Preferred Language
Articles
/
alkej-452
The Effect of Wind Velocity on the Suppression of Composite Wing Airfoil NACA 0012
...Show More Authors

The first studies on shocks and vibrations were carried out at the beginning of the 1930s to improve the behavior of buildings during earthquakes. Vibration tests on aircraft were developed from 1940 to verify the resistance of parts and equipments prior to their first use. Flutter is a well-known example of dynamic aero elasticity, where when oscillation of structure interacted with unsteady aerodynamic forces the flutter will occur. Vibration on any structure without damping means that self-harmonic oscillation will occur, and in most cases the oscillation may start to increase until structural failure. This behavior is very similar to resonance phenomena if only the oscillation is being studied as a vibration case. In vibration suppression, the active vibration control is one of the more effective technique which is used for attenuating bad effects of disturbances on structure. In this work, two different composite wings have been used; one of them is made of Glass-fiber random matt and the other is made of woven ({0/90} Glass-fiber). The proportional-integral-derivative (PID) control is employed here for studying the suppression of active vibration wing affected by wind velocity flow through wind tunnel in the laboratory of mechanical engineering department at the university of Baghdad. Piezoelectric (PZT (transducers are used as sensors and actuators in vibration control systems. The attack angle was 10 degrees and three different velocities (15, 20, 35 m/s) have been taken to show their effect on the wings vibrations suppression. Is noticed that the suppression of the wing amplitude is reduced when the wind velocity increases for both woven and random composite wing matt. This is happened due to the vortex which has became more violent increase in wind velocity. It is concluded that the composite woven wing has high resistance more than the composite random wing. Also, the maximum control amplitude of woven matt is 1.9 cm and the damping is about 33% at 25 m/s wind velocity while the amplitude is 2.22 cm and the damping is about 53% at 10 m/s wind velocity for random wing.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Dec 01 2023
Journal Name
Political Sciences Journal
Exploring the Effects of European Union Conditionality Language on European Mediterranean Human Rights Dialogue
...Show More Authors

Since more than a decade, human rights dialogue in the European Mediterranean Region has been marked by a number of tensions. Although a number of factors contribute to such disputes, the effect of human rights conditionality, which ties EU economic cooperation progression with partner countries human rights advancement, on the dialogue has not been studied. Understanding the aspects, impacts, and effects of conditionality on Euro-Med relations is crucial for furthering dialogue. Yet this variable has been almost entirely neglected in academic and policy research. The research concludes several direct and indirect impacts of conditionality on human rights dialogue using a mixed methodology approach. Direct effects are reflected in the wi

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Sep 22 2019
Journal Name
Baghdad Science Journal
Synthesis and Characterization of New Selenonitrone Derivative and Its Effect on Breast Cancer Cell Line Viability in Vitro
...Show More Authors

          New nitrone and selenonitrone compounds were synthesized. The condensation method between N-(2-hydroxyethyl) hydroxylamine and substituted carbonyl compounds such as [benzil, 4, 4́-dichlorobenzil and  2,2́ -dinitrobenzil] afforded a variety of new nitrone compounds while the condensation between N-benzylhydroxylamine and substituted selenocarbonyl compounds such as [di(4-fluorobenzoyl) diselenide and (4-chlorobenzoyl selenonitrile] obtained selenonitrone compounds. The condensation of N-4-chlorophenylhydroxylamine with dibenzoyl diselenide obtained another type of selenonitrone compounds. The structures of the synthesized compounds were assigned based on spectroscopic data (FT-IR,

... Show More
View Publication Preview PDF
Scopus (5)
Scopus Clarivate Crossref
Publication Date
Mon Sep 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Suggested Model for accounting disclosure proactive and reflect on the decisions of investors: Applied research in a sample of industrial companies listed on the Iraq Stock Exchange
...Show More Authors

Often requires the investor to know the result of the company's activity contribute to the investor or by wanting to invest in them because profit or loss of the company affect positively or negatively in the price of shares of the company and with the end of the fiscal year delayed companies often to issue its financial statements after it is approved and audited by an observer External Auditor, From here came the idea of ​​research that appears to stakeholders of financial statements proactive appear, including actual figures for earlier stages have been prepared lists about lists and planned by the administration reflect the results of its phase remainder of the year as if they are (half a year or season or month) to offer At the

... Show More
View Publication Preview PDF
Publication Date
Wed Aug 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of knowledge Workers in Organizational Excellence Field research in a number of the Iraqi industrial companies
...Show More Authors

The Knowledge Workers is The Largest And Most Powerful Resource Of The Organizational Excellence it is A Precious  Treasure, Therefore Find Organizations at present is looking for them and seek to invest their ideas For achieving excellence, creativity and access to the excellence Organizational , As a result of their importance in terms of engagement and influence in the success or failure of the as an organizational Of The Research is Measuring The Correlation And  Impact Between Knowledge Workers And Organizational Excellence in Sample Of Companies Iraqi Industrial By Standing The Dimensions Of Knowledge Workers ( Characteristics , Skills , Roles , Competencies ) And

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Nov 03 2020
Journal Name
Modern Sport
The effect of using multimedia in learning the skill of passing from the bottom of volleyball
...Show More Authors

The aim of the research is to:. Preparation and implementation of special educational units using multimedia to learn the skill of scrolling from below. 2 to recognize the impact of the use of multimedia in learning the skill of scrolling from below. 3 to identify the differences between the tests after the two groups research in learning the skill of passing from the bottom volleyball. The research represented the students of the first stage and the sample of the research was drawn randomly and the number of (50) students were divided into two experimental and control groups and each group (25) students were used standardized tests and conducting pre-tests and the implementation of the main exp

... Show More
View Publication
Crossref
Publication Date
Sun Sep 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Investment portfolio risks of the insurance company and their impacts on profitability ratios: An applied research at the national insurance co. for the period 2004-2014
...Show More Authors

The research is trying to identify the investment portfolio risks of the insurance company and their impact, on the Profitability ratios of the company, and whether the company's scientific methods followed in the measurement of these risks, and conducted research in the National Insurance Company. by relying on its annual budget as well as the annual reports, The search dealing with these data in theoretical and practical major premise to statistically significant between to investment portfolio risk and financial performance correlation and reach a set of conclusions and recommendations which are the following.                

investments include many ri

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Fri Sep 15 2023
Journal Name
Al-academy
The role of the sound effect to represent the psychopathic character in cinema
...Show More Authors

The process of employing modern technology in a consistent manner is what the researcher is interested in, and the psychological role of the sound effect in enhancing psychopathic representations in cinematic characters, which had a wide resonance in the field of cinematic films, and after the predominance of digital technology in the production of contemporary films, the sound effect has a higher efficiency And a good level of advanced aesthetic and dramatic expression in film employment, so many directors resorted to this type of films by using various new and advanced techniques and technological programs in their industry, since the traditional construction does not achieve the dazzling that the viewer desires.

Accordingly, th

... Show More
View Publication
Crossref
Publication Date
Mon Oct 01 2018
Journal Name
European Journal Of Dentistry
The anti-inflammatory effect of the platelet-rich plasma in the periodontal pocket
...Show More Authors
ABSTRACT<p> Objective: Chronic periodontitis (CP) is a common inflammatory disease that causes destruction to the supporting tissues of the teeth. Many treatment modalities tried to stop the disease progression. Platelet-rich plasma (PRP) is one of the regenerative methods that used in adjunct to conventional periodontal treatment. The aim of this study was to evaluate the anti-inflammatory effect of PRP by monitoring the lymphocyte count before and after its application to the periodontal pocket. Materials and Methods: Twenty patients, with CP and a pocket depth equal to or deeper than 4 mm, subjected to scaling, root planing, and PRP injection into the pocket. The lymphocyte count measured before an</p> ... Show More
View Publication
Scopus (35)
Crossref (28)
Scopus Crossref
Publication Date
Tue Dec 13 2011
Journal Name
Iraqi Journal Of Laser
The Efficacy of Er:YAG Laser on Intrapulpal Temperature Rise of Class V Cavity Preparation
...Show More Authors

The objective of this study is to determine the efficacy of class V Er:YAG laser (2940 nm) cavity preparation and conventional bur cavity preparation regarding Intrapulpal temperature rise during cavity preparation in extracted human premolar teeth. Twenty non carious premolar teeth extracted for orthodontic purposes were used and class V cavity preparation was applied both buccal and lingual sides for each tooth .Samples were equally grouped into two major groups according to cavity depth (1mm and 2mm). Each major group was further subdivided into two subgroupsof ten teeth for each (twenty cavities for each subgroup). TwinlightEr:YAG laser (2940 nm) with 500mJ pulse energy, P.R.R of 10 Hz and 63.69 J/cm2 energy density was used. The ana

... Show More
View Publication Preview PDF
Publication Date
Fri Apr 01 2022
Journal Name
Baghdad Science Journal
Effect of different levels and sizes of walnut seed residues on phosphorus availability and alkaline phosphatase activity in calcareous soil
...Show More Authors

A laboratory experiment has been carried out in the College of Science-University of Salahaddin to study the effect of different levels (0,5,10 and 15%) and sizes(250 and 1000µm) of walnut seeds residues and (160mg.kg-1) phosphorus fertilization on the concentration of phosphorus availability and alkaline phosphatase activity in calcareous soil during 15 and 30 days period of incubation, the experimental design in factorial complet randomize design (C.R.D) with three replications. The results indicated that the application of different levels of walnut seed residues decreases the concentration of phosphorus availability and alkaline phosphatase activity, however the results revealed that combination between levels and sizes o

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref