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 Aug 09 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A Study of the Change of the Total Solar Radiation Above Baghdad City for the Period from 1985.1989 By Using Satellite Antenna Data
...Show More Authors

 The solar radiation plays an important role on the energy balance of the earthatmosphere, which is the main source of energy.  Also the solar radiation is a main factor of all applications which use a solar energy as renewable energy source.  The purpose of this research is to study the monthly average changes for solar radiation for the period from 1985 to 1989 by using satellite Antenna Alignment from (NASA). The result shows that the monthly average radiation changes from one year to another because of the changing of it component of atmosphere, (gases, clouds and Aerosols) and as an enhancement for this conclusion, we compared the results with the monthly average radiation at clear atmosphere where the change was slig

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 14 2014
Journal Name
Al-khwarizmi Engineering Journal
Determination of Optimum Welding Parameters for FSW AA2024-T351
...Show More Authors

 

Abstract

Friction stir welding is a relatively new joining process, which involves the joining of metals without fusion or filler materials. In this study, the effect of welding parameters on the mechanical properties of aluminum alloys AA2024-T351 joints produced by FSW was investigated.

Different ranges of welding parameters, as input factors, such as welding speed (6 - 34 mm/min) and rotational speed (725 - 1235 rpm) were used to obtain their influences on the main responses, in terms of elongation, tensile strength, and maximum bending force. Experimental measurements of main responses were taken and analyzed using DESIGN EXPERT 8 experimental design software which was used to develop t

... Show More
View Publication Preview PDF
Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
OPTIMUM WATER ALLOCATION FOR ABO-ZIRIQ MARSH ECOLOGICAL RESTORATION
...Show More Authors

Optimum allocation of water for restoration of Iraqi marshes is essential for different related authorities. Abo-Ziriq marsh area about 120 km2 is situated 40 km east of Al-Nassryia city. After comparing the measured annual water qualities with the Iraqi standards for surface water quality evaluation, Abo-Ziriq marsh water quality was in acceptable limit. Hydro balance computation were done for each month by using interface among the HEC-RAS, HEC-GeoRAS and ArcView GIS software and built a number of eco-hydro relationships to simulate the marsh ecosystem by using HEC-EFM program to estimate water allocation adequate for ecosystem requirement and constructs a GIS hydraulic reference map to show inundation area, depth grid and velocity dis

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sat Dec 15 2018
Journal Name
Journal Of Baghdad College Of Dentistry
The accuracy of ridge mapping procedure in determining the alveolar ridge width
...Show More Authors

Background: Post-extraction alveolar ridge resorption is unavoidable phenomenon ending with insufficient ridge width. Measuring the physical dimensions of the available bone before implant surgery is an important aspect of diagnosis and treatment planning. Bone height can be calculated from radiographs, while bucco-lingual ridge width can be measured by conventional tomography, CT scanning and ridge mapping.

Radiographic techniques have certain disadvantages. Therefore the ridge mapping technique was used as an option for determining alveolar ridge width.

The purpose of this study was to compare the validity of alveolar ridge width measurements obtained with ridge mapping technique before surgical flap reflection against

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Sat Dec 01 2018
Journal Name
Political Sciences Journal
The Patterns of the Strategic Environment and its Role in Determining Strategies for Dealing with Conflict and Peace Situations
...Show More Authors

Abstract

The decision maker needs to understand the strategic environment to be addressed through different means and methods. It is obvious that there is a difference between the three strategic environments (conflict environment, peace environment, post- peace environment) in terms of inputs and strategies to deal with each one of them. There is an urgent need to understand each pattern separately, analyze its inputs, and identify the factors and variables that affect the continuity of this situation (conflict, peace, post-peace). It is not appropriate to identify treatment without diagnosis of the condition, so it is very important to understand the type of strategic environment to be dealt with it.

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Mon Dec 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
USING SENSITIVITY ANALYSIS IN DETERMINING THE OPTIMAL&EFFICIENT PRODUCTION PLANS IN GREENHOUSES IN ASSOCIATION OF AL-WATAN UNDER CONDITION OF RISK &UNCERTAINTY
...Show More Authors

 The objectives of this research are to determine and find out the reality of crops structure of greenhouses in association of Al-Watan  in order to stand on the optimal use of economic resources available for the purpose of reaching a crop structure optimization of the farm that achieves maximize profit and gross and net farm incomes , using the method of linear programming to choose the farm optimal plan with the highest net income , as well as identifying production plans farm efficient with (income - deviation) optimal (E-A) of the Association and derived, which takes into account the margin risk wich derived from each plan using the model( MOTAD), as a model of models of linear programming alternative programming m

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jan 01 2015
Journal Name
Al–bahith Al–a'alami
News coverage of Arab revolutions in satellite channels An analytical study of the news bulletins in Al - Tijah satellite channel
...Show More Authors

The news media material to any means of mass media, and increasingly

 important in TV; what the associated word and image effects, which do different cover events (political, economic, sports, and social .... etc.) directly from the event site and gather the news and do prepared formulation and arranged within the framework provided by the newsletter, as it requires the viewer to provide the public with information about this news correlated; to achieve the greatest gravity following the shapes and styles and technical fees (Alkraveks) during the submission. What we are witnessing today from technological developments help existing staff to cover the news activity quickly and efficiently prohibitivel

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jan 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Birefringence for Elliptical-Core Fibers with Low Ellipticities
...Show More Authors

Model birefringence was measured for elliptical-core fibers with low ellipticities, note the birefringence depends strongly on the frequency, especially when fiber is being operated near the higher mode cutoff where ν  for circular fiber of the single-mode type that correspond to the birefringence maximum. When ν  this also correspond to the birefringence maximum that can be introduced in an elliptical core fiber while still operating in the single-mode regime near the higher mode cutoff. Also the birefringence is proportional to the fiber core ellipticity when core ellipticity is much less than unity, but this birefringence deviates from the linear for the large core ellipticities.

View Publication Preview PDF
Crossref
Publication Date
Fri Jul 12 2024
Journal Name
World Water Policy
The effect of natural factors on changing soil uses in the marshes: An experimental study using Landsat satellite data
...Show More Authors

The study aimed to analyze the effect of meteorological factors (rainfall rate and temperature) on the change in land use in the marshes of the Al‐Majar Al‐Kabir region in southern Iraq. Satellite images from Landsat 7 for 2012 and Landsat 8 for 2022 were used to monitor changes in the land coverings, the images taken from the Enhanced Thematic Mapper Plus (ETM+) and Operational Land Imager (OLI) sensors of the Landsat satellite. Geometric correction was used to convert images into a format with precise geographic coordinates using ArcMap 10.5. The maximum likelihood classification method was used to examine satellite image data using a supervised approach, and the data were analyzed statistically. We obtained clear images of the area,

... Show More
View Publication
Scopus Crossref
Publication Date
Sun Mar 01 2009
Journal Name
Diyala Journal Of Human Research
Stability of the Finite Difference Methods of Fractional Partial Differential Equations Using Fourier Series Approach
...Show More Authors

The fractional order partial differential equations (FPDEs) are generalizations of classical partial differential equations (PDEs). In this paper we examine the stability of the explicit and implicit finite difference methods to solve the initial-boundary value problem of the hyperbolic for one-sided and two sided fractional order partial differential equations (FPDEs). The stability (and convergence) result of this problem is discussed by using the Fourier series method (Von Neumanns Method).

View Publication Preview PDF