Preferred Language
Articles
/
LRfrW5IBVTCNdQwCiK0_
State-of-the Art-Powerhouse, Dam Structure, and Turbine Operation and Vibrations
...Show More Authors

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.

Scopus Clarivate Crossref
View Publication
Publication Date
Thu Oct 01 2020
Journal Name
International Journal Of Electrical And Computer Engineering (ijece)
Design of an adaptive state feedback controller for a magnetic levitation system
...Show More Authors

This paper presents designing an adaptive state feedback controller (ASFC) for a magnetic levitation system (MLS), which is an unstable system and has high nonlinearity and represents a challenging control problem. First, a nonadaptive state feedback controller (SFC) is designed by linearization about a selected equilibrium point and designing a SFC by pole-placement method to achieve maximum overshoot of 1.5% and settling time of 1s (5% criterion). When the operating point changes, the designed controller can no longer achieve the design specifications, since it is designed based on a linearization about a different operating point. This gives rise to utilizing the adaptive control scheme to parameterize the state feedback controll

... Show More
View Publication
Scopus (8)
Crossref (1)
Scopus Crossref
Publication Date
Wed Dec 30 2009
Journal Name
Iraqi Journal Of Physics
Electrical Investigation of PSi/Si (n-type) structure
...Show More Authors

In this work, porous Silicon structures are formed with photochemical etching process of n-type Silicon(111) wafers of resistivity (0.02.cm) in hydrofluoric acid (HF) of concentration (39%wt) under light source of tungeston halogen lamp of (100 Watt) power. Samples were anodized in a solution of 39%HF and ethanol at 1:1 for 15 minutes. The samples were realized on n-type Si substrates Porous Silicon layers of 100m thickness and 30% of porousity. Frequency dependence of conductivity for Al/PSi/Si/Al sandwich form was studied. A frequency range of 102-106Hz was used allowing an accurate determination of the impedance components. Their electronic transport parameters were determined using complex impedance measurements. These measu

... Show More
View Publication Preview PDF
Publication Date
Wed Jan 01 2020
Journal Name
Periodicals Of Engineering And Natural Sciences (pen)
Estimating the reliability function of the asymmetrical hybrid parallel-series system: Applied study at the state company for vegetable oils industry
...Show More Authors

The research studied and analyzed the hybrid parallel-series systems of asymmetrical components by applying different experiments of simulations used to estimate the reliability function of those systems through the use of the maximum likelihood method as well as the Bayes standard method via both symmetrical and asymmetrical loss functions following Rayleigh distribution and Informative Prior distribution. The simulation experiments included different sizes of samples and default parameters which were then compared with one another depending on Square Error averages. Following that was the application of Bayes standard method by the Entropy Loss function that proved successful throughout the experimental side in finding the reliability fun

... Show More
Scopus
Publication Date
Thu Feb 07 2019
Journal Name
Iraqi Journal Of Laser
Antibacterial Photodynamic Effect of 532 nm Diode-Pumped Solid State and 650 nm Diode Lasers on Methicillin Resistant Staphylococcus Aureus in Vitro
...Show More Authors

The photodynamic inactivation against Methicillin-resistant Staphylococcus aureus using two different lasers, 532 nm diode pumped solid state laser (DPSS) in combination with safranin O and 650 nm diode laser in combination with methylene blue was investigated in the present work. A hundred swab samples were collected from patients with burn and wound infections admitted to two hospitals in Baghdad (Specialized Burns Hospital in Medical City and Al Imamein Al Jwadein Medical City Hospital) from December 2015 to February 2016 Antimicrobial susceptibility was performed by using Kirby- Bauer method. The irradiation experiments included four groups; a control group, a photosensitizer only group, a laser irradiation only group and a laser irr

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 01 2023
Journal Name
Aip Conference Proceedings
Structure properties of cobalt dioxide (CoO2) thin films effected by violet and red lasers irradiation using (SCSP) technique
...Show More Authors

View Publication
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Mon Feb 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
The compatibility of the Development Fund for Iraq to the requirements of sovereign wealth funds An analytical study of the legal framework and institutional structure in accordance with the standards of the Santiago
...Show More Authors

Sovereign wealth funds have attracted the attention of the governments of the oil and non-oil countries alike, with a variation of the size of those funds to those states, based on the size of the financial surpluses resulting from Alriadat oil or foreign reserves, or state revenues for other sovereign assets. Raj use these funds remarkably during the financial crises the world has seen, including the crisis of 2008-2007., And Iraq is a oil-producing countries, which has the third largest reserves of crude oil (Crude Oil) at the level of the Arab world and of 140 300)) million barrels after Saudi Saudi Arabia and the Islamic Republic of Iran, and the fourth reserves of crude oil in the world after issued Venezuela to the reserve

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Aug 20 2019
Journal Name
Political Sciences Journal
Towards completion of state construction : stations in legitimacy of contemporary Iraqi political system
...Show More Authors

The power of the state in Iraq has been influenced by legitimacy, which may have resembled the belt of transmission, affecting the rule of law and social cohesion. The emergence of the political system may have come about as a result of balancing the competing forces within society today as a basis for collective action. The country's march in Iraq was not a result of a series of gradual transitions such as the established ones. For almost a century, there was an extraordinary succession of succession. At each of the three stages of the state there was an internal or external change. They change or disintegrate and others appear. Social and economic conditions may change or the society is exposed to external invasion or our ideas are imp

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 31 2019
Journal Name
Journal Of Economics And Administrative Sciences
The Reflection of the application TD-ABC approach on profits persistence Applied study in the General State of Hydraulic Industries Factory of Plastic*
...Show More Authors

The interest of many companies has become dealing with the tools and methods that reduce the costs as one of the most important factors of successful companies, and became the subject of the attention of many economic units because of the impact on the profits of company, and since the nineties of the last century the researchers and writers gave great attention to this subject, especially in light of the large competition and rapid developments in cost management techniques, as well as the wide and significant change in production methods that have been directed towards achieving customer satisfaction, all this and more driven by economic units in all sectors whether it is service or productivity to find methods that would reduc

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Sep 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
The impact of political thinking on the decision maker in analyzing the strategic environment of the state (applied study in the Iraqi Ministry of Finance)
...Show More Authors

The Political Thinking Regarded as an important element for the formulation of the stat, weather in its formation, the structure of it s entity, its political system and it s governmental instruments .The political thinking can not act without determined strategy, So they intend to work hard to formulate a railed strategy that make them able to determine its  directions to general issues.

   The Study aimed to solve the problem through the following question:

1- What are the levels of Political Thinking and Strategic Analysis in the financial ministry?

2- What are the relation ship between the dimensions of Political  T

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of Combine Level of Capital Structure and Dividend Policy on Firm Stock Price An apply study of companies listed on Amman Stock Exchange
...Show More Authors

Although a great deal of works has been done on the area of capital structure and dividend policy, there is still insufficient knowledge of how these policies affect stock prices. This shortcoming may have been originated from the separation between both policies when investigating their effect on stock prices. Based on this point, this research adopts a new technique (completely randomized design), to combine the effect of capital structure and dividend policy on stock prices rather than separating between them. The study used panel based regression analysis depending on the sample of 30 service and industrial Jordanian firms for the period of 2001-2010. The result of test hypotheses found the following; 1) dividend payout has a

... Show More
View Publication Preview PDF
Crossref