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ijcpe-299
Influences of Operating Variables on Hydrodynamic Performance of Plunging Water Jet Downflow Bubble Column
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The hydrodynamics of a co-current down flow bubble column has been investigated with air – water system. A Perspex bubble column of 5cm in diameter and 1.5m height is used as a test contactor using nozzles of 7, 8 and 9 mm diameter for air-water distributing. The column is provided with three electro-resistivity needle probes for bubble detection.
Experimental work is carried out with air flow rates from 0.09 to 0.45 m3/hr and liquid flow rates from 0.65 to 1.1m3/hr in order to study the effects of superficial gas velocity, nozzle diameter and liquid flow rate on the characteristics of hydrodynamic interactions viz. gas hold up, bubble diameter and bubble velocity by using two technical methods, direct height measurements for air-water mixture in the column and resistivity probe techniques.
Gas hold up is found to be progressively increased with increasing superficial gas velocity and with decreasing liquid flow rate. Lower gas hold up is obtained with smaller nozzle diameter. However, gas hold up in two-phase zone is considerably higher than the corresponding value in mixing zone.
The mean bubble velocity is increased with increasing superficial gas velocity, liquid flow rate and nozzle diameter for both mixing and two phase zones. Experimental data are found to be fairly fitted with the Drift Flux model of Zuber and Findly.
The bubble diameter is considerably increased with increasing superficial gas velocity and with decreasing liquid flow rate, whereas it is slightly influenced by nozzle diameter. However, the bubbles in two-phase zone are relatively bigger than those observed in mixing zone. Finally, mathematical correlations have been developed from the experimental data to describe the gas hold up and bubble velocity in the uniform two-phase zone.

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Publication Date
Sun Jan 01 2017
Journal Name
International Journal Of Economic Research
Credit derivatives: Do they matter to avoid credit exposure? (Some evidences from the US market)
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Credit derivatives (CDs) have been increasingly acknowledged as an important requirement to hedge and transfer credit risk CR. Nonetheless, they have been extensively criticized for destabilizing the whole economic system bringing about the latest subprime credit crisis. The study’s main aim is to investigate the reason for the use of (CDs), whether it is used for hedging or trade purpose, for four of the US international financial institutions that had made it through the 2007 crisis to resume functioning post-crisis. This will be for three different and critical periods, namely the pre, during and after crisis periods (Q1, 2000-Q1, 2014). Adopting the SUR technique, the investigation of the factors that influence the net position of (CD

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Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
A Linear Programming Method Based Optimal Power Flow Problem for Iraqi Extra High Voltage Grid (EHV)
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The objective of an Optimal Power Flow (OPF) algorithm is to find steady state operation point which minimizes generation cost, loss etc. while maintaining an acceptable system performance in terms of limits on generators real and reactive powers, line flow limits etc. The OPF solution includes an objective function. A common objective function concerns the active power generation cost. A Linear programming method is proposed to solve the OPF problem. The Linear Programming (LP) approach transforms the nonlinear optimization problem into an iterative algorithm that in each iteration solves a linear optimization problem resulting from linearization both the objective function and constrains. A computer program, written in MATLAB environme

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Publication Date
Mon Jul 01 2024
Journal Name
Iop Conference Series: Earth And Environmental Science
Changes in the Growth and Yield of Broccoli Grown in the Alternative Solution ABEER, Affected by Gas Enrichment and Spraying with Organic Nutrients under the Hydroponic Cultivation System
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Abstract<p>A Field experiment was conducted in Horticulture and Landscape Department, College of Agricultural Engineering Sciences, University of Baghdad, Al-Jadriah during fall 2019-2020 to study changes in the growth and yield of broccoli grown in the alternative solution ABEER, affected by gas enrichment and spraying with coconut water and moringa aqueous extract under the hydroponic cultivation system. Nested design with three replications adopted in the experiment, each of them included in main plot the first factor, which is gas enrichment (O<sub>2</sub> and O<sub>3</sub>), Then levels of second factor were randomly distributed within each replicate, which included spra</p> ... Show More
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Publication Date
Wed Jun 18 2014
Journal Name
Geological Quarterly
Stable carbon and nitrogen isotopes and elemental composition and origin of organic matter from the Euphrates, Injana and Dibdibba formations in Iraq: discrimination between marine and terrestrial environments
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Publication Date
Sun Dec 04 2016
Journal Name
Baghdad Science Journal
Synthesis, Characterization, Antimicrobial and Theoretical Studies of V(IV),Fe(III),Co(II),Ni(II), Cu(II), and Zn(II)Complexes with Bidentate (NN) Donar Azo Dye Ligand
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The new 4-[(7-chloro-2,1,3-benzoxadiazole)azo]-4,5-diphenyl imidazole (L) have been synthesized and characterized by micro elemental and thermal analyses as well as 1H.NMR, FT-IR, and UV-Vis spectroscopic techniques. (L) acts as a ligand coordinating with some metal ionsV(IV), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II). Structures of the new compounds were characterized by elemental and thermal analyses as well as FT-IR and UV-Vis Spectra. The magnetic properties and electrical conductivities of metal complexes were also determined. Study of the nature of the complexes formed in ethanol following the mole ratio method.. The work also include a theoretical treatment of the formed complexes in the gas phase, this was done using the (hyperch

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Publication Date
Sat Jun 07 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of marginal gap at the composite/enamel interface in Class II composite resin restoration by SEM after thermal and mechanical load cycling (An in vitro comparative study)
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Background: This study compared in vitro the marginal adaptation of three different, low shrink, direct posterior composites Filtekâ„¢ P60 (packable composite), Filtekâ„¢ P90 (Silorane-based composite) and Sonic fillâ„¢ (nanohybrid composite) at three different composite/enamel interface regions (occlusal, proximal and gingival regions) of a standardized Class II MO cavity after thermal changes and mechanical load cycling by scanning electron microscopy. Materials and methods:Thirty six sound human maxillary first premolars of approximately comparable sizes were divided into three main groups of (12 teeth) in each according to the type of restorative material that was used: group (A) the teeth were restored with Filtekâ„¢ P6

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Publication Date
Sat Jun 04 2022
Journal Name
Al–bahith Al–a'alami
Iraq's Image in the British Press An analytical study of the Guardian and The Daily Telegraph for 1 / 1- 31/3/2019: Research extracted from a master's thesis
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The topic of the research dealt with the image of Iraq in the British press based on a sample of the newspapers (The Guardian and the Daily Telegraph), which are among the most important and largest newspapers in the United Kingdom and the world, because of its active role in guiding local and international public opinion towards important issues and events, Since these two newspapers are interested in the accuracy of sensitive political topics, the message aimed at knowing the media image that these two newspapers painted about Iraq in the period that was limited to the first quarter of 2019, and also to know the nature of the contents promoted by these newspapers about the Iraqi reality, The method of content analysis was used as an ap

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Publication Date
Sun Dec 31 2023
Journal Name
College Of Islamic Sciences
Imam Al-Mubarakpuri's Jurisprudential Choices (d.1353 AH) in the Borders from his book "Tuhfat Al-Ahwadi" with the explanation of "Jami' Al-Tirmidhi / a comparative jurisprudential study
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Praise be to God, Lord of the Worlds, and prayers and peace be upon the Master of Messengers and his family and companions.

The study of the jurisprudential opinions of scholars, their choices, or their weightings, sheds light on the approach they followed in their choices, and reveals the originality of the scholar or his influence on those who preceded him from among the scholars.

And the commentators of the noble hadith of the Prophet have their important contributions in this aspect, as they undertake the task of explaining the noble hadith, the second source of legislation

Contemporary commentators have their share in the service of the honorable hadith, and the statement of their choices and preferences, and am

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Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Exercise the leadership of the tax administration leaders to drive away the strategic orientation And its relation to organizational excellence: Practical research in the General Authority for Taxes
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The aim of the research is to assess the practice of tax administration to diminish the strategic direction of (proactive, analytical, defensive, response) and the nature of its relationship to organizational excellence represented by (leadership, strategic planning, focus on taxpayers, information and analysis and knowledge management, focus on operations, focus on forces. The questionnaire was adopted as a main tool in collecting data and information from the sample members of the General Authority for Taxes (110) who are in the site (m.  Second Division Manager, Ms The statistical program (SPSS) was used to calculate (mean, standard deviation, difference coefficient, correlation coefficient, t-test). The research reached a number

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Publication Date
Wed Jan 23 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Active Role of Admin strative Skills in Reinforcing Strategic Entrepreneur Ship Through Organizational Flexibility: دراسة استطلاعية لأراء عينة من الإدارات العليا والوسطى في المصارف العراقية الخاصة / بغداد
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The study has tackled three important variables on the strategic and organizational level, that are : (Administrative skill, strategic Entrepreneurship  and organizational flexibility). Through the statistical analysis is, the research hers have sought to identify the relation among them. The study has been applied on a sample of (44) private banks in Iraq. A questionnaire, which has been designed according to a number of international standards, has been used. It's made of (29) items that cover the three variables to test their hypotheses. A number of statistical tools have been used A number of conclusion have been reached and recommendations have also been suggested.

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