The differential protection of power transformers appears to be more difficult than any type of protection for any other part or element in a power system. Such difficulties arise from the existence of the magnetizing inrush phenomenon. Therefore, it is necessary to recognize between inrush current and the current arise from internal faults. In this paper, two approaches based on wavelet packet transform (WPT) and S-transform (ST) are applied to recognize different types of currents following in the transformer. In WPT approach, the selection of optimal mother wavelet and the optimal number of resolution is carried out using minimum description length (MDL) criteria before taking the decision for the extraction features from the WPT tree. In ST approach,
the spectral energy index and the standard deviation (STD) are calculated from the S-matrix obtained by discrete S-transform. The two approaches are tested for generating a trip signal and disconnecting the transformer supply experimentally using 1KVA, 220/110V, 50Hz, ∆ / Y threephase transformer. The experimental results show that the trip signal is initiated faster in WPT approach while the transformer is disconnected from the supply after a delay of 10-15msec in the
two approaches due to computer interface and the relay circuit used.
The oxidative degradation of Orange G dye by nanosized CeO2 catalyst has been performed in this study. The catalyst was prepared by precipitation method. Various characterization techniques were carried out to study the physical and chemical properties of the synthesized catalyst. The XRD result confirms well the formation of CeO2 cubic phase. The FTIR result showed the effect of calcination temperature for CeO2 was clearly observed due to reduction in band intensity compared to uncalcined Ce nitrate sample. Meanwhile, the diffused reflection spectra recorded reflection spectra at 414 nm with an energy gap of 3.2 ev. The decolorization of Orange G dye by oxidation process were carried out unde
... Show MoreThe objective of this study is to determine the sources of growth of the cement industry in Iraq for the period 1990-2014 and to indicate the nature of the technological progress used in it. To achieve this objective we have built an econometric model, by adapting the production function constant elasticity for substitution, using multiple regression, and enforcement, SPSS program, and using the ordinary least squares method (OLS). The results showed that quantitative factors (labour and capital) are the main sources of growth the cement industry in Iraq, and the qualitative factors (technological progress) did not contribute effectively to achieve this growth. And that the production techniques adopted in the cement industry in
... Show MoreAbstract
Abstract has many advantages as has historically been one of the regions leading cultural centers . for centuries , it has been a center of commertial and financial operations in Iraq. it is also rich in archeological sites and natural resources, but because of its wars and implementation of urban development strategies are effective and sustainable , so contracted the secretariat of Baghdad with the company (khatib and scirntiffic) for the preparation of the comprehensive development plan for the city of Baghdad in 2030 and funded by the world bank and the fact that the plan was approved ( three stages of it ) and only one phase remains the fourth stage, which is under discussion the aim of the
... Show MoreReinforced concrete slabs are one of the most important and complicated elements of a building. For supported edges slabs, if the ratio of long span to short span is equal or less than two then the slab is considered as two-way slab otherwise is consider as one-way slab. Two-way reinforced concrete slabs are common in use in reinforced concrete buildings due to geometrically arrangement of columns suggested by architects who prefer a symmetric distribution of columns in their plans. Elastic theory is usually used for analysis of concrete slabs. However, for several reasons design methods based on elastic principles are limited in their function. Correspondingly, limit state analysis o
In the present work, leaching process studiedusing organic acids (acetic acid and lactic acid) to extract phosphate from the Iraqi Akashat phosphate ore by separation of calcareous materials (mainly calcite). This approach characterized by energy conservation, environmental enhancement by recovery of calcite as calcium sulfate (gypsum), keeping the physical and chemical properties of apatite. Samples were analyzed using X-ray diffraction and FTIR spectrophotometer. From the obtained experimental data it was found that using the two organic acids yields closed purity values of the produced apatite at the optimum conditions, while at different acid concentrations, it was found that the efficiency of acetic acid is higher at the low acid co
... Show MoreIn this study, a proposed process for the utilization of hydrogen sulphide separated with other gases from omani natural gas for the production of sulphuric acid by wet sulphuric acid process (WSA) was studied. The processwas simulated at an acid gas feed flow of 5000 m3/hr using Aspen ONE- V7.1-HYSYS software. A sensitivity analysis was conducted to determine the optimum conditions for the operation of plant. This included primarily the threepacked bed reactors connected in series for the production of sulphur trioxidewhich represented the bottleneck of the process. The optimum feed temperature and catalyst bed volume for each reactor were estimated and then used in the simulation of the whole process for tw
... Show MoreThe Journal of Studies and Researches of Sport Education (JSRSE)