Preferred Language
Articles
/
5WGWI5kBdMdGkNqjrROy
Aeroelastic response and limit cycle oscillations for wing-flap-tab section with freeplay in tab
...Show More Authors

A linear and nonlinear theoretical and experimental aeroelastic investigation of a wing-flap-tab typical section model undergoing two-dimensional incompressible airflow is described. The linear flutter velocity (LFV) and frequency are predicted using linear analysis. Then a freeplay structural nonlinearity is considered in the tab. The structural equations of motion have been coupled with Theodorsen aerodynamic theory to produce the theoretical aeroelastic model which is analyzed by a state space method to predict the LFV and flutter frequency. Linear piecewise function has been used to introduce the tab spring stiffness in the freeplay state. The ground vibration test is used to measure the model structural dynamic characteristics. Then the experimental aeroelastic model is placed in a low speed wind tunnel to measure the LFV and the limit cycle oscillation (LCO) of the physical model induced by freeplay. The root main square amplitude value of the pitch, flap pitch, tab pitch and plunge degrees of freedom of the tab nonlinearities are normalized with freeplay gap size to produce a bifurcation diagram with normalized airflow velocity as the bifurcation parameter. The results show that the LCO frequency jumps from low to high frequency at a yet higher flow velocity. At the same flow velocity, the pitch and plunge motion response amplitudes drop while the flap pitch and tab pitch degrees of freedom response amplitude increase. In general the experimental measured LCO is more complicated than the theoretically calculated LCO in terms of the harmonic content of the response. On the other hand there is good agreement between the theoretical and experimental result of the linear system as well the LCO for the tab freeplay nonlinearities

Scopus Clarivate Crossref
View Publication
Publication Date
Fri Jun 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Dumping and Its Challenges in Extent of World Trade Organization "Models for selected Agricultural Goods"
...Show More Authors

The subject of dumping is considering today one of the subjects in which form an obstruction arise in front of the cycle of growth for some countries , such as the study of dumping is capturing a large attention by the competent because either a big  role and effect in growing the economies of nations then the subject of dumping became a field turn around its sides many measures and laws … and may be done resorting to by many states of the world to anti-dumping as approach of determent weapon delimit  the impact of dumping and gives the national agriculture sector the opportunity for rising and growing so this section of international economics is capturing a special importance and represent in same time an important

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Dec 30 2009
Journal Name
Iraqi Journal Of Physics
Capacitance-Voltage and Current-Voltage Characteristic for Multi- Walled Carbon Nanotubes Grown in Oxygen Atmosphere
...Show More Authors

Carbon nanotubes were prepared by an arc-discharge method,
under different values of pressure of oxygen gas. The structure of
multi-walled carbon nanotubes powders has been characterized by
low-angle X-ray diffraction .The morphology of carbon nanotube
powder was examined by transmission electron microscope. The
capacitance-voltage and current- voltage (dark and illumination
current) characterization were measured under different values of
pressure (10-3, 10-4, 10-5) mbar of oxygen gas

View Publication Preview PDF
Publication Date
Sun Dec 01 2013
Journal Name
Toxicon
Methods for simultaneous detection of the cyanotoxins BMAA, DABA, and anatoxin-a in environmental samples
...Show More Authors

View Publication Preview PDF
Scopus (35)
Crossref (34)
Scopus Clarivate Crossref
Publication Date
Fri Sep 22 2006
Journal Name
Journal Of Physical Education
The Percentage Of Success And Failure Of Some Compound Offense Skills In Basketball For Joiners
...Show More Authors

The aim of the research is to identify the percentage of success and failure of some compound offensive skills in joiner basketball. It was evident that development only occurred though the mastery of the basic single offence skills as well as the ability to perform compound skills accurately and consistently. Not paying enough attention to compound skills leads evidentially to weakness in the athlete's level that in turn leads to mistakes in performance. Six joiner games of the best four teams in Baghdad were filmed and analyzed. The results of analyzing the compound offence skills were as follows:  There was some weakness in the athletes' ability in using compound offence skills specially receiving, dribbling and following through that

... Show More
Preview PDF
Publication Date
Wed May 17 2023
Journal Name
Journal Of The Australian Ceramic Society
Dielectric and scattering properties of transparent SiC composite in X-band range for radome application
...Show More Authors

View Publication
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Fri Mar 27 2020
Journal Name
Solid State Technology
Seepage and Slope Stability Analysis for Hemrin Earth Dam in Iraq Using Geo-Studio Software
...Show More Authors

View Publication
Publication Date
Mon Feb 21 2022
Journal Name
Научный форум: Филология, искусствоведение и культурология: сб. ст. по материалам Lvi междунар. науч.-практ. конф. – No 2 (56). – М
Comparative analysis of zoomorphic metaphors in Russian and Arabic as a method for studying linguoculturology
...Show More Authors

: zonal are included in phraseological units, form metaphorical names for a person, give him various emotional and evaluative characteristics. This article examines the topic of zoomorphic metaphors that characterize a person in the Russian and Arabic languages in the aspect of their comparative analysis, since the comparative analysis of the metaphorical meanings of animalisms is an important method for studying cultural linguistics, since zoomorphic metaphors are a reflection of culture in a language.

Preview PDF
Publication Date
Sat Oct 28 2023
Journal Name
Baghdad Science Journal
Indirect Flow Injection Spectrophotometric and Chromatographic Methods for the Determination of Mebendazole in Pharmaceutical Formulations
...Show More Authors

Chromatographic and spectrophotometric methods for the estimation of mebendazole in
pharmaceutical products were developed. The flow injection method was based on the oxidation of
mebendazole by a known excess of sodium hypochlorite at pH=9.5. The excess sodium hypochlorite is then
reacted with chloranilic acid (CAA) to bleach out its color. The absorbance of the excess CAA was recorded
at 530 nm. The method is fast, simple, selective, and sensitive. The chromatographic method was carried out
on a Varian C18 column. The mobile phase was a mixture of acetonitrile (ACN), methanol (MeOH), water
and triethylamine (TEA), (56% ACN, 20% MeOH, 23.5% H2O, 0.5% TEA, v/v), adjusted to pH = 3.0 with
1.0 M hy

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (2)
Scopus Crossref
Publication Date
Wed Jun 01 2016
Journal Name
Journal Of Engineering
Seismic Effects and Static Analysis for the Artificial Damped Outrigger Systems in Tall R.C Buildings
...Show More Authors

This paper studies the combination fluid viscous dampers in the outrigger system to add supplementary damping into the structure, which purpose to remove the dependability of the structure to lower variable intrinsic damping. It works by connecting the central core, comprising either shear walls or braced frames, to the outer perimeter columns.

     The modal considered is a 36 storey square high rise reinforced concrete building. By constructing a discrete lumped mass model, and using frequency-based response function, two systems of dampers, parallel and series systems are studied. The maximum lateral load at the top of the building is calculated, and  this load  w

... Show More
View Publication Preview PDF
Publication Date
Thu Aug 01 2019
Journal Name
Ieee Internet Of Things Journal
A New Task Allocation Protocol for Extending Stability and Operational Periods in Internet of Things
...Show More Authors

Scopus (17)
Crossref (11)
Scopus Clarivate Crossref