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Experimental Estimation of Critical Buckling Velocities for Conservative Pipes Conveying Fluid
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Conservative pipes conveying fluid such as pinned-pinned (p-p), clamped–pinned (c-p) pipes and clamped-clamped (c-c) lose their stability by buckling at certain critical fluid velocities. In order to experimentally evaluate these velocities, high flow-rate pumps that demand complicated fluid circuits must be used.

     This paper studies a new experimental approach based on estimating the critical velocities from the measurement of several fundamental natural frequencies .In this approach low flow-rate pumps and simple fluid circuit can be used.

Experiments were carried out on two pipe models at three different boundary conditions. The results showed that the present approach is more accurate for estimating the critical velocities of p-p and c-p pipes. However, for c-c pipes it was not so unless a higher flow rate is used.

 

 

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Publication Date
Thu Mar 01 2018
Journal Name
Journal Of Engineering
Permeability Estimation by Using the Modified and Conventional FZI Methods
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There many methods for estimation of permeability. In this Paper, permeability has been estimated by two methods. The conventional and modified methods are used to calculate flow zone indicator (FZI). The hydraulic flow unit (HU) was identified by FZI technique. This technique is effective in predicting the permeability in un-cored intervals/wells. HU is related with FZI and rock quality index (RQI). All available cores from 7 wells (Su -4, Su -5, Su -7, Su -8, Su -9, Su -12, and Su -14) were used to be database for HU classification. The plot of probability cumulative of FZI is used. The plot of core-derived probability FZI for both modified and conventional method which indicates 4 Hu (A, B, C and D) for Nahr Umr forma

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Publication Date
Tue Dec 01 2020
Journal Name
Periodicals Of Engineering And Natural Sciences
Constructing a new mixed probability distribution with fuzzy reliability estimation
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This paper deals with constructing mixed probability distribution from mixing exponential

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Publication Date
Tue Dec 01 2020
Journal Name
Baghdad Science Journal
Partial Sums of Some Fractional Operators of Bounded Turning: Partial Sums of Some Fractional Operators
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            In this paper, several conditions are put in order to compose the sequence of partial sums ,  and  of the fractional operators of analytic univalent functions ,  and   of bounded turning which are bounded turning too.

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Publication Date
Thu Dec 15 2011
Journal Name
Iraqi Journal Of Laser
The Optical Limiting Behaviour of Prepared Silver Nanoparticles Embedded in Polymer Film
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In the present work, silver nanoparticles were prepared. Nonlinear optical properties and
optical limiting of silver nanoparticles were investigated.Standard chemical synthesis method was used at
diffrent weight ratio(0.038, 0.058 and 0.078) of silver nitrate. Several testing were done to obtain the
characteristics of the sample. Z-Scan experiments were performed using 30 ns Q-switched Nd:YAG
laser at 1064 nm and 532 nm at different intensities. The results showed that the nonlinear refractive
index is directly proportional to the input intensities, which caused by the self-focusing of the material.
In addition, the optical limiting behavior has been studied. The results showed that the sample could be
used as an opt

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Publication Date
Thu Sep 08 2022
Journal Name
Al-khwarizmi Engineering Journal
Study of Microbial Desalination Cell Performance; Power Generation and Desalination Efficiency using Pure Oxygen in a Cathode Chamber
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Microbial Desalination Cell (MDC) is capable of desalinating seawater, producing electrical power and treating wastewater. Previously, chemical cathodes were used, which were application restrictions due to operational expenses are quite high, low levels of long-term viability and high toxicity. A pure oxygen cathode was using, external resistance 50 and 150 k Ω were studied with two concentrations of NaCl in the desalination chamber 15-25 g/L which represents the concentration of brackish water and sea water. The highest energy productivity was obtained, which amounted to 44 and 46 mW/m3, and the maximum limit for desalination of saline water was (31% and 26%) for each of 25 g / L and 15 g / L, respectively, when using an ex

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Publication Date
Tue Jun 30 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Using TD-ABC technology to determine idle production capacity: An applied research in Al-Wasat Oil Company
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The aim of the research to apply TD-ABC technology to determine the idle capacity of the central oil companies (oil field east of Baghdad), as a modern cost management technology based on time-oriented activities (TD-ABC) is used by industrial companies in general and oil companies on In particular to build a sustainable Calvinist pillar and make future decisions by identifying idle energy to gain it a competitive advantage, the descriptive analytical approach has been adopted in calculating and analyzing the company’s data for 2018, and the most prominent conclusions of this research are managing idle energy and the task of applying cost technology on the basis of time-oriented activities and providing Convenient spatial infor

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Publication Date
Wed Sep 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Extraction of Monocyclic Aromatic Hydrocarbons From Petroleum Products Using Sulfolane as Industrial Solvent
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            Liquid – liquid equilibria data were measured at 293.15 K for the pseudo ternary system (sulfolane + alkanol) + octane + toluene. It is observed that the selectivity of pure sulfolane increases with cosolvent methanol but decreases with increasing the chain length of hydrocarbon in 1-alkanol. The nonrandom two liquid (NRTL) model, UNIQUAC model and UNIFAC model were used to correlate the experimental data and to predict the phase composition of the systems studied. The calculation based on NRTL model gave a good representation of the experimental tie-line data for all systems studied. The agreement between the correlated and the experimental results was very good

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Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
Using Smart Control System to Enhancement the Split Air Conditioning System Performance
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In IRAQ, the air conditioners are the principal cause of high electrical demand. In summer, the outer temperature sometimes exceeds 500C which significantly effects on the A/C system performance and power consumed. In the present work, the improvement in mechanical and electrical performance of split A/C system is investigated experimentally and analytically. In this paper, performance and energy saving enhancement of a split-A/C system was experimentally investigated to be efficiently compatible with elevated temperature weathers. This improvement is accomplished via Smart Control System integrate with Proportional-Integral- Differential PID algorithm. The PIC16F877A micro-controller has been programmed with the PID and PWM c

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Publication Date
Wed Dec 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
مقدرات الاختبار الأولي المقلصة ذات المرحلة الواحدة لمعلمة القياس للتوزيع الأسي
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A preliminary test single stage Shrinkage (PTSSS) techniques is used for estimation the scale parameter q of an exponential distribution when a prior knowledge about q is a available in the form of initial estimate q0 of q. It is proposed to estimate q by a testimator  that is based upon the result of a test of the hypothesis H0 :q = q0 against the hypothesis HA

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Publication Date
Thu Mar 01 2007
Journal Name
Al-khwarizmi Engineering Journal
An investigation into the performance of counter rotating floating ring journal under different working conditions
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The steady state performance of the counter rotating floating ring Journal bearing is analyzed with isothermal finite bearing theory. The effect of different parameters affecting the performance of the bearing (namely speed ratio, clearance ratio and radii ratio), have been investigated. The load carrying capacity of the bearing increasing with decreasing the radii ratio (R2/R1) of the ring and clearance ratio (c1/c2), in the other hand, the coefficient of friction increases with increasing the clearance and radii ratios, while decreases with incre4asing the bearing to journal speed ratio (γ). It is shown during this work that different operating conditions are greatly enhanced the performance

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