows characteristics of various stretching and bending vibration bands, as well as shifts in some band locations and intensity changes in others. Hall effect was stu

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Sat Mar 01 2008
Journal Name
Al-khwarizmi Engineering Journal
Minimizing error in robot arm based on design optimization for high stiffness to weight ratio
...Show More Authors

In this work the effect of choosing tri-circular tube section had been addressed to minimize the end effector’s error, a comparison had been made between the tri-tube section and the traditional square cross section for a robot arm, the study shows that for the same weight of square section and tri-tube section the error may be reduced by about 33%.

A program had been built up by the use of MathCAD software to calculate the minimum weight of a square section robot arm that could with stand a given pay load and gives a minimum deflection. The second part of the program makes an optimization process for the dimension of the cross section and gives the dimensions of the tri-circular tube cross section that have the same weight of

... Show More
View Publication Preview PDF
Publication Date
Thu Dec 01 2022
Journal Name
University Of Baghdad, College Of Education For Pure Sciences / Ibn Al-haitham, Department Of Mathematics
Fibrewise Multi-Topological Spaces and Related Concepts
...Show More Authors

We define and study new ideas of fibrewise topological space namely fibrewise multi-topological space . We also submit the relevance of fibrewise closed and open topological space . Also fibrewise multi-locally sliceable and fibrewise multi-locally section able multi-topological space . Furthermore, we propose and prove a number of statements about these ideas. On the other hand, extend separation axioms of ordinary topology into fibrewise setting. The separation axioms are said to be fibrewise multi-T0. spaces, fibrewise multi-T1spaces, fibrewise multi-R0 spaces, fibrewise multi-Hausdorff spaces, fibrewise multi-functionally Hausdorff spaces, fibrewise multi-regular spaces, fibrewise multi-completely regular spaces, fibrewise multi-normal

... Show More