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.
This research aims the effects of negative media on the educational identity of community. Whereas display the concept of educational identity and its basic components, as well as the role of educational institutions for example the school and the family in form it and reinforcing this identity to individuals. The study showcasing the harmful impact of both traditional and modern media on identity and values, spotlight several examples like the promotion of consumerism and materialism through television programs. which results in the young people to adopt materialistic values like simplicity. The study concludes that media is a double-edged weapon: it can instill virtues and support education if used duly, but it can also weaken the educat
... Show MoreThe history of the impact of nuclear radiation on the environment, as illustrated by the Hiroshima bombing, reveals a multifaceted interplay of scientific, ecological, and ethical dimensions. From the historical context and immediate environmental consequences to long-term ecological effects and human health implications, the effects of nuclear radiation are pervasive. Comparatively analyzed with other nuclear incidents, case studies of affected ecosystems, and through education, ongoing challenges and opportunities toward nuclear technology are revealed. Moreover, it is through the echoes of past nuclear events that lessons were learned which until today guide current efforts on striking a balance between technological advancement
... Show MoreBackground: Fracture of different types of acrylic denture base is a common problem associated with dental prosthesis. Studies suggested that the repair strength may be improved by several means including surface treatment with chemical agents. The aim of the study was to evaluate the effect of surface treatment with acrybond-bonding agent and monomer on fractured denture base in respect to transverse, tensile and shear bond strength and evaluation of the mode of failure by light microscope. Materials and methods: Two hundred seventy specimens were prepared and divided into 3 groups according to the material used (regular conventional, rapid simplified and high impact) heat cure acrylic. The specimen in each groups were prepared specificall
... Show MoreThe research aims at shedding light on the impact of information technology in reducing tax evasion in the General Authority for Taxation. In order to achieve this, the research relied on the analysis of its variables as a main tool for collecting data and information. The results showed that there is a positive and positive effect of information technology on tax evasion. The impact of information technology on increasing tax revenues and reducing the phenomenon of tax evasion In the performance of the research sample, the research sought to highlight the importance of tax information technology through its data and information to the tax administration for the purpose of completing the process Taxpayers for persons subject to income ta
... Show Moreيسعى هذا البحث الى تقديم اطار عملي ونظري حول موضوع "تأثير الاقتصاد المنزلي في تعزيز الاداء العالي" وتم اختبار مخطط الدراسة الفرضي في القطاع التعليمي الحكومي في محافظة البصرة ,ويتضمن عدد من تشكيلات الجامعة التقنية الجنوبية. واستخدمت الاستبانة والمقابلة الشخصية كأسلوب لجمع البيانات للدراسة وكان حجم العينة114 موظف. وقد استخدمت عدد من الاساليب الاحصائية لاختبار فرضيات الدراسة. واظهرت النتائج بأن هناك تأثير ايج
... Show MoreThis research aims to test the effect of strategic cohesion with its dimensions (organizational excitement, organizational casting, organizational synergy) as an independent variable on administrative excellence as a dependent variable in the Ministry of Planning, and through surveying several employees (general managers, heads of departments, and units managers). As a research community, and based on the importance of the research topic in the aforementioned research community. The researchers have adopted the descriptive-analytical using the questionnaire as the main data collection. 155 questionnaires were distributed, yet,114 of them were retrieved and 110 were used for final statistical analysis. The researchers used the relev
... Show MoreReceipt date:11/19/2020 acceptance date:10/1/2021 Publishing date:12/31/2021
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Human rights are one of the basic concepts of modern and contemporary times, and political thought as the origin of political science and its source of knowledge have impact in this science and its branches
... Show MoreComposite materials are widely used in the engineered assets as aerospace structures, marine and air navigation owing to their high strength/weight ratios. Detection and identification of damage in the composite structures are considered as an important part of monitoring and repairing of structural systems during the service to avoid instantaneous failure. Effective cost and reliability are essential during the process of detecting. The Lamb wave method is an effective and sensitive technique to tiny damage and can be applied for structural health monitoring using low energy sensors; it can provide good information about the condition of the structure during its operation by analyzing the propagation of the wave in the
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