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.
The objective of the present work was to estimate water requirements and water use efficiency for Broccoli under normal irrigation conditions and sewage irrigation. Field experiment was carried out during the season 2018 at station/Sulaimni agricultural station/Bakrajo –College of Agricultural Sciences. The experiment included three treatments: River water irrigation in all season growth (I1), Sewage water irrigation in all season growth (I2), Alternate irrigation (one river irrigation followed by two sewage water irrigation) in all season growth (I3). The experimental Design was Randomized Complete Block Design (RCBD) w
Nanoparticles of humic acid and iron oxide were impregnated on the inert sand to produce sorbent for treating groundwater contained of cadmium and copper ions by technology of permeable reactive barrier (PRB). Sewage sludge was the source of the humic acid to prepare the coated sand by humic acid—iron oxide (CSHAIO) sorbent; so, this work is consistent with sustainable development. For 10 mg/L metal concentration, batch tests at speed of 200 rpm signified that the removal efficiencies are greater than 90% at sorbent dosage 0.25 g/ 50 mL, pH 6 and contact time 1 h. The kinetic data was well described by the Pseudo first-order model indicating that physicosorption is the predominant mechanism. The maximum adsorption capacities (qmax) were c
... Show MoreIron is one of the abundant elements on earth that is an essential element for humans and may be a troublesome element in water supplies. In this research an AAN model was developed to predict iron concentrations in the location of Al- Wahda water treatment plant in Baghdad city by water quality assessment of iron concentrations at seven WTPs up stream Tigris River. SPSS software was used to build the ANN model. The input data were iron concentrations in the raw water for the period 2004-2011. The results indicated the best model predicted Iron concentrations at Al-Wahda WTP with a coefficient of determination 0.9142. The model used one hidden layer with two nodes and the testing error was 0.834. The ANN model coul
... Show MoreInvestigating the thermal and electrical gains and efficiencies influence the designed photovoltaic thermal hybrid collector (PVT) under different weather conditions. The designed system was manufactured by attaching a fabricated cooling system made of serpentine tubes to a single PV panel and connecting it to an automatic controlling system for measuring, monitoring, and simultaneously collecting the required data. A removable glass cover had been used to study the effects of glazed and unglazed PVT panel situations. The research was conducted in February (winter) and July (summer), and March for daily solar radiation effects on efficiencies. The results indicated that electrical and thermal gains increased by the incre
... Show MoreThis research has presented a solution to the problem faced by alloys: the corrosion problem, by reducing corrosion and enhancing protection by using an inhibitor (Schiff base). The inhibitor (Schiff base) was synthesized by reacting of the substrates materials (4-dimethylaminobenzaldehyde and 4-aminoantipyrine). It was diagnosed by infrared technology IR, where the IR spectrum and through the visible beams proved that the Schiff base was well formed and with high purity. The corrosion behavior of carbon steel and stainless steel in a saline medium (artificial seawater 3.5%NaCl) before and after using the inhibitor at four temperatures: 20, 30, 40, and 50 C° was studied by using three electrodes potentiostat. The corrosion behavior was
... Show MoreThis research has presented a solution to the problem faced by alloys: the corrosion problem, by reducing corrosion and enhancing protection by using an inhibitor (Schiff base). The inhibitor (Schiff base) was synthesized by reacting of the substrates materials (4-dimethylaminobenzaldehyde and 4-aminoantipyrine). It was diagnosed by infrared technology IR, where the IR spectrum and through the visible beams proved that the Schiff base was well formed and with high purity. The corrosion behavior of carbon steel and stainless steel in a saline medium (artificial seawater 3.5%NaCl) before and after using the inhibitor at four temperatures: 20, 30, 40, and 50 C° was studied by using three electrodes potentiostat. The corrosion behavior
... Show MorePoly (viny1 alcohol) (PVA) of 72000 g mol -1 molar mass was cross linked through cold cast esterification with different mol % of MA and EDTA (10 % , 20 % and 30 % ), and two different mol % mixture of MA l EDTA (20 %/5% and 20%/10% .
The use of performance measures modern and sophisticated one of the most important factors that help organization management in achieving customer satisfaction which today is the premise of The scales cell performance and value stream performance measures that will help organization management elimination of waste in all its forms, by allowing the organization opportunities and strengths to help them in achieving their goals. as well as achieving market share and growth in sales and increase cash inflows Where research deals with the concept of lean performance and managerial and its measurement and the evolution of these measure, and the ability of these organizations to achieve customer satisfaction through the application of these mod
... Show MoreThe purpose of this research that, the performance budget is the best style of budget styles that can help and contribute in forming preparing federal typical budget in Iraq , By taking advantage of the application of the principles of scientific rules that would ensure optimal allocation and investment of the financial resources of the state and achieve the best performance and the lowest possible cost, both with regard to the administrative and accounting side, reducing the waste of public money, so that can enhance the success , power , and safety of financial activity of managerial system that it focuses on the magnetite and quality of the work done and the objectives wanted to meet. so application of performance budget require
... Show MoreThat researchers in the play Science Find a theatrical form of an experimental creative, and these experiences taken from the innovation space aesthetic dialogue with the receiver, especially since with previous theatrical experience and is an extension of her, because the interactive theater theatrical terms that assume a pattern do from the depth of the relationship between supply playwright and the audience, which alters the receiving skills actually change, and to monitor these differing divided into three classes that include research, methodological framework (Chapter I) and includes, research problem, the importance of research and the need to him, the goal of the research, the limits Find it border, and the theoretical framework
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