Preferred Language
Articles
/
ijp-726
Simulation of Small Radio Telescope Antenna Parameters at Frequency of 1.42 GHz
...Show More Authors

The paper presents an overview of theoretical aspects of small radio telescope antenna parameters. The basic parameters include antenna beamwidth, antenna gain, aperture efficiency, and antenna temperature. These parameters should be carefully studied since they have vital effects on astronomical radio observations. The simulations of antenna parameters were carried out to assess the capability and the efficiency of small radio telescopes to observe a point source at a specific frequency. Two-dimensional numerical simulations of a uniform circular aperture antenna are implemented at different radii. The small diameter values are chosen to be varied between (1-10) m. This study focuses on a small radio telescope with a diameter of 3 m since this telescope is very common in the world. The simulated results of this study illustrated that the power pattern of a 3 m antenna has a half-power beamwidth of approximately 5 degrees. Also, the maximum peak antenna temperature is estimated to be more than 3000 K. All of these results were in good agreement with observations of the neutral hydrogen spectral line at the frequency of 1.42 GHz using a small radio telescope.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Mar 03 2025
Journal Name
Iop Conference Series: Earth And Environmental Science
Study on Frequency of Hard Tick Isolated from Goat (<i>Capra hircus</i> Linnaeus, 1758) in Iraq
...Show More Authors
Abstract<p>In Iraq, the domestic goat <italic>Capra hircus</italic> is valued as a valuable commercial resource. As obligatory ectoparasites, ixodid ticks cause significant harm to their animal hosts. Hard ticks parasitize the abdomen, inside limbs, ears, and head. Out of a total of 200 samples evaluated, 150 goat- infested samples had a total of 450 Hard ticks (303male and 147 female) and were infested at a rate of 75%. The results of the current research eight species of hard ticks were recognized. Goat species belonging to the family Ixodidae (Capra hircus: Linnaeus, 1758), obtained from distinct areas involving: the Iraqi capital Baghdad governorate [Al-Yusifiya], Al-Anbar governor</p> ... Show More
View Publication
Scopus Crossref
Publication Date
Sun Jul 02 2023
Journal Name
Journal Of Pakistan Association Of Dermatologists
The frequency of acute radiodermatitis and associated risk factors among patients with breast cancer treated by radiotherapy
...Show More Authors

Background: Acute radiodermatitis is a common side effect during and after radiotherapy course in breast cancer patients treated by radiotherapy. This study assess the frequency of acute radiodermatitis and record the predictive factors for acute radiodermatitis. Patients and Methods: A descriptive case series study conducted at Baghdad, Iraq from August 2020 to September 2021. 70 female scheduled for radiotherapy sessions enrolled in this study. sociodemographic data were recorded and Skin examination before radiotherapy and weekly till the end of the radiotherapy sessions was done to report the frequency, risk factors, clinical picture and grades of acute radiodermatitis based on The National Cancer Institute’s Common Terminology Crite

... Show More
View Publication Preview PDF
Scopus
Publication Date
Tue Jun 21 2022
Journal Name
Peerj Computer Science
Performance evaluation of frequency division duplex (FDD) massive multiple input multiple output (MIMO) under different correlation models
...Show More Authors

Massive multiple-input multiple-output (massive-MIMO) is considered as the key technology to meet the huge demands of data rates in the future wireless communications networks. However, for massive-MIMO systems to realize their maximum potential gain, sufficiently accurate downlink (DL) channel state information (CSI) with low overhead to meet the short coherence time (CT) is required. Therefore, this article aims to overcome the technical challenge of DL CSI estimation in a frequency-division-duplex (FDD) massive-MIMO with short CT considering five different physical correlation models. To this end, the statistical structure of the massive-MIMO channel, which is captured by the physical correlation is exploited to find sufficiently

... Show More
View Publication
Scopus (5)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Sun Jul 02 2023
Journal Name
Journal Of Pakistan Association Of Dermatologists
Acute cutaneous side effects of radiotherapy in patients with pelvic cancer: Frequency, severity and risk factors estimation
...Show More Authors

Background  Radiotherapy is one of the main modalities in the management of cancer along with chemotherapy and surgery. Despite its great benefit it has many side effects on many systems and organs including the skin.   Objective To record the frequency, grades and types of acute cutaneous side effect in patients with pelvic tumors treated with radiotherapy, in order to report the risk factors and to find appropriate strategies for prevention and management. Patient and methods.   Methods A prospective observational study was carried out in Baghdad Radiation and Nuclear Medicine Centre between August 2020 and August 2021.A total 70 patients were enrolled in this study.All patients had full history and full baseline skin exam and were ass

... Show More
View Publication Preview PDF
Scopus
Publication Date
Sun Mar 01 2020
Journal Name
Baghdad Science Journal
Discussing Fuzzy Reliability Estimators of Function of Mixed Probability Distribution By Simulation
...Show More Authors

This paper deals  with constructing mixed probability distribution  from exponential with scale parameter (β) and also Gamma distribution with (2,β), and the mixed proportions are (  .first of all, the probability density function (p.d.f) and also cumulative distribution function (c.d.f) and also the reliability function are obtained. The parameters of mixed distribution, ( ,β)  are estimated by three different methods, which are  maximum likelihood, and  Moments method,as well proposed method (Differential Least Square Method)(DLSM).The comparison is done using simulation procedure, and all the results are explained in tables.

View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Thu Mar 09 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Simulation Study of Sputtering Yield of Zn Target Bombarded By Xenon Ions
...Show More Authors

    Using a reduction of TRIM simulation data, the sputtering yield behaviour of Zinc target bombard by heavy Xenon ions plasma is studied. The sputtering yield as a function of Zinc layer width, Xenon ion number, energy of ions, and the angle of ion incidence are calculated and illustrated graphically. The corresponding energy loss due to ionization, vacancies and phonons, are graphically shown and discussed. Further, we fit the calculations and expressions for fitted curves are presented with its coefficients.

View Publication Preview PDF
Publication Date
Thu Nov 02 2023
Journal Name
Journal Of Engineering
Numerical Simulation of the Thermal Performance of a Tubular Solar Air Heater
...Show More Authors

In this work, a flat-plate solar air heater (FSAH) and a tubular solar air heater (TSAH) were designed and tested numerically. The work investigates the effect of increasing the contact area between the flowing air and the absorber surface of each heater and predicts the expected results before the fabrication of the experimental rig. Three-dimensional two models were designed and simulated by the ANSYS-FLUENT 16 Program. The solar irradiation and ambient air temperature were measured experimentally on December 1st 2022, at the weather conditions of Baghdad City- Iraq, at three air mass flow rates, 0.012 kg/s, 0.032 kg/s, and 0.052 kg/s. The numerical results showed the advantage in the thermal performance of

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Aug 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
Simulation of Sediment Transport in the Upper Reach of Al-Gharraf River
...Show More Authors
Abstract<p>For the past few years, the sediment began to accumulate in Al-Gharraf River which reduces the flow capacity of the River. In the present research, a numerical model was developed using Hec-Ras software, version 5.0.4. to simulate the flow and sediment transport in the upper reach of the river. The hydrological and cross-section data measured by the Ministry of Water Resources, for the reach located between Kut and Hai cities and having a length of 58200 m, was used to perform calibration and verification of the model. Moreover, field sampling of suspended and bed loads was gathered for five months starting from 7/2/2019, and laboratory tests of samples were conducted to be used as in</p> ... Show More
View Publication
Scopus (7)
Crossref (1)
Scopus Crossref
Publication Date
Mon Aug 01 2016
Journal Name
Arpn Journal Of Engineering And Applied Sciences
SURVEY ON VANET TECHNOLOGIES AND SIMULATION MODELS
...Show More Authors

Vehicular ad hoc network (VANET) is a distinctive form of Mobile Ad hoc Network (MANET) that has attracted increasing research attention recently. The purpose of this study is to comprehensively investigate the elements constituting a VANET system and to address several challenges that have to be overcome to enable a reliable wireless communications within a vehicular environment. Furthermore, the study undertakes a survey of the taxonomy of existing VANET routing protocols, with particular emphasis on the strengths and limitations of these protocols in order to help solve VANET routing issues. Moreover, as mobile users demand constant network access regardless of their location, this study seeks to evaluate various mobility models for vehi

... Show More
View Publication Preview PDF
Publication Date
Mon Jun 05 2023
Journal Name
Journal Of Economics And Administrative Sciences
Fuzzy Bridge Regression Model Estimating via Simulation
...Show More Authors

      The main problem when dealing with fuzzy data variables is that it cannot be formed by a model that represents the data through the method of Fuzzy Least Squares Estimator (FLSE) which gives false estimates of the invalidity of the method in the case of the existence of the problem of multicollinearity. To overcome this problem, the Fuzzy Bridge Regression Estimator (FBRE) Method was relied upon to estimate a fuzzy linear regression model by triangular fuzzy numbers. Moreover, the detection of the problem of multicollinearity in the fuzzy data can be done by using Variance Inflation Factor when the inputs variable of the model crisp, output variable, and parameters are fuzzed. The results were compared usin

... Show More
View Publication Preview PDF
Crossref