ANALYSIS OF TRANSIENT FLOW PHENOMENON IN PRESSURIZED PIPES SYSTEM AND METHODS OF PROTECTION
Nashaat A.
Ali
Civil Eng. Dept, Assiut University, Assiut, Egypt
author
Hassan
Ibrahim
Civil Eng. Dept, Assiut University, Assiut, Egypt
author
Mohamed E.
El-Darder
Civil Eng. Dept, Assiut University, Assiut, Egypt
author
Alaa A.
Mohamed
Civil Eng. Dept, Assiut University, Assiut, Egypt
author
text
article
2010
eng
Water hammer phenomenon is an important consideration in designing of many hydraulic systems due to extreme variations in pressure it causes. For example, the dramatic pressure rise can cause pipes to rupture. Accompanying the high pressure wave, there is a negative wave that can cause very low pressures leading to the possibility of contaminant intrusion or column separation. This paper investigates the effect of different parameters such as fluid density, steady flow velocity, air entrainment, pipeline material type and pipeline friction factor on transient flow in pipeline system due to pump shut down, effect of protection devices on the transient pressure head along the pipeline and effect of existence of a crack in pipeline flow. WHAMO software was used in the analysis which uses the implicit finite difference scheme for solving the momentum and continuity equations at unsteady state case. The study was applied on a pipeline composed of six segments of different diameters and elevations with a total length of 2523 m. The flow is pumped in the pipeline by pumping station to a constant head reservoir at the end of the pipeline. The results showed that many parameters such as fluid density, steady flow velocity, air entrainment, pipeline material type and pipeline friction factor have significant effect on the water hammer phenomenon. Also, it was found that in spite of the non-return valve protects the pump from water hammer effect, increases the pressure head in the pipeline. Surge tank or air chamber fitted at the beginning of the pipeline can protect it effectively from the water hammer effect. At the end, it was found that a crack in pipeline can cause intrusion from outside the pipe to inside and inversely can cause leakage to outside or both.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
323
342
https://jesaun.journals.ekb.eg/article_124369_b6cc8b8176b83bbb7df57f535c5365cc.pdf
dx.doi.org/10.21608/jesaun.2010.124369
EFEECT OF FINE AGGREGA TYPE ON MECHANICAL PROPERTIES OF ADMEXTURED/NON-AMIXTURED CONCRETE
Hassan S.
Abdul-Moghni
Civil Engineering Dept., Faculty of Engineering, Sana'a University, Sana’a, Yemen
author
text
article
2010
eng
This paper reports the results of a study conducted to evaluate the effects of three types of fine aggregates on the compressive and tensile strength of concrete. The three fine aggregates used here are Saddah, Thelaa, and Mareb sands which were named after their sources and they represent the common types being used in broad regions in Yemen. A number of concrete mixes were prepared and tested at the curing ages of 1, 7, 14 and 28 days. Two types of superplasticizers were used with some mixes, named F and G. The results showed that concrete containing Saddah sand had the highest strength capacities in both compression and tension while concrete made with Mareb sand had the lowest strength. On the other hand, it was observed that concrete mixes made with superplasticizers showed higher strengths compared to those made without admixtures.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
343
353
https://jesaun.journals.ekb.eg/article_124371_b3a70a4ee375ebb125a4d86894bf8f10.pdf
dx.doi.org/10.21608/jesaun.2010.124371
BEHAVIOR OF HIGH-PERFORMANCE CONCRETE BEAMS WITH AND WITHOUT FIBER AS AFFECTED BY RIB GEOMETRY OF REINFORCEMENT BARS
Aly Abdel-Zaher
ELsayed
Civil Engineering Department, Faculty of Engineering, Assuit University, Assiut, Egypt
author
Hosny M.
Soghair
Civil Engineering Department, Faculty of Engineering, Assuit University, Assiut, Egypt
author
Mohamed M.
Rashwaan
Civil Engineering Department, Faculty of Engineering, Assuit University, Assiut, Egypt
author
Ali M.
Abdallah
Engineer in the general Authority of Educational Buildings Sohag, Egypt
author
text
article
2010
eng
The need of high-performance concrete is increased in the recent years. Using steel of high grade and maximize the benefit of using these material become necessary, but these material were brittle and the failure also were brittle .So, fibers are used to enhance composite properties. The enhanced properties include tensile strength, compressive strength, elastic modulus, crack resistance, crack control, durability, fatigue life, resistance to impact and abrasion, shrinkage, expansion, thermal characteristics, and fire resistance. .There is little information in the available literature about the flexure behavior of high-performance and high-performance fiber-reinforced concrete beams with different rib geometry under partial bond The main objective of this research is to study the effect of rib geometry for steel bars and fibers types on the flexure behavior of high-performance and high-performance fiber-reinforced concrete beams under partial bond, also Pattern of cracks, final mode of failure and deformational characteristics (deflection, slip, concrete strain and slope for beams) were investigated.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
355
380
https://jesaun.journals.ekb.eg/article_124372_53c99f2ab86079cdd6da3977f17f7ac7.pdf
dx.doi.org/10.21608/jesaun.2010.124372
EVALUATION OF SEISMIC PERFORMANCE OF MULTISTORY BUILDINGS DESIGNED ACCORDING TO EGYPTIAN CODE
Khaled A.
Abdel-Raheem
Civil Engineering, Faculty of Engineering,
Assiut University
author
Shehata E
Abdel Raheem
Civil Engineering Dept, Faculty of Engineering, Assiut University, Assiut 71516
author
Hosny M.
Soghair
Civil Engineering, Faculty of Engineering,
Assiut University
author
Mahmoud H.
Ahmed
Civil Engineering, Faculty of Engineering,
Assiut University
author
text
article
2010
eng
The seismic response of building structures can be estimated by several analysis methods. Each approach incorporates different assumptions and varies in complexity of application. The traditional approach is to employ equivalent static analysis methods while current design practice is moving towards an increased emphasis on nonlinear analysis methods. This study examined the seismic performance of multistory buildings designed according to Egyptian code. Nonlinear time history analysis is used for evaluation of equivalent static and response spectra procedures that recommended by Egyptian codes for seismic design of building structures. In this study, a preliminary seismic response analysis of two buildings was performed using three analysis procedures to evaluate the building seismic performance and the difference in global response predicted by the three methods. Moreover, three analysis procedures are evaluated for their ability to predict deformation demands in terms of inter-story drifts and potential failure mechanisms. Three ground motions of earthquake records are used for seismic demands evaluation of these buildings. The results demonstrated that, for the three analysis methods used in this study, different predictions of seismic response occurred. Furthermore, the results of the analyses are used to evaluate the advantages, limitations, and ease of application of each approach for seismic analysis. Each method is shown to have merits and deficiencies that should be considered when selecting a seismic analysis method for a particular building structure.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
381
402
https://jesaun.journals.ekb.eg/article_112113_e937809e1c1784dcbbf453f55a8222f0.pdf
dx.doi.org/10.21608/jesaun.2010.112113
ROLE OF SHEAR WALLS IN HIGH RISE BUILDINGS
Hamdy H. A.
Abd-el-Rahim
Associate Professor, Civil engineering department, Assiut university
author
Ahmed Abd El-Raheem
Farghaly
Lecturer, Faculty of Industrial Education, Sohag University
author
text
article
2010
eng
The slender high rise buildings are wide spreading in Egypt and no probabilistic assessment procedures have been proposed or developed for seismic risk evaluation of these special buildings. So, the objective of this study is to numerically investigate the role of both edge shear walls and raft foundation projection out of the boundary of building in the seismic resistant of such structures. Several three-dimension models were developed including the subgrade modulus as a variable and the multi-purpose commercial finite element program SAP2000 [6] was utilized for all runs in the current study. The loading is considered using acceleration time history with a peak ground acceleration of 0.25g provided in the new Egyptian code (ECOL2008)[2] for seismic loads on structures and building works. The results conclude that the slender high rise buildings provided with edge shear walls and raft projection insure significant improvement in the induced base shear and internal forces in the raft foundation. On the contrary, the study shows the large values of base shear in the corner columns under seismic loads in a projected raft foundation building. The results give a wide vision that can be used as an aid to the engineer for dealing with such slender high buildings.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
403
420
https://jesaun.journals.ekb.eg/article_124373_f76cddd1a80c54d8fd5a5df5fae29cf6.pdf
dx.doi.org/10.21608/jesaun.2010.124373
INFLUENCE OF REQUISITE ARCHITECTURAL OPENINGS ON SHEAR WALLS EFFICIENCY
Hamdy H. A.
Abd-el-rahim
Associate Professor, Civil engineering department, Assiut university
author
Ahmed Abd El-Raheem
Farghaly
Lecturer, Faculty of Industrial Education, Sohag University
author
text
article
2010
eng
Executions of the shear walls along the exterior perimeter of slender high rise buildings enhance the efficiency of such buildings to resist the seismic forces. But uncertainties in the locations of shear walls are very high because of the demandable architectural openings (windows – doors) in the exterior views of such buildings. So, this study presents a considerable interest in establishing design guide lines for numerical investigation of seismic response of shear walls taking into account such openings and their locations. Five three dimensional models of different configurations of the openings are chosen and compared to figure out the best installation of openings having more efficiency on the performance of shear walls under earthquake excitation. Computer generated models are analyzed by SAP2000 program[11] and the loading is considered using acceleration time history with a peak ground acceleration 0.25g provided in the new Egyptian code (ECOL2008)[13] for seismic loads on structures and building works. The comparative results showed that the top displacement, base shears and stress distributions around the openings depend on the openings arrangement system. The results of staggered opening system in the shear walls (spatial arrangement) are very much close to those resulted in the shear walls without openings than the other opening arrangement cases. Finally the staggered arrangement of openings between the stories in shear walls are suggested to be applied in engineering practice since it satisfies both the architectural and seismic requirements.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
421
435
https://jesaun.journals.ekb.eg/article_124374_a8861ce150df3523e49e4dfa927b14c2.pdf
dx.doi.org/10.21608/jesaun.2010.124374
LIGHTWEIGHT CONCRETE IN YEMEN
Hassan S.
Abdul-Moghni
Civil Engineering Dept., Faculty of Engineering, Sana'a University, Sana’a, Yemen
author
text
article
2010
eng
Light-weight concrete (LWC) has been successfully used since the ancient Roman times and it has gained its popularity due to its lower density and superior thermal insulation properties Compared with normal weight concrete (NWC).The main objective of the present study is to provide some information on properties of light-weight concrete using Yemeni light-weight aggregate, this study covers the use of light-weight coarse aggregate, two types of fine aggregates, superplasticizer and silica fume in concrete. The effects on density, absorption, compressive and splitting tensile strengths of lightweight concrete are reported. The resulting concretes were seen to have densities varying from 1420 to 1760 kg/m3, with the corresponding compressive strengths varying from 13.4 to 22.7 MPa .The results of absorption, show that the mixes containing superplasticizer and silica fume have lower levels of absorption compared to the mixes without admixtures. Further, the mixes made with light-weight fine aggregate have absorption values greater than that mixes made with normal fine aggregate.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
437
447
https://jesaun.journals.ekb.eg/article_124375_33a193bc6fa9ccf9991a5ecd94ed1b1a.pdf
dx.doi.org/10.21608/jesaun.2010.124375
A FRAMEWORK FOR EVALUATING AND COMPARING INVENTORY CONTROL POLICIES IN SUPPLY CHAINS
Mohammad
Abd El-Aal
Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
Mahmoud A.
El-Sharief
Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
Ahmed Ezz
El-Deen
Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
Abo-Bakr
Nassr
Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
text
article
2010
eng
Supply chains, always, face increased uncertainty in demand. For that reason, inventory control presents a critical issue of supply chain management. Controlling inventories with proper policies can enhance customer service levels, smooth production plans, and reduce operation costs. In this paper, a framework is suggested for evaluating and comparing different types of inventory control policies. Four distinct inventory control policies are discussed and modeled. Different types of measures are used to evaluate the performance of the supply chains which implement these inventory control policies; performance measures used are; fill rate, as an example of desired measures (to be increased), and inventory level, as an example of undesired measures (to be decreased). A framework for evaluating and comparing the overall performance of the inventory policy is developed and applied. A discrete event simulation with ARENA simulation package is used for developing a simplified supply chain model consists of two echelons, with one supplier that prepares and supplies raw materials to a production/inventory system, which has two different inventories, one for supplied raw materials, and the other for finished products. A numerical example is provided to illustrate the applicability of the developed framework. The applied numerical example clarified the ability of the evaluation framework to deal with different types of inventory control policies, and different practice scenarios.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
449
465
https://jesaun.journals.ekb.eg/article_124377_12ecbb466181b62f841ddcbdccf49ea3.pdf
dx.doi.org/10.21608/jesaun.2010.124377
INFLUENCE OF AUXILIARY INTAKE VALVE WITH VARIABLE TIMING ON SPARK IGNITION ENGINE PERFORMANCE
S.A.
Ahmed
lecture assistant - Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
A. M.
Ibrahim
Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
F. M.
Wassef
Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
H.
Selim
Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
text
article
2010
eng
A new variable valve timing strategy based on using an auxiliary valve having a variable timing (VVT) is used in this study. The valve is driven by a new VVT mechanism achieving valve duration and opening angle variations. The auxiliary valve acts as intake valve. Experiments and simulation models are carried out at different loads. The results show improvements in brake thermal efficiency, fuel consumption, volumetric efficiency, residual gas fraction and engine emissions over the whole range of load. Swirl and tumble ratios are decreased.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
467
487
https://jesaun.journals.ekb.eg/article_124378_c33f96d6cb47c85b86b5d8e92f722bae.pdf
dx.doi.org/10.21608/jesaun.2010.124378
INFLUENCE OF AUXILIARY EXHAUST VALVE WITH VARIABLE TIMING ON SPARK IGNITION ENGINE PERFORMANCE
S.A.
Ahmed
lecture assistant - Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
A. M.
Ibrahim
Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
F. M.
Wassef
Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
H.
Selim
Mechanical Engineering Department, Faculty of Engineering, Assiut University, 71516 Assiut
author
text
article
2010
eng
New Variable valve timing strategy based on using auxiliary valve having variable timing (VVT) is used in this study. The valve is driven by a new variable valve timing mechanism constructed for this purpose. The auxiliary valve acts as an exhaust valve and the experiments and simulation model are carried out at different loads. The results show that engine performance is improved at full load and worsens at part loads. The study proves that using an auxiliary exhaust valve having variable timing is not recommended in engines applications.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
489
508
https://jesaun.journals.ekb.eg/article_124379_8ab5eaa8b422bcc4526e213a74e92bf3.pdf
dx.doi.org/10.21608/jesaun.2010.124379
CHARACTERIZATION OF A LOW-SPEED WIND TUNNEL SIMULATING URBAN ATMOSPHERES
Hamoud A.
Al-Nehari
Department of Mechanical Engineering, Faculty of Engineering, Assiut University, Assiut 71516, EGYPT
author
Ali K.
Abdel-Rahman
Department of Mechanical Engineering, Faculty of Engineering, Assiut University, Assiut 71516, EGYPT
author
Hamdy M.
Shafey
Department of Mechanical Engineering, Faculty of Engineering, Assiut University, Assiut 71516, EGYPT
author
Abd El-Moneim
Nassib
Department of Mechanical Engineering, Faculty of Engineering, Assiut University, Assiut 71516, EGYPT
author
text
article
2010
eng
A new low-speed boundary-layer wind tunnel has been designed and constructed at the University of Assiut. A series of flow-characteristic evaluations were performed in this wind tunnel to determine the uniformity of flow and to verify its adequacy to simulate the atmospheric boundary layer (ABL) for environmental flow studies and pollutants dispersion in urban atmospheres. This paper presents the measurements of mean velocity and turbulence intensity distributions in the wind tunnel. The measurements showed uniform velocity distributions and low turbulence intensities at the entrance of boundary development section in the empty wind tunnel. The simulated ABL at the entrance of the test section using the Irwin's method that consists of a combination of spires and roughness elements has a thickness up to 500 m corresponding to urban area. The results show that the present wind tunnel is capable to maintain long run steady flow characteristics and reproducible flow patterns. In addition, the capability of the wind tunnel to simulate the flow in the urban area atmospheres is verified by comparing the measured mean velocity and turbulence intensity distributions against its counterparts obtained from Computational Fluid Dynamics (CFD) which employ two-equation k-ε turbulence model around and above buildings model. The numerical results agree well with the experimental data.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
509
532
https://jesaun.journals.ekb.eg/article_124380_9ae0e2da0519e6e25f8ec59eb71d69ee.pdf
dx.doi.org/10.21608/jesaun.2010.124380
COMPOUND IMAGE SEGMENTATION
Ibrahim
Ismail
Professor Doctor Engineer faculty of engineering, Helwan University, Cairo, Egypt.
author
Alaa
Hamdy
Doctor Engineer faculty of engineering, Helwan University, Cairo, Egypt.
author
Seham
Mostafa
Engineer.
author
text
article
2010
eng
Compound document images contain a mixture of natural image and text/graphics. They are very common forms of documents found in magazines, websites, etc. Text and graphics components need special care in the use of compression because text and graphics cannot withstand the significant distortion that is acceptable for natural images. This paper represents a study of different algorithms for segmentation to identify the compound image components. This study focuses on discrete cosine transform (DCT) algorithm, fast Fourier transform (FFT) algorithm, and block based segmentation algorithm; mean, variance, and mean/variance. The segmentation process in general starts with dividing the whole image into non overlapping blocks. Then each block has to be classified either to text/graphics or image via a certain threshold according to the algorithm. the results show that after applying any algorithm the compound image is already classified and the percentage of correct classified text pixels CCPt is calculated and also the percentage of correct classified image pixels CCPi is calculated to present the efficiency of the algorithm, that FFT algorithm is the best one of them that the CCPi between 87.59% in CNN image and 100% in letter image also CCPi between 97.33% TOY image and 100% in leteer image.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
533
546
https://jesaun.journals.ekb.eg/article_124381_2233ca8d1974720d803ba826aa8290a2.pdf
dx.doi.org/10.21608/jesaun.2010.124381
REMEDIAL STRATEGIES OF THE FAULTS IN THE DRIVE CIRCUIT OF AIRCRAFT FUEL PUMP
Ahmed AbdEl-malek
AbdEl-hafez
Lecturer in Electrical department, faculty of engineering, Assiut University
P.O. 71561
author
text
article
2010
eng
This paper is aimed at examining the performance of H-bridges supplying fault-tolerant Permanent magnet machine in the aircraft fuel pump under short circuit condition. A significant DC component flows in the windings with a subsequent of saturation and higher iron losses, which possibly deteriorates the performance of the fuel pump. Expressions are derived to predict the inverter current during the fault. Also, the paper discusses all the possible remedial actions and highlights the most suitable one.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
547
554
https://jesaun.journals.ekb.eg/article_124382_ce8c7c5af432dcf6713a4c4707110c02.pdf
dx.doi.org/10.21608/jesaun.2010.124382
INDIGENOUS ALKHABRA VILLAGE A SUSTAINABLE COMMUNITY
Mohamed
Alnowaiser
Associate Professor College of Architecture& Urban Planning King Saud University
author
text
article
2010
eng
Traditional settlement of Alkhabra is an ideal example of a true sustainable built environment. It is comprehensive, protective, ecological, self-sufficient, and integrated with its natural context. The village spatial fabric displays and an organic hierarchy of various spatial systems with great integration and depth of interaction with all human activities. The spatial-behavioral systems are well intermingled to coordinate between the various human activities with their corresponding domains and their natural environment. This study uses the spatial-behavioral analysis and sustainability approaches at the different hierarchal levels. These include the context, sustainable spatial systems, perceptions, movement, neighborhoods, plazas, streets and dwellings. Also some important themes of spatial security, privacy, sociopetality, environmental protection, and sustainability will be covered.
JES. Journal of Engineering Sciences
Assiut University, Faculty of Engineering
1687-0530
38
v.
No 2
no.
2010
555
567
https://jesaun.journals.ekb.eg/article_124383_bb511242f834840428ddcfa7dfc5252c.pdf
dx.doi.org/10.21608/jesaun.2010.124383