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.
Experimental and numerical studies have been conducted for the effect of injected air bubbles on the heat transfer coefficient through the water flow in a vertical pipe under the influence of uniform heat flux. The investigated parameters were water flow rate of (10, 14 and 18) lit/min, air flow rate of (1.5, 3 and 4) lit/min for subjected heat fluxes of (27264, 36316 and 45398) W/m2. The energy, momentum and continuity equations were solved numerically to describe the motion of flow. Turbulence models k-ε was implemented. The mathematical model is using a CFD code Fluent (Ansys15). The water was used as continuous phase while the air was represented as dispersed. phase. The experimental work includes design, build and instrument a test
... Show MoreThe research aims to form a clear theoretical philosophy and perceptions about strategic Entrepreneurship through the relationship between high Involvement management practices, the basis in creating that leadership and high-performance work systems as a support tool in achieving them according to the proposals (Hitt et al, 2011), in an attempt to generalize theoretical philosophy and put forward how to apply it within The Iraqi environment, and on this basis the problem of the current research was launched to bridge the knowledge gap between the previous proposals and the possibility of their application, aiming to identify the practices of high Involvement management and the possibility of high-performance work systems and thei
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The aim of the research is to identify psychological toughness and its relationship to some coordination, physical abilities and accuracy of some basic performance skills among the players of the Iraqi junior national handball team players. The hypothesis is the existence of a correlation between psychological toughness, coordination, physical abilities, and the accuracy of some basic skills performance among the players of the Iraqi junior national handball team players. The descriptive approach in the style of correlational relations used to suit the research problem, as the community was determined by (18) players for the Iraqi junior national handball team players, while the sample was (14) players, and the samp
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This experimental study focuses on scouring in box culvert inlets under steady-state conditions and at different percentages of blockage ranging from 0% to 65%, and also looks at the hydraulics of water in the culvert. The investigation shows that the blockage of the culverts has influenced the scouring pattern at the blocked culverts' entrances. Ten experiments were carried out at the laboratory to see how blockage impacts the scouring pattern upstream of a box culvert during steady flow. Both partially blocked and unblocked cases were implemented in this study. The experimental tests were done until the equilibrium scour occurred, which took about 3.5 hours of water flow to reach equilibrium conditions. The results r
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THE EFFECT OF SPREACL of KNOWLEDGE ON ETHICS
Objective(s): To determine the effectiveness of lactation counseling on maintenance of breastfeeding after
cesarean section for study group.
Methodology: A quasi-experimental study was conducted on non probability sample (purposive) of (60) women
who had cesarean section and sample divided in to two groups (30) of them as a study group from Fatima AlZahra'a
Maternity and Pediatric Teaching Hospital & implement lactation counseling on it and another group (30)
as control group from Baghdad Teaching Hospital in Baghdad City. Study implemented for the period of April 24th
2011 to August 2nd 2011. A questionnaire was used as a tool of data collection to fulfill with objective of the study
and consisted of three parts
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... Show MoreAutorías: Nuha Mohsin Dhahi, Muhammad Hamza Shihab. Localización: Revista iberoamericana de psicología del ejercicio y el deporte. Nº. 6, 2022. Artículo de Revista en Dialnet.
When the drawdown pressure amounts to a value below the dew point pressure, a minor droplet of condensate is shaped and accumulated in the close area of wellbore. As the accumulation happens, the saturation of the liquid will grow and a reduction in gas relative permeability will happen, therefore it will affect the productivity. Generally, condensate baking problem in gas wells is being deliberated and studied and numerous techniques have been suggested to solve the problem. The studying of condensate banking dynamics is essential to evaluate the productivity and behavior of the wells of the gas fields.
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This paper is concerned with the blow-up solutions of a system of two reaction-diffusion equations coupled in both equations and boundary conditions. In order to understand how the reaction terms and the boundary terms affect the blow-up properties, the lower and upper blow-up rate estimates are derived. Moreover, the blow-up set under some restricted assumptions is studied.
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