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alkej-211
Effect of Bearing Compliance on Thermo-hydrodynamic Lubrication of High Speed Misaligned Journal Bearing Lubricated with Bubbly Oil
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Abstract

In the present work  the effect of bearing compliance on the performance of high speed misaligned journal bearing lined with a compliant PTFE liner lubricated with bubbly oil at high speeds has been studied. The effect of induced oil film temperature due to shearing effect has been implemented. Hydrodynamic effect of the complaint bearing and the influence of aerated oil have been examined by the classical thermohydrodynamic lubrication theory modified to include the effect of oil film turbulence and oil film temperature with suitable models for bubbly oil viscosity and density. The effect of liner elastic deformation has been implemented by using Winkler model. The effects of variable density and specific heat on the most importantbearing parameters such as maximum pressure, maximum temperature, bearing load carrying capacity and power losses have been investigated.The results obtained show that the oil film pressure and load carrying capacity increased for the bearing lubricated with bubbly oil of higher aeration level and smaller size of air bubbles. Including the effect of elastic deformation of the bearing liner reduces the oil film pressure, load carrying capacity and frictional power loss for the misaligned bearing working at the same circumstances

Keywords: Journal bearings, hydrodynamic lubrication, THD, compliant effect, bubbly oil, misalignment effect.

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Publication Date
Mon Mar 18 2019
Journal Name
Al-khwarizmi Engineering Journal
Effect of optimal shot peening time on fatigue life for aluminum alloy 6061-T651
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The compressive residual stresses generated by shot peening, is increased in a direct proportional way with shot peening time (SPT). For each metal, there is an optimum shot peening time (O.S.T) which gives the optimum fatigue life. This paper experimentally studied to optimize shot peening time of aluminium alloy 6061-T651 as well as using of and analysis of variance (ANOVA).

Two types of fatigue test specimens’ configuration were used, one without notch (smooth) and the other with a notch radius (1,25mm), each type was shot peened at different time. The (O.S.T) was experimentally estimated  to be 8 minutes reaching the surface stresses at maximum peak of -184.94 MPa.

A response surface methodology (RSM) is presen

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Publication Date
Mon Mar 11 2019
Journal Name
Baghdad Science Journal
Study the Effect of Cold Plasma on the Nonlinear Properties of Polymeric Membranes Rod Amine (R3Go)
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The nonlinear optical properties for polymeric (PMMA) doping with dye Rhodmine (R3Go) has been studied .The samples are prepared by normal polymerization method with concentrations of 5x10-5mol/l and a thickness of 272.5µm.

                         Plasma effect was studied on samples prepared before and after exposure to the Nd: YAG laser for three times 5, 10 and 15 minutes. Z-Scan technique is used to determine the nonlinear optical properties such as; refractive index (n2) and the coefficient of nonlinear absorption (β). It was found that the nonlinear properties is change by increasi

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Publication Date
Thu Oct 01 2015
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Biochemical studies on the effect of Crataegus aqueous extract on oxidative stress during ischemia/reperfusion induced myocardial injuries
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Background: myocardial ischemia-reperfusion (I/R) injury may occur in a variety of clinical settings and this remains a significant problem. Oxygen free radicals, produced on reperfusion have been shown to play a major role in myocardial I/R injury. Various therapeutic effects have been described for Crataegus. Additionally, it has been presented that Crataegus has protective effect against ischemia reperfusion induced myocardial injuries to various organs. Therefore, it seems possible that the administration of Crataegus might protect the heart against the ischemia reperfusion injury.
Objectives: I detected the chemical components and trace elements of the aqueous extract of Crataegus leaves and determine whether Crataegus extract pr

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Publication Date
Tue Nov 30 2021
Journal Name
Iraqi Journal Of Science
Detection of Chlamydia Pneumoniae in Lung Tissues Derived from Lung Tumor-Bearing Iraqi Patients
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Chlamydia pneumoniae is an intracellular gram-negative bacteria associated with lower and upper respiratory tract infections. Several studies, mostly achieved by serological assays, proposed a role for this bacteria in lung cancer risk. Therefore, this study aimed to evaluate the prevalence of Chlamydia pneuomoniae in fresh lung tissues of a sample of Iraqi patients with lung tumors, utilizing polymerase chain reaction (PCR) technique. . Chlamydia pneumoniae DNA was detected in 86.67% of samples. Besides, DNA sequencing of 16S rRNA gene revealed that our isolate is closely related to Chlamydia pneumoniae TW183 strain. It is concluded that Chlamydia pneumoniae  is found in fresh l

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Publication Date
Sun Jul 30 2023
Journal Name
Iraqi Journal Of Science
Anti-Breast Cancer Activity of Some Synthesized Pyrazole Derivatives Bearing Imidazo[1,2a]pyridine Moiety
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     A novel series of pyrazole derivatives containing imidazo[1,2-a]pyridine D1-D8 moiety has been synthesized. The reaction of 2-aminopyridine with 4-phenylphenacyl bromide and 4-bromophenacyl bromide gave the products A and A1, respectively. These products then reacted with DMF and POCl3 to obtain new aldehyde derivatives B and B1. These two aldehydes were condensed with various acetophenone substitutes to yield the corresponding chalcone derivatives C1-C10. Following this, the cycloaddition reaction with hydrazine hydrate provided new pyrazole derivatives D1-D8. The prepared compounds

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Publication Date
Thu Dec 01 2022
Journal Name
Journal Of Engineering
Evaluation of the Influence of De-sanding (Recycling System) Process on the Pile Bearing Capacity Using Full Scale Models
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The present study investigates the effect of the de-sanding (recycling system) on the bearing capacity of the bored piles. Full-scale models were conducted on two groups of piles, the first group was implemented without using this system, and the second group was implemented using the recycling system. All piles were tested by static load test, considering the time factor for which the piles were implemented. The test results indicated a significant and clear difference in the bearing capacity of the piles when using this system. The use of the recycling system led to a significant increase in the bearing capacity of the piles by 50% or more. Thus it was possible to reduce the pile length by (15 % or more) thus, and implementation c

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Publication Date
Thu Dec 01 2022
Journal Name
Journal Of Engineering
Evaluation of the Influence of De-sanding (Recycling System) Process on the Pile Bearing Capacity Using Full Scale Models
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The present study investigates the effect of the de-sanding (recycling system) on the bearing capacity of the bored piles. Full-scale models were conducted on two groups of piles, the first group was implemented without using this system, and the second group was implemented using the recycling system. All piles were tested by static load test, considering the time factor for which the piles were implemented. The test results indicated a significant and clear difference in the bearing capacity of the piles when using this system. The use of the recycling system led to a significant increase in the bearing capacity of the piles by 50% or more. Thus it was possible to reduce the pile length by (15 % or more) thus, and implementation costs

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Publication Date
Fri Mar 15 2019
Journal Name
Al-khwarizmi Engineering Journal
Studying the effect of Different wt % AL2O3 Nanoparticles of 2024Al Alloy / AL2O3 Composites on Mechanical Properties
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The nanocompsite of alumina (Al2O3) produced a number of beneficial effects in alloys. There is increasing in resistance of materials to surface related failures , such as the mechanical properties , fatigue and stress corrosion cracking .The experimental results observed that the adding of reinforced  nanomaterials  type Al2O3  enhanced the   HB hardness, UTS, 0.2 YS and ductility of 2014 Al/Al2O3 nano composites . the analysis of experiments, indicated that The maximum enhancement was observed at 0.4 wt.% Al2O3. The ultimate improvement percentage were 15.78% HB hardness, 18.1% (UTS), 12.86% (

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Publication Date
Mon Apr 01 2013
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Effect of ureteric stone location on the success rate of ureteroscopic Holmium laser lithotripsy
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Background: Ureteral stone can cause obstructive uropathy and subsequent deterioration of renal function. There are four treatment options for ureteral calculi: lithotripsy, ureteroscopy, laparoscopic ureterolithotomy, and open stone surgery. Holmium YAG laser is an excellent intracorporial lithotripter for all kinds of stones. Accordingly, there is steady increase in number of ureteroscopic laser lithotripsy operations in the managmant of Ureteral stone.

Objectives: this study was designed to demonstrate the effect of ureteric stone location on the success rate of ureteroscopic Holmium laser lithotripsy in the management of ureteric stones.

Patients and Methods: Ninety m

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Publication Date
Thu May 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Restrained Edges Effect on the Dynamics of Thermoelastic Plates under Different End Conditions
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Frequency equations for rectangular plate model with and without the thermoelastic effect for the cases are: all edges are simply supported, all edges are clamped and two opposite edges are clamped others are simply supported.   These were obtained through direct method for simply supported ends using Hamilton’s principle with minimizing Ritz method to total energy (strain and kinetic) for the rest of the boundary conditions. The effect of restraining edges on the frequency and mode shape has been considered. Distributions temperatures have been considered as a uniform temperature the effect of developed thermal stresses due to restrictions of ends conditions on vibration characteristics   of a plate with different

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