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Performance Evaluation of Three Phase Spray Direct Contact Heat Exchanger
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The present investigation deals with experimental study of three-phase direct-contact heat exchanger, for water-Freon R11 system, where water is the continuous phase (liquid) and Freon R11 (liquid-gas) is the dispersed phase. The test section consisted of a cylindrical Perspex column with inner diameter 8cm and 1.2m long, in which, water was to be confined. Liquid Freon R11 drops were injected into the hot water filled column, through a special design of distributors at the bottom of the column. The liquid Freon R11 drops rose on their way up and evaporated into two-phase bubbles at atmospheric pressure. The study was devoted to express the effect of process variables such as column height, Freon R11 mass flow rate and initial temperature of water on the average percentage holdup, heat transfer rate, volumetric heat transfer coefficient and effectiveness.

The obtained experimental results showed that the average percentage holdup increased with increasing in the process variables. The heat transfer rate increased clearly with increasing in mass flow rate of Freon R11 while it increased very little when column height and initial temperature of water increased, it increased two times when increase the mass flow rate from 1.8 to 5.4 kg/hr. The volumetric heat transfer coefficient was found to decrease with increasing in column height and initial temperature of water, while it was increased with increasing in mass flow rate of Freon R11. The effectiveness was found to increase (maximum 90%) with increasing in column height and decreasing in the mass flow rate of Freon R11 and initial temperature of water. A statistical analysis was performed to get general correlations for the average percentage holdup, heat transfer rate, volumetric heat transfer coefficient and effectiveness as a function of the studied parameters.

 

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Publication Date
Wed Dec 01 2010
Journal Name
Al-khwarizmi Engineering Journal
An Optimum Design of Cam Mechanisms with Roller Follower for Combined Effect of Impact and High Contact Loads
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     The problem in the design of a cam is the analyzing of the mechanisms and dynamic forces that effect on the family of parametric polynomials for describing the motion curve. In present method, two ways have been taken for optimization of the cam size, first the high dynamic loading (such that impact and elastic stress waves propagation) from marine machine tool which translate by the roller follower to the cam surface and varies with time causes large contact loads and second it must include the factors of kinematics features including the acceleration, velocity, boundary condition and the unsymmetrical curvature of the cam profile for the motion curve.

     In the theoretical solution

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Publication Date
Mon Mar 01 2010
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The dropping of three zeroes from Iraqi dinar
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           The purpose of this research is to explain the effect of the dropping of three zeroes from Iraqi dinar on the basic role of the dinar and derivative and dynamic in transaction of Iraqi economic. the importance of this research comes from the effect of this operation on the evaluation of the exchange between the individuals of Iraqi society and the other between the Iraqi individuals and the foreign whom use the Iraqi dinar as a tool for exchange also the effect of the operation on the reserves of the Iraqi dinar the results of this research are as the following:-

1-the operation of dropping of zeroes must be associated with increase of the sharing of economic sectors wi

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Publication Date
Tue Jun 01 2010
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Relevance of Budgeting Estimations for Control and Performance Evaluation in Adopting Kaizen: Hypothetical & Empirical Study
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The kaizen is considered as one of the most important modern techniques which has been adopted by various economics entities especially manufacturing firms and its beginnings return to the middle of the earlier century that has been used by companies like Toshiba, Matsushita Electric, and Toyota. Which realized that these modern techniques would make a total change in the competitive environment and started qualifying and its staff in such away that enables them to go along with this unique environment. The continuous improvement (Kaizen) depends on the small continuous improvements in the product and the production operations during the production stage. Consequently, the research problem is represented in the improperly of the budg

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Publication Date
Sun Dec 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Evaluation of Material Technical Engineering Department Performance by Staff Member and student in Technical College -Baghdad
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The research intent evaluates the performance of material technical department / Technical College -Baghdad.

The study depend on the descriptive analytical approach to determine and treating the variables to get data and information that related to study, the researchers depended on questionnaire designed for this purpose and contains eight main dimensions that’s are scientific reference , academy course, staff member , administrative system, physical facilities , student ,scientific research, graduate service , in addition each dimension  involved (5) items contacted with mean dimensions, which translate aspects of  performance evaluation, the questionnaire applied on two samples staff member

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Publication Date
Sat Feb 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Evaluation the performance efficiency of the Public Manufacturing Sector in Iraq for the Period (2000-2009)
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The industrial production sector has an important role in the national economy of the advanced countries as well as the developing ones to get higher levels for their economy . We in Iraq , just like most of the develpoing countries , our economy still suffers of great shortage in this active sector in spite of the repeated statements about the desire of activating the contribution of this sector in the national economy . The industrial sector in Iraq suffers in general of many problems , especially the public industrial sector (manufacturing) . These problems have been  existed because of the unnatural conditions that Iraq has passed during the previous decades especially in the political and security sides . which reflecte

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Publication Date
Tue Mar 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Performance evaluation criteria"Applied Study in the General Company for the manufacture of glass and ceramics"
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Contemporary management is interested in the process of performance assessment  because of its significance in the field of planning and controlling the multiactiveties to attain its goals and uncovering digression of virtual performance after comparing it with the plan or equitable performance.

Digression is analyzed to enable management control centers of authority.

Assessment process significance is closely related by setting definite categories to evaluate the economic activity to know the ability to achieves aims.

This study concentrated on the most important categories that used to evaluate  company understudy with ather categories suggested to complete assessment process.

This study is in

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Publication Date
Mon Dec 01 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of the Efficiency of Three Different Obturation Techniques to Obturate the Isthmus Area of Roots Canals Prepared by Two Different Instrumentation Techniques (An In Vitro Study)
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Background: The isthmus is a difficult area in the root canal complex to manage. The research aimed to evaluate the efficiency of three different obturation techniques (lateral condensation, EandQ (thermoplasticized gutta percha system) and Soft Core (thermoplasticized core carrier gutta percha system)) to obturate the isthmus area of roots prepared by two different instrumentation techniques (rotary ProTaper universal and ProTaper Next systems). Material and method: Sixty freshly extracted teeth were randomly divided into two main groups (A and B) of 30 teeth each. Group A was prepared by rotary ProTaper Universal whereas group B was prepared by ProTaper Next system. Each main group was then randomly subdivided into three subgroups of 10 t

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Publication Date
Sun Mar 02 2014
Journal Name
Baghdad Science Journal
Comparison of Properties of Various Heat Storage Fluids used with Evacuated Tube of Solar Water Heater
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The aim of this work was to capture solar radiation and convert it into solar thermal energy by using a storage material and the heat transfer fluid like oil and water and comparison between them, we used the evacuated tube as a receiver for solar radiation, The results showed that the oil better than water as storage material and the heat transfer fluid and the effective thermal conductivity material and good for power level, rates and durations of charge and discharge cycles.

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Publication Date
Sun Jan 01 2017
Journal Name
Optics & Laser Technology
Finite element thermal analysis for PMMA/st.st.304 laser direct joining
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This work is concerned with building a three-dimensional (3D) ab-initio models that is capable of predicting the thermal distribution of laser direct joining processes between Polymethylmethacrylate (PMMA) and stainless steel 304(st.st.304). ANSYS® simulation based on finite element analysis (FEA) was implemented for materials joining in two modes; laser transmission joining (LTJ) and conduction joining (CJ). ANSYS® simulator was used to explore the thermal environment of the joints during joining (heating time) and after joining (cooling time). For both modes, the investigation is carried out when the laser spot is at the middle of the joint width, at 15 mm from the commencement point (joint edge) at traveling time of 3.75 s. Process par

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Publication Date
Tue Jul 01 2014
Journal Name
Political Sciences Journal
Foreign direct investment in Iraq and its role in economic development
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الاستثمار الاجنبي المباشر في العراق ودوره في تحقيق التنمية الاقتصادية

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