Preferred Language
Articles
/
alkej-156
Aircraft Lateral-Directional Stability in Critical Cases via Lyapunov Exponent Criterion

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 .

View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Educational And Psychological Researches
The psychometric Properties of Emotional Stability scale among university students according to the response theory

The current research aims at extracting the standard characteristics of the emotional balance of the university students according to the response theory. This was accomplished by following accredited scientific steps, to achieve this goal, the researcher followed scientific steps in the procedures of the analysis of the scale. She translated the scale from English to Arabic and then made a reverse translation. it was presented to a committee of experts in English to ensure and verify the validity of the paragraphs logically and prove the face validity of the scale, which consists of (30) paragraphs, it was presented to (6) experts who are specialists in the educational and psychological sciences and in the light of their observations ha

... Show More
View Publication Preview PDF
Publication Date
Wed Oct 17 2018
Journal Name
Journal Of Economics And Administrative Sciences
Study About The Robustness Of The Bayesian Criterion

In this research work an attempt has been made to investigate about the Robustness of the Bayesian Information criterion to estimate the order of the autoregressive process when the error of this model,  Submits to a specific distributions and different cases of the time series on various size of samples by using the simulation,  This criterion has been studied by depending on ten distributions, they are (Normal, log-Normal, continues uniform, Gamma , Exponential, Gamble, Cauchy, Poisson, Binomial, Discrete uniform) distributions, and then it has been reached to many collection and recommendations related to this object , when the series residual variable is subject to each  ( Poisson , Binomial , Exponential , Dis

... Show More
Crossref
View Publication Preview PDF
Publication Date
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
Preparation of Industrial Greases from Aircraft Waste Oils

The aim of this research is to benefit from recycl the aircraft waste oils which is discarded in sewage network, to be used in preparation of greases for industrial purposes and to reduce the environmental pollution. In this research synthetic greases were prepared with special specifications by mixing the waste oils after treating with (silica gel as adsorbent agent, and filtration to precipitate impurities then heated to 110 C? to get rid of water) bentonite produced in Iraq which is available and cheap with existence of high density polyethylene at specific conditions of ( heating and mixing) . The best weight proportion were reached, then paraffin wax and additives were added to improve the properties of grease and give the

... Show More
Crossref
View Publication Preview PDF
Publication Date
Mon Jun 01 2020
Journal Name
Journal Of The College Of Languages (jcl)
Criterion of Scientific Translation: Criterios de la traducción

This research focuses on shedding light on the most important criteria by which the translator can achieve total success with regard to the translation of scientific texts whose written language in Spanish is greatly influenced by expressions and words adopted from the English language and other world languages, in addition to exposing the most outstanding difficulties that translators face when translating from Spanish to Arabic, giving the most appropriate solutions in this regard.

Resumen

El presente trabajo de investigación se centra en echar luz sobre los criterios más importantes por los cuales el traductor puede conseguir el total éxito en la traducción de los textos científicos cuyo lenguaje

... Show More
Crossref
View Publication Preview PDF
Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Engineering
Numerical and Experimental Analysis of Aircraft Wing Subjected to Fatigue Loading

This study deals with the aircraft wing analysis (numerical and experimental) which subjected to fatigue loading in order to analyze the aircraft wing numerically by using ANSYS 15.0 software and experimentally by using loading programs which effect on fatigue test specimens at laboratory to estimate life of used metal (aluminum alloy 7075-T651) the wing metal and compare between numerical and experimental work, as well as to formulate an experimental mathematical model which may find safe estimate for metals and most common alloys that are used to build aircraft wing at certain conditions. In experimental work, a (34) specimen of (aluminum alloy 7075-T651) were tested using alternating bending fatigue machine rig. The t

... Show More
View Publication Preview PDF
Publication Date
Wed Dec 29 2021
Journal Name
Al-khwarizmi Engineering Journal
Analysis of Magnetorheological Normally Close Directional Control Valve

This valve is intended for use in valves for steering movement, using the qualities of the Magneto-rheological (MR) fluid to regulate the fluid, direct contact without the utilization of moving parts like a spool, a connection between electric flux, and fluid power was made, The simulation was done to employ the" finite element method of magnetism (FEMM)" to arrive at the best design. This software is used for magnetic resonance valve finite element analysis. The valve's best performance was obtained by using a closed directional control valve in the normal state normally closed (NC) MR valve, with simulation results revealing the optimum magnetic flux density in the absence of a current and the shedding condition, as well as the optimum pr

... Show More
Preview PDF
Publication Date
Tue Nov 01 2011
Journal Name
Advanced Materials Research
Experimental Test of Magneto-Rheological Directional Control Valve

Directional control valve is the main part in hydraulic system which has complex construction, such as moving spool to control the direction of actuator for required speed. Utilizing MR fluid properties, direct interface can be realized between magnetic field and fluid power without the need for moving parts like spool in directional control valves. This paper dedicates the experimental test of four ways, three position MR directional control valve. The experimental methods were done by connecting the MR directional control valve with hydraulic actuators. The experiment was conducted to show the principle work of the valve functionally and performance test for valve was done. The valve works proportionally to control the direction a

... Show More
Scopus (4)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Sun Oct 02 2016
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Assessment of early side effects of radiotherapy in breast cancer patients

Background: Breast cancer is the commonest cancer in women. In radiotherapy practice, it comprises 25% of patient caseload. This makes understanding the breast irradiation toxicities of prime importance. Early radiation toxicities occur during treatment and up to six months after treatment finished.
Objectives: assessment of the early side effects of adjuvant external beam radiotherapy (EBRT) in breast cancer patients.
Patients and Methods: A cross sectional survey with analytic component conducted on 60 patients treated in the oncology teaching hospital of medical city from January to April 2016.
Results: The most prevalent toxicities were radiation dermatitis, fatigue, pain, sore throat, nausea, dysphagia,&

... Show More
Crossref
View Publication Preview PDF
Publication Date
Tue Nov 19 2024
Journal Name
Journal Of Baghdad College Of Dentistry
The value of lateral cephalometric image in sex identification

Background: Determination of sex and estimation of stature from the skeleton is vital to medicolegal investigations. Skull is composed of hard tissue and is the best preserved part of skeleton after death, hence, in many cases it is the only available part for forensic examination. Lateral cephalogram is ideal for the skull examination as it gives details of various anatomical points in a single radiograph. This study was undertaken to evaluate the accuracy of digital cephalometric system as quick, easy and reproducible supplement tool in sex determination in Iraqi samples in different age range using certain linear and angular craniofacial measurements in predicting sex. Materials and Method The sample consisted of 113of true lateral cepha

... Show More
View Publication Preview PDF
Publication Date
Mon Mar 01 2021
Journal Name
Al-khwarizmi Engineering Journal
Hurst Exponent and Tsallis Entropy Markers for Epileptic Detection from Children

The aim of the present study was to distinguish between healthy children and those with epilepsy by electroencephalography (EEG). Two biomarkers including Hurst exponents (H) and Tsallis entropy (TE) were used to investigate the background activity of EEG of 10 healthy children and 10 with epilepsy. EEG artifacts were removed using Savitzky-Golay (SG) filter. As it hypothesize, there was a significant changes in irregularity and complexity in epileptic EEG in comparison with healthy control subjects using t-test (p< 0.05). The increasing in complexity changes were observed in H and TE results of epileptic subjects make them suggested EEG biomarker associated with epilepsy and a reliable tool for detection and identification of this di

... Show More
Crossref (2)
Crossref
View Publication Preview PDF