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A case study of sedimentation problems of Wadi Arbaat's dams reservoirs
Taha, Abubakr Taha Bakheit,Aldrees, Ali Techno-Press 2021 Advances in nano research Vol.11 No.5
The proper management of reservoir sedimentation is of critical importance for the sustainable development of surface water resources. Dams' reservoirs are losing their ability storage due to sedimentation processes worldwide. These losses vary from one reservoir to another depending on the characteristics of the watershed and water streams. Therefore, the performance of reservoirs is incredibly vulnerable. The area surrounding Red Sea State is under arid and semi-arid condition, and immensely suffering from a shortage of safe and reliable drinking water supplies. Wadi Arbaat is the primary source of water supply in Port Sudan city. Valleys mostly surround the Red Sea State and Wadi Arbaat suffer from a severe decline with the steep slope of 6-10 m/km. Therefore, the Wadi carries large quantities of sediments, which deposit in dams' reservoirs during the flood periods. The siltation strongly influences these dams and their reservoirs suffer from serious problems represented by increasing silting level and shortage in storage capacities. Consequently, this study aims to investigate the current situation and problems of the three existing dams and make a proper decision with a comprehensive and specific vision in the future. The main problems caused by reservoir sedimentation in the Red Sea Mountains are described as a reduction in the storage capacities, and entry of sediments into control structures such as sluice gates. The problems are further exacerbated as there is no guidance on the decision supports tool that is needed to underpin silting in the flood period and water resources management in these steep slope areas. The sedimentation processes, problems and changes of dam operation are discussed in this paper.
Vapor-liquid equilibrium of ethanol/ethyl acetate mixture in ultrasonic intensified environment
Taha Mahdi,Arshad Ahmad,Adnan Ripin,Mohamed Mahmoud Nasef 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.5
A vapor-liquid equilibrium (VLE) study was conducted on ethanol/ethylacetate mixture as a preliminarystep towards developing an ultrasonic-assisted distillation process for separating azeotropic mixtures. The influenceof ultrasonic intensity and frequency on the vapor-liquid equilibrium (VLE) of the mixture was examined using a combinationof four ultrasonic intensities in range of 100-400W/cm2 and three frequencies ranging from 25-68 kHz. Thesonication was found to have significant impacts on the VLE of the system as it alters both the relative volatility andazeotrope point, with preference to lower frequency operation. A maximum relative volatility of 2.32 was obtainedat an intensity of 300 W/cm2 and a frequency of 25 kHz coupled with complete elimination of ethanol-ethyl acetateazeotrope. Results from this work were also congruent with some experimental and theoretical works presented in theliterature. These findings set a good beginning towards the development of an ultrasonic assisted distillation that iscurrently in progress.
Optimization of Product Design to Reduce Environmental Impact of Machining
Taha, Zahari,Gonzales, Julirose,Sakundarini, Novita,Ghazila, Raja Ariffin Raja,Rashid, Salwa Abdul Korean Institute of Industrial Engineers 2011 Industrial Engineeering & Management Systems Vol.10 No.2
This paper presents a study on product design optimization to reduce the environmental impact of machining. The objective is to analyze the effect of changing the product design parameters such as its dimensions, and basic features on the environmental impact of machining process in terms of its energy consumption, waste produced and the chemicals and other consumables used up during the process. To realize this objective, we used a CAD model of a product with different design scenarios, and analyze their energy consumption using an environmental impact calculator method developed. The waste produced, and the consumables used up, such as lubricants and coolants were analyzed using environmental emission factors. Optimization methods using Genetic Algorithm and Goal Programming are applied to the product design parameters in order to get the best possible product dimensions with the least environmental impact of the machining process.
Sphingosine Kinase: Biochemical and Cellular Regulation and Role in Disease
Taha, Tarek Assad,Hannun, Yusuf Awni,Obeid, Lina Marie Korean Society for Biochemistry and Molecular Biol 2006 Journal of biochemistry and molecular biology Vol.39 No.2
Sphingolipids have emerged as molecules whose metabolism is regulated leading to generation of bioactive products including ceramide, sphingosine, and sphingosine-1-phosphate. The balance between cellular levels of these bioactive products is increasingly recognized to be critical to cell regulation; whereby, ceramide and sphingosine cause apoptosis and growth arrest phenotypes, and sphingosine-1-phosphate mediates proliferative and angiogenic responses. Sphingosine kinase is a key enzyme in modulating the levels of these lipids and is emerging as an important and regulated enzyme. This review is geared at mechanisms of regulation of sphingosine kinase and the coming to light of its role in disease.
Taha Özyürek,Koray Yılmaz and Gülşah Uslu 대한치과보존학회 2017 Restorative Dentistry & Endodontics Vol.42 No.1
Objectives: The aim of this study was to evaluate the cyclic fatigue resistance of the ProTaper Universal D1 file (Dentsply Maillefer) under continuous and adaptive motion. Materials and Methods: Forty ProTaper Universal D1 files were included in this study. The cyclic fatigue tests were performed using a dynamic cyclic fatigue testing device, which had an artificial stainless steel canal with a 60° angle of curvature and a 5 mm radius of curvature. The files were randomly divided into two groups (Group 1, Rotary motion; Group 2, Adaptive motion). The time to failure of the files were recorded in seconds. The number of cycles to failure (NCF) was calculated for each group. The data were statistically analyzed using Student’s t-test. The statistical significant level was set at p < 0.05. Results: The cyclic fatigue resistance of the adaptive motion group was significantly higher than the rotary motion group (p < 0.05). Conclusion: Within the limitations of the present study, the ‘Adaptive motion’ significantly increased the resistance of the ProTaper Universal D1 file to cyclic facture.
Users Involvement in New Product Development Process: A Designers' Perspectives
Taha, Zahari,Alli, Hassan,Rashid, Salwa Hanim Abdul Korean Institute of Industrial Engineers 2011 Industrial Engineeering & Management Systems Vol.10 No.3
The purpose of this paper is to study user's involvement in new product development (NPD). It seeks to identify the factors involving user and design practices in the design process of new product development. A survey was conducted on 20 respondents consisting of designers involved in product development from various industries. The study focused on the early activities of the product design process which is called product specification. The analysis performed considers the importance of involving users in design decision. The outcome of this research is the significance of involving users and its effect on product development activities. The research also provides a model for an integrated user, designer and product knowledge activity in the product development process.
Tardive Dyskinesia Associated with Bupropion
Taha Can Tuman,Uğur Çakır,Osman Yı ıd ldı ır rı ı m,Mehmet Akif Camkurt 대한정신약물학회 2017 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.15 No.2
Present report describes a 46 year old male patient with a diagnosis of major depression who developed tardive dyskinesia during bupropion therapy. Our patient had no history of neuroleptic use and his laboratory and neurologic examinations were normal. He had no family history of neurologic diseases. Although bupropion induced dyskinesia has been previously reported in the literature, it is rare and our case is the first case regarding tardive dyskinesia.
Pressure effects on dynamics behavior of multiwall boron nitride nanotubes
Taha Talebian 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1
The dynamic behavior of Multiwall boron nitride nanotubes (MWBNNTs) is investigated by employing multiple elastic shells model. The influences of van der Waals interactions on layers are shown as nonlinear functions of the interlayer distance of MWBNNTs. Governingequations are solved by using the developed finite element method and by employing time history diagrams. The radial wavespeed from the outermost layer to the innermost layer is computed. The effects of geometrical factors such as diameter-to-thickness ratioon dynamic behavior of MWBNNTs are determined. The magnification aspects of MWBNNTs are computed, and the effects of surroundingpressures on wave speed and magnification aspect of MWBNNTs are discussed.