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Aircraft Lateral-Directional Stability in Critical Cases via Lyapunov Exponent Criterion
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Based on Lyapunov exponent criterion, the aircraft lateral-directional stability during critical flight cases is presented. A periodic motion or limit cycle oscillation isdisplayed. A candidate mechanism for the wing rock limit cycle is the inertia coupling between an unstable lateral-directional (Dutch roll) mode with stable longitudinal (short period) mode. The coupling mechanism is provided by the nonlinear interaction of motion related terms in the complete set equations of motion. To analyze the state variables of the system, the complete set of nonlinear equations of motion at different high angles of attack are solved. A novel analysis including the variation of roll angle as a function of angle of attack is proposed. Furthermore the variation of Lyapunov exponent parameter as function of time is introduced. The numerical result indicated that the system became lightly damped at high angle of attack with increasing the amplitude of aircraft state variables limit cycle. A good agreement between the numerical result and published work is obtained for the onset of limit cycle oscillation, almost at .

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Publication Date
Sat Mar 30 2013
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Studying the Performance of Refrigeration Units Powered by Solar Panel
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An experimental study was conducted to determine the performance of a solar electric refrigeration system. The system contained flat photovoltaic solar panel which absorbs the solar energy and convert it to electrical energy, used to run the refrigeration cycle. Two refrigeration cycles with electrical solar panel were used over a period of 12 months, the first one with classical parts known in refrigeration cycle, while the second one introduced heat exchanger which improves the coefficient of performance by saving the consumed energy. The coefficient of performance of these refrigeration cycles with compressor efficiency 85% are 2.102 and 2.57 respectively. The overall efficiency of the two systems are 18.9% and 23.13%.

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Engineering
Design of a PID-Lead Compensator for a Twin Rotor Aerodynamic System (TRAS)
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This paper deals with a Twin Rotor Aerodynamic System (TRAS). It is a Multi-Input Multi-Output (MIMO) system with high crosscoupling between its two channels. It proposes a hybrid design procedure that combines frequency response and root locus approaches. The proposed controller is designated as PID-Lead Compensator (PIDLC); the PID controller was designed in previous work using frequency response design specifications, while the lead compensator is proposed in this paper and is designed using the root locus method. A general explicit formula for angle computations in any of the four quadrants is also given. The lead compensator is designed by shifting the dominant closed-loop poles slightly to the left in the

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Publication Date
Mon Jan 27 2020
Journal Name
Iraqi Journal Of Science
Software Development for First Aid Decision Support System
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This work presents an approach to deal with modelling a decision support system framework to introduce an application for decisions in medical knowledge system analysis. First aid is extremely important worldwide and, hence, a decision support framework, know as First Aid Decision Support System (FADSS), was designed and implemented to access experimental cases exerting danger to the general population, offering advanced conditions for testing abilities in research and arranging an emergency treatment through the graphical user interface (UI). The design of first aid treatment in FADSS depends on the general cases in first aid. We presented a strategy to manage first aid treatment  by modelling an application (FADSS) that assists pe

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Publication Date
Tue Oct 01 2019
Journal Name
Journal Of Engineering
The Effect of Diyala River Water Quality on the Quality of Tigris River Water using GIS Mapping
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The assessment of a river water’ quality is an essential procedure of monitor programs and is used to collect basic environmental data. The management of integrated water resources in a sustainable method is also necessary to allow future generations to meet their water needs. The main objective of this research is to assess the effect of the Diyala River on Tigris River water quality using Geographic Information System (GIS) technique. Water samples have been collected monthly from November 2017 to April 2018 from four selected locations in Tigris and Diyala Rivers using the grab sampling method. Fourteen parameters were studied which are Turbidity, pH, Dissolved Oxygen, Biological Oxygen Demand, Electrical Conductivi

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Publication Date
Tue Mar 30 2021
Journal Name
Baghdad Science Journal
User-Oriented Preference Toward a Recommender System
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            Nowadays, it is convenient for us to use a search engine to get our needed information. But sometimes it will misunderstand the information because of the different media reports. The Recommender System (RS) is popular to use for every business since it can provide information for users that will attract more revenues for companies. But also, sometimes the system will recommend unneeded information for users. Because of this, this paper provided an architecture of a recommender system that could base on user-oriented preference. This system is called UOP-RS. To make the UOP-RS significantly, this paper focused on movie theatre information and collect the movie database from the IMDb website that provides informatio

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Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
Structural and Optical Properties for Nanostructure (Ag2O/Si & Psi) Films for Photodetector Applications
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Ag2O (Silver Oxide) is an important p-type (in chasm to most oxides which were n-type), with a high conductivity semiconductor. From the optical absorbance data, the energy gap value of the Ag2O thin films was 1.93 eV, where this value substantially depends on the production method, vacuum evaporation of silver, and optical properties of Ag2O thin films are also affected by the precipitation conditions. The n-type and p-type silicon substrates were used  with porous silicon wafers to precipitate  ±125 nm, as thick Ag2O thin film by thermal evaporation techniques in vacuum and via rapid thermal oxidation of 400oC and oxidation time 95 s, then characterized by measurement of

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Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Science
Agriculture Cadaster Map of Al-Shehimea
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The cadastral map is very important because it has technical and materialist
specification of the property borders and these maps which are land registration
based on it in Iraq, the problem is an ancient maps and unfit for use, despite its
importance, Therefor the updating and digitize the cadastral map is very pivotal, this
is what we have done in the present work.
In the present work, we have an old cadastral map (as a paper) was made in 1932
with modern satellite image (Quick Bird ) 2006, which has 61 cm resolution for the
same area after. Geometric correction technique has been applied by using image-toimage
method or (image registration ) and after that we get new agricultural cadaster
map and connect the

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Publication Date
Tue Oct 01 2019
Journal Name
Engineering Journal
the effect of diyala river water qulity on the quality of tigris river water using GIS mapping
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The assessment of a river water’ quality is an essential procedure of monitor programs and isused to collect basic environmental data. The management of integrated water resources in asustainable method is also necessary to allow future generations to meet their water needs. Themain objective of this research is to assess the effect of the Diyala River on Tigris River waterquality using Geographic Information System (GIS) technique. Water samples have beencollected monthly from November 2017 to April 2018 from four selected locations in Tigris andDiyala Rivers using the grab sampling method. Fourteen parameters were studied which areTurbidity, pH, Dissolved Oxygen, Biological Oxygen Demand, Electrical Conductivity, TotalDissolved Solids,

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Publication Date
Fri Jun 24 2022
Journal Name
Iraqi Journal Of Science
Determination local geoid Heights Using RTK-DGPS/Leveling and transformation methods
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Geodesy is concerned with the relative positioning of points and the gravity field of the earth. For this task, a well-defined coordinate system is needed on which measurements are normally tied to a set of reference points called a geodetic datum (geoid or ellipsoid). The Global Positioning System GPS gives accurately the three-dimensional position of a point (latitude, longitude, and ellipsoidal height) and can measure under all weather conditions. The coordinates of the GPS reference to the World Geodetic System1984 (WGS 84), a global ellipsoid having its origin as the mass center of the earth, and height, referenced to the surface of the ellipsoid . In this research , using RTK-DGPS technique Data collection for study local and level

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Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
High Order Sliding Mode Observer-Based Output Feedback Controller Design For Electro-Hydraulic System
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A perturbed linear system with property of strong observability ensures that there is a sliding mode observer to estimate the unknown form inputs together with states estimation. In the case of the electro-hydraulic system with piston position measured output, the above property is not met. In this paper, the output and its derivatives estimation were used to build a dynamic structure that satisfy the condition of strongly observable. A high order sliding mode observer (HOSMO) was used to estimate both the resulting unknown perturbation term and the output derivatives. Thereafter with one signal from the whole system (piton position), the piston position make tracking to desire one with a simple linear output feedback controller after ca

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