Dam and powerhouse operation sustainability is a major concern from the hydraulic engineering perspective. Powerhouse operation is one of the main sources of vibrations in the dam structure and hydropower plant; thus, the evaluation of turbine performance at different water pressures is important for determining the sustainability of the dam body. Draft tube turbines run under high pressure and suffer from connection problems, such as vibrations and pressure fluctuation. Reducing the pressure fluctuation and minimizing the principal stress caused by undesired components of water in the draft tube turbine are ongoing problems that must be resolved. Here, we conducted a comprehensive review of studies performed on dams, powerhouses, and turbine vibration, focusing on the vibration of two turbine units: Kaplan and Francis turbine units. The survey covered several aspects of dam types (e.g., rock and concrete dams), powerhouse analysis, turbine vibrations, and the relationship between dam and hydropower plant sustainability and operation. The current review covers the related research on the fluid mechanism in turbine units of hydropower plants, providing a perspective on better control of vibrations. Thus, the risks and failures can be better managed and reduced, which in turn will reduce hydropower plant operation costs and simultaneously increase the economical sustainability. Several research gaps were found, and the literature was assessed to provide more insightful details on the studies surveyed. Numerous future research directions are recommended.
The effect of thermal treatment on optical constants of pure PMMA and with addition (15 and 35) ml of coumarin at different temperatures (100, 110 and 120) C0 for 1 hour were investigated. Cast method used to prepares films of pure PMMA and PMMA with (15 and 35) of coumarin. UV/VIS spectrometer technique used to measure the absorption spectra for these films. The optical constant (absorption spectra and absorption coefficient) don’t changes after applied temperatures in pure PMMA film but the optical constant (absorption spectra and absorption coefficient) in PMMA with (15 and 35) ml of coumarin increased with applied temperatures. The optical energy gap of pure PMMA and PMMA with (15 and 35) ml of coumarin sl
... Show MoreThe public budget is regarded a main tool for economic and social development. The preparation of the public budget constitute an important stream which enriches the developmental efforts and the definition of its priorities, therefore it is the focus point of many specializations. The public budget has numerous functions. It is a means to precise and to execute the political and economic goals of the executive authority, a mirror of the economic structure which reflects its strength and weakness points, specifies its revenues and others. Since the parliament is the voice of the society which expresses its interests, then, it must monitor the performance of the government so that the participation of the legislative authority in
... Show MoreThe aim of the present research is to know the following : What are the Science and technology, society and environment issues (S.T.S.E) which included in the content of thechemistry Book second grade intermediate ? And to achieve the objective of search The two researchers has prepares a list of science and technology, society and environment issues (STSE) consisted of (9) key issues namely (Air quality and the atmosphere, sustainable development, water security, health and preventive security, mineral resources investment, pollution of various kinds, energy, food industry, production of weapons technology) and from which (70) sub-issues emerge,Arbitrators competent agreement has been received . Then, thetwo researchers analyzed the con
... Show MoreA field experiment was carried out during the 2020 season at the College of Agricultural Engineering/ University of Baghdad, Al-Jadriya to evaluate the effect of dry farming when applying water stress under the subsurface drip irrigation system on water productivity and rice yield. The experiment was conducted with three levels of irrigation water stress when 10, 20 and 40% of the available water was depleted and in three dimensions between drip lines 10, 15 and 20 cm. The experiment was designed according to a randomized complete block design, according to the split plot design, with three replications. Determine the depth of irrigation water depending on the moisture depletion of th
Laryngoscopy and tracheal intubation are considered the most invasive stimuli in anesthesia. They provoked cardiovascular responses that include hypertension, tachycardia and dysrhythmias. Various pharmacological approaches have been used to blunt or attenuate such pressor responses. The present study was designed to evaluate the effect of medazolom, lignocaine and propranolol as a valuable adjuvant to fentanyl in attenuating hemodynamic responses to endotracheal intubation in normotensive patients. Thirty two patient with physical status I or II according to the score of American Society of Anesthesiologist (ASA), scheduled for elective surgery under standard general anesthesia, were randomly allocated into four groups (8 patients in ea
... Show MoreIn this study, high quality ZnO/Ag-NPs thin transparent and conductive film coatings were fabricated
This paper examined accounting information systems (AIS) as a mediator between small and medium-sized enterprises (SMEs) strategies, including (finance source, administrative innovation, organizational culture, developing capabilities levels of SMEs, information source, development of business managers, and technological innovation) and organizational performance. In this quantitative study, 450 self-administered questionnaires were distributed to the managers and owners of SMEs using purposive sampling. Data were analyzed using the structural equation modeling (SEM) method via SmartPLS3 Software. The study offers empirical findings on the importance of AIS as a mediator, considers various factors, a
Industrial product is one of the things of daily use and direct interaction with the user, so the ranges of its association to the user, took a varied and multiple aspects. The user today sees the products as things have specifications related directly to the psychology of the user, so he can reflects his values, principles and ideas on the composition of the total structure of the product, making them a means by which manifested the internal entity's of the user took an external materiality. And then counting the products being things excite positive feelings among different user was a natural result given the complexity of the relationship between the user and the industrial product. So pleasure is one important effects that result fro
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