The response of the combustor’s liner to the air-flow that passes through it is the key reason for the combustion chambers noise, hence the instabilities of those chambers that decreases the mechanical efficiency of such sections, by increased its mechanical vibrations, which increases the failure rate created during originating of the cracks spreading by the shakes producing by the series of high-level frequencies. Accordingly, any work debating the impact of the context of liners in the combustion chamber can provide grasping for the combustion noise generated by the undesirable vibrations, and benefits the industrial firms to design an ideal production procedure which increases the lifespan of the combustor. The goal of this work is to examine the influence of the acoustic treatment using a double layers cylindrical perforated liner on the acoustic transmission loss of gas turbines. The liners layout influences on this acoustic parameter was examined using an experimental data gained by the insertion of a full scale single and double patterns of perforated liners into the unique large scale acoustic wind tunnel at the acoustic research center at Hull University. The experimental tests under-designed acoustic signals were established firstly using 0m/s air cross-flow velocity, then by changed velocities with interval 5m/s ranging between 10m/s to 25m/s. MATLAB script was used to simulate, analyze, and figure out the data collected the insertion of single and double layer patterns of the perforated liner. The experiments demonstrated that, if the perforation acoustic treatments are applied, the acoustic transmission loss will decrease, particularly obvious at higher level frequencies. Further, the results exposed that the air tunnel with the insertion of the liner with double layers reveals an improved perforation acoustic treatment.
Dissolution of gypsum rock in water is significant, which may result in hydrocarbon reservoir formation and evaporate deposits. However, the complexity of the gypsum dissolution process is still of interest because of its uncleanness that requires more critical analysis. The objectives of this experimental study are emphasis on the dissolution characteristics of gypsum rock under room temperature and by various types of water; namely: deionized, tap, fresh, acidic, well, and normal rainwatre. In addition, the influences of dissolution on gypsum rock's mechanical and physical characteristics. Gypsum rock was obtained from Agjalar area, in the southwest of Sulaymaniyah city, Northern Iraq. Experimental results show that we
... Show MoreThe present study investigated the impact of fuel kind on the emitted emissions at the idling period. Three types of available fuels in Iraq were tested. The tests conducted on ordinary gasoline with an octane number of 82, premium gasoline with an octane number of 92, and M20 (consist of 20% methanol and 80% regular gasoline). The 2 liters Mercedes-Benz engine was used in the experiments.
The results showed that engine operation at idle speed emits high levels of CO, CO2, HC, NOx and noise. The produced emission levels depend highly on fuel type. The premium gasoline (ON=92) represents the lower emissions level except for noise at all idling speed. Adding methanol to ordinary gasoline (ON=82) showed high levels of emi
... Show MoreVapor-liquid equilibrium data are presented for the binary systems n-hexane - 1-propanol, benzene - 1-propanol and n-hexane – benzene at 760 mm of mercury pressure. In addition ternary data are presented at selected compositions with respect to the 1-propanol in the 1-propanol, benzene, n-hexane system at 760 mmHg. The results indicate the relative volatility of n-hexane relative to benzene increases appreciably with addition of 1-propanol.
This article briefly analyzing contemporary works appeared in theater writer from Latin America, which comes within the theme of "power." Latin American Literature, such as two-way extremely clear: the vanguard of social and attention, have arrived at certain moments to some extent be regarded as a two-way rival. That desire to participate in the revolution of expression and artistic significance, has appeared evident in the literature of Latin America in the late nineteenth century and ended in the third decade of the twentieth century. The writers that stage would prefer not to serve the objectives of the revolution of Arts own but the objectives of social and political revolution that stimulate the world. These acts were issued
... Show MoreThe research aims to identify decent work and its impact in enhancing job immersion. The questionnaire was adopted as a tool to analyze the sample responses of (81) workers to represent an estimated response rate of (88 per cent) out of the total population of (92) individuals. The research adopted descriptive-analytical approach, and reliability calculation, arithmetic means standard deviations, relative importance, and regression analysis adopted on SPSS v.25. The conclusion shows that there is a medium correlation between decent work and job immersion, and there is a low impact of decent work with its dimensions in job immersion; extract the most important acceptable components for job from the sample point of view about the o
... Show MoreThe changes that have occurred in the business environment and scientific and technological progress, as well as the complexity of administrative problems resulting from its practice of various activities, have led to an increase in the responsibilities entrusted to it, and for the purpose of achieving its strategic objectives, which has made the pillars of corporate governance an inevitable matter required by the nature of modern scientific management of the governorate, the success that companies seek is based on the fertile environment and the dialectical relationship between the individual and the company, and to achieve this success there must be a compatible and harmonious audit environment between the internal and external
... Show MoreAugmented reality technology is a modern technique used in all fields, including: medicine, engineering and education, and has received attention from officials in the educational process at present; The focus of this research is on the degree of use of augmented reality among field experience students in the project's optimal investment program for teaching staff and their difficulties, applied to a sample of 75 students, through a questionnaire prepared by the researcher as a tool to determine the degree of use, as well as difficulties. The researcher addressed the subject through two main axes to determine the degree of use, as well as the difficulties preventing teachers and learners from using this technique. The results of the rese
... Show MoreDiyala Governorate has many unique and diverse geomorphological features that the region enjoys, which are among the attractions for natural tourism, as the natural environment is considered a maker of tourism. The importance of geomorphological aspects as components of natural tourism is due to their association with tourism and entertainment, as a result of the enjoyment of many geomorphological aspects of the beauty of its natural landscape on the one hand, and on the other hand, the association of these manifestations with different types of tourism activity. Any tourist area as it is the main factor for tourist attractions, such as the presence of the Hamrin hills, and sand dunes. Planning for the development of tourism activity in the
... Show MoreThe research aims to measure the economic efficiency and technological change and the total productivity of resources using the parameter and non-parameter methods, for agricultural companies registered in the Iraqi stock exchange, the number of 6 companies for the period from 2005 to 2017 based on the hypothesis that the agricultural companies do not achieve economic efficiency and does not control the management of its operations, and It may be technically efficient but the size of its operations is not optimal. From non-parametric methods, the data envelope analysis method was used. Using the DEAP program, the Middle East Company achieved the highest average technical and cost efficiency of 0.62 and 0.58, respectively. The Iraq
... Show MoreThe research aims to shed light on the nature of the tax gap in the income tax by the method of direct deduction and its reflection on the financial objective of the tax, and to determine the reasons for this gap in the deduction between the tax due in accordance with the laws and instructions in force and the tax actually paid. The tax gap is a real problem that cannot be ignored for what it represents loss of financial revenues due to the state.
The research problem is represented in the existence of a gap between the tax due according to direct deduction instructions and the tax actually paid according to the financial statements, and to achieve the objectives of the research and test the hypotheses, t
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