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Effect of Journal Misalignment on the Static Characteristics of Porous Journal Bearings Lubricated with Couple Stress Fluid
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In this paper, a theoretical study to the effect of journal misalignment on the static characteristics of oil filled porous journal bearing when lubricated with couple stress fluid has been carried out.

The analytical model used through this work is for a bearing with isotropic permeability. Considering isotropic permeability the Reynolds' equation for the oil film is modified to include a so – called filter term and the effect of fluid coupled stress. The pressure equation for the porous medium is obtained from Darcy's law and continuity equation. The equation which was used to evaluate the oil film thickness was modified to include the effect of possible misalignment in longitudinal and transverse directions. The governing equations with appropriate boundary conditions are numerically solved using a suitable numerical technique. A computer program has been prepared to solve the governing equations. The validity of the program has been tested by comparing the results obtained through this work with that published in  available works. The comparison shows a good agreement between the results obtained through this work and that published by other workers.        

By comparing the behavior of aligned and misaligned bearing it was found that the journal center misalignment has a considerable effect on the performance parameters of the bearing which can not be neglected.

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Publication Date
Mon Nov 26 2018
Journal Name
Al-khwarizmi Engineering Journal
Study the Effect of Different Percentages of Natural (Orange Peels and Date Seeds) and Industrial Materials (Carbon and Silica) on the Mechanical and Thermal Properties of Polymeric Reinforced Composites
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Mechanical and thermal properties of composites, consisted of unsaturated polyester resin, reinforced by different kinds of natural materials (Orange peels and Date seeds) and industrial materials (carbon and silica) with particle size 98 µm were studied. Various weight ratios, 5, 10, and 15 wt. % of natural and industrial materials have been infused into polyester. Tensile, three-point bending and thermal conductivity tests were conducted for the unfilled polyester, natural and industrial composite to identify the weight ratio effect on the properties of materials. The results indicated that when the weight ratio for polyester with date seeds increased from 10% to 15%, the maximum Young’s modulus decreased by 54%. When the weight rat

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Publication Date
Mon Apr 04 2022
Journal Name
Journal Of Educational And Psychological Researches
The Effect of the Interaction between the Use of the Improve Strategy in Teaching Mathematics and Achievement Levels on the Acquisition of Algebraic Concepts and Habits of Mind among Tenth Grade Students in Oman
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The current study aims to investigate the effect of the interaction between the use of the improve strategy in teaching mathematics and the level of academic achievement on the acquisition of algebraic concepts and habits of mind among tenth-grade students in Oman. The study adopted the experimental method, based on a quasi-experimental design with two groups: experimental and control groups and pre-post-measurement. The study sample consisted of (28) 10th-grade students as an experimental group and 26 of 10th-grade students as a control group in Al-Tufail bin Amr School in South Al Batinah. The differences in the pretest and posttest gains were analyzed using mean, standard deviation, ANCOVA, t-test, effect size (eta-square), and two-wa

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Publication Date
Fri Oct 01 2010
Journal Name
Iraqi Journal Of Physics
Investigation of plasma characteristics of center region of post cylindrical magnetron sputtering device
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A d.c. magnetron sputtering system was designed and fabricated. The chamber of this system is consisted from two copper coaxial cylinders. The inner one used as the cathode and the outer one used as anode with magnetic coil located on the outer cylinder (anode). The axial behavior of the magnetic field strength along the cathode surface for various coil current (from 2A to 14A) are shown. The results of this work are investigated by three cylindrical Langmuir probes that have different diameters that are 2.2mm, 1mm, and 0.45mm. The results of these probes show that, there are two Maxwellian electron groups appear in the central region. As well as, the density of electron and ion decreases with increases of magnetic field strengths.

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Publication Date
Mon Oct 01 2018
Journal Name
Iraqi Journal Of Physics
SiO2 particles effect on the mechanical properties of the starch/PVA blends
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The present work studies the mechanical properties of SiO2 μPs, and NPs in St/PVA blends. The samples were prepared by casting method as PVA, St/PVA blends at different concentrations (30, 40, 50, and 60 %). DSC and TGA tests were carried out to the samples evolved. The result showed a single glass transition temperature (Tg) for all St /PVA blends that was attributed to the good miscibility of the blends involved. It was found that (Tg) decrease with starch ratio increase. It was seen that (PVA) of (Tg=105 oC); The glass transition temperature which was decrease with starch ratio that was attributed to glass transition relaxation process due to micro-Brownian motion of the main chain back bond. The endothermic peak at 200 oC was attrib

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Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Engineering
The Effect of Recycled Heating and Cooling and The Effect of The Speciment Size on The Compressive Strength of Concrete Exposed To High Temperature
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     In the present work effect of recycled heating and cooling on the values of concrete compressive strength due to high temperature of 4000C was studied.

    The tests show that the percent of reduction in compressive strength of the samples which exposed to a temperature of 4000C for one cycle was 32.5%, while the reduction was 52.7% for the samples which were exposed to recycled heating and cooling of ten times .      

   Moreover a study of the effect of specimen sizes on the percentages of compressive strength reduction due to high temperature

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Publication Date
Sun Sep 22 2019
Journal Name
Baghdad Science Journal
Spectral Properties of Hybrid of Rhodamine (6G) Dyes Doped Epoxy Resin Dissolved in Chloroform
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            The research is dealing with the absorption and fluorescence spectra for the hybrid of  an Epoxy Resin doped with organic dye Rhodamine (R6G) of different concentrations (5*10-6, 5*10-5, 1*10-5, 1*10-4, 5*10-4) Mol/ℓ at room temperature. The Quantum efficiency Qfm, the rate of fluorescence emission Kfm (s-1), the non-radiative lifetime τfm (s), fluorescence lifetime τf and the Stokes shift were calculated. Also the energy gap (Eg) for each dye concentration was evaluated. The results showed that the maximum quantum effi

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Publication Date
Sun Mar 01 2015
Journal Name
Baghdad Science Journal
The Effect of Age and Gender on Fetuin-A and Some Biochemical parameters in Blood Sera of Iraqi patients with T2DM: A comparative study
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The serum protein test includes measurement of the level of total protein(albumin, globulin). Fetuin-A is a blood protein made in liver. It can inhibit insulin receptor, enhance insulin sensitivity and make the individuals more likely to develop type 2 diabetes, then disorder in lipid profile (Total cholesterol(TC), low density lipoprotein cholesterol (LDL-c), high density lipoprotein cholesterol (HDL-c), Triglyceride(TG) and very low density lipoprotein cholesterol (VLDL-c) . To evaluate Fetuin-A, total protein, albumin, globulin, HbAlc and lipid profile in 200 adult and elderly Iraqi patients with type 2 Diabetes Mellitus were taken and compare them with 200 subjects as a healthy control. The laboratory analysis(for patients and

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Publication Date
Sun Jun 12 2011
Journal Name
Baghdad Science Journal
The parameters effect on the holographic optical elements
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In this work we fabrication holographic optical element diffraction grating thickness 40?m and mirror90?m by using dichromated gelatin,to perform that we have to use the Nd-yaG laser doubling frequency of wavelenght (532)nm and its powers of (80)mWatt.we have studyed the thickness and concentration dichromat effect in mirror reflaction ,effect of angle of reconstruction beam in band width and diffraction efficiency ,study effect gelatin hardener of the diffraction efficiency.

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
“The impact of the critical factors for the transfer of knowledge on opportunities and strategic success”
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The current research discusses “The impact of the critical factors for the transfer of knowledge on opportunities and strategic success ", the attention have been increased on knowledge transfer and strategic success subjects because on being one of the important and contemporary issues, which have a significant impact on the existence of organizations and its future. The research aims to identify the critical factors for knowledge transfer in private high education environment which enables (the college community surveyed) to achieve strategic success, also the research sought to answer questions related to research problem by testing a number of major and minor hypothes in impact, in order to test the hypotheses I used a fiel

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Publication Date
Tue Jan 02 2018
Journal Name
Journal Of Educational And Psychological Researches
The Effect of Using Brainstorming Technique on the Essay Writing and Self- regulation Learning of the Iraqi Secondary Students
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         This study investigated the effect of using brainstorming as a teaching technique on the students’ performance in writing different kinds of essays and self regulation among the secondary students. The total population of this study, consisted of (51) female students of the 5th Secondary grade in Al –kawarzmi School in Erbil during the academic year 2015-2016. The chosen sample consisted of 40 female students, has been divided into two groups. Each one consists of (20) students to represent the experimental group and the control one. Brainstorming technique is used to teach the experimental group, and the conventional method is used to teach the control group. The study inst

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