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Load Characteristics Effect On Dynamic Voltage Stability Analysis In Hvdc Systems., I. Bedir, A. Lotfy, G. Aly Sep 2021

Load Characteristics Effect On Dynamic Voltage Stability Analysis In Hvdc Systems., I. Bedir, A. Lotfy, G. Aly

Mansoura Engineering Journal

The modeling of loads has a significant effect on the accuracy of dynamic voltage stability analysis of HVDC system. This paper investigates the dynamic nature of voltage instability considering static and dynamic load models. The load effect al different control modes of HVDC system is considered for different configurations of single infeed HVDC systems at different effective short circuit ratios. The results are validated using nonlinear simulations.

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Modelling And Experimental Validation Of Turbulent Flame Propagation Is Spark Ignition Engines., H. Abdel-Salam, C. Shoppard, M. Awad, A. Desoky Sep 2021

Modelling And Experimental Validation Of Turbulent Flame Propagation Is Spark Ignition Engines., H. Abdel-Salam, C. Shoppard, M. Awad, A. Desoky

Mansoura Engineering Journal

This work is concciped with modeling and experimental validations of turbulent flame propagation in spark ignition engines. An existing engine cycle model, developed in leads for single chamber spark ignition engines, has been modified in order to obtain more realistic model predictions. The most significant improvement involved the incorporation of a sub-model for blow by and piston top land crevice flow. To optimize and then verify the modified model predictions, the model was initially applied to data derived from experiments using an optically accessed two stroke spark ignition engine. The modified model was optimized an engine cycle at the running …

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Investigation And Analysis Of The Precision Criteria In Free And Fixed Levelling Networks., Hisham Abou Halima Sep 2021

Investigation And Analysis Of The Precision Criteria In Free And Fixed Levelling Networks., Hisham Abou Halima

Mansoura Engineering Journal

In the last few years. the use of free levelling networks in the different engineering constructions has been increased It was clear that comparing the results of the free levelling networks with the fixed levelling networks. having the same configurations and the same measurement technologies, yielded unexpected smaller numerical values of common precision criteria than those of the fixed levelling network . The aim of this research is to study the reasons for this phenomena by interpreting and illustrating the variation In the geometrical meanings for precision criteria of both free and fixed levelling networks New criteria suitable to describe …

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A Combined Technique For Elimination Of Islanding Phenomenon., Fadia Ghali Sep 2021

A Combined Technique For Elimination Of Islanding Phenomenon., Fadia Ghali

Mansoura Engineering Journal

As a growing tendency substantial number of PV-systems are interconnected to the utility on medium and distribution levels. Due to disconnection of some faulty sections. A number of PV's could be cut off from the grid but continue to operate. This generates what is called the islanding phenomenon. Active techniques to suppress this phenomenon utilizing a reactor or a capacitor show a considerable change of voltage and frequency from normal values. This paper introduces a novel combined technique to eliminate the islanding phenomenon with maintained power quality operation of the isolated sections.

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Turbulent Flow Between Concentric Rotating Cylinders., M. Mohamed Sep 2021

Turbulent Flow Between Concentric Rotating Cylinders., M. Mohamed

Mansoura Engineering Journal

The turbulent flow between concentric cylinders both rotating in the same or opposite directions is investigated theoretically. A finite difference scheme is developed to solve the boundary layer equations covering the flow. A two-equation model of turbulence was employed in this study. Modifications have been made to the model to take into account the effect of rotating on of the cylinders and the existing of the wall. The effect of changing the radius ratio, axial Reynolds number and angular velocity ratio on the hydraulic friction head loss of air is studied . Distributions for axial mean velocity, tangential mean velocity, …

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Non-Newtonian Drag Reducing Fluid Flow In A Circular Pipe Filled With Porous Medium In The Non-Darcian Effects., M. El-Kady, M. Tolba, L. Rabie Sep 2021

Non-Newtonian Drag Reducing Fluid Flow In A Circular Pipe Filled With Porous Medium In The Non-Darcian Effects., M. El-Kady, M. Tolba, L. Rabie

Mansoura Engineering Journal

This work presents an analysis of a non-Newtonian drag reducing fluid (dilute polymer solutions) in a circular pipe filled with porous media. The flow is developed by modifying the momentum equation for the flow in porous media to account for the elougational viscosity of drag reducing fluids. The modified Darcy-Forschheimer-Brinkman's equation is solved using the finite difference method. The results are obtained for flow Reynolds number up to 105, a non-Newtonian drag parameter range of 0≤ up < /strong>≤5000, and nondimensional pressure gradient B up to 1010. The results show that the non-Newtonian effect of drag reducing fluids have a significant …

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Determination Of Electromechanical Transient Process Characteristics Using Equation Of Variable., Ibraheem Mansy Sep 2021

Determination Of Electromechanical Transient Process Characteristics Using Equation Of Variable., Ibraheem Mansy

Mansoura Engineering Journal

The equation of variables (EV) is an approximation of a mathematical method. It is used to linearize nonlinear equations. It is simple and accurate method and it offers quick solutions. This paper explains this equation and uses it to determine the characteristics of electromechanical transient process (EMTP) in electrical power systems. The characteristics of EMTP are studied in this paper in two cases: first, simple disturbance ( as a result of parameter variation ) and second, large disturbance (as a result of occurring single S.C.) in this paper also, a comparison between the proposed method and another three methods is …

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Evaluation Of Rein Forced Flexible Pavements By Repeated Load Testing., Hazem Sakr Sep 2021

Evaluation Of Rein Forced Flexible Pavements By Repeated Load Testing., Hazem Sakr

Mansoura Engineering Journal

In a previous research , the C.B.R. Test has proved to be useful in evaluating reinforced subgrade soils [1] . When testing specimens after soaking with and without reinforcement one can come up with two values of C.B.R. for comparison . However , the need to evaluated reinforced subgrade soils in a loading conditions that are as similar as possible to fields is warranted . The purposed of this research is to investigate the life cycle improvements of pavements when they are reinforced by geotextiles and a geonet , Four pavement test groups were constructed to simulated the field conditions …

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Evapotranspiration And Irrigation Water Requirements In Nile Delta Region., Saad Moharram Sep 2021

Evapotranspiration And Irrigation Water Requirements In Nile Delta Region., Saad Moharram

Mansoura Engineering Journal

FAO-Penman method is reliable to predict the reference evapotranspiration, ETo under climatic conditions in Nile-Delta region, Egypt. This method is developed by comparing and evaluating selected estimation methods (PA0-Penman, FAO-Radiation, and FAO-Blaney-Criddle) with results obtained from field data (Class A Pan). Monthly values of Eto are estimated by each of the selected methods using climatic data collected from six observation stations (records of 1995) within the area under study. The irrigation/crop water requirements, ETC, for main crops growth in this region are then computed. Considering FAO-Pengan formula, an empirical equation is developed to predict ETc for each crop under climatic …

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Performance Of Steam Regenerative-Turbine Compressors., Mohamed Wasel Sep 2021

Performance Of Steam Regenerative-Turbine Compressors., Mohamed Wasel

Mansoura Engineering Journal

In this work, the performance of steam regenerative-turbine compressor is studied. In spite of the simple construction of this compressor, it is rarely used in practical application . The flow of steam inside the compressor is described through the continuity , momentum and energy equations in integrate form . These governing equations are solved. Numerically, by design a computer program. Tlus program is designed , such that the steam properties are calculated taking into account the behavior of steam as a pore substance. The effect of operating conditions, such as speed of compressor impeller and sucnon pressure, on the performance …

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A Hybrid Stochastic Model For Characterization Of Subsurface Heterogeneity., Amr Elfeki Sep 2021

A Hybrid Stochastic Model For Characterization Of Subsurface Heterogeneity., Amr Elfeki

Mansoura Engineering Journal

This study proposes a methodology for characterization of subsurface heterogeneity using a hybrid approach. The hybrid approach will incorporate soft geological information in addition to the available hard data to characterise geological heterogeneity under two scales of variability. The geometric shapes of the geological features are modelled stochastically based on soft information using the Coupled Markov Model developed by Elfeki et al. (1995), while hard data are used to model the variability inside these geometric shapes. This will lead to an improved characterization of the subsurface heterogeneity. The proposed hybrid model can be used to generate realizations of conductivity within …

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Forced Convective Heat Transfer Through Horizontal Annular Porous Channel., Mohamed Mahgoub, Mohamed Wasel, H. Sarhan Sep 2021

Forced Convective Heat Transfer Through Horizontal Annular Porous Channel., Mohamed Mahgoub, Mohamed Wasel, H. Sarhan

Mansoura Engineering Journal

In present work, the forced convective heat transfer through horizontal annular porous channel is theoretically and experimentally studied in the experimental work, annular channel with aspect ratio of 1.85 is designed such that one can study the effect of various parameters controlling the behaviour of the flow. Heat flux of 12.6 Kw/m2 to 16.9 Kw/m2 is applied to examine the effect of heat flux on heat transfer process. Porous media of diameters 3 mm and 5 mm stainless steel spherical beads are used to examine the effect of porosity on flow. Water, as a test-liquid, is used with mass flow …

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Application Of Finite Element Residual Scheme To Steady Unconfined Flow Subject To Rainfall., Saad Moharam, Adel El-Masry Sep 2021

Application Of Finite Element Residual Scheme To Steady Unconfined Flow Subject To Rainfall., Saad Moharam, Adel El-Masry

Mansoura Engineering Journal

A two- dimensional finite element method is used to study the problem of steady-state unconfined seepage due to rainfall through porous media. The method is based on the finite element residnal scheme. Homogeneous and nonhomogeneous soil domains are considered and solved numerically. Numerical results are compared with that obtained from the analytical approximations to be in the same order of magnitude. To facilitate its practical use, the scheme has been programmed for computer solution using FORTRAN-IV language.

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Maximum Sett Of Woven Fabrics., Hamdy Ebraheem Sep 2021

Maximum Sett Of Woven Fabrics., Hamdy Ebraheem

Mansoura Engineering Journal

The woven fabric cannot be produced with any yam density as there is a maximum value of yarn sett which cannot be exceeded This limit depends on yarn geometry, properties, adjustments and type of weaving machine. Exceeding this limit causes increasing stresses on pans of the weaving machine and affects the quality of the woven fabric. Researchers tried to find out formulae to express this limit as a function of yarn type, yarn count and weave structure. They reached different formulae. Some researchers verified these formulae experimentally. They found that some formulae need correction. This paper aims to find mathematical …

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Coarse Segmentation Of Textured Images Using Variance Analysis., Fatma Samir, Ayman Ibrahim, Samir Shaheen Sep 2021

Coarse Segmentation Of Textured Images Using Variance Analysis., Fatma Samir, Ayman Ibrahim, Samir Shaheen

Mansoura Engineering Journal

This paper presents a novel approach for the segmentation of a textured scene. The algorithm is image-based; no specific model is assumed for the image. Also, no a priori knowledge about the different texture regions, neither their number, nor their behavior is assumed. The algorithm partitions the image into small disjoint square windows, and the Variance for each window data is calculated. Then the K-means clustering algorithm is applied upon these windows. Together with the K-means algorithm, a new distance measure has been defined. This new distance measure was deduced from a statistical test known as Bartlett's test based on …

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Stabilizing Highways Earth Slopes By Nailing., Hazem Saker, Ashraf Badr Sep 2021

Stabilizing Highways Earth Slopes By Nailing., Hazem Saker, Ashraf Badr

Mansoura Engineering Journal

A major problem that faces the highways engineer is the failure of roads side slopes, specially after being opened to traffic. In most cases this obstacle is treated either by building gravity or reinforced concrete walls. In fact, these types of retaining structures have proven successful if they are well designed and constructed. However; they are time consuming and they necessitate excavating large volumes of soils, in some cases requiring the construction of a temporary retaining system and importing a better sandy soil for refilling behind the wall. Other methods of earth slope stabilization are by geosynthetics reinforcement or by …

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The Possible Algebraic Solutions For Rough Collision In Three Dimensional Multibody Systems., Hesham Elkaranshawy Sep 2021

The Possible Algebraic Solutions For Rough Collision In Three Dimensional Multibody Systems., Hesham Elkaranshawy

Mansoura Engineering Journal

The sliding direction of the collision point for single point rough collision in three dimensional multibody systems continuously swerves during collision period. Numerical integrations for the bi dimensional nonlinear differential equations of motion are usually required. It is proved that if sliding starts along one of a finite number of directions, called invariant directions, algebraic solutions can be obtained. The invariant directions are specified. All the possible dynamic scenarios for the motion of the collision point that starts with sliding along an invariant direction are enumerated and algebraic solutions are obtained. On the other hand, the conditions required to have …

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Thermodynamic Studies Of 5-(P-Bromophenylazo)-3 Phenylrhodanine And Its Metal Complexes., M. Ei-Komy Sep 2021

Thermodynamic Studies Of 5-(P-Bromophenylazo)-3 Phenylrhodanine And Its Metal Complexes., M. Ei-Komy

Mansoura Engineering Journal

The dissociation constant of 5-(p-bromophenylazo)-3-phenylrhodanine (HL) and metal-ligand stability constants of its complexes with bivalent (Mn2+, Co2+, Ni2+ and Cu2+) metal icons have been determined potentiometrically in 0.1 M KÇI and 40% (v/v) ethanol-water mixture. The order of the stability constants of the formed complexes was found to be Mn2+

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An Efficient Technique For Smoothing Project's Demand For Multiple Resources., Adel Eldosouky Sep 2021

An Efficient Technique For Smoothing Project's Demand For Multiple Resources., Adel Eldosouky

Mansoura Engineering Journal

The objective of the resource smoothing problem is to schedule Project activities so that the project duration does not exceed its early start duration and the project's maximum demand for resources, or the variation in this demand from one time period to another, is kept to a minimum. Many heuristic and optimal methods have been developed for solving this problem. almost all of them are concerned with smoothing a single resource. For a contractor who is required to manage several resources simultaneously, the process can be done by adding the resource rates together, according to predetermined weightings of the resources, …

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Influence Of Water Temperature And Side Slope On Sand Bed Channels., Abdel Razik Zidan Sep 2021

Influence Of Water Temperature And Side Slope On Sand Bed Channels., Abdel Razik Zidan

Mansoura Engineering Journal

A mathematical model was used to study the effect of both water temperature and side slope on sand bed channel geometry and longitudinal slope. The study has revealed no responses occurred for both mean width and water depth due to the change in water temperature over 0OC for canal having median particle size ≤ 0.5 mm. For canals having dso ≥ 0.6 mm, moan width decreased and water depth increased especially from Octo about 20 OC, Bed slopes decreased regularly with the increasing value of water temperature. Statistical analysis was used to fit this variation. Both mean width and water …

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The Effect Of Having An Adverse Rear Floor On Scour Holes., Adel El-Masry Sep 2021

The Effect Of Having An Adverse Rear Floor On Scour Holes., Adel El-Masry

Mansoura Engineering Journal

Experimental investigations using clear-water were conducted to study the effect of having an adverse rear apron on the scour depth and length. Dimensional analysis to find different non-dimensional terms affecting the phenomenon were obtained and verified with the help of the experimental data. It is observed that the maximum scour depth occurs at about 3-5 times of that depth from the end of the floor. The ratio of scour length to its depth has been increased by increasing the adverse slope of the apron. Increasing the adverse slope of the rear apron clearly decreases the scour hole downstream of the …

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Reliability And Profitability Study Of Conventional - Photovoltaic - Battery Storage Combined System., Mohamed El-Sayes, M. Osman, Sahar Kaddah Sep 2021

Reliability And Profitability Study Of Conventional - Photovoltaic - Battery Storage Combined System., Mohamed El-Sayes, M. Osman, Sahar Kaddah

Mansoura Engineering Journal

indices of systems integrated with unconventional ones donot deal with the impact of interconnecting storage batteries with them. The methods and developed inthese works aremodified here and modified to reflect the influence of interconnecting storage batteries with these systems, This paper deals with the following important topics : 1. Derivation of an hourly operation strategy for the comoined system selected for the study, 2. Modification of the previous methods used in providing the reliability 1nd1ces of combined system to include the impact of storage batteries, 3. Determination of the profit resulting from the Interconnection . A number 1cal study 1s …

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Laser Beam Profile Shaping For Lidars With Diffraction Grating., Ahmed Samra Sep 2021

Laser Beam Profile Shaping For Lidars With Diffraction Grating., Ahmed Samra

Mansoura Engineering Journal

A laser beam profile shaper was designed. It transforms a fundamental mode laser beam profile into flat top profile at a local plane. The shaper uses an ion-exchanged diffraction grating. The performance was tested and a good agreement between theoretical and experimental results was obtained.

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Performance Analysis Of Loads Individually Or Combindelly Powered By Seperate Or Common Photovoltaic Sources., Mohamed Mohamed El-Sayes Sep 2021

Performance Analysis Of Loads Individually Or Combindelly Powered By Seperate Or Common Photovoltaic Sources., Mohamed Mohamed El-Sayes

Mansoura Engineering Journal

No abstract provided.

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Design The Main Shaft Of Wide Weaving Machine For Equally Sided Reed Advance., Abdallah El-Toukhy Sep 2021

Design The Main Shaft Of Wide Weaving Machine For Equally Sided Reed Advance., Abdallah El-Toukhy

Mansoura Engineering Journal

As a result of driving wide weaving machines double warp beam from one side, torsion occurs in the main driving shaft, which in turn affects on the non uniform advance of the reed. during the beat up of the weft yarn. This in turn leads to the increase in the rate of warp yarn tension from the checking side than the picking side., hence the warp yarn in the checking side will be consumed than that in the picking side. In the present work the proplem of non-uniform advance of the reed has been solved by reducing the twisting angle …

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Cad For Gears Part 1 Spur, Helical And Double Helical Gears., Ahmed El-Bahloul Sep 2021

Cad For Gears Part 1 Spur, Helical And Double Helical Gears., Ahmed El-Bahloul

Mansoura Engineering Journal

The aim of this paper is to construct a software containing a complete design procedure and detailed drawing for spur, helical and double helical gears. This software can be executed on all the IBM personal computers XT/AT or compatibles. The main elements of the design In this program are : input data, type end shape of gear tooth system (IS. US, BS and DIN), module, minimum number of teeth to avoid interference, tooth profile modification, centre distance, contact ratio, face width, helix angle, material, equations for bending strength (Lewis, modified Lewis and Buckingham) and surface durability, and load carrying capacity …

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A Proposed Solar Desalination-Heating System With Heat Recovery., Helmy Gad Sep 2021

A Proposed Solar Desalination-Heating System With Heat Recovery., Helmy Gad

Mansoura Engineering Journal

In the present work, a solar desalination-heating system with heat recovery is proposed. The system includes a solar collector, humidifier, storage tank and a water-cooled condenser. The thermal design of a typical unit is presented. Both latent heat of the condensed vapour and the sensible heat of the circulating air are recovered, and added as a sensible heat to the inlet water in the condenser. The system is simple in construction, operation and control. Therefore, it is a suitable option for remote areas where only the ground water, or wells are available. The thermal performance of the system is also …

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A Methodology For Human Factors Utility Analysis In Quality Inspection Workstation Design., Ahmed Abd El-Shafi, Syed Naqvi Sep 2021

A Methodology For Human Factors Utility Analysis In Quality Inspection Workstation Design., Ahmed Abd El-Shafi, Syed Naqvi

Mansoura Engineering Journal

This paper addresses a very crictial Issue relating human factor to the quality Inspection workstation design. In lot of lstance these workstation lack the consideration of human capabilities and limitations in their design, which could be included to enhance both the productivity and safety of the workplace and more importantly of the inspector, the paper presents a methodology which is easy to use and can be effectively applied to provide an analyst with a measure to compare the existing quality inspection station design utility with the utility of many number of alternate options having varying applications of human factors in …

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Autolisp /Ices/Cdf And Sdf Multilateral Communication Language Between Autocad And Cam Activities., Tawfik El-Midany, M. El-Baz Sep 2021

Autolisp /Ices/Cdf And Sdf Multilateral Communication Language Between Autocad And Cam Activities., Tawfik El-Midany, M. El-Baz

Mansoura Engineering Journal

Great benefits have been obtained from the fully integration between CDA system with the other computer aided engineering CAE activates NC programming and turning had been successfully demonstrated for both milling work these programs generate automatically the NC part program negative for any specific product through the geometry data from the DFX file extracted from AUTOCAD , excellent results and benefits have been demonstrated.

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Performance Study Of The Modified Fast Serial Parallel Multiplier With Reco Technique., Ali El-Desoky, Aida Abd El-Gawad, Yasser El-Sheshnagy Sep 2021

Performance Study Of The Modified Fast Serial Parallel Multiplier With Reco Technique., Ali El-Desoky, Aida Abd El-Gawad, Yasser El-Sheshnagy

Mansoura Engineering Journal

This paper studies the speed and hardware performance of the modified fast serial-parallel (MFSP) multiplier with concurrent error detection (CED) by REcomputing with Circularly shifted Operands (RECO) technique. The MFSP multiplier has been proposed primarily to increase the speed of the fast serial parallel (FSP)multiplier by using fast parallel adder instead of the parallel ripple carry adder. This multiplier can be used for VLSI when the chip size is limited for high speed applications. By using RECO technique for CED applied to the MFSP multiplier, the copmromise between suitable error coverage, small error latency , suitable multiplication speed improvement and …

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