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.
Abstract
Heritage represents the center around which poets revolve around and take advantage of its inexhaustible specific, and the connotations that this heritage holds of various values, values and ideas, and the poet Bashar bin Bard from prominent poets who were inspired by that heritage and the culture of the first Abbasid era and whoever and others was worthy of studying and tracking his potentials and capabilities Creativity is based on the inspiration of the legacy of his predecessors, and the development of this legacy and renewal in it. The research methodology required its division into two topics, the first topic, a description of the beauty of women, a description of wine, while the second topic is a description
... Show MoreThe study of the future of the international system currently appears, according to scientific data and existing facts in light of the emergence of international actors from non-states and international informal institutions, to be heading towards a non-polarity system and this trend is fueled by many variables to reduce polarity, and it is expected in the future that the international system will turn into a non-polarity.
The current study aimed at identifying the impact of each of the full and part time summer enrichment programs on the performance of gifted students. Moreover, it aimed to study the difference between the full and part time programs on the performance of gifted students. The study sample consisted of (115) students from the full time programs and (137) students from the part time programs, they have been randomly selected from the gifted students participating in the full and part time summer enrichment programs. The researcher used the scale of student performance. The results indicated that there were statistically significant differences between the averages of the pre and post applications of the
... Show MoreBackground; Perforated duodenal ulcer (PDU) is a common surgical emergency that is associated with high mortality and morbidity. Early diagnosis and prompt surgical treatment is required to prevent grave complications.
Objective; The study was designed to evaluate the diagnostic accuracy of different radiological investigations in the diagnosis of perforated duodenal ulcer.
Methods; A prospective study of 185 pts with PDU at al kindy teaching hospital, Baghdad, Iraq from June 2008- august 2010. patients were examined clinically and investigated by blood test, chest x ray, plain X ray of the abdomen. Ultrasonography (U/S) and CT scanning done for those patients with negative X- ray finding. Resuscitation by intravenous fluid and ant
Background: Trigeminal neuralgia (TN), or Tic Douloureux, is one of the most common neuropathic pains. Gamma knife stereotactic radiosurgery (GNSRS) has been considered one of the procedures for treating primary TN. Objective: This study evaluates the effectiveness of GNSRS in treating primary TN in patients who are unresponsive to medical treatment in a single-center experience. Subjects and Methods: This study was conducted on 180 patients from January 2018 to October 2021. The study utilized the Barrow Neurological Institute (BNI) pain intensity score to assess pain before and after GNSRS treatment. Results: A total of 180 patients with primary TN were included in this study, 108 female with a 1.5:1 female: male ratio. Results
... Show MoreIn this research, the performance of electrocoagulation (EC) using aluminum (Al) electrodes with Monopolar- parallel (MP-P), and bipolar - series (BP-S) arrangement for simultaneous removal of dissolved silica, and hardness ions (calcium, and magnesium) from synthetic blowdown water of cooling tower were investigated. The effects of current density, initial pH and time of electrolysis on the removal efficiency were studied in a batch stirred unit to find out the best-operating conditions. The obtained results for each target species are evidence that BP-S approach is the best for both electrodes configuration operated at a Current density of 1mA/cm2 through 30 min of treatment and pH=10 with the removal of
... Show MoreThe study focuses on identifying the reality of administrative creativity of secondary schools' managers in Al-zarqaa province. The descriptive approach was adopted to conduct this study. To achieve the study objective, the author designed a questionnaire composed of (24) items included (4) domains applied on (80) male and female school managers were selected randomly. The results showed that the administrative creativity level of secondary school's managers over all domains were too high which ranked as school management domain followed by public community domain then teacher domain and finally, school environment domain. Additionally, each of male, private sector, and experience over 10 years revealed significant differences.
Objective(s): To evaluate students’ communication skills and their academic performance; to compare between the students relative to communication skills and their academic performance in the University of Baghdad and to identify the relationship between students’ communication skills, academic performance and their socio-demographic characteristics of age, gender, grade and socioeconomic status. Methodology: A descriptive design, using the evaluation approach, is carried through the present study to evaluate colleges’ students’ communication skills and their academic performance in the University of Baghdad for the period of January 7th 2019 to August 28th 2019. A non-probability, purposive sample, of (80) university students, i
... Show MoreBac kground: The transfer of the tibialis posterior tendon to the anterior aspect
of the ankle not only replaces the function of the paralyzed muscles, but also
removes the deforming force on the medial aspect of the foot.
Objec t i ves : In this study, we evaluated patients who underwent tibialis
posterior tendon transfer for the treatment of foot drop, and comparison through
interosseous membrane route versus anterior to lower tibia route of tibialis
posterior tendon transfer, with evaluation of the results according to carayon
criteria
Methods: Nine patients with foot drop secondary to different causes treated with
tibialis posterior tendon transfer from January 2011 to January 2012 were
followed up for a
Esterification reaction is most important reaction in biodiesel production. In this study, oleic acid was used as a suggested feedstock to study and simulate production of biodiesel. Batch esterification of oleic acid was carried out at operating conditions; temperature from 40 to 70 °C, ethanol to oleic acid molar ratio from 1/1 to 6/1, H2SO4 as the catalyst 1 and 5% wt of oleic acid, reaction time up to 180 min. The optimum conditions for the esterification reaction were molar ratio of ethanol/oleic acid 6/1, 5%wt H2SO4 relative to oleic acid, 70 °C, 90 min and conversion of oleic 0.92. The activation energy for the suggested model was 26625 J/mole for forward reaction and 42189 J/mole for equilibrium constant. The obtained results s
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