@article { author = {Ahmed, A. Megahid and Hassan, Khairy and Abd-Elrazek, Mostafa}, title = {FLEXURAL BEHAVIOR OF HIGH STRENGTH OVER REINFORCED CONCRETE BEAMS UNDER STATIC & REPEATED LOADING}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1351-1380}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114572}, abstract = {The Flexural behavior of over reinforced sections is faster grown due to the popular retrofit technique among researchers and engineering worldwide. The main purpose of this work is to give a better and full understanding of the flexural behavior of over reinforced high strength concrete beams subjected to both static and repeated loading. Experimental tests were carried out on different beams having different grades of concrete and percentages of main steel under static or repeated loads. Concrete and steel strains and central deflection of cracking and ultimate loads were recorded for each tested beam. It is shown that the flexural behavior of over reinforced beams under repeated loading is quite different than that under static loading.}, keywords = {}, url = {https://jesaun.journals.ekb.eg/article_114572.html}, eprint = {https://jesaun.journals.ekb.eg/article_114572_a0cd9645dc044a092e3a24df5f06ff3f.pdf} } @article { author = {Abd El-Naiem, Mostafa Abdou and Abo El-Wafa Mohamed, Waleed}, title = {BEHAVIOR OF EXISTING TUNNEL DUE TO THE CONSTRUCTION OF A NEW TUNNEL PASSED PARALLEL UNDER IT}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1381-1400}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114576}, abstract = {The study of the behavior of existing underground structures, such as transportation tunnels, due to construction of a new tunnel is an engineering problem of soil-structure interaction. Many problems arise when parts of a new construction tunnel cross under, or near an existing tunnel during the construction. One of these problems is expected to occur related to soil stability around a new construction tunnel and between new and an existing one. Even though in engineering practice tunnels are often designed considering only static or quasi static (creep), loading conditions, a non-negligible research effort has been devoted to investigate their behavior in near-field construction conditions. In the present study, the behavior of existing tunnels under passed by a new construction one by using Finite Element Method has been studied. The tunnel lining is meshed with two dimensional elements, called BEAM 6 element. The soil is meshed with two dimensional elements called LST, (Linearly Varying Strain Triangular Element. In this study, the main parameters were taken into consideration are excavated tunnel diameter (D2), soil thickness between tunnels (H), and horizontal distance (X). The results obtained from this study were compared with the initial values obtained from case of no tunneling under the existing tunnel.}, keywords = {Tunnel,soil-structure interaction,Finite element method,stresses,Forces,deformation,Construction}, url = {https://jesaun.journals.ekb.eg/article_114576.html}, eprint = {https://jesaun.journals.ekb.eg/article_114576_b60e58a010232a5b56d0dc4252a3b7ad.pdf} } @article { author = {A. Aly, Ayman}, title = {FLOW RATE CONTROL OF VARIABLE DISPLACEMENT PISTON PUMP WITH PRESSURE COMPENSATION USING NEURAL NETWORK}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1401-1412}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114595}, abstract = {One of the most important components in hydraulic circuits is the pump that generates hydraulic power supply. The performance and the versatility of a variable displacement piston pump are, to a large extent, determined by its controller. Upgrading of existing controllers is considered one of the major means of improving the characteristics of the pump. The dynamic performance of hydraulic systems with a demand flow supply not only depends on the performance of the flow modulation valve, but also on the performance of the pump. In this study, the performance of soft computing methodology, trained Neural Network (NN) based on the conventional PID controller, is used for the control of a swash plate displacement while the compensation of the effect of the back up pressure is implemented by inverse NN model. The feasibility of system is simulated and issue of implementation such pumps control is established. It is seen that the use of the proposed methodology results in some desirable characteristics.}, keywords = {Flow Rate Control,Neural network,Variable Displacement Axial Piston Pump,Inverse Model}, url = {https://jesaun.journals.ekb.eg/article_114595.html}, eprint = {https://jesaun.journals.ekb.eg/article_114595_a4c70d093eaf2f3dbc9f85f353343391.pdf} } @article { author = {A. Aly, Ayman}, title = {A NON LINEAR OPTIMAL PID CONTROL OF A HYDRAULIC CRANE}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1413-1426}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114596}, abstract = {In this work, an adaptation-based method for deriving tuning guidelines for proportional-integral-derivative (PID) controllers that take explicitly into account the presence of nonlinear behavior is proposed. The central idea behind the proposed method is to adjust the PID controller parameters to force the nonlinear system response to follow a second order critically damped model reference (MR). The design method starts by using classical tuning guidelines (typically derived on the basis of linear approximations) to obtain reasonable bounds on the tuning parameters. A modifier technique will produce a correction signal to upgrade the PID controller signal to eliminate the relative error between the nonlinear system and the MR. The efficiency of the proposed tuning method is demonstrated through application to a hydraulic crane which is inherently nonlinear and contains components exhibiting strong friction, saturation, variable inertia mechanical loads, etc. The characteristics of these non-linear components are usually not known exactly as structure or parameters. It is found that the MR-PID control policy provided the most consistent performance in terms of rise time and settling time with set-point changes regardless of the nonlinearities characteristics.}, keywords = {optimal control,Nonlinear PID Control,Model Reference,Hydraulic Crane}, url = {https://jesaun.journals.ekb.eg/article_114596.html}, eprint = {https://jesaun.journals.ekb.eg/article_114596_dfc655de7c2618d897220528dd67e7b9.pdf} } @article { author = {Abdelrazek Khalil, Khalil}, title = {MECHANICAL PROPERTIES AND MICROSTRUCTURAL BEHAVIOR OF HYDROXYAPATITE/TIO2 ELECTROSPUN NANOFIBERS CONSOLIDATED USING HIGH FREQUENCY INDUCTION HEAT SINTERING}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1427-1441}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114598}, abstract = {In order to improve fracture toughness of hydroxyapatite (HAp), TiO2 electrospun nanofibers were used as reinforcement. TiO2 nanofibers with diameters of 50–400 nm were first prepared by calcining and presintering of electrospun nanofibers of polyvinyl acetate (PVac)/Titania composite at different temperatures. The composite of HAp with 5 wt % of electrospun TiO2 nanofibers were then sintered by high frequency induction heat sintering technique. Mechanical properties were evaluated by three-point bending tests, indentation tests and compression test. The results indicated that the morphology and crystalline phase of TiO2 nanofibers were strongly influenced by the calcination temperature. Additionally, the SEM results showed that the nanofibers calcined at 600  C are porous structure due to the low densification. There was a significant change of microstructure with increasing calcination temperature to 800  C. The nanofibers were appeared with dense microstructure due to the high temperature calcination. A number of large size particles or particle aggregates connected by a small neck were found after the nanofibers were calcined at 1000 ◦C. The sintering behaviors, toughness and hardness of the resulting composites were significantly affected by the calcinations temperature of the included TiO2 nanofibers. The bending and compressive strength values of HAp/5 wt. % TiO2 composites sintered at 1050  C were 119 and 120 MPa respectively, when the calcination temperature of the TiO2 nanofiber was 800  C, while the strength is decreased with decreasing or increasing calcination temperature than 800  C.}, keywords = {Hydroxyapatite,Electrospinning,Nanofibers,Consolidation,Mechanical Properties,Microstructure}, url = {https://jesaun.journals.ekb.eg/article_114598.html}, eprint = {https://jesaun.journals.ekb.eg/article_114598_e7093c2fcfb7f436bd156f489ebf46fd.pdf} } @article { author = {Saad, E. M. and Keshk, H. A. and Saleh, M. A. and Hamam, A.A.}, title = {SCHEDULING HARD REAL-TIME TASKS WITH PRECEDENCE CONSTRAINTS ON MULTIPROCESSOR SYSTEMS}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1443-1453}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114578}, abstract = {In this paper, a scheduling algorithm based on deadline time and precedence constraints was developed to schedule hard real-time tasks on multiprocessor systems. The real-time tasks are characterized by their arrival time, deadline time, computation time and precedence constraints. Scheduling problem for these tasks has been solved to determine the order of scheduling tasks on the processors to minimize the overall computation time, and obtain speeding up. The effectiveness of the developed algorithm is shown through a simulation study.}, keywords = {Task Graph,Optimization,Real-time system,Parallel processing,multiprocessor scheduling}, url = {https://jesaun.journals.ekb.eg/article_114578.html}, eprint = {https://jesaun.journals.ekb.eg/article_114578_390c60b5178dec9f2f59302049e83a57.pdf} } @article { author = {Noureldeen, Omar}, title = {EFFECT OF GEOMETRICAL ARRANGEMENT OF POWER TRANSFORMER INSULATION AND ITS TEMPERATURE ON DIELECTRIC RESPONSE MEASUREMENTS}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1455-1465}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114579}, abstract = {This paper investigates the modelling of dielectric response measurements for power transformer condition assessment. The insulation of a power transformer consists of oil and cellulose (insulation paper). The dielectric properties of both materials generally change during the life of the transformer and dielectric measurements have therefore been applied to assess the quality of the transformer insulation system. Recently, a new method, the Frequency Domain Spectroscopy (FDS) measurements, has been applied which is based on the measurements of the dielectric response of the insulation in the frequency domain. In this paper, the effect of transformer insulation geometry and the insulation system temperature on the transformer insulation properties are studied. Different transformer insulation geometrical arrangements and their temperatures are simulated using the dielectric spectroscopy program MODS from General Electrical company (GE). It is used to model different cases of insulation geometry arrangement by changing the percentage ratio of oil and paper of insulation.}, keywords = {geometrical arrangement oil-paper insulation,dielectric response,frequency domain spectroscopy,real and imaginary permittivity,dielectric loss}, url = {https://jesaun.journals.ekb.eg/article_114579.html}, eprint = {https://jesaun.journals.ekb.eg/article_114579_75867d440c58a1b1bfef5fffc43be84f.pdf} } @article { author = {EL-Sadek, M. Z. and Abdo, A. and Mohammed, M. A.}, title = {ADVANCED MODELING OF FACTS IN NEWTON POWER FLOW}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1467-1479}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114590}, abstract = {The latest generation FACTS controller named the convertible static compensator (CSC) was recently installed at the New York Power Authority (NYPA) Marcy substation as part of a project that will increase power transfer capability and maximize the use of the existing transmission network. Within the general framework of the CSC, two innovative FACTS controllers are used. The static synchronous series compensator (SSSC) coupled with a transformer is connected in series with a transmission line. The interline power flow controller (IPFC) combining at least two converters, can be configured. Mathematical models of the SSSC and the IPFC and their implementation in Newton power flow are reported. Numerical results based on the IEEE 30-bus are presented to demonstrate the performance of the Newton power flow algorithm with incorporation of the SSSC and IPFC.}, keywords = {Flexible AC Transmission System (FACTS),static synchronous series compensator (SSSC),interline power flow controller (IPFC),Newton power flow}, url = {https://jesaun.journals.ekb.eg/article_114590.html}, eprint = {https://jesaun.journals.ekb.eg/article_114590_81960d5d0e992b7cc5248fe1f82c57fe.pdf} } @article { author = {M. Hassan, Mohamed and A. Aly, Amer and F. Rashwan, Asmaa}, title = {DIFFERENT IDENTIFICATION METHODS WITH APPLICATION TO A DC MOTOR}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1481-1493}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114591}, abstract = {Neural networks and fuzzy inference systems are becoming wellrecognized tools of designing an identifier / controller capable of perceiving the operating environment and human operator with high performance. The purpose of this paper is to identify different models for a DC-servo system using the previous identification methods and linear identification methods as ARX, ARMAX and state space models. The paper compares between these methods and presents the practical results for the application these methods.}, keywords = {identification,Neural network,neuro-fuzzy,DC motor}, url = {https://jesaun.journals.ekb.eg/article_114591.html}, eprint = {https://jesaun.journals.ekb.eg/article_114591_d88b0a2f66837b52c96b1eda74b7c303.pdf} } @article { author = {Saad, E. M. and El Ghandour, Dr. Osama and M. K, Jehan,}, title = {EVALUATION OF QOS IN UMTS BACKBONE NETWORK BY USING DIFFERENTIATED SERVICES}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1495-1509}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114592}, abstract = {A distinguishing feature of the Universal Mobile Telecommunications System (UMTS) is the support of different levels of quality of service (QoS) as required by subscribers and their applications. To provide QoS, the UMTS backbone network needs an efficient QoS mechanism to provide the demanded level of services on UMTS network. We implement a model to investigate end-to-end quality of service (QoS) provisioning approaches for UMTS networks in a DiffServ IP network environment. The effort was put on QoS classes mapping from DiffServ to UMTS, Access Control, buffering and scheduling optimization. The DiffServ Code Point was utilized in the E2E UMTS QoS provisioning to differentiate different types of traffic. We hybridized our work by applying Resource reservation protocol (RSVP) in routers and hosts. The main advantages and drawbacks are discussed. We found that our proposed model (hybridized model (DiffServ/RSVP)) improves the end-to-end delay and end-to-end variation compared with DiffServ model only, and it is superior to DiffServ regarding to throughput, utilization and packet loss ratio. The overall work guarantees the E2E QoS parameters of each service class, especially for real-time applications and improved the bandwidth utilization. Simulation results show that DiffServ can be an effective candidate for UMTS backbone bearer service.}, keywords = {UMTS,DiffServ,End-to-End QoS,Scheduling,OPNET,QoS Metrics}, url = {https://jesaun.journals.ekb.eg/article_114592.html}, eprint = {https://jesaun.journals.ekb.eg/article_114592_309b041adec81d7087b64ea010c9c0ed.pdf} } @article { author = {Thomas, Jean and W. Gomma, Hesham}, title = {ATTAINABILITY TECHNIQUE BASED ON POLYHEDRAL APPROACH: APPLICATION TO HYBRID TEMPERATURE CONTROL SYSTEM}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1511-1523}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114593}, abstract = {This paper presents a new attainability technique based on a polyhedral approach for hybrid systems. The main aim of the proposed technique is to obtain a robust-control closed loop system with attainable behavior under all possible and allowable disturbances. Moreover, and in contrast to existed approaches, this technique considers a new switching mechanism that allows the exploration of all different sub-models of piecewise affine systems that represent the interaction between continuous and discrete parts in the hybrid systems. The proposed technique is applied to a temperature control system to examine its ability in providing a reliable attainability.}, keywords = {}, url = {https://jesaun.journals.ekb.eg/article_114593.html}, eprint = {https://jesaun.journals.ekb.eg/article_114593_47e0e801f051d21f26bb88f1b15220c4.pdf} } @article { author = {I. Abdel-Rasoul, Elseman}, title = {STUDY OF SOME FACTORS AFFECTING DETERMINATION OF DYNAMIC ELASTIC CONSTANTS OF ROCKS}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1525-1540}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114599}, abstract = {Measurements of the seismic wave velocities as well as the density of the rock material are necessary for calculating dynamic elastic constants. Correct determination of the dynamic elastic constants is the base for correct calculation of dynamic strains and stresses. These calculations use equations that haves been formulated according to some assumptions. This study investigates the effect of the assumptions of 1-D and 3-D wave propagation on the magnitudes of the estimated dynamic elastic constants. Also some relations between densities, seismic velocities, velocity ratio, Poisson’s ratio, Young’s modulus, and shear modulus will be developed. The study depicted a significant effect of the assumption of 1-D or 3-D wave propagation on the calculated magnitudes of the dynamic elastic constants and came up with some useful relationships between the above mentioned parameters.}, keywords = {Rock density,seismic wave velocities,dynamic elastic constants,dynamic stress and strain}, url = {https://jesaun.journals.ekb.eg/article_114599.html}, eprint = {https://jesaun.journals.ekb.eg/article_114599_e2403bb04d9b70262323041f78251fc8.pdf} } @article { author = {S. Ahmed, Sameh and Durucan, S.}, title = {A METHODOLOGY TO DETERMINE THE OPTIMUM SAMPLING FREQUENCY FOR CONTINUOUS WATER QUALITY PARAMETERS}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1541-1558}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114600}, abstract = {This paper presents a methodology for determining the optimum sampling frequency using long-term monitoring data, with a high sampling frequency, from a real field case in an industrial site. The initial data used in the development of the methodology using Fast Fourier Transformer (FFT) was obtained from an already established continuous surface water monitoring location for conductivity variable. The methodology was later applied to the laboratory test data of different Reference TUBERs provided by two industrial companies. The suggested methodology aims at providing a guideline for the suitable sampling frequency for some water quality parameters such as: (temperature, pH, electrical conductivity, dissolved oxygen, nitrate, and chloride, as they are being monitored around mining and landfill sites. Results showed that the current sampling interval could be increased by 4 times for some parameters and more for others without much change in the main information recorded in the final output signal.}, keywords = {Sampling frequency,water quality parameters,FTT,power spectrum density}, url = {https://jesaun.journals.ekb.eg/article_114600.html}, eprint = {https://jesaun.journals.ekb.eg/article_114600_823e986bd45d00fed5acccfa53664b96.pdf} } @article { author = {S. Ahmed, Sameh and El Tahlawi, M. R. and Rashad, M. Z. and Saleem, H. A.}, title = {KRIGING TECHNIQUES AND GIS FOR MANAGEMENT OF PHOSPHATE EXTRACTION AT HAGARIA DISTRICT, EGYPT}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1559-1574}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.114601}, abstract = {Ordinary Kriging (OK) and Indicator Kriging (IK) techniques were used in conjunction with Geographic Information System (GIS) to understand the spatial distribution and variation of the P2O5% and phosphate thickness at Hagraria district, Egypt. The aim is to aid mining engineers in identifying the best areas that have high and low values of P2O5% with their associated thickness in order to manage the extraction scheme. This paper illustrates how the kriging results can be interpreted easily when they are integrated with other geological and mining data using suitable Geographic Information System. Both OK and IK were examined with the available data from the study area to estimate the two variables affecting the quantity and quality of phosphate; Additional information such as geological feature, boundaries of the area and sampling locations were integrated with the Kriging results and a GIS software (ARC/GIS 9.0) has been used to create contour and sensitivity maps that delineate the relative magnitudes of the measurements recorded at the study area, so a better management of the phosphate extraction could be planned.}, keywords = {Ordinary Kriging,Indicator kriging,Hagaria,P2O5,GIS}, url = {https://jesaun.journals.ekb.eg/article_114601.html}, eprint = {https://jesaun.journals.ekb.eg/article_114601_6363b462c41737d1e638ae0b17a930af.pdf} } @article { author = {Jamal Jamil, Samira}, title = {THE ARCHITECTURAL AND CONSTRUCTING TREATMENTS FOR THE CLIMATIC AND ENVIRONMENTAL FACTORS}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1575-1596}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.115579}, abstract = {Is the personification and the modification of these solutions, in accordance to our climate that provide our environment and architecture with the real sense that we search for to form our modern architecture to be the extension for our cultural and civil heritage.}, keywords = {}, url = {https://jesaun.journals.ekb.eg/article_115579.html}, eprint = {https://jesaun.journals.ekb.eg/article_115579_de1eebddb1298ae2efd15cef8b33fb5b.pdf} } @article { author = {Nasser Barashed, Khaled and Salem EL-Azab, Sabet}, title = {DEVELOPING THE TRADITIONAL METHODS FOR MODERNIZATION AND MAINTENANCE THE MUD BRICK HOUSE (THE CITY OF SHIBAM HADHRAMOUT AS A MODEL)}, journal = {JES. Journal of Engineering Sciences}, volume = {35}, number = {No 6}, pages = {1597-1615}, year = {2007}, publisher = {Assiut University, Faculty of Engineering}, issn = {1687-0530}, eissn = {2356-8550}, doi = {10.21608/jesaun.2007.115581}, abstract = {Yemen in general and Hadhramout in particular is replete with a rich cultural, tradition and ancient heritage. The most important one is the clay architecture arts; in Hadhramout there are many of the examples of the clay architecture such as some existed cities full of life. The most famous and important one is the Historical City of Shibam with its wall. Shibam with its palaces, fortresses, towers and houses with over 500 years of age. Their altitude reaches up to eight floors. They are considered the oldest altitude skyscrapers in the world. Despite that the city is inhabited but its buildings still need maintenance. Also the existence of its buildings in an old architecture environment makes them suffer from physical infrastructure limitations and their inability to meet the emerging needs of life and the prosperity of modern health services - such as health services, spacious rooms and other requirements of the Modern House in addition to ongoing maintenance requirements. This made them vulnerable to emigrate and serious neglect, and hence the deterioration and oblivion. Despite their traditional expertise for hundreds of years in building operations and maintenance, but there were some errors and deficiencies in circulation across generations need to be correct and re-examined in order to access to scientific solutions in the industry of mud bricks, roofing, and the outside layer (the coating) as well as addressing the cracks and mud building diseases . This research aims to study the buildings-maintenance of the historical city of Shibam Hadhramout, at this time as a model for ways to restore mud buildings with the traditional methods to come up with recommendations aimed to develop the maintenance and modernization of the house in a steady scientific method . }, keywords = {maintenance,repair,mud buildings,the city of Shibam Hadhramout,Yemen}, url = {https://jesaun.journals.ekb.eg/article_115581.html}, eprint = {https://jesaun.journals.ekb.eg/article_115581_10fcd4e11ff96d3c5c9c38c35e4bb75d.pdf} }