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
Sun Aug 07 2022
Journal Name
Engineering, Technology & Applied Science Research Etasr
Flexural Strengthening of Prestressed Girders with Partially Damaged Strands Using Enhancement of Carbon Fiber Laminates by End Sheet Anchorages
...Show More Authors

This paper examines the impact of flexural strengthening on the percentage of damaged strands in internally unbonded tendons in partially prestressed concrete beams (0, 14.28%, and 28.57%) and the recovering conditions using CFRP composite longitudinal laminates at the soffit, and end anchorage U-wrap sheets to restore the original flexural capacity and mitigate the delamination of the soffit of longitudinal Carbon Fiber Reinforced Polymer (CFRP) laminates. The composition of the laminates and anchors affected the stress of the CFRP, the failure mode, and thus the behavior of the beam. The experimental results revealed that the usage of CFRP laminates has a considerable impact on strand strain, particularly when anchors are employed

... Show More
Crossref (12)
Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Results In Chemistry
Effect of Polyeugenol coating on surface treatment of grade 23 titanium alloy by micro arc technique for dental application
...Show More Authors

Titanium alloy (Ti-6Al-4V or Gr.23) was widely used as a dental alloy. In the current study, polymerization of eugenol (PE) on Gr.23 titanium alloys was conducted by an electrochemical process before and after being treated by Micro Arc Oxidation (MAO). The formed films were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion behavior of Gr.23 alloy in an artificial saliva environment at a temperature range of 293–323 K has been studied and assessed by means of electrochemical polarization and impedance spectroscopy techniques. Three cases are taken into consideration; bare Gr.23, Gr.23 coated by PE, and Gr.23 coated by PE after MAO treatment. The maxi

... Show More
View Publication
Scopus (9)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
Selection of Optimal Conditions of Inulin Extraction from Jerusalem Artichoke (Helianthus Tuberosus L.) Tubers by using Ultrasonic Water Bath
...Show More Authors

Ultrasonic extraction is an inexpensive, simple and efficient alternative to conventional extraction techniques, as compared with other novel extraction techniques such as microwave-assisted extraction & supercritical fluid extraction techniques, the ultrasound apparatus is cheaper and its operation is easier. Ultrasound assisted extraction has risen rapidly in the latest decade, and for most applications it has proven to be effective compared to traditional extraction techniques. In this paper, a method of ultrasonic-assisted extraction was used to extract Inulin from tubers of Jerusalem artichoke, which have been reported to have several medicinal properties and uses. Inulin is a storage carbohydrate found in many plants especially

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Study the effect of thermal annealing on some physical properties of thin Cu2SiO3 films prepared by pulsed laser deposition
...Show More Authors

The Cu2SiO3 composite has been prepared from the binary compounds (Cu2O, and SiO2) with high purity by solid state reaction. The Cu2SiO3 thin films were deposited at room temperature on glass and Si substrates with thickness 400 nm by pulsed laser deposition method. X-ray analysis showed that the powder of Cu2SiO3 has a polycrystalline structure with monoclinic phase and preferred orientation along (111) direction at 2θ around 38.670o which related to CuO phase. While as deposited and annealed Cu2SiO3 films have amorphous structure. The morphological study revealed that the grains have granular and elliptical shape, with average diameter of 163.63 nm. The electrical properties which represent Hall effect were investigated. Hall coeffici

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Dec 01 2010
Journal Name
Iraqi Journal Of Physics
The effect of anode temperature on the Optical characteristic of Se films prepared by direct current planar magnetron sputtering
...Show More Authors

This work describes, selenium (Se) films were deposited on clean glass substrates by dc planar magnetron sputtering technique.The dependence of sputtering deposition rate of Se film deposited on pressure and DC power has been studied. The optimum argon pressure has range (4x10-1 -8x10-2 )mbar. The optical properties such as absorption coefficient (α) was determined using the absorbance and transmission measurement from UnicoUV-2102 PC spectrophotometer, at normal incidence of light in the wavelength range of 200-850 nm. And also we calculated optical constants(refractive index (n), dielectric constant (εi,r), and Extinction coefficient (κ) for selenium films.

View Publication Preview PDF
Publication Date
Tue Jan 01 2019
Journal Name
Indian Journal Of Public Health Research & Development
Effects of Artificial Aging on Some Properties of Room-Temperature-Vulcanized Maxillofacial Silicone Elastomer Modified by Yttrium Oxide Nanoparticles
...Show More Authors

Abstract Background: The daily usage of maxillofacial prostheses causes them to mechanically deteriorate with time. This study was aimed to evaluate the reinforcement of VST50F maxillofacial silicone by using yttrium oxide (Y2O3) nanoparticles (NPs) to resist aging and mechanical deterioration. Materials and Method: Y2O3 NPs (30–45nm) were loaded into VST50F maxillofacial silicone in two weight percentages (1 and 1.5 wt%), which were predetermined in a pilot study as the best rates for improving tear strength with minimum increase in hardness values. A total of 120 specimens were prepared and divided into the control and experimental groups (with 1 and 1.5 wt% Y2O3 addition). Each group included 40 specimens, 10 specimens for each paramet

... Show More
View Publication
Scopus (4)
Crossref (4)
Scopus Crossref
Publication Date
Sun Oct 01 2023
Journal Name
Baghdad Science Journal
Molecular detection by some virulence genes of Salmonella enterica subsp. enterica isolated from the stool of children with diarrhea
...Show More Authors

Diarrhea is a real disease in childhood which could cause death. Therefore, this study was conducted to isolate Salmonella from 350 stool samples taken from children under five years in age, suffering from diarrhea during the period from March 2019 to March 2020 in Tikrit city / Iraq. The results showed the possibility to isolate ten isolates of Salmonella enterica subsp. Enterica, an infection rate, represents 2.875% of the total rate of patients who suffer from diarrhea. The virulence genes were investigated for ten isolates of S. enterica subsp. enterica, the result is that all isolates possessed the genes stn, invA, lpfA with an appearance percentage of 100%, whi

... Show More
View Publication Preview PDF
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Engineering
Identificatio n Of Key Factors Affecting Waste Management In Life Cycle Of The Construction Project By Using Delphi Technique
...Show More Authors

The problem of generated waste as a result of the implementation of construction projects, has  been aggravated recently because of construction activity experienced by the world, especially Iraq, which is going through a period of reconstruction, where construction waste represents (20-40%) of the total generated waste and has a negative effect on the environment and economic side of the project. In addition, the rate of consumpted  amounts of natural resources are estimated to be about 40% in the construction industry, so it became necessary to reduce waste and to be manage well. This study aims to identify the key factors affecting waste management through the various phases of the project, and this is accom

... Show More
View Publication Preview PDF
Publication Date
Tue Apr 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Organizational citizenship behaviors under theory of servant leadership: A exploratory study in a sample of faculties of the University of Alqadisiya
...Show More Authors

This study aimed to identify the role of servant leadership in promoting organizational citizenship behaviors in a sample of faculties of the University of Alqadisiya .It tried to answer several questions represented its problem.

 

 The most important questions are the followings:

1- Is there enough perception among administrative leaders in the aforementioned faculties toward the concept of servant leadership? And under what level?                                    &

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jun 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
The impact of corporate governance in the promotion of business ethics A prospective study in a sample of private banks
...Show More Authors

 The study aims to know the role of governance in the consolidation of the principles of business ethics, through the application of the principles of governance and the dimensions of business ethics in the private sector. And knowledge of the validity of the hypothesis key of the current study according to which "increases the ethics of business organizations strength and coherence in the presence of the principles of governance" as it was distributed the questionnaire to a sample of a chairman and board members and managers department  and heads of sections in some of the private banks. I have been using correlation analysis and regression testing (t) to see the moral differences and to find out the c

... Show More
View Publication Preview PDF
Crossref