Preferred Language
Articles
/
alkej-544
Semi-Active Damping of Mechanical Vibrating Systems Using Variable Stiffness Actuator
...Show More Authors

      In this research, a variable stiffness actuator is proposed to enhance the damping of the mechanical vibrating system. The frequency response analysis of the vibrating system is dependant in order to analyze and synthesis this semi-active damping, where the suggested process is using active filter to estimate the present frequency of the vibration system, and this will limit the value of the stiffness of the vibrated system. Two active filter s are needed, low-pass-filter (LPF) to choose the higher stiffness of the actuator at small frequencies as well as more damping and high-pass-filter (HPF) to choose the lower stiffness of the actuator at high frequencies as well as more damping, and so the result will be good damping as a wholre.

      These smart systems and others will increase the importance of the mechatronics systems. This job has a case study to explain the semi-active damping system proposed.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Oct 20 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Semi-Small Compressible Modules and Semi-Small Retractable Modules
...Show More Authors

Let  be a commutative ring with 1 and  be left unitary  . In this paper we introduced and studied concept of semi-small compressible module (a     is said to be semi-small compressible module if  can be embedded in every nonzero semi-small submodule of . Equivalently,  is  semi-small compressible module if there exists a monomorphism  , ,     is said to be semi-small retractable module if  , for every non-zero  semi-small sub module in . Equivalently,  is semi-small retractable if there exists a homomorphism  whenever  .     In this paper we introduce and study the concept of semi-small compressible and semi-small retractable s as a generalization of compressible  and retractable  respectively and give some of their adv

... Show More
Crossref
Publication Date
Sat Jul 31 2021
Journal Name
Iraqi Journal Of Science
Semi-T-Hollow Modules and Semi-T-Lifting Modules
...Show More Authors

Let be an associative ring with identity and let be a unitary left -module. Let  be a non-zero submodule of .We say that  is a semi- - hollow module if for every submodule  of  such that  is a semi- - small submodule ( ). In addition, we say that  is a semi- - lifting module if for every submodule  of , there exists a direct summand  of  and  such that  

The main purpose of this work was to develop the properties of these classes of module.

 

View Publication Preview PDF
Scopus Crossref
Publication Date
Sat Jun 06 2020
Journal Name
International Journal Of Psychosocial Rehabilitation
A comparative study of the mechanical and electrical activities of the heart according to the energy systems of advanced players
...Show More Authors

The study aims to identify the mechanical and electrical activities of the heart according to the energy systems of advanced players and to detect the differences between the energy systems in terms of the mechanical and electrical activities of the heart for advanced players. It was clear from the results of the significance of the differences between the three groups according to the energy systems of the advanced players in all research variables that (the non-oxygenic system "Lactic"), which represents the advanced players in the arches (800 m, 1500 m) was the first in most tests of mechanical and electrical activities of the heart, which is (Margaria-Kalamen, Wingate, systolic muscle strength of the heart FC, Stroke Volume SV

... Show More
View Publication
Publication Date
Fri Jan 01 2016
Journal Name
Bulletin Of Mathematics And Statistics Research
New Approximation Operators Using Mixed Degree Systems
...Show More Authors

This paper is concerned with introducing and studying the first new approximation operators using mixed degree system and second new approximation operators using mixed degree system which are the core concept in this paper. In addition, the approximations of graphs using the operators first lower and first upper are accurate then the approximations obtained by using the operators second lower and second upper sincefirst accuracy less then second accuracy. For this reason, we study in detail the properties of second lower and second upper in this paper. Furthermore, we summarize the results for the properties of approximation operators second lower and second upper when the graph G is arbitrary, serial 1, serial 2, reflexive, symmetric, tra

... Show More
View Publication Preview PDF
Publication Date
Tue Jun 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
مستقبل الصناعة العربية في ظل اقتصاد عالمي متغير
...Show More Authors

أن التطور الاقتصادي  في أية دولة إنما يقاس بالدور الذي يلعبه القطاع الصناعي في اقتصادياتها، ومقدار ما يسهم به في الناتج المحلي الأجمالي. ولا يخفى أن ينسب ذلك إلى خصوصيات هذا القطاع بوصفه الميدان الذي تتحقق فيه انجازات الثورة العلمية والتكنولوجية أكثر من غيره من الميادين، وأرتباطاته الأمامية والخلفية مع سائر القطاعات. يضاف إلى ذلك أن القطاعات الأخرى تتأثر ايجاباً بنمو القطاع الصناعي، كما انه المسؤول

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Apr 02 2014
Journal Name
Iraqi Journal Of Physics
The evaluation of left ventricle stiffness index in patients suffering from hypertension
...Show More Authors

Many diseases can produce cardiac overload, of these disease hypertension, valve disease congenital anomaly in addition to many other disease. One of the most common diseases causing left ventricle overload is hypertension. A long term hypertension can cause myocardium hypertrophy leading to changes in the cardiac contractility and reduced efficiency. The investigations were carried out using conventional echocardiography techniques in addition to the tissue Doppler imaging (TDI) from which many noninvasive measurements can be readily obtained. The study has involved the effect of hypertension on the myocardium stiffness index through the measurement of early diastolic filling (E) and the early velocity of lateral mitral annulus (E

... Show More
Publication Date
Mon Feb 18 2019
Journal Name
Iraqi Journal Of Physics
The evaluation of left ventricle stiffness index in patients suffering from hypertension
...Show More Authors

Many diseases can produce cardiac overload, of these disease hypertension, valve disease congenital anomaly in addition to many other disease. One of the most common diseases causing left ventricle overload is hypertension. A long term hypertension can cause myocardium hypertrophy leading to changes in the cardiac contractility and reduced efficiency. The investigations were carried out using conventional echocardiography techniques in addition to the tissue Doppler imaging (TDI) from which many noninvasive measurements can be readily obtained. The study has involved the effect of hypertension on the myocardium stiffness index through the measurement of early diastolic filling (E) and the early velocity of lateral mitral annulus (Ea

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jun 29 2023
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
The Effect of Variable Parameters on Carbon Residue of Iraqi Vacuum Gas Oil using Ultrasound Techniques
...Show More Authors

An ultrasonic treatment was applied to the vacuum gas oil at intervals of 5 to 30 minutes, at 70°C.  In this work, the improvement of the important properties of Iraqi vacuum gas oil, such as carbon residue, was studied with several parameter conditions that affect vacuum efficiency, such as sonication time (5, 10, 15, 20, 25, and 30) min, power amplitude (10–50%). After ultrasonic treatment, the carbon residue of vacuum gas oil was evaluated using a Conradson carbon residue meter (ASTM D189). The experiment revealed that the oil's carbon residue had decreased by 16%. As a consequence of the experiment It was discovered that ultrasonic treatment might reduce the carbon residual and density of oil samples being studied. It also notice

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Dec 17 2017
Journal Name
Al-khwarizmi Engineering Journal
Study the Effect of Different Reinforcements on the Damping Properties of the Polymer Matrix Composite
...Show More Authors

In this research, damping properties for composite materials were evaluated using logarithmic decrement method to study the effect of reinforcements on the damping ratio of the epoxy matrix. Three stages of composites were prepared in this research. The first stage included preparing binary blends of epoxy (EP) and different weight percentages of polysulfide rubber (PSR) (0%, 2.5%, 5%, 7.5% and 10%). It was found that the weight percentage 5% of polysulfide was the best percentage, which gives the best mechanical properties for the blend matrix. The advantage of this blend matrix is that; it mediates between the brittle properties of epoxy and the flexible properties of a blend matrix with the highest percentage of PSR. The second stage

... Show More
View Publication Preview PDF
Publication Date
Thu Oct 25 2018
Journal Name
Journal Of Economics And Administrative Sciences
Find the fuzzy maximum flow of Imam Kadhimen visitors using fuzzy dynamic programming University of Baghdad - Faculty of Administration and Economics
...Show More Authors

    Baghdad and the other Iraqis provinces have witnessed many   of celebrations which have the significant effect on the souls of Arabic and Islamic people in general , and Iraqi people, especially the birthday and death of two al-kadhimen Imams(peace upon them) and others .From here the researcher begin to study the visiting of imam kadhimen (peace upon him) on 25 Rajab the commemoration of his sacrifice, simply because have implications of religious, ideological and cultural sectors which represents in finding the greatest flow of visitors .the problem of research appeared due to the clear difference in number of visitors during one day, beside the significant increase in number of visitors  throu

... Show More
View Publication Preview PDF
Crossref