Total Artificial Heart, Halbach array linear motor, Finite element method, Genetic Algorithm, blood circulation dynamics
The total artificial heart (TAH) is a mechanical device to be integrated with mammal’s blood flow dynamics to reinstate the functionality of biologically defected heart. In this paper, a Halbach array linear synchronous motor (HALSM) is used as a TAH. In this paper, the optimal control of the TAH that utilizes HALSM is studied to investigate its performance driving blood circulation. The optimal control system is relied on enabling the TAH of following certain pattern of blood flow. Analytical formulas for the HALSM developed force is presented depending on space harmonic analysis for the solution of the multilayer boundary field problem. Parameters of the formulas are obtained by means of magnetic field analysis using finite element method (FEM). The dynamic model of the blood circulation driven by HALSM is developed as a main step before control system design. PID controller is designed to control the TAH system. The genetic algorithm (GA) is used to obtain the optimized controller parameter .Simulated study is carried out for the TAH optimal control as integrated element in the blood cycle of an adult human. The obtained results, presents valuable guide for the design of TAH control system implementing Halbach linear motors.
عرفة سيد محمد منصور( arafamnsr@yahoo.com - 01221623442 )
Induction motor drive, fault diagnosis, inverter faults, open-circuit fault, reliability.
Induction motors are robust machines used not only for general purposes, but also in hazardous locations and severe environments. Although these are very reliable, they are susceptible to many types of faults. However, induction motor drive faults can be detected in an early stage, in order to prevent the complete failure of the motor drive and ward off unexpected production costs. In this paper, a simple diagnostic and detection method that allows the real-time detection and localization of single and multiple open-circuit faults in the voltage source inverter (VSI) for a three-phase induction motor drive system using just the motor phase currents, is presented. A model of the system is built using MATLAB/SIMULINK. Simulation results are presented showing the diagnostic method performance under distinct operating conditions.
Cuk converter, Multizonal proportional integral controller, separately excited DC motor. Speed control, AC to DC converter
In this paper a multizonal proportional integral (P I) speed controller for a closed loop speed control of a separately exited dc motor is presented. The motor is fed from a dc power supply and a Cuk converter. Step – up and step – down characteristics of the output voltage can be obtained. A high performance is achieved with a simple control circuit having only one switch (MOSFET) for the proposed system. The output voltage and current are smooth and free of ripples. The converter operates in both open and closed loop speed control. A multizonal proportional integral speed controller is used to overcome the possibility of change in the system parameters. The proposed modeling and simulation of the proposed system are performed using differential equations, which describe the system behavior in the different operating conditions .The run up, transient and steady state are presented. Speed control using multizonal proportional integral speed controller is given to satisfy the best required response for the load disturbances Also, the motor speed can follow the desired reference speed smoothly in the different operating zones. The experimental results will be have ensured the proposed controller robustness, simple, and powerful control application capabilities. The experimental and simulation results of the system for both open and closed loop speed control are verified and a good correlation between them was found.
The aim of present work is to expand and enhance the performance of the new plate design that previously introduced by the author. The main notice for the first plate design introduced in the first part of this study is the lake of swirling closed to the walls. Increasing the number of ejectors from 5 to 14 ejectors by adding a new circumferential row with 9 new ejectors could improve the rate of swirling process near the wall. Accordingly the diameter of the bed has increased from 46.9 mm to 150 mm. A cold run study was conducted to test the new distribution plate. The bed was tested on cold conditions with two sizes of sand grains, 300 ?m and 600 ?m at different flow rates of a mixture of gas and air. The results showed that the new modification for the distribution plate that introduced previously resulted in the same advantages of good mixing and swirl flow, fast ignition response and no region for de-fluidization in the center of the plate beside avoiding the little settling on the bed bottom previously obtained due to the lack of the number of ejectors close to the walls.
The aim of the present work is to study and test flame stability and blow off for natural gas by use two design for conical stabilizer to enhance the swirl phenomena through the combustion. An experimental test rig is used to study the effect of the two designs of conical stabilizer on flame stability. In the present work flame stabilization using conical stabilizer is investigated to study the flame stability limits for a free jet premixed flame burner. The stability limit (blow off) is examined through changing some parameters in particular of the inclination angle of exit jet of conical stabilizer. The effect of these parameters on the flame stability discussed. The measurements of experiment is mainly depends on visualization. So that an experimental test rig is constructed to fulfill these objectives and different measurements are recorded and analyzed. The study showed that the conical stabilizer has improved the flame stability extend of free flame. The conical stabilizer case I has an effect on the stability limit more than on the conical stabilizer case II. The exit jet with angle on vertical axis for higher velocities of the premixed mixture.
This paper investigates the effect of bonding pressure, overlap length and adherent thickness on the strength and failure load of the single-lap joints of dissimilar materials (GFRE composite and aluminum). Eighteen groups of joints made of glass fiber epoxy composite laminates and Al have been manufactured. The stacking sequences [0/±45/90] and [0/±45/90]s were used to manufacture 2 mm and 4 mm thick GFRE composite laminates, whereas Al thickness was 1.5mm and 3mm. In all cases, the CY219 adhesive thickness was 0.12 ±0.02 mm, and the specimen width was 25mm. Besides, various values of bonding pressure [1, 2, 3, 4, 5, 6 atm.] were applied. The experimental results show that, the failure load and strength of the joint increase with bonding pressure up to 4 atm. Higher bonding pressures do not considerably affect the failure load and strength. Hence, a bonding pressure of 4 atm. was found suitable for bonding composite to aluminum. Moreover, the failure load increased and the bonding strength decreased with increasing the overlap length. However, the increase of failure loads slightly at overlap lengths larger than 30 mm. Also, increasing the adherent thickness resulted in an increase of the failure load. Finally, the failure mode of tested joints was composite delaminating.
فاطمة عبد المحيي عجرمة( Fatmagrama@hotmail.com - 01005070611 )
إدارة عقود التشييد, عقد المقاولة الإداري, العقد المتوازن, الاحتفاظ بالأولوية.
رغم سعي الدولة الدائم لتعديل التشريعات المتعلقة بعقد المقاولة الإداري- لارتباطه بقطاع التشييد الحكومي- إلا أن التحرر من الفكر السائد لعقود الإذعان بتحقيق المصلحة العامة يجابه تفعيل هذه التعديلات؛ وهذه الدراسة تتناول أحد أهم المشكلات التي تصاحب عقد المقاولة الإداري وهي ”آلية تطبيق الإحتفاظ بالأولوية”. تتأصل مشكلة تطبيق الإحتفاظ بالأولوية بعقد المقاولة الإداري في تباين أسس تحديد الأولوية عند البت وعند حساب ختامي الأعمال من حيث: 1) اختلاف الكميات المدرجة بمستندات المناقصة عن الكميات النهائية المنفذة, 2) إعمال شرط التقييم الفني بنظام النقاط عند البت دون ختامي الأولويات, 3) تطبيق معاملات معادلة تعديل الأسعار عند حساب ختامي الأولويات دون البت. لم تتطرق هذه الدراسة نحو تحسين الآلية التي يتم بها تقييم العطاءات وإنما اهتمت بالأطر التشريعية لإجراءات وجوب احتفاظ المتعاقد بأولويته طوال مدة تنفيذ المشروع دون الإخلال بمبدأ العقد المتوازن.
محمد محمد فؤاد صبيح( sobeih999@yahoo.com - 01223660954 )
Dams, Blue Nile Basin, RIBASIM Simulation Model
This investigation was initiated due to the importance of using decision support tools for water resources planning so as management and due to the significance of the Blue Nile together with the impacts of population growth so as economic expansion. RIBASIM model was used to study the effect of some proposed control structures on the Blue Nile basin. The model was set up using readily available input data which includes river basin network schematization, hydrologic data and model data characterizing each node so as the links. The model was calibrated using annual volume-discharge of the Blue Nile basin. The yearly incomes were used to quantify the outflow from the Blue Nile. The performance of the calibrated model was assessed with different techniques. A reasonable agreement was observed in the annual water balances and hydrographs’ shape. Confident with the calibration process results, the model was used for further analysis of the whole Nile basin and elemental sub-basins related to future trends of the main river flow and its hydrological components. Different scenarios were designed and the expected effects of constructing the proposed dams on the yearly income of the Blue Nile were calculated. It was found that, the yearly income would decrease by 2.17, 2.42, 2.26, 1.99, 10.24, 9.05 or 10.38% if 1, 2, 3, 4, 5, 6or 7 dams, respectively, were constructed. These results were based on a randomly selected representative year to show the effect of the proposed dams on the yearly income of the Blue Nile.
Recirculation, Thermal Plume, Tides, Hydrodynamic Model
This research aims at investigating the optimum location of the intake and outfall of the cooling system of the Suez Power Plant. The Plant is planed to be built along the Suez Gulf. There is an existing power plant (Attaka Plant) at about 5km west of the proposed Suez Plant. Hydrothermal numerical modeling was carried out. This model was developed to study the recirculation of the effluents at the intake of the Suez Plant and the distribution of the water temperature at its vicinity. The model is calibrated with the measured data. The results showed that when the Suez and Attaka Plants are in operation, the thermal plumes of both plants merge under specific conditions of wind direction and tides. This results in plume concentration between the two plants, which makes it difficult to locate the intake of the cooling system of Suez Power Plant. Different model scenarios were tested to optimize the cooling system of Suez Power Plant to avoid the recirculation of effluents. Based on the scenarios results, one option was selected to achieve the optimum design of the plant cooling system to determine the shape and location of the intake and outfall of the plant from both recirculation and marine life point of view.
The current research intends to study the possibility of producing ultra high strength concrete using local materials in the Egyptian market. The effect of silica fume, quartz powder, steel powder, steel fibers, type and dosage of superplacitizers were investigated in forty nine different concrete mixes. The effect of the variables were considered and investigated. Three percentages of silica fume (10%, 15% and 20 %) were applied as a replacement of cement content. Quartz powder with a percentage of 10% of sand content was considered. Steel Powder with a percentage of 10 % of sand content was used. Also, different types of high range water reducer ranged from (0.5 to 2%) by weight of powder (cement and filler) were used. The weight of the steel fibers was 40 and 80 kg/m3.The water content was determined by trail mixes and the water-to-powder ratio (w/p) was in the rang of (0.2 - 0.45). The results indicated the possibility of using local materials in the Egyptian market in producing ultra high strength concrete. The use of 10% silica fume as a replacement of cement content and 30% water per powder resulted in compressive strength after 3, 7 and 28 days 43 MPa, 67.4 MPa and 127 MPa, respectively. Moreover, using the steel fibers with 40 kg/m3 increased the compressive strength 64.3 Mpa, 88.0 Mpa, and 135 MPa at 3, 7 and 28 days, respectively
جميع البيانات التي يتم تسجيلها على النظام هي ملك للجهة صاحبة هذه البيانات
لا يتم الاطلاع على هذه البيانات من قبل مهندسي المركز إلا للضرورة القصوى ولغرض الدعم الفني وبالاتفاق مع الجهة صاحبة البيانات شفوياً أو كتابياً
لا يتم إعطاء أي بيان من بيانات النظام لأي فرد او جهة فرعية تنتمي للجهة صاحبة البيانات او لأي جهة أخرى إلا بموافقة كتابية من الجهة صاحبة البيانات
يمكن استخدام البيانات المسجلة على النظام بهدف عمل إحصائيات يستفاد منها فى قياس اداء النظام وكفاءة استخدامه من قبل مستخدميه
يتم تأمين جميع البيانات الخاصة بالنظام من خلال تأمين الحاسب الخادم الذي يستضيف البيانات ومن خلال تأمين انتقال البيانات بين جهاز المستخدم والحاسب الخادم وكذلك تأمين واجهة النظام التي يستخدمها المستخدم
كل مستخدم للنظام مسئول مسئولية كاملة عن كلمة المرور الخاصة به وعليه اتخاذ كافة الاحتياطات الممكنة حتى لا يستطيع أى شخص آخر الحصول عليها
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