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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 Jan 01 2024
Journal Name
Baghdad Science Journal
Acute Toxicity of Chlorpyrifos on the Freshwater Bivalves (Unio Tigridis) and Effects on Bioindicators
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A freshwater bivalve plays a crucial function in aquatic habitats as the filtered water and burrowing mussels mix the sediment, thus increasing oxygen content and making the ecosystem healthier. The aim of the study is to see how chlorpyrifos affects biochemical markers in freshwater mussel Unio tigridis. About 180 individuals per taxon and water samples were collected from the Qandil water resource on the Greater Zab River, Erbil Province, Iraq. Once arrived at the lab, the individuals were kept in aquaria with river water and an air-conditioned room Temperature: 25±2 and Light: 12h/12h and acclimatized to laboratory conditions for seven days in aged tap water. The mussel's identification molecularly and the DNA sequence of t

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Publication Date
Mon Mar 15 2021
Journal Name
Al-academy
Effect of formation Methods on Sintering Process of Ceramic Materials: هديل سلمان سعيد
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The current research is concerned with methods of formation and their effect on the sintering process of ceramic materials. The research is divided into a number of chapters. The first chapter addressed the research structure (the research problem, importance, objective, limits, and it also defined the terms used in the research). The second chapter addressed the theoretical framework, where the theoretical framework has been divided into three sections. The first section dealt with methods of formation of ceramic materials including: Plasticizing method 2- semi-dry pressing method 3- dry pressing method 4- extrusion method 5- casting method.
The researcher found that there is a clear difference between the methods through her formati

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Publication Date
Tue Oct 08 2002
Journal Name
Iraqi Journal Of Laser
Effect of Gas Mixture on the Output Characteristics of a CW CO2 Laser
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In this work, the effect of partial amounts of gases in gas mixture of a CW CO2 laser on the output power was investigated. Also their effect on the condition determining the glow-discharge self-sustaining required for pumping the active medium was studied. Two fit relations were derived to predict the output laser power and the electric field to unit pressure ratio as functions to the partial amounts of gases. Results presented in this work could be used fruitfully to determine some of the optimum operational conditions of glow-discharge low-power CW CO2 lasers.

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Publication Date
Sun May 12 2019
Journal Name
Al-khwarizmi Engineering Journal
Effect of Quenching Media Variations on the Mechanical Behavior of Martensitic Stainless Steel
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The purpose of this study is designate quenching and tempering heat treatment by using Taguchi technique to determine optimal factors of heat treatment (austenitizing temperature, percentage of nanoparticles, type of base media, nanoparticles type and soaking time) for increasing hardness, wear rate and impact energy properties of 420 martensitic stainless steel. An (L18) orthogonal array was chosen for the design of experiment. The optimum process parameters were determined by using signal-to-noise ratio (larger is better) criterion for hardness and impact energy while (Smaller is better) criterion was for the wear rate. The importance levels of process parameters that effect on hardness, wear rate and impact energy propertie

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Publication Date
Tue Mar 01 2022
Journal Name
Iraqi Journal Of Physics
Effect of Carbon Nanoparticles on the Performance Efficiency of a Solar Water Heater
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Carbon nanoparticles are prepared by sonication using carbon black powder. The surface morphology of carbon black (CB) and carbon nanoparticles (CNPs) is investigated using scanning electron microscopy (SEM). The particles size ranges from 100 nm to 400 nm for CB and from 10 nm to 100 nm for CNPs. CNPs and CB are mixed with silicon glue of different ratios of 0.025, 0.2, 0.05, and 0.1 to synthesis films. The optical properties of the prepared films are investigated through reflectance and absorbance analyses. The ratio of 0.05 for CNPs and CB is the best for solar paint because of its higher solar water heater efficiency and is then added to the silicon glue . Temperature of cold water and temperature of hot water in storage tank were ta

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Publication Date
Fri Sep 01 2023
Journal Name
Al-khwarizmi Engineering Journal
Tracked Robot Control with Hand Gesture Based on MediaPipe
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Hand gestures are currently considered one of the most accurate ways to communicate in many applications, such as sign language, controlling robots, the virtual world, smart homes, and the field of video games. Several techniques are used to detect and classify hand gestures, for instance using gloves that contain several sensors or depending on computer vision. In this work, computer vision is utilized instead of using gloves to control the robot's movement. That is because gloves need complicated electrical connections that limit user mobility, sensors may be costly to replace, and gloves can spread skin illnesses between users. Based on computer vision, the MediaPipe (MP) method is used. This method is a modern method that is discover

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Publication Date
Thu Dec 31 2020
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
EVALUATING THE QUALITY OF IMPORTED AND LOCAL FLOUR IN TERMS OF QUALITY WITH IRON AND FOLIC ACID AND ITS COMPLIANCE WITH IRAQI STANDARD: EVALUATING THE QUALITY OF IMPORTED AND LOCAL FLOUR IN TERMS OF QUALITY WITH IRON AND FOLIC ACID AND ITS COMPLIANCE WITH IRAQI STANDARD
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Food fortification has an important and necessary role in compensating for the shortage of nutritional micronutrients, especially in developing and least developed countries. So, 12 samples of flour available in the local market, whether imported or locally produced flour, were obtained during 2019. The amount of base metal of the necessary iron element in the flour models studied which are available in local markets, measured by spot testing and was compared with the values ​​that should be added according to the specification Iraqi standard. Results revealed the qualitative evaluation of iron in locally produced flour does not conform to the Iraqi standard and is almost free of any reinforcement. While the percentage of imp

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Publication Date
Mon Jan 01 2007
Journal Name
Journal Of Educational And Psychological Researches
قياس تاثير وسائل اتصال العولمة على العلاقات الانسانية لدى طلبة جامعة بغداد
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يعد مفهوم العولمة ظاهرة عالمية كونها نزعة طاغية في الوقت الحالي منسوبة الى العالم ، ولم تدخل بعد قوائم المفردات في القواميس السياسية والاقتصادية . (الأسدي ،2004-ص88).وأن العولمة  " Globlization أخذت مدلولان ، الاول يدل على الانفتاح وحرية التفكير ومتابعة الاكتشافات في مختلف المجالات والابتعاد عن الرتابة والروتين . اما الثاني فيدل على سطحية التفكير وحب التغيير لأجل التغيير ونبذ الماض

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Publication Date
Sun Jun 01 2008
Journal Name
Journal Of The College Of Languages (jcl)
İslamiyet Öncesi Türk Destanlarının Bilim ve Kültür Hayatına Etkisi Üzerine Bazı Düşünceler
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İlk çağlarda yaşayan insanların hayal dünyasını tanıtan masallar görünümünde olan destanlar‚ aslında‚ milleylerin tarih öncesi devirlerde başlayan kuruluşlarını‚ inanışlarını‚ erdemlerini‚ fikir ve sanatlarını anlatır.
Destanlar‚ kökü tarihe dayanan olayların, halk gözüyle görülen‚ halk ruhuyla duyulan masallaşmış görüntüleridir. Destanlarda milletlerin dinleri, türlü inanışları‚ Tanrı karşısındaki davranışları, yaşadıkları coğrafyanın özellikleri ile birleşmiş duyguları vardır.
Su köpüğünden yaratılmış‚ bir ağacın karnından doğmuş, ışık kümelerinin içinden çıkmış‚ fil kadar kuvvetli, güneş kadar güzel insanların maceralarını

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Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
Effect of Flaring Angle of Transition Structure On the Scouring of outlet structure
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The transition structure is considered as the most important hydraulic structure controlling the w/s transtion, morever it decrease the scouring of outlet structure.

seven experiment samples for transition structure was used in this research at different angles ( 10° - 90° ).

       It was shown that froud number has a clear effect on the depth of the scouring, morever the high discharge rates cause an increase of the ratio between the length of the scour and its depth.

       In order to select the best flaring angle it was shown that the angle of 40° has the most discharge rate, least structure length and least angle scour depth, with the firmly of t

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