The hydraulic behavior of the flow can be changed by using large-scale geometric roughness elements in open channels. This change can help in controlling erosions and sedimentations along the mainstream of the channel. Roughness elements can be large stone or concrete blocks placed at the channel's bed to impose more resistance in the bed. The geometry of the roughness elements, numbers used, and configuration are parameters that can affect the flow's hydraulic characteristics. In this paper, velocity distribution along the flume was theoretically investigated using a series of tests of T-shape roughness elements, fixed height, arranged in three different configurations, differ in the number of lines of roughness element. These elements were used to find the best configuration of roughness elements that can be applied to change the flow's hydraulic characteristics. ANSYS Parametric Design Language, APDL, and Computational Fluid Dynamics, CFD, was used to simulate the flow in an open channel with roughness elements. CFD can be used to study the hydrodynamics of open channels under different conditions with inclusive details rather than relying on the costly field and time-consuming. Runs were implemented with different conditions, the discharge, and water depth in upstream and downstream of the flume. T-shape roughness elements with height equal to 3cm placed in three different configurations, two lines, four lines, and fully rough configurations were tested. The results show that the effect of roughness elements increasing with increasing the number of lines of roughness elements. Cases of four lines and fully rough configurations have almost the same hydraulic performance by having the same results of the velocity decrease percentage, which is decreased by approximately about 66% and 61% of the control case's velocity in the zone near the roughness elements consequently. But the difference is that four lines configuration is affected in a part of the test section. This behavior increases the velocity values by about 11% in the other side and by about 10% near the free surface in the case of four lines configuration and increased by about 32% above the roughness elements in a fully rough configuration.
Frictional resistance occurs whenever sliding happens, negatively impacting treatment outcomes and duration. It is a clinical challenge and must be dealt with efficiently to achieve the best orthodontic results. Aims of this study: compare and evaluate the static frictional forces under the wet condition to mimic the oral environment produced by using a polycrystalline ceramic bracket, monocrystalline ceramic bracket, 0.014 of an inch nickel-titanium (Rhodium coated archwires, and ilusio aesthetic archwires), and 0.019 x 0.025 of an inch stainless steel (Rhodium coated archwires, and ilusio aesthetic archwires). Ninety-six aesthetic brackets (48 monocrystalline and 48 polycrystalline brackets) were used and stored in different incub
... Show MoreKE Sharquie, AA Noaimi, SJ Murtada…, Journal of Cosmetics, Dermatological Sciences and Applications, 2016 - Cited by 4
The present paper deal with the issue of the beginning of the culturally
renaissance in emirates of Arab Gulf from 1914-1945 between tow world war
has been attracting the attention of academic about the developments in many
fields in the Arab Gulf at this time.
The paper is divided into five sections. First section, deals with the
geographic importance for the Arab Gulf region. Second section, the economic
situations in the region before and after oil. The third section, talk for social
situations, like population, tribe and tribes in society, and immigration. The
fourth section, deals with the factors of rise the culture and political in the Arab
Gulf before discovery of oil period. The five section, the cultu
This study is concerned with the reality of total quality management and its role in achieving the excellence performance of the employees of the Institute of Technology / Baghdad, excellence performance is described by the extent to which the organization is able to invest the effort of the human resource to achieve its Objectives by adopting the principles of Total Quality Management (TQM) according to some of its basic dimensions in proportion to the reality and Possibilities Institute, the aim is to study to know the reality of total quality management ,and indicate the levels of excellence performance in the Institute of Technology / Baghdad,
... Show MoreThe current research seek to known the strategic planning for the taxes and its important , and its effect upon the investment , and this research was be in the general board of taxes, and the economical directorate of the ministry of finance , therefore this research started from the problem below:
- What level of the important and type of the research changeable of the research ( the strategic planning for the taxes and investment) in the research organization ?
- Is there any relation of the join and effect of the changeable of the research (the strategic planning for the taxes and investment)in the research organization ?
Therefore this research depended a hypotheti
... Show MoreBackground: Osteoporosis is one of the major public health problems from which more and more people in the world are suffering. There is evidence suggesting that osteoporosis knowledge is one contributor to osteoporosis preventive behavior. Aim of the Study: To assess the knowledge regarding osteoporosis risk factors, prevention, and management in women of reproductive ages. To identify any association between knowledge and studied factors.
The subject of the organizational Ambidexterity of the vital Topics through which it seeks organizations to provide mentalities renewable for their members and maintain its survival and continuity according to different organizational methods of access for strategic success. The research aims to demonstrate the impact of organizational Ambidexterity in achieving strategic success in the National bank of Iraq, and the questionnaire was prepared as a tool for collecting data and information through sample survey of (16) managers and heads of departments , The results were analyzed by using the statistical program (SPSS) in calculating mean, standard deviation, percent and test (f), coefficie
... Show MoreThe electrode in the microbial fuel cell has a significant effect on cell performance. The treatment of the electrode is a crucial step to make the electrode surface more habitable for bacteria growth, thus, increases the power production as well as waste treatment. In the current study, two graphite electrodes were treated by a microwave. The first electrode was treated with 100W microwave energy, while the second one was treated with 600W microwave energy. There is a significant enhancement in the surface of the graphite anode after the pretreatment process. The results show an increase in the power density from 10 mW/m2 to 15 mW/m2 with 100w treatment and to 13.47 mW/m2 with 600w treatment. An organic
... Show MoreSAIs has a pivotal role in enhancing public sector performance through its quest to achieve the greatest possible efficiency and effectiveness in its, so it has to adopt applied framework for abilities building, the research aims to shed light on the role of SAIs and the nature of their work, and the definition for its abilities building, and to prepare a proposal for abilities building applied to work with the SAI in the Republic of Iraq (of the Federal Board of Supreme Audit ),the Researchers reached conclusions, namely: abilities building is the outcome of the interaction between the reality of all of the employees of the SAI and the institution itself and the environment and the specific requirements of the de
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