Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Application of Geographical Information System (GIS) for Computing Stored Water in Front of Dams: Analytical Case Study of Al-Mojib Dam in Hashemite Kingdom of Jordan31332211152310.21608/jesaun.2007.111523ENSalman Abdallah AL-DuheisatRoyal Jordanian Geographic Center College,
P.O. BOX 20214- Amman 11118- Jordan.Moahmmed Abu-Dayeh MatouqRoyal Jordanian Geographic Center College,
P.O. BOX 20214- Amman 11118- Jordan.Journal Article20061028This research aims to study the ability of using the technical methods of GIS in order to predict and calculate the capacity of restored water in front of dams, either under constructions, or already present. In this study, Al-Mojib Dam was chosen as a model for this research. The results obtained shows that GIS can be successfully be used to calculate the volumes of water accumulated in front of dams, and to calculate its capacity. It is concluded here that this application can be successfully applied for different dams in the Kingdom, to give an idea how to appoint water resources, and best location for dams to be constructed. Applying this techniques in Jordan, which suffering from water scarcity.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301A Mathematical Expression for Split Tensile Strength of Steel Fiber Reinforced Concrete32333511152710.21608/jesaun.2007.111527ENMazen A. MusmarCivil Engineering Department, Faculty of Engineering Technology, Al-Balqa' Applied
University Amman 11134, P.O. Box 15008, JordanMuhammad I. RjoubCivil Engineering Department, Faculty of Engineering Technology, Al-Balqa'
Applied University. Amman 11134, P.O. Box 15008, JordanJournal Article20061111Use of fiber reinforced concrete is increasing recently, brought forth by the enhancements of concrete matrix engineering properties upon adding fiber. The resulting material possesses higher tensile strength, consolidated response and better ductility, which ultimately minimize immature failures. Thus it is beneficial to comprehend more the engineering properties of the material. Accordingly, this study moves toward deriving a mathematical expression that relates fiber reinforced concrete compressive strength to split cylinder tensile strength. Literature survey is carried out to collect data, pertinent to split cylinder tensile strength versus compressive strength values, for fiber reinforced concrete. Gathered data comprise compressive strengths from 20 MPa to 102 MPa. Regression analysis is performed; a mathematical expression that predicts split cylinder tensile strength of steel fiber reinforced concrete is eventually derived. The predicted values fit well with experimental data. The findings of this study shed more light on the tensile strength of fiber reinforced concrete.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Experimental and Theoretical St.udy on Maximum Reinforcement Ratios of High Strength Concrete Flexural Beams33736011153510.21608/jesaun.2007.111535ENKhairy Hassan AbdelkareemCivil Engineering Department, Faculty of Engineering, Assiut
University, Assiut, EGYPTJournal Article20061214In the current study, experimental and analytical analysis were carried out to propose models for the maximum reinforcement ratios for high strength concrete flexural beams and to compare the behavior of HSC beams with normal strength concrete beams with respect to this point of view. The behavior is represented by failure mode, ultimate load, deflection and strain. The failure mode of HSC beams is relatively different than that of normal strength beams and this is mainly due to the higher degree of brittleness of HSC. High strength beams require more quantity of steel reinforcement to achieve the ductility. Using HSC leads to an increase of the cracking and ultimate loads of beams and to a decrease of ductility. The steel reinforcement of HSC beams should be increased in such a way that yielding of steel should occur first before crushing of concrete to avoid brittle failure. From the given results of failure mode, load deflection relations and from recording the propagation of cracks and failure mode of beams and following the concept of the required steel reinforcement which is given by the code for normal strength concrete, the required reinforcement of HSC flexural beams is determined and given by equations 4 and 5 in the text. The equations are applicable to all grades of concrete (normal and high strength concrete). Analytical analysis is carried out to consider the effect of size of cross section on the required reinforcement. Nonlinear plane stress finite element model is utilized to give the required steel reinforcement considering the size effect. Based on experimental and theoretical results and by using parametric analysis and curve fitting, a model of the maximum required steel reinforcement of high strength concrete flexural beams considering the effect of size is recommended and represented by equation 15 in the text. The model is recommended to be used in the design of beams.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Shear Behavior of RC Beams Strengthened Externally with Bonded CFRP–U Strips36137911153610.21608/jesaun.2007.111536ENAtif M. Abdel HafezCivil Eng. Dept., Assiut UniversityJournal Article20070106This paper aims to contribute to a better understanding and modeling of the shear behaviour of RC beams strengthened externally with carbon fiber reinforced polymer CFRP–U strips. Nine RC beams without internal shear reinforcement were tested; one beam was kept as a control beam; whereas other beams were strengthened externally with CFRP–U strips. Test variables were, effective height (depth) of CFRP–U strips, number and width of strips for the same shear reinforcement ratio, and spacing or amount of strips. Test results showed that, the ultimate shear capacity of RC beams can be increased significantly using this techniques, a maximum increase of 93% was obtained. For beams strengthened with the same amount of CFRP strips, increasing the number of fiber by decreasing the strip width has a slight effect on both carrying capacity and ductility of the beams. A simple improved model has been proposed to predict the contribution of CFRP–U strips to the shear capacity of the strengthened beams, which fail by CFRP debonding. Research recommendations have been given at the end.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Influence of Stirrups and Concrete Strength on Behavior of RC Beams Strengthened in Shear with CFRP–Strips38140011153710.21608/jesaun.2007.111537ENAtif M. Abdel HafezCivil Eng. Dept., Assiut UniversityJournal Article20070226This paper presents the results of an experimental investigation conducted on rectangular RC beams strengthened externally in shear with CFRP-U strips. The main objective of this research was to evaluate experimentally and analytically the influence of the following parameters on the shear performance of such beams; amount of internal shear reinforcement with and without (stirrups), amount of longitudinal steel, and concrete compressive strength (normal and high strength). Test results indicated that the contribution of CFRP strips to the shear capacity of beams is strongly influenced by the studied parameters. CFRP strips are less effective when beams are heavily reinforced with stirrups. The gain in shear capacity increases as amount of longitudinal steel and/or concrete compressive strength increases. After analyzing the experimental results, the empirical model previously proposed by the author, to predict the contribution of CFRP-U strips, was modified to take the effect of the studied parameters into consideration. The modified model can predict the experimental results with acceptable accuracy, while ACI code guidelines fail to capture the influence of the studied parameters. At the end, recommendations for further work have been given.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Effect of Opening Dimensions and Positions on Static Behavior of High strength RC Perforated T-Beams40142011153810.21608/jesaun.2007.111538ENZainab EbraheemAssistant lecturer, Civil Eng. Dept., Assiut UniversityMohamed M. AhmedAssociate Professor of Structural Eng., Civil Eng. Dept., Assiut UniversityYehia A. HassaneanProfessor of Reinforcement Concrete, Civil Eng. Dept., Assiut UniversityAbd El-Rahman MegahidProfessor of Structural Eng, Civil Eng. Dept., Assiut UniversityJournal Article20070313The provision of transverse openings in floor beams to facilitate the passage of utility pipes and service ducts results not only in a more systematic layout of pipes and ducts; but also translates into substantial economic savings in the construction of a multi-storey building. Over the past several decades, many researchers exerted great efforts to predict and interpret the behavior of beams with web openings. Eleven beams were tested under static loading up to failure, ten of them were simulated the negative moment regions of reinforced concrete T- beams, were fabricated with large opening through the web and the other beam has solid web. In this study the effect of openings depth, openings length and the distance between the nearest support to the opening and its center is investigated. These beams made from high strength concrete of 90 MPa. The pattern of cracks and modes of failure were observed. The concrete strain and reinforced steel strain around openings were recorded. The maximum midspan deflection, at inner edge of opening and difference between maximum deflections of two edges of the opening were measured. The cracking and ultimate loads as well as crack width were measured. The results were given in shape of photos, tables and curves.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Calibrating the Nonlinear Elastic and Viscoelastic Tissue Properties of Left Ventricular Muscle from Guinea Pig Heart42144211286210.21608/jesaun.2007.112862ENM. A. HassanMechanical Engineering Department, Faculty of Engineering, Assiut University,
Assiut,71516Journal Article20061122Mechanical behavior of the heart muscle tissues is the central problem in finite element simulation of the heart mechanics. Nonlinear elastic and Viscoelastic behaviors and their constitutive relations are determined from experimental data in order to characterize the passive response of the left ventricular myocytes (muscle cells) taken from guinea pig heart. Uniaxial tension test was made to determine the constants of the nonlinear elastic model (hypoelastic) in which Eulerian or exponential stress-strain relationship was assumed to describe the passive response of the heart material. Nonlinear elastic behavior was also described by hyperelastic strain energy functions such as Ogden models and Mooney–Rivlin models and the corresponding energy functions coefficients were determined. Stress relaxation test was conducted to assess relaxation behavior as well as viscosity of the tissues. Viscohyperelastic behavior was constructed by a multiplicative decomposition of a standard Mooney-Rivlin or Ogden strain energy function,W , for instantaneous deformation and a relaxation function, tR , in a Prony series form. Nonlinear least square fitting and constrained optimization was conducted under MATLAB and MARC in order to obtain the material constants. From the physics of heart motion we found that hypoelastic or hyperelastic behaviors could be safely used for heart mechanics simulation, because the characteristic relaxation time is very large compared with the actual time of heart beating cycle. To get more precise mechanical properties, needed for very accurate bio-simulation and development of new material for artificial heart, an optimization algorithm was proposed to correct and estimate material parameters from clinical intact heart measurements.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301A Modified Method for Fabrication Porous Silicon Nitride/Silicon Carbide Nanocomposites44345611286310.21608/jesaun.2007.112863ENM. K. HassanDepartment of Mechanical Design and Materials, High Institute of Energy,
South Valley University, Aswan, EgyptMontasser DewidarDepartment of Mechanical Design and Materials, High Institute of
Energy, South Valley University Aswan, Egypt.
Material & Fracture Lab., Department of Mechanical Design, Chonbuk
National University, Duckjin 1-664-14, Jeonju, JB561-756, South Korea.S. Z. El-AbedenDepartment of Production Engineering and Design, Faculty of Engineering
Minia University, 61111, Minia, Egypt.Journal Article20061202The synthesis and characterization of porous silicon nitride/ silicon carbide nanocomposites have been studied. Porous Si3N4/SiC nanocomposites with 30 and 60 vol.% SiC were fabricated by two sintering steps of the mixture powder of Si3N4, carbon, and yttria Y2O3. The powder mixtures were uniaxially pressed using 25 MPa and sintered in nitrogen gas at 1650, 1750, and 1850oC for 1, 2, and 3 h respectively. The characteristics of porous Si3N4/SiC nanocomposites were investigated by using X-ray diffraction and SEM. Also the compressive strength and microstructure of the Si3N4/SiC nanocomposites were investigated. The strength of Si3N4/SiC nanocomposites depends mainly on the sintering temperature, and the holding time of the sintering. The best holding time for sintering at 1650oC, 1750oC, and 1850 oC are 1, 2, and 3 h respectively.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Automatic Color Image Segmentation Using Deformable Net45747611154310.21608/jesaun.2007.111543ENKhaled M. ShaabanElectrical Engineering Department, Assiut University, Assiut, EgyptNagwa M. OmarElectrical Engineering Department, Assiut University, Assiut, EgyptJournal Article20061119This paper proposes the use of deformation as a foundation for color image segmentation. Instead of deforming a single contour, typically used with other deformable contour methods, the proposed technique deforms a planner net. This net consists of a group of vertices connected by edges without crossing each other. The connected edges form polygons that represent the segmented regions boundaries. During the deformation process, the algorithm changes the location and the number of vertices as well as the number of polygons to enhance the segmentation fit. The deformation forces are generated based upon the homogeneity of the color distribution within the regions. The algorithm is completely autonomous and does not require any training or pre-knowledge about the image contents. The experimental results demonstrated the capability of the algorithm to segment color images from arbitrary sources within reasonable time. Furthermore, the compact mathematical representation of the resulting boundaries could be of value for further image analysis.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301New Simultaneous Approximation for Wave Digital Lattice Filters Based on the Alternative and Iterative Generation of the Two Branch Polynomials47748811154710.21608/jesaun.2007.111547ENMohamed YaseenElectrical Engineering Department, Faculty of Engineering, Assiut University,
Assiut, EgyptUsama Sayed MohammedElectrical Engineering Department,Faculty of Engineering,Assiut University,
Assiut, EgyptJournal Article20200909In this contribution, a new simultaneous amplitude and phase approximation for wave digital lattice structures is introduced. It is relying on the orientation of one of the two branch polynomials to adjust the amplitude, while the other is oriented to adjust the phase. The approximation process starts with proper initial settings for the two branch polynomials according to the given amplitude and phase specifications. Then, the two branch polynomials are generated alternatively. This means that during one polynomial is generated to approximate the amplitude or the phase, the other polynomial is fixed. By iterating this alternative procedure, the two polynomials and consequently the amplitude and phase converge to their optimal response. Interpolation method combined with the Remez-exchange algorithm is employed for this purpose. Finally, the filter structure is synthesized and the wave digital realization is reached.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301A Simulink Multi-Band Power System Stabilizer48950711235410.21608/jesaun.2007.112354ENYoussef A. MobarakElectric Engineering Department, High Institute of Energy, South
Valley University, Aswan, EgyptJournal Article20061211A Multi-Band Power System Stabilizer (MB-PSS) is developed in this paper to get a moderate phase advance at all frequencies of interest in order to compensate for the inherent lag between the field excitation and the electrical torque induced to ensure robust oscillation damping. Its performance is compared with two conventional power system stabilizers (PSS) used to add damping to the rotor oscillations of the synchronous machine by controlling its excitation currents during disturbances. One of them is fed from acceleration power signal and called (Pa-PSS) and the other is fed from speed deviation signal and called (dω-PSS). Digital time responses simulations of the nonlinear system performance during and after severe disturbances have proved effectiveness of the developed (MBPSS). The (MB-PSS) is found to be more effective than those with (dωPSS) and (Pa-PSS). The (MB-PSS) act very fast to follow transient system conditions and to restore its stability subsequent to severe disturbances.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Onset Voltage of Negative Corona on Stranded Conductors50952511235710.21608/jesaun.2007.112357ENM. M. EL-BahyFaculty of Engineering, Benha University, Cairo, EgyptM. AbouelsaadFaculty of Engineering, Benha University, Cairo, EgyptN. Abdel-GawadFaculty of Engineering, Benha University, Cairo, EgyptM. BadawiFaculty of Engineering, Benha University, Cairo, EgyptJournal Article20061103Theoretical investigation of the onset voltage of negative corona on stranded conductors is described in this paper. The method of calculation is based on the criterion developed for the formation of repetitive negative corona Trichel pulses. This calls at first for accurate calculation of the electric field in the vicinity of stranded conductors. The investigated gap is a three dimensional field problem. To solve this problem, a new modification of the charge simulation technique (CST) is presented, where the simulation charges are helical of infinite length. Laboratory measurements of the onset voltage on stranded conductors are carried out to check the accuracy of the present calculations. The effects of varying the field nonuniformity on the onset voltage values are investigated. The calculated onset voltage values for stranded conductors agree satisfactorily with those measured experimentally.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Performance of Three-Product Hydrocyclone: Distribution of the Feed Solids Content in the Product Streams52754411286410.21608/jesaun.2007.112864ENG.A. IbrahimMining and Metallurgical Engineering Department, Faculty of Engineering,
Assiut University, Assiut 71516, EgyptM.M. AhmedMining and Metallurgical Engineering Department, Faculty of Engineering,
Assiut University, Assiut 71516, EgyptM.G. FarghalyMining and Petroleum Engineering Department, Faculty of Engineering,
Al-Azhar University, Qena, EgyptJournal Article20060918The hydrocyclone is considered one of the most important industrial separators. It has been used for more than 100 years due to its simple design, low cost, easy operation, and low maintenance. One of the most important areas of application of hydrocyclone in industry is the separation of solids from liquid. A cyclone used for this duty is usually referred to as a cyclone thickener. Under the general heading of the separation of solids from liquid; two extreme cases can be recognised. These are "thickening" and "clarification". A hydrocyclone as a single unit can not be used for this purpose efficiently. Accordingly, the concept of the three-product cyclone is developed from the need to have a cyclone which can be used efficiently in the separation of solid from liquid applications. In an attempt to put this concept into effect, a new design of three-product hydrocyclone has been developed to generate a third product in which the middling particles should be collected for further treatment. In this paper, the design and operation of the three-product hydrocyclone are described. The influence of some parameters such as vortex finder diameter, middling opening diameter, and apex diameter on the solid percent recovered in the three products is investigated. The obtained results showed that the new three-product hydrocyclone has the ability to produce efficiently three different products according to their solids percent, water percent and particle size distributions.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301The Role of Flexibility in Sustainable Prototype Unit Design: Riyadh Commercial Housing Developments, RCHD, Case Study54556711286610.21608/jesaun.2007.112866ENRaeyd M. Al-DakheelAssistant Professor, College of Architecture and Planning,
King Saud UniversityJournal Article20061123Up to four decades ago Saudi traditional housing units were designed and built with local materials and expertise that corresponded with cultural values and fitted well with the local environment and climate. Local materials and technology were affordable to the majority of the population due mainly to the environmental sustainability of construction practices and building materials at the time. The boom of the mid-1970 witnessed the opening of local markets to a variety of building materials and technologies from all over the world. These materials and technologies were used to construct housing units in massive numbers without substantial research to test their compatibility with local culture and environment. One of the important factors contributing to the sustainability and life cycle cost of current housing units is design flexibility and the prediction and planning of unit future expansion, modifications and alterations. Modifications to the housing unit are normal phenomenon’s that accompany the household life cycle changes. For every stage of the families life has a different type of requirements dealing with play, study, storage and outdoor areas. Providing pre-designed alternatives for additions to existing housing units is beneficial in terms of the unit's life cycle cost and in maintaining healthy, diverse stable and sustainable communities. In the city of Riyadh, Saudi Arabia, the recent trend of building large number of units in commercial housing developments was perceived to decrease the flexibility of individual units. This study documented a representative sample of prototype units built recently in commercial housing developments in the city of Riyadh (RCHD). According to survey participants, RCHD units were moderate to highly flexible. The study identified three main categories of flexibility options with subcategories as significant predictors of overall flexibility namely functional flexibility (including ability to interchange and exchange spaces), structural flexibility (ability to extend the unit vertically or horizontally, and apply a system of standardized modularization), and cultural flexibility (ability to personalize the space). The last category of predictors was the only one that was negatively rated by RCHD survey participants. The study concludes with suggestions and recommendations to improve the flexibility options of RCHD units.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Toward a Methodology of Defining Stakeholders and their Roles in Urban Upgrading Projects56959611286910.21608/jesaun.2007.112869ENAhmed Abdalla Abdel-GhanyAssociate Professor Faculty of Urban and Regional Planning,
Cairo UniversityJournal Article20070210In urban upgrading projects, although many experiences shows efforts in the application of participatory planning concept, yet, the definition of participative parties (stakeholders) and their roles in the project does not take the enough attention. The present research adopts the following statement: "definition of stakeholders and their roles in urban upgrading projects must be achieved accurately in the first stage of the project, and the process must take into account potentials and skills of each stakeholder. The research aims at soliciting indicators and principles which can help in the definition of participative parties in urban upgrading projects. The research is consisted of three main parts. In the first part, a theoretical review of stakeholders and their potentials and skills is made. The second part includes an analytical study of many participatory upgrading projects in Egypt. The third part contains solicited indicators and principles which can help in designing a more realistic and reliable methodology for participatory planning in urban upgrading projects.Assiut University, Faculty of EngineeringJES. Journal of Engineering Sciences1687-053035No 220070301Bioclimatic Design of Tall Buildings59761511287110.21608/jesaun.2007.112871ENRasha Mazen Abdel-SalamFaculty of Engineering Assiut UniversityMohamed Abdel Samea EidFaculty of Engineering Assiut UniversityAymen Eissa Abd-ElalimFaculty of Engineering Assiut UniversityJournal Article20070325The concept of tall buildings is determined by the level of civilization and technological progress of the countries, where their heights in some regions can exceed 400 meters. With increasing the importance of the public environmental problems and the rapid increase of tall buildings in city centers, it became necessary to study and define how these buildings are compatible to the environment. This research aims at surveying the design considerations of tall buildings in order to study the bioclimatic design of these buildings to satisfy the comfort for the building's users over the year by using passive energy sources, which depend on natural ventilation and the utilization of Sun light. This reduces the energy consumption and the associated emission of carbon dioxide and other pollutants of the surrounding environmental. This research is focused on the study of the design features for tall buildings including service cores (which ensure natural lighting and ventilation for these cores) as well as orientation of the building and defining openings' places in facades (for energy conservation) and natural ventilation (in order to design the spaces in these buildings to move air from outside into inside taking into account the minimum limit of privacy, which is requested by the building's users). This research is concluded by studying the Commerzbank Headquarters Building in Germany being considered one of the examples of bioclimatically-designed tall buildings.