2024-03-29T16:12:45Z
https://jesaun.journals.ekb.eg/?_action=export&rf=summon&issue=16619
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
ESTIMATION OF LONGITUDINAL DISPERSION COEFFICIENT IN RIVERS USING ARTIFICIAL NEURAL NETWORKS
Hassan
Ibrahim
M.
HASHEM
This study presents an artificial neural network (ANN) model to predict the values of the longitudinal dispersion coefficient in rivers and streams from their main hydraulic parameters. The model can be considered as a useful aid to water quality and sediment transport monitoring in rivers. The ANN model is a relatively new promising technique which can make use of the river width, depth, velocity, and shear velocity for predicting longitudinal dispersion coefficient. The used ANN model is based on a back propagation algorithm to train a multi-layer feed-forward network. The proposed model was verified using 116 sets of field data collected from 62 streams ranging from straight manmade canals to sinuous natural rivers. The ANN model predicts longitudinal dispersion coefficient, where more than 83% of the calculated values range from 0.50 to 2.0 times the observed values in the field. A comparison of the ANN model estimates with the outputs of the most recent and accurate equations in the literature, for the longitudinal dispersion coefficient, using three different statistical methods for analysis, has shown that the accuracy of the ANN model compared favourably with other equations. Finally, a new accurate predictor for the values of longitudinal dispersion coefficient in polluted rivers and streams that based on readily measurable hydraulic quantities is presented.
water quality
Dispersion Coefficient
Rivers
Neural network modelling
2006
09
01
1341
1352
https://jesaun.journals.ekb.eg/article_111026_e9b86563b7611a5ba4402b7884e8935c.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
EVALUATION OF RIVERBANK FILTRATION AS DRINKING WATER TREATMENT PROCESS USING BACK-PROPAGATION TECHNIQUE
M.
Hashem
Riverbank filtration (RBF) is a natural process, using alluvial aquifers to remove contaminants and pathogens in river water for the production of drinking water as a low-cost water treatment technology. This study illustrates the development and application of feed-forward backpropagation network (BPN) as a type of artificial neural networks. The BPN prediction results produced good agreement with measured data at a correlation coefficient above 0.98 for filtrate water quality parameters, including temperature as well as turbidity, heterotrophic bacteria, and coliform removal.
Riverbank
filtration
drinking water and backpropagation
2006
09
01
1353
1361
https://jesaun.journals.ekb.eg/article_111027_344512d6bc9d207e0ca4fb1ac6eab66b.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
GROUNDWATER EVALUATION IN AL-GOFRA OASIS, MIDDLE LIBYA, USING STATISTICAL METHODS
Sameh
S. Ahmed
Mohamed
Hashem
With its two main aquifers that feed five villages and serve about 60000 capita, Al-Gofra Oasis, middle Libya, has seldom been subjected thoroughly for water quality evaluation. This paper aims at addressing the current situation of the groundwater at the oasis, studies the sources of pollution to the aquifers and introduces a methodology based on multivariate statistics for better monitoring and regular evaluation of the water quality at that oasis. Multiple Regression Analysis was used to correlate the field water quality data with the laboratory measured chemical parameters. Groundwater is the main/only source of water in that region. The aquifer in Sokna and Wadan is confined and its rocks consist of sand, clay and sandstone. The quality of water in this aquifer is fairly good and the Total Dissolved Solids (TDS) range between 1200 to 1500 ppm. The aquifer in Hun is deep confined aquifer and the quality of water is poor, where the TDS ranges between 4000 and 5000 ppm.
water quality
TDS
regression statistics
Al-Gofra oasis
2006
09
01
1363
1375
https://jesaun.journals.ekb.eg/article_111028_392028b4979ff07cb4032d0af576ffa3.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
MINIMUM STIFFNESS OF AN INTERMEDIATE SUPPORT FOR A BEAM TO MAXIMIZE ITS FUNDAMENTAL FREQUENCY
Mohamed
Abdel-Basset Abdo
The concept to increase the fundamental natural frequency (below which no vibration could occur) of a structure as high as possible is commonly adopted to make the structure better in dynamic environment. Due to design limitations, the fundamental frequency of a beam can be increased via adding additional intermediate point supports. If the intermediate supports are rigid, the optimum locations of the supports should be at the nodal points of a higher vibration mode without the supports, and the fundamental frequency is correspondingly raised. For elastic supports, which often occurs in practice, the optimum locations are still the same as the case of rigid supports with no decrease in fundamental frequency provided that the support stiffness exceeds a certain minimum value. Indeed, the minimum stiffness prediction is very important in the design of beams, since the bracing or support materials can be reduced without any loss of performance. This paper investigates and discusses the minimum stiffness of an intermediate support through the span of a beam for maximum value of its fundamental frequency. In this study it is assumed that the intermediate support of the beam is provided through the span of the beam (at an interval of 0.05 of the span). The finite element technique is used in the analysis of a beam model with different end conditions. It is found that when the intermediate support is not at the optimum location, there exists a minimum stiffness of the support to give the fundamental frequency of the rigidly supported beam (such minimum stiffness phenomenon also occurs in the buckling of beams). Design curves are obtained to estimate the minimum stiffness of an intermediate support through the span of a beam and the corresponding fundamental frequency.
Minimum stiffness
intermediate support
maximum fundamental frequency and dynamic environment
2006
09
01
1377
1393
https://jesaun.journals.ekb.eg/article_111048_7f26b04228f9a5bd8befe7cbac4c4878.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
PARAMETRIC STUDY OF THE EFFECT OF CROSS-FRAMES ON THE BEHAVIOUR OF COMPOSITE STEEL-CONCRETE GIRDERS CURVED IN PLAN AND CONSTRUCTED WITH SHORING
Mohamed
Abdel-Basset Abdo
Waleed
Abo El-Wafa Mohamed
The use of cross frames in bridge is provided to act together with the longitudinal girders to form a system that behaves as a unit. In horizontally curved bridges, the interaction of bending and torsion causes these components to become major load-carrying elements (primary members) and not secondary members as that in straight girders. This study is concerned with parametric study of the effect of cross frames on the behaviour of composite steel-concrete girders curved in plan using finite element technique. Shoring is assumed to be used during construction and both dead and live loads according to ECP are taken into consideration in the analysis. The concrete deck slab and both steel webs and flanges are modeled using shell elements. However, both studs and cross frames are modeled using beam elements. The study includes not only the displacements but also the tangential stresses through the inner edge, middle and outer edge of the tension flange along the span of the critical outside girder. Based on the numerical results it is shown that slenderness ratio of cross frames, cross frame spacing, radius of curvature, span length and flange width have greatest effect on the warping-to-bending stress ratio. It is shown that equations which can be used for composite girders subjected to noncomposite dead loads and recommended by other authors may give inaccurate results for curved composite systems constructed with shoring. Also, they do not take the slenderness ratio of cross frames into consideration. Two equations are proposed for the preliminary design of cross frame spacing and warping-to-bending stress ratio for curved composite systems constructed with shoring. The accuracy of the results using the new equations is checked for various variables. From equations, it is recommended that the maximum slenderness ratio of cross frames should not exceed 140. Also, the distance between cross frames should be ranged from 3 to 5 m.
parametric study
cross frames
composite steel-concrete girders
horizontally curved bridges and shoring
2006
09
01
1395
1415
https://jesaun.journals.ekb.eg/article_111060_b583ec028490ecaeac2a496d2dd2f591.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
EFFECT OF BOTTOM LATERAL BRACINGS ON THE BEHAVIOUR OF COMPOSITE STEEL-CONCRETE BRIDGES CURVED IN PLAN
Mohamed
Abdel-Basset Abdo
The present study is concerned with the effect of the presence of bottom lateral bracing systems on the behaviour of horizontally curved composite bridges. A careful numerical study is carried out by using the finite element method in the elastic range of loading. Shoring is assumed to be used during construction and the system is provided with cross frames. The present study includes tangential stresses, warping-tobending stress ratio, vertical displacements and radial displacements through the inner edge, middle and outer edge of the bottom flange along the span of the critical outside girder. Also, the maximum axial forces in bracing members for the most effective type are studied. Based on the numerical results, it is shown that the presence of bottom lateral bracings in curved composite bridge results in significant reduction of not only bending and warping stresses but also vertical and radial displacements as well as torsional angle of bottom flanges. The reduction in stresses of curved bridges due to the presence of lateral bracings may exceed 25% of the stresses obtained using cross frames only and the reduction in stresses is more pronounced for small radii of curvatures. So, lateral bracings can be used effectively in strengthening of existing bridges or to decrease the cross sectional area of new curved composite bridges. Also, the results show that the most effective pattern of lateral bracings is that which consists of X-bracings in all bays. However, the pattern of bracing which consists of X-bracings in end panels only give the greatest stresses and displacements of all of the studied reinforcement patterns. Furthermore, for high degree of curvature, the stresses in bracing members should be checked since they are subjected to large stresses due to curvature in addition to those due to wind loads.
Lateral bracings
composite steel-concrete girders
degree of curvature
warping and bending stresses
Displacements
2006
09
01
1417
1432
https://jesaun.journals.ekb.eg/article_111061_5c68d00bdf9417392f4a88471ffa64f8.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
EVALUATION OF THE SEISMIC RESPONSE OF BASE ISOLATED FRAME STRUCTURES WITH DIFFERENT HEIGHTS
Waleed
Abo El-Wafa Mohamed
Mohamed
Abdel-Basset Abdo
Base isolation technology has emerged in the last decades as an innovative seismic design approach aimed at reducing the damage of structures when subjected to earthquake excitations by separating the building from the surrounding ground motions. This paper presents nonlinear seismic analysis of steel structures with 5, 10 and 20 stories designed to meet the requirements of a newly developed code. The structure is either conventional with fixed base or base isolated with different types of elastomeric bearings. A numerical parametric study is carried out to recommend the effective range of isolation bearing parameters represented by the ratio of fundamental period of the isolated structure related to that of corresponding fixed base one. This range is evaluated relying on the performance of both superstructure and elastomeric isolation bearings. The peak responses of the different studied frames are examined to determine the effectiveness of the utilized system.
seismic response
Steel frames
base isolation
elastomeric bearings and ductility demand
2006
09
01
1433
1448
https://jesaun.journals.ekb.eg/article_111063_6da698436eab48386bf605c1da0875ae.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
STATIC BEHAVIOR OF RC COLUMN JOINTS AS AFFECTED BY CHANGING OF ITS GRADE OF CONCRETE AND DETAILS OF REINFORCEMENT
Abdel Rahman
Megahid Ahmed
Khairy
Hassan Abdelkareem
The columns of high-rise structures are usually constructed from high strength concrete and the connecting beams and slabs at floors are of normal strength concrete. Consequently, the beam column joint is of normal strength concrete. The purpose of the study is to investigate the strength of high strength concrete columns as affected by the low strength concrete of connecting beams, and to study the effect of reinforcement details of the joint of high strength concrete column and normal strength beam on failure mode of such column and its strength. Experimental study was carried out to investigate the effect of changing the grade of concrete on the behavior of RC column and its joint considering the interaction of the column with the floor beams. Floor beams and the joint are constructed from normal strength concrete, while the other parts of the column below and above the joint are constructed using different grades of high strength and normal strength concretes. Another significant parameter affecting the behavior of such columns is the details of reinforcement of the joint represented by horizontal or inclined stirrups. Twelve specimens of RC columns and intersecting beams are prepared and tested under axial compressive loading on the column as well as under vertical load on the beam. The results include the failure mode, strain distribution, ultimate load and strength of the columns considering the change of concrete strength and the details of reinforcement. It has been found that failure mode of such structures occurs at the joint because of its low strength which has been constructed with the floor beams. It has been shown that inclined stirrups at joints do not change the failure mode even it reduces its severity. Other steel arrangement is still needed to change the failure mode. However, inclined stirrups have significant influence on increasing the ultimate strength of the columns. This is because the inclined stirrups cause an increase on the shear strength of the column resulting in the increase of the strength. The strain distribution is highly affected by the interaction of beam and the column. Maximum strain occurred at the joint due to combined state of stress. An equation was deduced to estimate the strength of axially loaded columns considering the interaction of floor beams, variation of concrete strength and details of reinforcement. The deduced equation is applicable to normal strength and high strength concrete.
High Strength and Normal Strength Concrete
Column joint
inclined stirrups
failure mode
Ultimate Load
strength of column
2006
09
01
1449
1468
https://jesaun.journals.ekb.eg/article_111064_928eb748da5f3524bd3ca102e8c65f76.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
A NUMERICAL STUDY FOR ANALYSING CRACKED REINFORCED CONCRETE BEAMS REPAIRED BY GLUING STEEL PLATES
Usama
Mostafa MAHRAN
The basic concept of using the finite element method of analysis in constructing an analytical models for the study of behavior of reinforced concrete members is discussed. The finite elements method chosen to represent the concrete, the steel reinforcement, and the bond links between the concrete and steel reinforcement are described, modeling with a proper finite element program in idealization the considered structure is greatly needed. This paper demonstrates the behavior of reinforced concrete cracked beams. Five reinforced concrete beams with cross section width (b= 10 cm) and thickness(t= 40 cm), the bottom reinforcements are is 4 φ 16 mm and top reinforcement (stirrups hanger) 2 φ 10 mm. Beams R8, C8, C6, C5 and C7, are with stirrups φ 6 mm each 10 cm from the span of the beam which equal 220 cm [ 5]. Beams C8, C6 and C5 were repaired by a steel plate 6 mm thickness with different length 2d, 4d and 6d respectively, in tension zone glued by epoxy material, while beam C7 was repaired by two steel plates 6 mm thickness with lengths 6d, one in tension zone and the other in compression zone [ 5 ]. The load was applied in the middle span of the beams and all beams were designed as tension failures so that, the distance of point of test load from the support equal more than three times of the depth of the tensile steel. I suggest new formula in the two dimensional for numerical modeling for the plane element.
repairing
gluing, numerical modeling
2006
09
01
1469
1485
https://jesaun.journals.ekb.eg/article_111065_bf940c25d4e14797b7457d7c7408f50b.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
A NUMERICAL INVESTIGATION FOR ANALYSING REINFORCED CONCRETE COLUMNS STRENGTHENED WITH SHOTCRETE
Usama
Mostafa MAHRAN
It’s clearly obvious that the use of computer programs, especially finite element method in structural analysis, gained a distinguished popularity in the presence of expensive hard experimental works in the field of concrete structures, modeling with a proper finite element program in idealization the considered structure is greatly needed. Today, the use of shotcrete for strengthen of the concrete structures in large scale is increasing due to it's advantage, the properties and the factors effect on it, has been discussed. This work presents an theoretically investigation concerning the efficiency for the reinforced concrete columns Four Columns (20x20x100) were tested under compression loading and had the same cross section of dimensions and main longitudinal reinforcement distribution and cross sections for all columns. (Usama 2002) made four Columns (20x20x100) were tested under compression loading and The deformations were measured by linear variable differential transducers LVDT’s, two transducers in both sides to measure the longitudinal deformations ( LO ) and three in the lateral direction to measure the lateral deformations: the first (EQ1) was near the end of the column, the second (EQ2) was in the middle and the third (EQ3) was in the middle between the fist and the secondhad the same cross section of dimensions and main longitudinal reinforcement distribution and cross sections for all columns. These Columns had four deformed longitudinal steel bars 10 mm diameter. New formula in the three dimensional for numerical modeling to compare between strengthening columns [5] was produced by the author.
Shotcrete (SpB)
strengthen
Numerical Modeling
2006
09
01
1487
1506
https://jesaun.journals.ekb.eg/article_111068_d4cce78636eedd89311e52b838f72871.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
FLANGE COMPACTNESS EFFECTS ON THE BEHAVIOR OF STEEL BEAMS WITH CORRUGATED WEBS
Mohamed
Dabon
A. S.
Elamary
In this paper, the effects of the flange compactness on the behavior of steel beams with corrugated webs are experimentally and analytically studied. The experimental program consists of four simply supported beams with different web configurations (Flat or Corrugated) and different flange compactness (non-compact or compact). Nonlinear finite element technique was used to model the tested specimens and to carry out the parametric study. The variables of the parametric study were the thickness and the width of the flange transversal stiffeners (FTS), and the flange thickness (FT). The results obtained from the finite element were compared with the corresponding experimental ones that show a reasonable degree of accuracy. Finally, comparison between beams with corrugated webs and those with flat webs was carried to exhibit the advantages and disadvantages of using web corrugation. The results indicate that; the flange transversal stiffeners enhances the beam yield load by 21% and the flange thickness can increase the yield load by 56%, where if both of them are used (FTS and FT) the beam yield load can achieved 72% more than beam without these enhancement.
Uniform moment
Simply Supported Beam
Corrugated webs
Nonlinear finite element analysis
Flange compactness
2006
09
01
1507
1523
https://jesaun.journals.ekb.eg/article_111070_34e68c64a61a0fe2d6903b1f102cfc88.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
HIGH-FREQUENCY INDUCTION HEAT SINTERING OF ULTRA-FINE AL2O3-(ZRO2+X%MOL Y2O3) BIOCERAMICS
Khalil
Abdelrazek Khalil
Alumina–zirconia composites Al2O3–20 vol. % yttria stabilized zirconia containing two types of yttria stabilized zirconia: 3mol% yttria doped ZrO2 (3YSZ) and 8mol% yttria doped ZrO2 (8YSZ) were consolidated very rapidly to full density by high frequency induction heat sintering (HFIHS). A comparison between 3YSZ and 8YSZ as a second phase toughening alumina has been made. Effects of sintering temperature on the mechanical properties have been studied. The consolidated samples were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The microhardness, strength and toughness of the composites are determined. The results showed that, 3YSZ is the most effective as a second phase toughening alumina than 8YSZ. Al2O3-3YSZ composites with higher mechanical properties and small grain size developed through this technique.
High frequency induction heat sintering
Yttria stabilized zirconia
Toughness
hardness
Nanostructures
2006
09
01
1525
1533
https://jesaun.journals.ekb.eg/article_111079_a40b7c585d8bd0b3b7484d65b31e804e.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
AN FPGA IMPLEMENTATION OF A DENOISIG ALGORITHM BASED ON STATIONARY WAVELET PACKET TRANSFORN
Nivin
A. Ghamry
Scientific datasets are often contaminated with noise, either because of the data acquisition and transmission processes, or because of naturally occurring phenomena such as atmospheric disturbances. A first pre-processing step in analyzing such datasets is denoising, that is, estimating the signal of interest from the available noisy data. Wavelet transforms represent signals with a high degree of sparsity. This is the principle behind the non-linear wavelet based signal denoising technique and is what distinguishes it from entire linear denoising techniques such as least squares. It is well known that the use of non-decimated (Stationary) Wavelet Transforms (SWT) gives a redundant representation of an input signal, which minimizes the artifacts in the reconstructed data. In this work the stationary wavelet basis and the Wavelet Packet Transform (WPT) method are exploited to develop a Stationary Wavelet Packet Transform (SWPT)-based denoising algorithm. The decomposition of noisy signals is performed with stationary wavelets according to the optimum decomposition tree structure, determined through the WPT method. The thresholding is performed on the coefficients of the best tree, to make the denoising process more efficient. The performance of the denoising algorithm is assessed in terms of the Mean Squared Error (MSE) as a measure of the quality of denoisign. The obtained simulation results indicate that the combination of the SWT and WPT achieves superior denoising than the application of each of them separately. The proposed SWPT-based denoising algorithm is efficiently implemented on Xilinx Virtex Field Programmable Gate Array (FPGA).
denoising
stationary wavelets
Wavelet Packet Transform
FPGA
2006
09
01
1535
1547
https://jesaun.journals.ekb.eg/article_111071_b24724be4bd1ce047029169ef6e48c1a.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
OUTPUT FEEDBACK SLIDING MODE CONTROL FOR UNCERTAIN DYNAMICAL SYSTEMS
Abdel-Magid
M. A. Mohamed
The paper presents a method to design sliding mode control for uncertain dynamical system using only output information. Switching surface is designed through system transformations and pole placement technique. The control law that comprises both equivalent and robust components is investigated. System stability is discussed by using Lyapunov function. Illustrative numerical examples are included to show the applicability and simplicity of the suggested method.
2006
09
01
1549
1559
https://jesaun.journals.ekb.eg/article_111073_677d1b800ffa14efdfffe02bddf64b92.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
WATER GATE DYNAMICS AS INFLUENCED BY PARAMETERS OF HYDRAULIC TURBINE SPEED GOVERNORS AND CONTROLLERS
M. Z.
El-Sadek
Gaber
Shabib
Wael
M. Soliman
The paper investigates the effect of hydraulic turbine speed governor parameters on water gates dynamics of the hydraulic turbines. These parameters are water starting time, temporary speed droop, transient time and permanent speed droop. This is done in order to improve the performance of the hydraulic turbine speed governor in power systems and to reduce water gate oscillations. This paper also investigates the application of the conventional and fuzzy logic controller based on the hydraulic turbine speed governor on water gate dynamics. Nonlinear simulations are performed in a 3 machine power system show that influences.
2006
09
01
1561
1573
https://jesaun.journals.ekb.eg/article_111074_cc0e34228d35c705606df52978440629.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
A MODIFICATION OF THE BLUETOOTH E0 STREAM CIPHER
Nawal
El-Fishawy
Ibrahim
El-Docanny
Eman
Soltan
In this paper we propose an modified model for the E0 stream cipher, which is the Encryption system used in the Bluetooth specification. The modified model is manipulated by adding a fifth linear feed back shift register (LFSR) to the main key stream generator of the E0 cipher. The contribution of this modification is indicated in increasing the computational complexity of Ophir Levy and Avishai Wool attack from 285 to 2125.25. Increasing the quality of encryption is also illustrated through different images encryption with the implementation of several measuring factors such as the correlation coefficient, the maximum deviation, and the irregular deviation.
2006
09
01
1575
1590
https://jesaun.journals.ekb.eg/article_111076_c1720210cb284b698d83d83cdd40f71e.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
A SELF-ORGANIZING SCHEME FOR CONTROLLING THE MUSCLE RELAXATION PROCESS
Nabila
M. El-Rabaie
Dr. Hamdi
A. Awad
Tarek
A. Mahmoud
The main roles which are the concern of a clinical anaesthetist are those of drugs induced unconsciousness, muscle relaxation, and analgesia. The first two roles are concentrated in the operating theatre, while the third role is mainly concerned with postoperative conditions. Unlike, measurement of unconsciousness and analgesia the measurement of muscle relaxation process is considerable easier via monitoring of evoked electromyogram (EMG) signals. Among the features characterizing this process, time delay in initiation of muscle relaxation is perhaps the most challenging one. This time delay resulted from the drug circulation around the body and variation of the cardiac output. Another problem called nonlinearity mismatch that is resulted from the wide variability of identified models and their nonlinearity in the socalled pharmacodynamics for relaxant drugs behavior. This nonlinearity is due to the large inter-individual and intra-individual variability of the patient's parameters. These challenges can be treated with quantitative or qualitative techniques. The former was proved ineffective in trying to overcome these challenges. This paper proposes predictive self-organizing Auto Regressive eXogenous (PSO-ARX) scheme to deal with such challenges with ease. This is due to two notable features of the proposed scheme one is its plastic structure and the other is its small computation required compared with Generalized Predictive Control (GPC) schemes. Simulation results reflect the superiority of the proposed PSO-ARX scheme with respect to such schemes.
Neural Networks
Medical systems
Self-organizing controllers
2006
09
01
1591
1604
https://jesaun.journals.ekb.eg/article_111077_414879494069c7a5e40e49fc018cee0b.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
INVESTIGATION OF TWO DIMENSIONAL WAKE PRESSURES DOWNSTREAM OF PERFORATED PLATES
Mohamed
F. Yassin
The construction, calibration and measurements made by a built up static pressure probe for measurement of unsteady pressures in the flow field are discussed. The wind tunnel experiments were conducted on a series of two-dimensional perforated normal plates to an air stream in order to study the characteristics of unsteady wake pressures and to ascertain if they could be correlated in some way. The velocity ranged from 5 to 15 m/s in the present study. The pressure field gets significantly modified as the perforation level increases. The present study is concerned with three plates with perforation level of 0%, 25% and 35%. A correlation between the maximum normalized value of the mean square pressure fluctuation levels, base pressure and the perforation level of the normal plate was done.
Fluctuation pressure
Perforated plate
Wake region
Wind Tunnel
2006
09
01
1605
1612
https://jesaun.journals.ekb.eg/article_111081_0d22fa0cc4f4baf513c97dad017c863c.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
HYDROPYROLYSIS OF OIL SHALE
Adnan
M. Khalil
Oil shale from Ellajjun area southern region of Jordan hydrogenated at different conditions. The impact of temperature on weight loss and product distribution was investigated. The experimental runs were conducted at different temperatures. Hydrogen gas introduced after purging to the retort with nitrogen thus; to avoid oxidization during heating process. A circulating coolant at 2 oC cooled the products. The non-condensable gases were released to the open atmosphere whereas the condensed liquid collected and sent for simple atmospheric distillation at laboratories of Jordan Petroleum Refinery. The rate of weight loss was increased as the temperature increased and the total oil yield increased with increasing temperature at constant hydrogen flow rate. The increasing of reaction temperature resulted in more volume distilled. The effect of temperature on product distribution of the produced shale oil was investigated, the increase in temperature resulted increased the kerosene and residue amount, and a decrease in the amount of diesel, mean while it has no effect on the gasoline – naphtha fraction. The sulfur content of the liquid product was influenced by the presence of hydrogen in reaction environment. The amount of sulfur was increased with the increase of temperature at constant hydrogen flow rate.
Oil shale
fixed bed
sulfur
distillation
Hydropyrolysis
2006
09
01
1613
1621
https://jesaun.journals.ekb.eg/article_111082_6edc50708e81c56cfda27db8f982360c.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
PARKING AREAS IN NEIGHBORHOODS IN EGYPTIAN CITIES: PROBLEMS AND SUGGESTED SOLUTIONS
Esam El-Din
Kamal Mahrous
Most of the Arabian cities, especially Egyptian ones, suffer from the lack of parking areas in most of its parts, due to-high rates of population density. This problem is common in all parts of the city either the city center or inside the residential districts. This problem exacerbates on an annual basis due to increasing car possession, while urban areas in Egypt is limited. The aim of this paper is to find the most important reasons and aspects of parking areas' problem within the residential areas and neighborhoods. The shortage of the legal and administrative aspects, the weakness public transportation systems are considered the most important reasons behind this problem. Consequently, according to the preliminary observations stated above, the research suggests some solutions, which formulate a comprehensive plan to overcome the parking areas' problem in the residential districts and neighborhoods in Egypt.
2006
09
01
1623
1636
https://jesaun.journals.ekb.eg/article_111085_dcc3f10b8023904150f059456d49e266.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
SUSTAINABLE DEVELOPMENT OF OLD AND HERITAGE CITY-CENTERS AND THE CHALLENGES OF MODERN URBAN DEVELOPMENT ( THE CASE OF OLD ASSIUT CITY CENTER )
Esam El-Din
Kamal Mahrous
Mohamed-Ayman
Abd-Elmajeed Daef
Old and heritage city-centres in Egypt represent unique urban entities characterized by historical atmospheres which mostly belong to Arab culture dating to Islamic eras, particularly the Mamloukian period. Singular activities aiming to conserve or restore certain heritage buildings in such areas are usually incapable to achieve the required development objectives. Therefore, adopting a comprehensive sustainable development strategy may represent a proper approach to deal with problems of degradation, and urban and economic deterioration facing old and heritage city-centers. Modern and rapid urban developments in old city-centres have contributed to the loss of cultural and economic values. Therefore, re-use and rehabilitation of such areas in coherence with current social and economic circumstances should be considered as a determining factor in any comprehensive sustainable urban development strategy for the given area. This paper proposes a development programme that comprises many stages: urgent ones aim at preventing rapid deterioration; and consequent stages aim to achieve sustainable development of such important areas of Egyptian cities.
2006
09
01
1637
1649
https://jesaun.journals.ekb.eg/article_111086_b126175630e514d913ab378a99e0c820.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
THE REALITY AND EXPECTATION OF THERMAL INSULATION OF HOUSING BUILDINGS: THE CASE OF RIYADH CITY IN THE KINGDOM OF SAUDI ARABIA
Dr. Ibrahim Ben Rashed
Ben Saad Al-Jowair
Being the largest in land occupation and population, City of Riyadh has the largest number of buildings in the Arab Gulf Countries. The assumption among practitioners that building external walls with insulated cement or adobe block will provide thermal insulation is wide spread. Any thermal insulation to any building should include all external horizontal and vertical structural elements beside windows and doors regardless of the used material or method of construction. The aim of the study is to represent the reality of thermal insulation to the city's housing buildings thorough the clarification of the practitioners' and clients' and related agencies' understanding of building thermal insulation. All necessary data were collected by using sample of housing units selected randomly as well as open-ended interviews to randomly selected practitioners, clients and engineers in the licensing department at the Municipality of Riyadh and the Saudi Electricity Company. Before mandatory application of housing building thermal insulation, it is necessary to implement the following regulations: 1- No issuing of building permit to new housing buildings which its construction drawings do not have a full thermal insulation. 2- The introduction of mandatory site supervision by the designer to insure the full and accurate implementation of thermal insulation. 3- Water and electricity services should be denied to any housing units does not have a written report signed by the Municipality of Riyadh and the consultant office indicating the full implementation of thermal insulation. The Municipality of Riyadh with its current authority can not insure the full implementation of thermal insulation in housing units without the starting the use of Building Occupancy Permits as a toll to insure the inclusion of full thermal insulation in new and old buildings.
2006
09
01
1651
1669
https://jesaun.journals.ekb.eg/article_111089_0e5c23d4060ce9062ac2dd851d9be37b.pdf
JES. Journal of Engineering Sciences
1687-0530
1687-0530
2006
34
No 5
POPULATION GROWTH AND ITS IMPACT ON ENVIRONMENTAL POTENTIALS CASE STUDY: RIYADH CITY – KINGDOM OF SAUDI ARABIA
Dr. Abdel Aziz
Naser El-dawsary
This study aims at reviewing the rates of population growth for the kingdom of Saudi Arabia in general and for the city of Riyadh in particular. This case study is intended to evaluate the changes in growth over the last thirty years, and the extent of its environmental potentials and features such as valleys, mountains, hills, desert areas, and agricultural zones around the city. All that leads to a future vision of a balanced population map which avoids any negative impact. In addition to population growth and congestion, other impacts such as air pollution and noise which results from the heavy traffic generation and the sprawl of the city as the Riyadh’s population increased to exceed four millions, and expected to reach 10.5 millions by 1442 H. It is evident that there is a great need to examine the city’s population growth within a comprehensive study of the Kingdom’s regions which produces migration to the capital. This migration is primarily for job opportunities or for education pursuance or for medical treatment. The main input for this study is the five year plans, and the national urban strategies as well as the regional structural plans to ensure a balanced growth and to limit migrations to large cities, especially Riyadh which reached 8% population growth. Dealing with population growth in Riyadh shall be viewed comprehensively at all levels; national, regional and local. This will be the way to avoid further deterioration of the problem and to ensure a better future environment.
2006
09
01
1671
1688
https://jesaun.journals.ekb.eg/article_111090_b50f5b1a27d3a391c253074d3f2f688e.pdf