Preferred Language
Articles
/
joe-250
Dynamic Stability Analysis and Critical Speed of Rotor supported by a Worn Fluid film Journal Bearings
...Show More Authors

In this paper, the effect of wear in the fluid film journal bearings on the dynamic stability of rotor bearing system has been studied depending on the development of new analytical equations for motion, instability threshold speed and steady state harmonic response for rotor with offset disc supported by worn journal bearings. Finite element method had been used for modeling the rotor bearing system. The analytical model is verified by comparing its results with that obtained numerically for a rotor supported on the short bearings. The analytical and numerical results showed good agreement with about 8.5% percentage error in the value of critical speed and about 3.5% percentage error in the value of harmonic response. The results obtained show that the wear in journal bearing decrease the instability threshold speed by 2.5% for wear depth 0.02 mm and 12.5% for wear depth 0.04 mm as well as decrease critical speed by 4.2% and steady state harmonic response amplitude by 4.3% for wear depth 0.02 mm and decrease the critical speed by 7.1% and steady state harmonic response amplitude by 13.9% for wear depth 0.04 mm.

 

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Jun 30 2017
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Waste Water Treatment by Liquid-Solid Adsorption Using Calcined Sand-Clay Mixture Adsorbent
...Show More Authors

Effluent from incompetent wastewater treatment plants (WWTPs) contains a great variety of pollutants so support water treatments are essential. The present work studies the removal of phosphate species from aqueous solutions by adsorption on to spherical Calcined Sand -Clay mixture (CSCM) used a natural, local and low-cost adsorbent. Batch experiments were performed to estimate removal efficiency of phosphate. The adsorption experiments were carried out as function of pH, dose of adsorbent, initial concentration, temperature and time of adsorption. The efficient removal was accomplished for pH between 10 and 12. The experimental results also showed that the removal of phosphate by (CSCM) was rapid (the % removal 98.9%, 92%, 90%, 89% in 6

... Show More
View Publication Preview PDF
Publication Date
Tue Mar 30 2021
Journal Name
Baghdad Science Journal
Solving Fractional Damped Burgers' Equation Approximately by Using The Sumudu Transform (ST) Method
...Show More Authors

       In this work, the fractional damped Burger's equation (FDBE) formula    = 0,

View Publication Preview PDF
Scopus (8)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Sun Jun 30 2013
Journal Name
Al-khwarizmi Engineering Journal
Effect the Grain Size on the Polymer Matrix Composites Reinforced by Reenia Particles
...Show More Authors

 Synthetic polymers such as polyurethane are used widely in the field of biomedical applications such as implants or part of implant systems.

This paper focuses on the preparation of base polymer matrix composite materials by (Hand Lay-Up) method, and studying the effect of selected grain size (32, 53, 63, 75, and 90) µm of (Reenia) particles on some properties of the prepared composite.

Mechanical tests were used to evaluate the prepared system (Tensile, Compression, Impact, and Hardness) tests, and a physical test of (Water absorption %), and all tests were accomplished at room temperature.

Where results showed tensile test (maximum tensile strength and modulus of elasticity) high at small grain size while

... Show More
View Publication Preview PDF
Publication Date
Mon Jun 01 2015
Journal Name
Journal Of The College Of Languages (jcl)
The Expectation in ( Why did you leave the horse alone ) By Mahmoud Darwish
...Show More Authors

Expectation in poetry is  the ability of the poet to exceed the existence of the universe . It is the revealing of the hidden and the familiar. This feature of expecting is not related to the modern poetry only . It is a well - known feature that has long been assigned to old poetry like Al-Mutannabi  an Al-Mu`arri  who had their own unique ways of expecting and going beyond the current time  and touching the future and making it a reality. Based on their awareness ,mature thinking and talent , they had the ability of reading what is to come ,even if they were mere suppositions and tentative readings. As for the modern poetry , we have poets like Amal Dunqil , Adonis ,and Al-Sayyab whose poems became expectati

... Show More
View Publication Preview PDF
Publication Date
Fri Aug 01 2025
Journal Name
Fikrotuna: Jurnal Pendidikan Dan Manajemen Islam
The Difficulties Faced by Teachers in Implementing the Smart Schools Project in Iraq
...Show More Authors

This research explores the obstacles teachers encounter in executing the smart schools initiative within the framework of Iraq, where educational facilities and digital preparedness are still at an early stage. Although worldwide trends reveal the growing use of smart technologies in education, Iraq has been hindered by systemic barriers, such as archaic curricula, restricted access to technologies, and an unqualified teaching staff. Data were collected using a validated questionnaire on 122 public school teachers working in Baghdad with a descriptive-analytical methodology. The study divided challenges into five areas: infrastructure, teacher preparedness, administrative support, curricular adaptation and cultural resistanc

... Show More
View Publication
Crossref
Publication Date
Tue Dec 15 2020
Journal Name
Journal Of Baghdad College Of Dentistry
Coated stainless steel archwires' discoloration measured by computerized system (An in-vitro study)
...Show More Authors

Background: Aesthetic archwires are used to overcome the aesthetic problems of stainless steel wires but the color of the coating layer can be changed with time when exposed to oral environments. The aim of this study was to evaluate the degree of color change of different aesthetic archwires from different companies under different coloring solutions. Materials and Methods: One hundred fifty samples of coated archwires from three companies (Highland, G&H and Dany) were immersed in 5 solutions (artificial saliva, turmeric, tea, coffee and Miranda) to evaluate the degree of color changes after 7, 14 and 21 days using visible spectrophotometer. Data were collected and analyzed using one way ANOVA and post hoc Tukey’s tests. Resu

... Show More
View Publication Preview PDF
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Tue Mar 30 2021
Journal Name
Baghdad Science Journal
Solving Fractional Damped Burgers' Equation Approximately by Using The Sumudu Transform (ST) Method
...Show More Authors

       In this work, the fractional damped Burger's equation (FDBE) formula    = 0,

View Publication
Scopus (8)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Sun Nov 30 2025
Journal Name
Journal Of Al-farabi For Humanity Sciences
The Challenges Faced by Iraqi EFL Secondary School Teachers in Teaching English Language
...Show More Authors

This paper aimed at specifying the leading obstacles which faced by Iraqi EFL secondary school teachers in teaching English language. According to studies and observations, lack of adequate materials, overcrowding classrooms, lack of infrastructures, and low job satisfaction are the main barriers to English language teaching in Iraq. Data were collected from 130 EFL teachers from Iraqi schools through a standard questionnaire. The data were analyzed using a descriptive statistic to summarize and present it in a meaningful way. The findings supported previous studies regarding the classroom overcrowding, lack of teaching aids and materials, and dilapidated facilities. Furthermore, regarding job dissatisfaction and salary, interesting and eye

... Show More
Preview PDF
Publication Date
Mon Mar 01 2010
Journal Name
Basrah Journal Of Science
Hiding Three Images at one image by Using Wavelet Coefficients at Color Image
...Show More Authors

Publication Date
Mon Jan 01 2018
Journal Name
International Journal Of Science And Research (ijsr)
The Linear Delay Fourth Order Eigen-Value Problems Solved By the Collocation Method
...Show More Authors