Preferred Language
Articles
/
rRh1AJYBVTCNdQwCm4BH
Determining the Optimum Reference Orbits Using Lagrange’s Series for Geocentric Satellite in Low Earth Orbit
...Show More Authors

The Taylor series is defined by the f and g series. The solution to the satellite's equation of motion is expanding to generate Taylor series through the coefficients f and g. In this study, the orbit equation in a perifocal system is solved using the Taylor series, which is based on time changing. A program in matlab is designed to apply the results for a geocentric satellite in low orbit (height from perigee, hp= 622 km). The input parameters were the initial distance from perigee, the initial time, eccentricity, true anomaly, position, and finally the velocity. The output parameters were the final distance from perigee and the final time values. The results of radial distance as opposed to time were plotted for dissimilar times in seconds and their comparison with the exact solution, with the aim of selecting an optimized reference orbit at a height of 622 km. The results indicated that the two series diverged excessively as the time increased from the exact solution, excluding the time of 850 sec. The f and g series had a little shift. Besides, the root mean square error (rmse) is computed for 750 sec. It was about 5 for the two series before diverging at about 180 sec and rapidly growing with time. For 850 sec, the (rmse) is approaching 10 for the two series and increasing quickly over time. So, the (rmse) is directly proportional to time, which means that as time increases, the diverging behavior and the value of the (rmse) will also increase. If more terms (Δt) are used for the two series and more time is included, the two series will deviate from the exact solution. The program's results are compared to other published studies in this field; they demonstrated high convergence.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Mar 30 2025
Journal Name
Samarra Journal Of Engineering Science And Research
Proposed low Xilinx FPGA power consumption for recursive NOMA applied in optical visible light communication
...Show More Authors

Today the NOMA has exponential growth in the use of Optical Visible Light Communication (OVLC) due to good features such as high spectral efficiency, low BER, and flexibility. Moreover, it creates a huge demand for electronic devices with high-speed processing and data rates, which leads to more FPGA power consumption. Therefore; it is a big challenge for scientists and researchers today to recover this problem by reducing the FPGA power and size of the devices. The subject matter of this article is producing an algorithm model to reduce the power consumption of (Field Programmable Gate Array) FPGA used in the design of the Non-Orthogonal Multiple Access (NOMA) techniques applied in (OVLC) systems combined with a blue laser. However, The po

... Show More
View Publication Preview PDF
Publication Date
Wed Dec 01 2021
Journal Name
Journal Of Molecular Liquids
The development of new homogenous and heterogeneous catalytic processes for the treatment of low grade palm oil
...Show More Authors

Low grade crude palm oil (LGCPO) presents as an attractive option as feedstock for biodiesel production due to its low cost and non-competition with food resources. Typically, LGCPO contains high contents of free fatty acids (FFA), rendering it impossible in direct trans-esterification processes due to the saponification reaction. Esterification is the typical pre-treatment process to reduce the FFA content and to produce fatty acid methyl ester (FAME). The pre-treatment of LGCPO using two different acid catalysts, such as titanium oxysulphate sulphuric acid complex hydrate (TiOSH) and 5-sulfosalicylic acid dihydrate (5-SOCAH) was investigated for the first time in this study. The optimum conditions for the homogenous catalyst (5-SOCAH) wer

... Show More
Scopus (12)
Crossref (13)
Scopus Clarivate Crossref
Publication Date
Fri Oct 21 2022
Journal Name
Surgical Neurology International
SNI/SNI Digital-Baghdad neurosurgery educational series
...Show More Authors
Background:

Access to high-quality neurosurgery online learning is limited in low- and middle-income countries, and Iraq is part of this category. The need for collaboration and connection of people worldwide to exchange ideas and experiences in neurosurgery is a challenge. Surgical Neurology International® (SNI)/SNI Digital stimulated the establishment of the joint effort to bring the discussion about the best experiences in neurosurgery from the United States and Iraq together in an internet meeting format.

Methods:

An online survey was formulated and distributed to the attendees of the SNI-Baghdad neurosurgery

... Show More
View Publication Preview PDF
Scopus (7)
Crossref (7)
Scopus Crossref
Publication Date
Sat Apr 15 2023
Journal Name
Journal Of Mechanical Engineering
Corrosion Resistance Enhancement for Low Carbon Steel by Gas Phase Coating
...Show More Authors

Corrosion Resistance Enhancement for low carbon steel is very important to extend its life service, the coating process is one of the methods which can using to achieve this, and it's the most important in surface treatments to improve the properties of metals and alloys surfaces such as corrosion resistance. In this work, low carbon steel was nitrided and coated with nano zinc using gas phase coating technical, to enhance the resistance of corrosion. The process included adding two layers. The first, a nitride layer, was added by precipitating nitrogen (N) gas, and the second, a zinc (Zn) layer, was added by precipitating Zn. The process of precipitating was carried out at different periods (5, 10, and 15 minutes). Scan electron mi

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (3)
Scopus Crossref
Publication Date
Tue Jan 12 2016
Journal Name
Wireless Networks
Low communication cost (LCC) scheme for localizing mobile wireless sensor networks
...Show More Authors

In recent years, the number of applications utilizing mobile wireless sensor networks (WSNs) has increased, with the intent of localization for the purposes of monitoring and obtaining data from hazardous areas. Location of the event is very critical in WSN, as sensing data is almost meaningless without the location information. In this paper, two Monte Carlo based localization schemes termed MCL and MSL* are studied. MCL obtains its location through anchor nodes whereas MSL* uses both anchor nodes and normal nodes. The use of normal nodes would increase accuracy and reduce dependency on anchor nodes, but increases communication costs. For this reason, we introduce a new approach called low communication cost schemes to reduce communication

... Show More
View Publication
Scopus (34)
Crossref (27)
Scopus Clarivate Crossref
Publication Date
Wed Aug 30 2023
Journal Name
Mathematical Modelling Of Engineering Problems
Dynamic Low Power Clustering Strategy in MWSN
...Show More Authors

View Publication
Scopus (1)
Scopus Crossref
Publication Date
Thu Feb 07 2019
Journal Name
Iraqi Journal Of Laser
Evaluation of Low Level Laser Therapy using 785 nm Diode Laser on the Enhancement of Chronic Wound Healing
...Show More Authors

Low-intensity laser irradiation has been explored as an alternative, non-invasive method to encourage chronic wounds to heal. This study aimed to evaluate the effects of low level laser therapy (biostimulation) using semiconductor diode laser with wavelength (785 nm) on the enhancement of chronic wound healing. Fifty patients with chronic wounds were selected to be treated with Low Level Laser Therapy. Their ages ranged between 1 to 76 years. The wound sites were distributed in the lower limb, upper limb, trunk , perineum and head (70%,14%,12%,2%,2%, respectively). Application of laser therapy by noncontact method few millimeters from the skin for 15 minutes per one session twice weekly for two months ; ie,16 sessions for each patient. R

... Show More
View Publication Preview PDF
Publication Date
Sat Feb 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
Applying some hybrid models for modeling bivariate time series assuming different distributions for random error with a practical application
...Show More Authors

Abstract

  Bivariate time series modeling and forecasting have become a promising field of applied studies in recent times. For this purpose, the Linear Autoregressive Moving Average with exogenous variable ARMAX model is the most widely used technique over the past few years in modeling and forecasting this type of data. The most important assumptions of this model are linearity and homogenous for random error variance of the appropriate model. In practice, these two assumptions are often violated, so the Generalized Autoregressive Conditional Heteroscedasticity (ARCH) and (GARCH) with exogenous varia

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Feb 25 2019
Journal Name
Iraqi Journal Of Physics
Determining the concentrations of radon and the rate of annual effective dose in some types of drinking water available in the Iraqi markets
...Show More Authors

           In this research, radon concentrations in some types of healthy drinking water samples available in Iraq's market were measured using a technique called Durridge RAD-7-H2O with closed loop. Then the rate of annual effective dose in human taken this water is determined.

          It was found that, radon concentrations in studied samples ranged between 1.2 Bq.m-3 to 142 Bq.m-3. The results of the radon concentrations and the rate of annual effective dose for drinking water samples were significantly lower than the USEPA and WHO recommended limits that equal 500 Bq/m3 and 1 mSv/y resp

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Al–bahith Al–a'alami
The Role of Iraqi TV Satellite Channels in Forming the Attitudes of University Students towards Terror-ism
...Show More Authors

            The phenomenon of terrorism is one of the most serious challenges facing the world at present. So this concept has occupied a great deal of interest of researchers and scholars in the relevant disciplines. There is no doubt that the study of the concept of terrorism requires a study of its various aspects. However, this study will be limited to knowing the role of television channels in providing the public with information about terrorist events, the extent to which young people rely on these channels to shape their attitudes towards terrorism issues. This study also seeks the relationship between satellite television channels and terrorism based on the relevant media li

... Show More
View Publication Preview PDF
Crossref (1)
Crossref