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.
Accompanied Activity Economic Unity some negative effects in the environment of air, water and soil pollution of difficult to measure each other for being the external costs and to be avoided such expenditures should be measured or estimated value to be disclosed environmental costs at the heart of the financial statements of economic unity to inform managers and users of the financial statements on the implications costs environmental .and impact in reducing environmental costs and increase future income and economic unit, was based on research into the inductive approach through books, letters, journals and the internet to cover the theoretical framework of the research. And to the analyt
... Show MoreFinancial inclusion refers to the access of financial services at low cost and high-quality from the formal financial sector to all segments of society, especially marginalized groups, and then use and benefit from them. Financial inclusion is also associated with banking stability, as well as with financial integrity and financial protection for the consumer, therefore, it achieves a number of objectives, the most important of which is to support and enhance banking stability. This is what made it attract the attention of many countries and central banks recently.
The study aims to show the impact of financial inclusion indicators on ban
... Show MoreThe objective of the research is to identify the nature of voluntary disclosure of insurance services and its impact on the financial performance of Iraqi insurance companies by knowing the relationship between increasing disclosure of financial services and financial performance indicators of insurance companies.In order to achieve this objective, the research was applied to a sample of the Iraqi insurance companies listed in the Iraqi Stock Exchange (Al Amin Insurance Company, Al Ahlia Insurance, Dar Al Salam Insurance, Gulf Insurance, Al Hamra Insurance) and based on their published financial statements (2014-2015) ) And by analyzing the sample lists were connected to the research objectives.The main conclusion of the study is that in
... Show MoreQ-switched lasers widely used in management skin diseases and
sometimes its effect may be inadequate or associated with
cytotoxicity. The current study aimed to investigate the effect of
Q-switched Nd:YAG laser upon cellular elements using in vitro
experimental model. Aqueous solutions of human albumin and pure
calf thymus double strand deoxyribonucleic acid (ctdsDNA)
irradiated with Q-switched Nd:YAG laser at different rates (1, 3 Hz)
and time exposure (up to 60 seconds) using 532 nm (400 mJ) and
1064 (1200 mJ) nm wavelength with fixed spot size of 4 mm. The
effect of laser irradiation on the albumin solution also studied in the
presence of elemental salts of copper, zinc and iron.
Q-switched laser irrad
Green areas are an essential component of city planning, as they serve as an outlet for them to spend their free time, in addition to the environmental role that these green areas play in improving the city’s climate by purifying the air and beautifying the city. The study’s problem is summarized in identifying the appropriateness of the current spatial distribution of green areas in the city of Najaf with the current population densities and the pattern in which green areas are distributed using GIS and knowing the per capita share of those green areas in the city, the research assumes that the inconsistency of spaces between regions Green and residential neighbourhoods need to c
Abstract
Although the subject of biofuels industry is linked directly to the energy sector, but has links and numerous indirect effects, in particular effects on the environment and agriculture, this study (opportunities and challenges of biofuels industry and impact on the development of the agricultural sector in developing countries) a modest step to identify the industry in detail and identify the types of products and raw materials entering, then define or limit the positive and negative impacts of this industry in General and for specific products In particular, detailed, and then flip all those effects on the agricultural sector in developing countries can benef
... Show MoreBackground: Mother-infant bonding is an important psychological step postpartum and disturbed relationship may carry dramatic consequences as a psychological disorder which may affect the periodontal health of the mother. The aim of the present study was to assess the effect of the postpartum Mother-infant bonding on their periodontal condition. Materials and Methods: Mothers in the postpartum period with age range 20-35 years were subjected to postpartum Bonding Questionnaire (PBQ). Periodontal health status was assessed by measuring probing pocket depth and clinical attachment level. Results: The mean values of both probing pocket depth (PPD) and clinical attachment loss (CAL) were higher among disordered mothers than mothers with normal
... Show MoreWater one of the most important sources Which is no doubt essential for life surviving, water is vital in many sectors of life e.g. ( agriculture, industrial, power and so many things can’t be restricted on the mentioned items, water has become major problem facing the world today. Competition over water resources between nations has made it as a vital commodity and a justification for waging wars against its neighbor’s countries, there are currently 263 rivers that either cross or demarcate international political boundaries. Geographically, Europe has the largest number of international basins (69), followed by Africa (59), Asia (57), North America (40), and South America (38).The absolute numbers of international basins, as well as t
... Show MoreThis study examines the impact of adopting International Financial Reporting Standards (IFRS) on the value of economic units. Given the global push toward standardization of financial reporting to enhance financial statement transparency, comparability, and reliability, this research seeks to understand the implications of these standards for economic valuation within a region characterized by its unique economic and regulatory challenges. A questionnaire was distributed to 86 Iraqi academics specializing in economics, accounting, and finance to collect their views on the impact of adopting international financial reporting standards. Through careful statistical analysis, the study concluded that applying international financial reporting s
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