The present paper deals with experimental investigation of the performance of air cooled split air conditioner, with evaporative water mist pre cooling to increase the cooling capacity and reduce the consumption power under hot and dry climate. This investigation considers how the performance can be enhanced by using water mist to pre-cool ambient air entering the condensers by adiabatic cooling process which depends on the ambient air wet bulb temperature; as well the condensing temperature and condensing pressure will be decreased accordingly. So the cooling capacity would be increased and consumption power would be decreased, consequently the energy ratio, EER would be improved. The performance of air cooled air conditioner with water mist pre cooling;
ECAC was compared to the performance of air cooled air conditioner, ACAC which tested under the same ambient condition that is ranged from 25 oC to 52 oC. Test results show that ECAC operating at EER of 10.5 BTV/W. The ECAC had an EER of 47 % higher than that of ACAC under the same and most serve hot and dry condition of 52 oC and 10% relative humidity.
The solidification process in a multi-tube latent heat energy system is affected by the natural convection and the arrangement of heat exchanger tubes, which changes the buoyancy effect as well. In the current work, the effect of the arrangement of the tubes in a multi-tube heat exchanger was examined during the solidification process with the focus on the natural convection effects inside the phase change material (PCM). The behavior of the system was numerically analyzed using liquid fraction and energy released, as well as temperature, velocity and streamline profiles for different studied cases. The arrangement of the tubes, considering seven pipes in the symmetrical condition, are assumed at different positions in the system, i
... Show More
(18)
(17)
Sediment samples were collected from main water processing and supply plants in Baghdad, and tested for radioactivity from both natural and artificial sources. These stations are: East Dijla (Tigris), Al-Kadisia, Al-Karama, Al-Rasheed, Al-Sader, Al-Wathba, and Al-Wihda supply stations. Qualitative measurements were made, and the results showed that most sediments exhibited natural radioactive level and sometimes less than the international regular standards. Specially, K-40 and Ra-226 results were much less than the standards for radioactive concentrations. Ac-228 concentration was found rather than Th-232 (in Al-Sader and Al-Wihda samples) but with low concentrations of about 10-15 Bg/kg and detection confidence ~45% , and Ce-141 and Be
... Show MoreThe current research deals with practical studies that explain to the Iraqi consumer multiple instances about the phenomenon of water hammer which occur in the water pipeline operating with pressure. It concern a practical study of the characteristics of this phenomenon and economically harmful to the consumer the same time. Multiple pipe fittings are used aimed to reduce this phenomenon and its work as alternatives to the manufactured arresters that used to avoid water hammer in the sanitary installations, while the consumer did not have any knowledge as to the non-traded for many reasons, including the water pressure decreases in the networks and the use of consumer pumps to draw water directly from the network. Study found a number of
... Show More
The current research deals with practical studies that explain to the Iraqi consumer multiple instances about the phenomenon of water hammer which occur in the water pipeline operating with pressure. It concern a practical study of the characteristics of this phenomenon and economically harmful to the consumer the same time. Multiple pipe fittings are used aimed to reduce this phenomenon and its work as alternatives to the manufactured arresters that used to avoid water hammer in the sanitary installations, while the consumer did not have any knowledge as to the non-traded for many reasons, including the water pressure decreases in the networks and the use of consumer pumps to draw water directly from the network. Study found a numbe
... Show MoreThis research dealt with the impact of internal control on tax performance using balanced scorecard indicators because of its special importance in improving tax performance and reform. The internal control system is a safety valve for senior management in all organizations, it plays an important role in the regularity and development of work and the fight against corruption To provide reliable and accurate data and information, follow up on compliance with laws, regulations and instructions. The aim of this research is to demonstrate how control affects tax performance and how to adapt internal control components to improve tax performance. In the General Authority for taxes and its branches,. The research resulted in a number of conclu
... Show MoreThis study was concerned with using ozone gas in drinking water treatment plant at Ibn-Sina Company. The main purpose of this research is to find the best contactor for ozone unit proposed. An investigation was conducted to study the absorption of ozone by water in two type of absorber. The effects of the process variables (such as height of water column, contact time, and pH) on the amount of ozone absorbed were investigated. Box-Wilson central composite rotatable design is used to design the experimental work for the mentioned variables. It was found that the optimum value of the variables studied was:
i) Height of water column (90 cm)
ii) Contact time (17-18 min)
iii) PH (7 - 7.5)
(3)
(3)
The implementation of nanotechnology in all industries is one of most significant research fields. Nanoparticles have shown a promising application in subsurface fields. On the other hand, various surfactants have been used in the oil industry to reduce oil/water interfacial tension and also widely used to stabilize the nano-suspensions. The primary objective of this study was to investigate the improvements of surfactants ability in term of interfacial tension (γ) reduction utilizing addition of silicon dioxide nanoparticles at different temperatures and salinity. The pendant drop technique has been used to measure γ and electrical conductivity has been used to measure the critical micelle concentration (CMC). The synergistic effects of
... Show More
(43)
(49)
The analysis and efficiency of phenol extraction from the industrial water using different solvents, were investigated. To our knowledge, the experimental information available in the literature for liquid-liquid equilibria of ternary mixtures containing the pair phenol-water is limited. Therefore the purpose of the present investigation is to generate the data for the water-phenol with different solvents to aid the correlation of liquid-liquid equilibria, including phase diagrams, distribution coefficients of phenol, tie-lines data and selectivity of the solvents for the aqueous phenol system.
The ternary equilibrium diagrams and tie-lines
... Show MoreDora petroleum refinery waste water is the one of the important source of pollution by priority pollutant aromatic compound discharged to Tigris river in Iraq. the station has waste water treatment unit contains many treatment subunits The most important sub units is :skimmer units ,physiochemical unit ,daf unit, biological unit. The aim of research project is to study the ability of unit to remove the priority pollutant aromatic compound and follow up these compounds in river to study ability of river to self removal. A solid phase extraction (SPE) followed by high performance liquid chromatography-ultra violet (HPLC-UV) technique is depicted for the quantitative estimation of benzidines and phenols. Experimental studies were performed to
... Show More