MULTICRITERIA GROUP DECISION MAKING BASED EXPERT SYSTEM: FRAMEWORK
Ahmed A.
Elsawy
Basic Engineering Science Department, Faculty of Engineering,
Menoufia University, Egypt.
author
Waiel F.
Abd El-Wahed
Basic Engineering Science Department, Faculty of Engineering,
Menoufia University, Egypt.
author
text
article
1998
eng
This paper presents a framework of a decision support system (DSS) with multicriteria group decision making (MCGDM) using both mathematical programming and expert system (ES). The study indicates the implementation of multicriteria techniques through group decision making in DSS. The main advantage of this framework is the combination of both the mathematical programming and expert system in a hybrid approach to achieve the interaction between the solution procedure and decision maker through group decision making.
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
1
8
https://erjm.journals.ekb.eg/article_72461_77c056afff326c8d883775608cc70143.pdf
dx.doi.org/10.21608/erjm.1998.72461
FATIGUE BEHAVIOUR OF AL-12 % Si/SiC, COMPOSITE PRODUCED BY SQUEEZE CASTING TECHNIQUE
A. M.
ABO EL-AINENE
Prod. Eng. & Mach. Design Dept., Faculty Of Engineering ,
Menoufia University Shebin El-Kom, Egypt.
author
text
article
1998
eng
In the present work, the fatigue behaviour of a- 12% SiISiC, composite containin (10% wt) Sic, particles have been compared with Al- 12% Si alloy. Dis f ocation structure and microprocesses of fatigue crack initiation and propagation in the composite have been investigated using SEM and TEM. The cyclic stress res onse characteristics and fkacture behaviour of the composite were7also stu a ied. The obtained results showed that the fatigue stren h at 10 cycles of the com osite is 1105 MP,, i.e. about 28.6% higher t ff an matrix alloy. The voids an d' microcracks initiated at and near the interface between Sic, and matrix, where the higher density dislocations are presented, will propagate and link up to form the fatigue crack. Cyclic response of the composite revealed hardening to failure at all strain amplitudes. The fatigue fracture sf the composite exhibits a macroscogical~y brittle characteristic at dl strain amplitudes, but has local matrix ductility.
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
9
20
https://erjm.journals.ekb.eg/article_72464_3299b1b98527ef782053db3b58628a0d.pdf
dx.doi.org/10.21608/erjm.1998.72464
FATIGUE BEHAVIOUR OF AL/SiC FIBERS COMPOSITES PRODUCED BY SQUEEZE CASTING TECHNIQUE
A.M.
ABO EL-AINENE
Prod. Eng. & Mach. Design Dept., Faculty Qd Engineering ,
Mensufia University Shebin El-&m, Egypt,
author
text
article
1998
eng
In the present work, the fatigue behaviour of pure aluminium reinforced with Sic fibers composite has been investigated. The composite was fabricated by squeeze casting technique with different values of fibers volume fraction Vf. Rotating bending fatigue test was used to compare the fatigue strength of the composite with matrix material. Fatigue fracture hrfaces of specimens were investigated by macroscopic and SEM observations. The influence of volume fraction of fibers on the fatigue life was discussed. The obtained results showed that, in comparison with pure aluminium, the fatigue strength at 10' cycles of the composites is superior by 9 1.3% and 90.2% fbr Vf = 45% and Vf = 3 5% , respectively. Fatigue crack does not propagate along the fibers-matrix interface, he propagates in the matrix. The fatigue strength ratio of Sic/& composites indicated about 0.71.
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
21
30
https://erjm.journals.ekb.eg/article_72466_4242fa01e2cc2beb47b40376f850978c.pdf
dx.doi.org/10.21608/erjm.1998.72466
جهد المقل العامل في تنقيح المعجم الوير الشامل للمصطلحات الفنية للهندسة والتکنولوجيا والعلوم
text
article
1998
eng
تعريب مصطلحات العلوم والتقانات والفنون في التعليم العالي والبحث العلمي فريضة وضرورة. والعربيةلغة فريدة في تراکيبها واشتقاقاتها، جميلة في کسها، عذبة في نطقها، ولا غرو فهي لغة القرآن الکريم ولغة الفائزينبالنعيم المقيم في جنات رب العالمين. وقد سبق لأمة العرب ومن آمن بالمصطفى * من أمة العجم أن کانوا إلى المعاليسابقين، ومن ناصية العلوم والفنون متمکنين، حتى إن البعوث من أوروبا کانت تستنهض إلى بلاد الإسلام لتستفيمن نبع المعرفة الصافي الذي استمد قوته وعذوبته من تعاليم الإسلام، يوم کانت هذه التعاليم الهيمنة الکامل علىالقلوب والجوارح.وقد کان الاتحاد المهندسين العرب فضل التنادي إلى إصدار مغجم موخير شامل اللمصطلحات العلميةوالفتية يتم الله به شغث العلماء والباحثين والدارسين في شرق بلاد الأمة العربية وغربها، وکان المؤسسة الکويتللتقدم العلمي فضل الوفاء بمتطلباته المادية والإشراف على إصداره. ولقد يسر الله تعالى صدور المعجم الوځالشامل للمصطلحات الفنية للهندسة والته و في أحد عشر جزء استغرقت ما يقارب 5500 صفحةوالعجم الوځ عمل کبير مننقص، إما لقصور في تنفيذ خطة إخراجه ومنهج إنشائي، وإما لک السنين عليوقد مضي على صدوره عشر سنواتتغير فيها وجه کثير من االعلوم الحديثة ومصطلحاتها، بل صار العصر کله
للتقدم العلمي فضل الوفاء بمتطلباته المادية والإشراف على إصداره. ولقد يسر الله تعالى صدور المعجم الوځيالشامل للمصطلحات الفنية للهندسة والتکنولوجيا و العلوم في أحد عشر جزء استغرقت ما يقارب 5500 صفحةوالمعجم الموحد عم کبير لم يخل من نقص، إما لقصور في تنفي خطة إخراجه ومنهج إنشائي، وإما لک السنين عليهوقد مضي على صدوره عشر سنوات تقريبا تغير فيها وجه کثير من العلوم الحديثة ومصطلحاتها، بل صار العصر کلهيوصف بوصفي لم يکن لفظه قبل عقدين من الزمان معروفة، ألا وهو وصفه بعصر المعلومات Informatics.AgeOوالبحث الذي بين أيدينا هو حصيلة ما يزيد على العامين من العمل الشاق - دون تکليف من بشر - فيتنقيح هذا المعجم النافع وتصويب أخطائه العديدة التي تزيد على 10% من مجموع مواده. وقد عضدت هذا العملخبرة عشرات السنين من التدريس في الجامعات والدراسة بها، بالإضافة إلى التطفل على مآدب أساتذة علوم القرآنوفقهاء اللغة. نسأل الله تعالى أن يجعل هذا العمل نافعة لأمتنا، وأن يجعله خالصا لوجهه تعالى، إنه سبحانه الجواد
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
31
52
https://erjm.journals.ekb.eg/article_72755_35658ddd777bb349cc7d2353085765a1.pdf
dx.doi.org/10.21608/erjm.1998.72755
Optimizing Feedback Coefficients Of A Practical Synchronous Generator Nonlinear State Observer Using Additional Signals
H. A.
Nour Eldin
Group of Automatic Control and Technical Cybernetics, University of Wuppertal,
Germany
author
F.
Fischer
Group of Automatic Control and Technical Cybernetics, University of Wuppertal,
Germany
author
A. M,
Abdel-Hamid
Department of Electrical Engineering, Faculty of Engineering, El-MonouJia University,
Shebin El-Kom, Egypt (Since 1996 on leave for Post-Doctoral visit at the University of
Wuppertal, Germany)
author
text
article
1998
eng
Synchronous generators are characterized by a nonlinearly interacting electrical and mechanical dynamics. Accurate and robust state reconsh-uction of this machine by an observer should be based on its nonlinear dynamic behavior to avoid intolerable errors. The authors of this paper had published a methodical design of a fill1 order nonlinear observer for turbogenerator systems and organized its experimental validation on a 120 MVA and 1000 MVA synchronous generators at Gud-Power Station in south Munich (Germany) and the Nuclear Power Station of Gosgen (Switzerland), Measured results from these power stations have proved a quite effectiveness of the proposed methodology on getting a stationary robust state reconstruction. However, some transient results are characterized with state oscillations. To prevent such transient oscillations, this paper introduces an optimum technique for the selection of the observer feedback constants. Moreover, additional signals, such as real, reactive and apparent power as well as the amplitude of the stator current are used for the observer feedback. These signals have proved to enhance damping of the observer states transient oscillations.
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
53
69
https://erjm.journals.ekb.eg/article_72469_a8147359f9b5523fb2e2c33d78e6dd7b.pdf
dx.doi.org/10.21608/erjm.1998.72469
A microprocessor-based Load voltage control using an AC chopper
A.S.
ZEIN EL DIN
department of Electrical Engineering, Faculty of Engineering, Menoufia University,
Shebin El-kom, Egypt.
author
Z.
MOHAMED
department of Electrical Engineering, Faculty of Engineering, Menoufia University,
Shebin El-kom, Egypt.
author
A.A.
EL-HEFNAWY
department of Electrical Engineering, Faculty of Engineering, Menoufia University,
Shebin El-kom, Egypt
author
A.S.
ABDEL-GHAFAR
department of Electrical Engineering, Faculty of Engineering, Menoufia University,
Shebin El-kom, Egypt
author
text
article
1998
eng
Pulse width Modulated (PWM) control technique for an a-c choppers using harmonic elimination method is proposed. The firing switching instants of a-c chopper for the proposed technique is derived theoretically. By using a microprocessor as a controller, makes it possible to store the firing switching instants time as a look-up table for different load voltage values. Two MOSFET's are used as an a-c chopper. Experimental results verifying the simulation analysis of the a-c chopper fed static (R-L) load and dynamic load (1-ph. induction motor). The proposed strategy is low cost, simplified, and control effective.
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
71
89
https://erjm.journals.ekb.eg/article_73018_0b02e9ccedb2fb27c2cd8cc6e4b81fbd.pdf
dx.doi.org/10.21608/erjm.1998.73018
A THEORETICAL STUDY OF A THERmOSYPHON SOLAR TOWER
A. A.
El-haroun
Mechanical Power Eng . Dept., Facluty of Engineering, Menoufia
University, Egypt
author
text
article
1998
eng
Thermosyphon solar tower can be used to increase the vehcit.y of air and consequently the specific power in locations with reasonable value of sdar radiation intensity when there ip a no enough area beside the tower to construct a solar collector. In this case the tower itself works as a collector. In this work the possibility of generating power by using a very high tower, haviing reciafiyula~ CLUSS section, open to the atmosphere at the top and bottolri and heated by the uur;, was studied theoretically. In this study, the eEect uf tower height, IJJW~L leugth, tower dep~h, suldr radiatiori intensity ard inlec. ~AL I~~tlgerature orr tile performance ui lie tower wab LLL vtisi;;cpL;;LZ. It was found that, the temperaf:.ure inside the tower increases by the irlcreaue in sular. radiaLir)n ia.r.Lein&.y, id& uir ierr~perature and tower height and decreases by the rise in tower length as well as in tower depth. The iibt ate vdociLy tcl tLa towex and consequently specific power was found to be x..aised by the growth in. tower height and scllar radiiitien intensity, and it is found to be decreased by the enlargement in tower length, tower depth and temperature of air at the inlet of the kower. The inlet air velocity and the specific power for tower height of 500 in were found LO La 5.2 &rid 141 times d their values ~OK 56 111 towef- height respectively. For solar radiation intensity of 1000 W/ni , the inlet air we1uc:ity anti the specific puueL a~ti cyected to Le 1.32 and 2.28 times of tiieir vdlues fur 200 W/m solar radiation intensity respectively.
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
91
104
https://erjm.journals.ekb.eg/article_73023_4d761f2cf783e015525dd532ed4ca46f.pdf
dx.doi.org/10.21608/erjm.1998.73023
Flow Past a Grooved Circular Cylinder
Gamal H.
Moustafa
Mechanical Power Engineering Dept.
Faculty of Engineering
Menoufia University, Shiben El-Kom
EGYPT
author
A. M.
Alam El-din
Mechanical Power Engineering Dept.
Faculty of Engineering
Menoufia University, Shiben El-Kom
EGYPT
author
text
article
1998
eng
An attempt is made to clearly distingxish the effect of a groove shape on the aerodynamic characteristics of a circular cylinder. The grooves are used as a passive control for the boundary layer separation. Grooves of different cross section shapes are made on the cylinder surface to investigate the effect of a regular surface configuration and to elucidate the flow structure in the wake region where the effect ofgrooves is existed. The results show that the grooves greatly affect the location of the separation point in which a shift of the flow regime to lower Reynolds number is found. The subcritical, critical and supercritical regimes can easily identified from flow measurements. It is found that the critical Reynolds number for tested grooved cylinders is 5x10~ which are below the subcritical Reynolds number of a smooth cylinder. The critical Reynolds number for a smooth cylinder is 3x10'. The main features of the boundary layer development are quit the same as that of the smooth cylinder. The boundary layer thckness and shape factor are large for grooved cylinders compared to that of the smooth cylinders and these results are in good agreement with previous available data.
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
105
119
https://erjm.journals.ekb.eg/article_73025_07e1730a00c3172ec901f95220bd7f83.pdf
dx.doi.org/10.21608/erjm.1998.73025
Modeling and Simulation of the Shape Error in the ECM Process
K. P.
Rajurkar
Nontraditional Manufacturing Research Center
Industrial and Management Systems Engineering Department
University of Nebraska-Lincoln, Lincoln, NE 68 5 88
author
W. H.
Liu
Nontraditional Manufacturing Research Center
Industrial and Management Systems Engineering Department
University of Nebraska-Lincoln, Lincoln, NE 68 5 88
author
B.
Wei
Nontraditional Manufacturing Research Center
Industrial and Management Systems Engineering Department
University of Nebraska-Lincoln, Lincoln, NE 68 5 88
author
M. S.
Hewidy
Visiting from Menoufia University, Egypt
author
J.
Kozak
Visiting from Warsaw university of Technologyz Poland
author
text
article
1998
eng
Accuracy in ECM is still a problem that restricts the application of this technology for accurate applications. The present investigation submits a theoretical and experimental study about shape error in the ECM process which has not been attempted before. Feed rate, applied voltage, electrolyte conductivity and initial gap size have been considered the main factors affecting the shape error value (sometimes reached 40 p1 for a 40 mm workpiece length). Experimental results have been found to agree with the estimated values with a difference less than 0.01 mm. The present results emphasize the importance of the consideration of the shape error factor for accurate tool design and shape prediction
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
121
139
https://erjm.journals.ekb.eg/article_73035_8b4cc377def719fc71e4de1dae8bd70f.pdf
dx.doi.org/10.21608/erjm.1998.73035
TEXTILE FIBERS AS A REINFORCEMENT FOR ASPHALT CONCRETE MIXTURES
Saad
El-Hamrawy
Faculty of Eng., El-Menoufia Uni.
author
Abou El Hassan
Rahil
Faculty of Eng., El-Menoufia Uni.
author
text
article
1998
eng
Growing road traffic has created the need of pavement structures which can adapt to this evolution. Concurrently, surfacing techniques have moved in the same direction to ensure user comfort and safety. Also, to resist the high deformation caused by these high loads. Stone-Mastic-Asphalt-mixtures (SMA) have been developed in Germany since 1984, and another mixtures were developed in France. In this investigation, a comparative study was made between SMA and mixtures produced using coarse gradation 3B, according to the specs of RBA . Also, a comparison was made between the two last mixtures and -the most common mixture in Egypt- the dense gradation 4C. It was concluded that the coarse gradation mixtures must be used with additives to increase the Marshall stability and to improve the tensile strength
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
141
153
https://erjm.journals.ekb.eg/article_73038_1eb06235e37c05d4e09d2b4aee1028c0.pdf
dx.doi.org/10.21608/erjm.1998.73038
A NEW LOOK FOR SERIES COMPENSATION OF ELECTRICAL NETWORKS CONSIDERING VOLTAGE COLLAPSE
Sobhy M.
Farrag
Faculty of Engineering
El-Menoufiya University, Egypt
author
text
article
1998
eng
The paper presents a new look for allocating controlled variable series compensation in electrical transmission networks from the view points of voltage collapse, capacity of transmission, and transmission losses, For more realistic and accurate representation, the load is manipulated as a state variable and voltage dependent throughout the solution process. The solution algorithm searches for the optimal line to be compensated and ratings of series capacitive compensation in order to increase capacity of transmission, enhance voltage stability margin, define voltage collapse point, and finally identifjr the most sensitive and vulnerable nodes in the network.
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
155
168
https://erjm.journals.ekb.eg/article_73041_21743a95663a4638b2d61aac94ecb399.pdf
dx.doi.org/10.21608/erjm.1998.73041
EFFECT OF TEMPERATURE ON THE BEHAVIOUR OF ASPHALTIC CONCRETE MIXTURES UNDER REPEATED Lams
Suad A.
El-Hamrawy
Faculty of Eng Menoufia Uni.
Shebin El-kom
author
text
article
1998
eng
In the recent years an important trend has been established towards the use of heavier highway md aircraft wheel loading. The high axle loads lead to excessive permanent deformation in asphalt pavements, especially at high temeratures in hot regions. The main objective of this research is to study the effect of test temperatures on the creep behavior of asphalt concrete mixtures. Dynamic creep test was used for this purpose. Creep strain, mix stiflkess modules and rate of deformation were obtained as a function of axial applied stress and/or test temperature. It is concluded that the creep strain, rate of deformation 'and mix stiffness modules depends upon the bitumen stifhess, and influenced proportionally by variation of test temperature.
ERJ. Engineering Research Journal
Menoufia University, Faculty of Engineering
1110-1180
21
v.
2
no.
1998
183
197
https://erjm.journals.ekb.eg/article_73049_5d93b5184a3247d725845078a15a03dc.pdf
dx.doi.org/10.21608/erjm.1998.73049