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
Wed Dec 15 2004
Journal Name
Iraqi Journal Of Laser
Low Power He:Ne Laser Radiation in Killing Photosensitized Helicobacter pylori in Vitro
...Show More Authors

Four photosensitizers were used to test inhibitory effect of Helicobacter pylori bacteria using
low power helium: neon red laser radiation. Biopsies were collected from 176 patients and H. pylori were
isolated, identified and bacterial suspension was prepared. Samples of this suspension were mixed with
various low concentrations of the test sensitizer. The mixture samples were exposed to different laser
radiation doses. The samples were then inoculated and the inhibition zones were studied and compared
with their analogues of control samples. The most effective sensitizer with optimum concentration and
irradiation dose was determined. Statistical analysis of results was performed. The sensitizers' toluidine
blue and

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 13 2011
Journal Name
Iraqi Journal Of Laser
Intra Cellular Fluorescence for Monitoring The Physiological Changes and Biostimulation of Yeast Irradiated with Low Power 532nm CW Nd:YAG Laser
...Show More Authors

The purpose of this study is to investigate the biostimulation effect of 532 nm CW laser on the metabolism of Saccharomyces cerevisiae yeast. Cells were irradiated by 532 nm Nd:YAG laser using 0.153 W/cm2 power density at 30, 45, 60,180 and 300 seconds exposure times in their respective orders. Intrafluorescence parameters were measured by detection the autofluorescence intensity, proliferation rate and Imaging the fluorescent mitochondria using confocal laser scanning microscope. The results showed that the 30 and 45 second exposure times seem to have stimulated changes in the cells that led to increase proliferation, viability and mitochondrial activity. Autofluorescence of cells increased after 45 and 60 seconds exposure time. After 3

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
The analysis of time series considers one of the mathematical and statistical methods in explanation of the nature phenomena and its manner in a specific time period.
...Show More Authors

The analysis of time series considers one of the mathematical and statistical methods in explanation of the nature phenomena and its manner in a specific time period.

Because the studying of time series can get by building, analysis the models and then forecasting gives the priority for the practicing in different fields, therefore the identification and selection of the model is of great importance in spite of its difficulties.

The selection of a standard methods has the ability for estimation the errors in the estimated the parameters for the model, and there will be a balance between the suitability and the simplicity of the model.

In the analysis of d

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Mon Mar 30 2026
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Characterization of fluid properties and pseudo-fraction analysis for oils with low gas oil ratios
...Show More Authors

   The Sadi reservoir is one of the largest and most important unconventional tight oil reservoirs in southern Iraq. However, it suffers from low production rates, necessitating many development strategies that require a correct and reliable characterization of reservoir fluid properties. Whilst these properties are originally obtained from laboratory experiments, measurement errors often occur despite rigorous workflows, which negatively affect the calculation of reservoir fluid properties. This study utilizes the fluid thermodynamics characterization program (PVTp) to generate a reliable model for determining the oil properties of Sadi reservoir. A methodology was developed to simulate fluid thermodynamic tests, including Differ

... Show More
View Publication
Crossref
Publication Date
Sat Dec 01 2018
Journal Name
Al-khwarizmi Engineering Journal
Investigation of Load and Pressure Distribution on Wing with Wake Rollup for Low Speed Aircraft
...Show More Authors

The presented work shows a preliminary analytic method for estimation of load and pressure distributions on low speed wings with flow separation and wake rollup phenomena’s. A higher order vortex panel method is coupled with the numerical lifting line theory by means of iterative procedure including models of separation and wake rollup. The computer programs are written in FORTRAN which are stable and efficient.

      The capability of the present method is investigated through a number of test cases with different types of wing sections (NACA 0012 and GA(W)-1) for different aspect ratios and angles of attack, the results include the lift and drag curves, lift and pressure distributions along the wing s

... Show More
View Publication Preview PDF
Publication Date
Tue Oct 01 2024
Journal Name
Indonesian Journal Of Chemistry
Microwave-Assisted, Preparation, Characterization, and Biological Activities of Schiff Bases Derived from 4-Aminoantipyrine with Acetonyl Acetone for Some New Rare-Earth Metals
...Show More Authors

Five new lanthanide complexes based on azomethine (Schiff bases) ligands have been synthesized, including La, Nd, Er, Gd, and Dy. Complexes were synthesized using the azomethine Schiff bases resulting from condensation reactions between 4-aminoantipyrine and acetonylacetone. The structural characteristics of azomethine obtained are characterized quantitatively and qualitatively through various techniques, including elemental analyses, magnetic susceptibility measurement, molar conductivity, infrared, ultraviolet absorption, GC-mass, and 1H- and 13C-NMR spectroscopy studies. The structural characteristics of Ln+3 complexes indicate that the complexes possess a composition of a specific type. Based on the elemental analyses, magnetic

... Show More
View Publication
Scopus (1)
Crossref (2)
Scopus Crossref
Publication Date
Mon Oct 12 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Validity of computed tomographic in assessment of genial tubercle and anterior mandible as a reference guide to locate osteotomy in genioglossus advancement
...Show More Authors

Background: Genioglossus advancement is a surgical procedure to advance the tongue in some patients with obstructive sleep apnea syndrome.The important step in this procedure is that of accurately capturing the bone segment attached to the genioglossus muscle to avoid complications such as mandibular fracture, devitalization of the inferior incisor roots, and incomplete incorporation of the genioglossus Materials and Method: Computed tomography scans were taken for 53 Iraqi adult patients (28 male and 25 female) range from (18-35) years with skeletal class I classification and intact anterior mandible dentition included in this study using sagittal and axial sections. The measurements were done for genial tubercle and anterior mandibular re

... Show More
View Publication Preview PDF
Publication Date
Fri Aug 20 2021
Journal Name
Iraqi Journal Of Laser
Effect of Low Energy Laser on the Healing of Tooth Extraction Wound: (Histological Study in Rat)
...Show More Authors

Aims: This study was done to investigate the effect of low energy laser therapy on bone healing at the extraction site. Materials and methods:(24) male albino rats were exposed to the extraction procedure of the maxillary first molar on the first day of a seven day experiment and these animals were divided into two main groups; the control group and the laser group. The laser experiment involved using (Ga-As infrared diode laser) from optodent by directing the probe over the extraction site. The control group consisted of 4 rats, and the laser group was subdivided into 5 subgroups of 4 rats each. The laser dose was as follows: B1: a single dose of 5 minutes immediately after extraction.,

... Show More
View Publication Preview PDF
Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
ESTIMATION OF THE OPTIMUM BED THICKNESS OF A FLOWTHROUGH POROUS ELECTRODE (FTPE) WORKING UNDER MASS TRANSFER CONTROL
...Show More Authors

In this paper, a theoretical analysis of optimum bed thickness operates under mass transfer control for realizing a high efficiency and reaction conversion of an electrochemical reactor has been made based on flowthrough porous electrode (FTPE) configuration. Many models have been used to represent the optimum bed thickness by taking a look into previous works concerned and collecting all related information, data, and models. The parameters that affect the optimum bed thickness have been visualized and reviewed, and almost all of them have been examined by experimental data from different sources and based on the various models. It has been found that the increase in electrolyte flow rate, concentration, limiting current density, and sp

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sat Dec 30 2017
Journal Name
Al-khwarizmi Engineering Journal
Low Cost Hardware Back Propagation Algorithm
...Show More Authors

The first successful implementation of Artificial Neural Networks (ANNs) was published a little over a decade ago. It is time to review the progress that has been made in this research area. This paper provides taxonomy for classifying Field Programmable Gate Arrays (FPGAs) implementation of ANNs. Different implementation techniques and design issues are discussed, such as obtaining a suitable activation function and numerical truncation technique trade-off, the improvement of the learning algorithm to reduce the cost of neuron and in result the total cost and the total speed of the complete ANN. Finally, the implementation of a complete very fast circuit for the pattern of English Digit Numbers NN has four layers of 70 nodes (neurons) o

... Show More
View Publication Preview PDF