×
The submission system is temporarily under maintenance. Please send your manuscripts to
Go to Editorial ManagerIn this research, a two – dimensional numerical investigation is conducted to show the ability of the jet-ejector to prepare the air – methane mixture at different equivalence ratio. The basic dimensions (diameters ratio, throat length, angle α , and angle θ ) of the jet-ejector are taken into account on calculating the equivalence ratio. The results showed that the ratio of the diameters has a higher effect than other parameters on preparing a mixture for equivalent ratios including both rich and lean mixture. The rest of the factors did not have a significant effect on the value of the equivalence ratio, and only had a role in preparing an equivalence ratio for rich mixture type.
Recently, methods have emerged to assess the vulnerability of groundwater to pollution, which has been adopted by many countries that depend on groundwater as an important and supportive resource for surface water to protect groundwater and monitor and control its pollution. Assessment methods adopt vulnerability maps and compare them with the real-life pollution map of the region. The study was conducted in Al-Teeb area, which is located in the northeast of Missan province, south of Iraq. This area is about 2450 km 2 . This study applied four models DRASTIC, GOD, SINTACS and Modified DRASTIC of vulnerability maps are analyzed using GIS technique and compared with the reality map which represent the nitrate concentration map as a basic comparison map; in order to choose the closest one with respect to the realistic acting. The results showed that 80.29 % of study area is classified under low vulnerability in DRASTIC method and moderate vulnerability in GOD, SINTACS and MD-DRASTIC which are covered 54.12 %, 83.18 % and 72.35 % of study area respectively. Pearson's correlation coefficient was used to compare the four methods with the nitrate concentration map, where the correlation value for DRASTIC, GOD, SINTACS and MD-DRASTIC was 73.05, 49.79, 83.23 and 87.94 %, respectively. So, the MD-DRASTIC is represented the best technique for evaluating vulnerability map in the study area which can be recommended.
Tn this paper, a hierarchical phoneme recognition system is proposed. The hierarchical approach is applied here to recursively partition the recognition problem into smaller and smaller sub-problems those are independently handled at the di~tinct nodes of the hierarchy. The nodes are individually set to chara~erize different properties of the input phoneme, or more precisely to make separate d~isioos on its pertinence to the different reference subgroups of phonemes. The full characteri:zation of the input phoneme is achieved by traversing some root-to-leaf path through the hierarchy. The relationships between the different features of phonemes and their pertinence to the different reference subgroups. are to be objectively characteriz.ed ttnd optimized here. This involves specifying the decisive subset of features for each pertinence decision and neglecting the remaining features those are irrelevam to (or probably have negative effect on) that decision, at each node of the hierarchy. The optimization applied through the feature election process here, is not aimed at reducing the amount of feamres to be used in the recognition process, for the purpose of decreasing the time-complexity of the systcn1, but, is interested in enhancing the decision making accuracy of the system by avoiding the misleading features.
In this paper, energy and exergy concepts have been carried out on one of the largest gas turbine power plants in Iraq (Rumaila-Basra). Both ISO operating conditions as well as actual operating data recorded for one month in hot season are considered. Results indicate that a lot of heat energy accompanied with remarkable exergy is discharged to the atmosphere. Also, it is found that the combustion chamber has the largest exergy destruction among the plant components. Possibility of cooling the intake air drawn by the compressor and its effects on the plant performance is studied. The required cooling load is found to be in the range 3379 T.R for part load operation to 4723.3 T.R for full load operation.
In this work, both energy and exergy analyses have been carried out on General Electric (GE) gas turbine unit found in Khor Al-Zubair gas turbine power plant located in Basra, Iraq. The analysis covers the ISO (international standards organization) operating conditions in addition to actual operating data recorded for one month in hot season July 2016. The feasibility of adopting a vapor compression cycle (VCC) for cooling the intake air is evaluated. Generally, the study reveals an obvious drop off for most plant performance characteristics while operating during the hot season. Energy and exergy analyses show that adopting the vapor compression cycle to enhance Khor Al-Zubair GE unit could improve the power output by 20% and 27% in case of part-load and full-load conditions respectively. Both of first and second law efficiencies could be improved by 3.5% at part- load and 9% at full load. The expected cooling load needed for the unit is in the range of 2697 to 3024.5 TR according to part- load and full-load operation respectively. Only total irreversibility of the unit is expected to increase in case of adopting VCC and this will not impair the improvement in second law efficiency of the unit. Among the unit components, combustion chamber has the largest computed irreversibility. Further improvement is recommended by utilizing the released heat energy to the atmosphere, which is characterized by significant work potential.