Preferred Language
Articles
/
joe-1780
Directive and Steerable Radiation Pattern using SASPA Array

This work examines the ability of a special type of smart antenna array known as Switched Active Switched Parasitic Antenna (SASPA) to produce a directive and electronically steerable radiation pattern. The SASPA array consists of antenna elements that are switchable between active and parasitic states by using P-Intrinsic-N (PIN) diodes. The active element is the element that is supplied by the radio frequency while short-circuiting the terminals of an element in the array results in a parasitic element. Due to the strong mutual coupling between the elements, a directional radiation pattern with high gain and a small beamwidth can be produced with only one active element operating at a time. By changing the parasitic state to the active state sequentially for all elements, the directed radiation pattern can be easily rotated. The antenna array structure used in this work is the uniform circular array (UCA) to achieve symmetrical radiation patterns and full coverage of the entire azimuth plane. Also, a novel method for reducing the mutual coupling effect in SASPA arrays is proposed in this work. By using this method, some parameters of the generated SASPA’s radiation pattern can be controlled. The simulated results obtained from this work depict that an N-element SASPA-UCA produces N-symmetrical, switchable, and steerable radiation patterns with high gain, small beamwidth, and a high Front-to-Back (F/B) ratio. Also, the results show that further improvements in these parameters can be achieved by increasing the number of elements in the array. Additional simulations demonstrate that by including decaying function weight in each element's circuitry, the mutual coupling between the components of the SASPA-UCA array can be minimized. The aforementioned parameters can then be efficiently modified using this mutual coupling reduction.

 

 

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Jan 01 2011
Journal Name
Journal Of Engineering
MIXED CONVECTION PHENOMINA AFFECTED BY RADIATION IN A HORIZONTAL RECTANGULAR DUCT WITH COCENTRIC AND ECCENTRIC CIRCULAR CORE

The numerical investigation has been performed to study the radiation affected steady state laminar mixed convection induced by a hot inner varied positions circular core in a horizontal rectangular channel for a fully developed flow. To examine the effects of thermal radiation on thermo fluid dynamics behavior in the eccentric geometry channel, the generalized body fitted co-ordinate system is introduced while the finite difference method is used for solving the radiative transport equation. The governing equations which used are continuity, momentum and energy equations. These equations are normalized and solved using the Vorticity-Stream function. After validating numerical results for the case without radiation, the detailed radiatio

... Show More
Crossref
View Publication Preview PDF
Publication Date
Sat Jun 27 2020
Journal Name
Iraqi Journal Of Science
Radiation and Mass Transfer Effects on MHD Oscillatory Flow for Carreau Fluid through an Inclined Porous Channel

This paper aims to study a mathematical model showing the effects of mass transfer on MHD oscillatory flow for Carreau fluid through an inclined porous channel under the influence of temperature and concentration at a slant angle on the centre of the flow with the effect of gravity. We discussed the effects of several parameters that are effective on fluid movement by analyzing the graphs obtained after we reached the momentum equation solution using the perturbation series method and the MATHEMATICA program to find the numerical results and illustrations. We observed an increased fluid movement by increasing radiation and heat generation while fluid movement decreased by increasing the chemical reaction parameter and Froude number.&nbsp

... Show More
Scopus (6)
Crossref (3)
Scopus Crossref
View Publication Preview PDF
Publication Date
Sat Jan 01 2011
Journal Name
Journal Of Engineering
MIXED CONVECTION PHENOMINA AFFECTED BY RADIATION IN A HORIZONTAL RECTANGULAR DUCT WITH COCENTRIC AND ECCENTRIC CIRCULAR CORE

The numerical investigation has been performed to study the radiation affected steady state laminar mixed convection induced by a hot inner varied positions circular core in a horizontal rectangular channel for a fully developed flow. To examine the effects of thermal radiation on thermo fluid dynamics behavior in the eccentric geometry channel, the generalized body fitted co-ordinate system is introduced while the finite difference method is used for solving the radiative transport equation. The governing equations which used are continuity, momentum and energy equations. These equations are normalized and solved using the Vorticity-Stream function. After validating numerical results for the case without radiation, the detailed rad

... Show More
Crossref
Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
Evaluation of Radiological Activity Levels and the Radiation Doses of Soil of Babylon Batteries Plant in Waziriya

In this research measuring the radioactivity of the soil batteries plant in Waziriya in Baghdad city ,where the collection of 60 samples from different locations and depth between(10cm-50cm)by using γ-ray spectrometer technique and sodium iodide detector to measure the activityof radiation of elements radiation ,where the results showed that there are aradioctivety of natural isotopes refers to the chains of U-238and Th-232and K-40and Cs-137the results show that ahigh concentration of Pb-214,Pb-212 within the permissible internationally values ,also the valuable parameters of radium and the external and internal hazard and the dose effect where its found to be permissible internationally.

View Publication Preview PDF
Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Effect of Gamma Radiation on Callus Induction and Plant Regeneration of four Wheats Triticum aestivum L. Genotypes

The effect of gamma radiation at the doses (0 , 5 , 10 or 15 ) Gray on the callus of four Triticum aestivum immature embryos genotypes (AL-Hashmiya , AL-Noor AL-Zahraa and AL-Mellad ) were studied . The fresh and dry weight for callus and shoot tips beside numbers and lengths of the shoots were used as indicators after 8 weeks . Results revealed that (AL-Noor and AL-Zahraa ) was superior by giving highest fresh and dry weight reached 274.2 and 269.2 mg and 26 and 24.3 mg respectively as compared with AL-Hashmiya and AL-Mellad. Moreover, the control treatment and the dose 10 Gray gave highest fresh weight reached 277.4 and 259.1 mg while the dry weight was highest in the control treatment and the dose 5 Gray. addition 10 Gra

... Show More
Crossref
View Publication Preview PDF
Publication Date
Sat Oct 01 2011
Journal Name
Journal Of Engineering
MAGNETO HYDRODYNAMIC NATURAL CONVECTION FLOW ON A VERTICAL CYLINDER WITH A PRESENCE OF HEAT GENERATION AND RADIATION

The present work investigates the effect of magneto – hydrodynamic (MHD) laminar natural convection flow on a vertical cylinder in presence of heat generation and radiation. The governing equations which used are Continuity, Momentum and Energy equations. These equations are transformed to dimensionless equations using Vorticity-Stream Function method and the resulting nonlinear system
of partial differential equations are then solved numerically using finite difference approximation. A thermal boundary condition of a constant wall temperature is considered. A computer program (Fortran 90) was built to calculate the rate of heat transfer in terms of local Nusselt number, total mean Nusselt number, velocity distribution as well as te

... Show More
Crossref
View Publication Preview PDF
Publication Date
Fri Nov 24 2023
Journal Name
Iraqi Journal Of Science
Influence of Thermal Radiation and MHD on the Boundary Layer Flow Due to an Exponentially Stretching Sheet

In this paper, the effect of thermal radiation and magnetic field on the boundary layer flow and heat transfer of a viscous fluid due to an exponentially stretching sheet is proposed. The governing boundary layer equations are reduced to a system of ordinary differential equations. The homotopy analysis method (HAM) is employed to solve the velocity and temperature equations.

View Publication Preview PDF
Publication Date
Tue Nov 19 2024
Journal Name
Mustansiria Dental Journal
View Publication
Publication Date
Sun Aug 23 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Development Accounting Rule disclosure by accounting policies in the light of Islamic and electronic banking Activities: Proposal pattern

the bank sect for any country  is very important  because  its represent a major  nerve   to feed a verity economic and finance activities .development any state measure by development  banking  sets and its represent  important  factor to investors attract . and because  important  of this subject ,teen accounting rule is a specialized for it .its related by  Disclosures in the Financial Statements Of Banks and The Similar Institutions, its accredit  by auditing and accounting standard  consul in republic of Iraq.in date 10/28/1998.                      &

... Show More
View Publication Preview PDF
Publication Date
Tue Nov 19 2024
Journal Name
Journal Of Baghdad College Of Dentistry
Assessment of tongue space area in a sample of Iraqi adults with class I dental and skeletal pattern

Background: Lateral cephalometric radiography is commonly used as a standard tool in orthodontic assessment and treatment planning. This study aimed to determine the tongue and surrounding space area in a sample of Iraqi adults with class I dental and skeletal pattern. Materials and methods: The study included thirty healthy subjects (15 males and 15 females) with an age ranged between 23-34 years and class I dental and skeletal pattern with no history of any sleep related disorders. The assessed cephalometric measurement included length and height of the tongue and position of hyoid bone from cervical line. Descriptive statistics were obtained for the data. Genders difference was evaluated by independent sample t-test. Results: There wer

... Show More
View Publication Preview PDF