Basrah Journal for Engineering Sciences

This study presents a speed control design for switched reluctance motor (SRM) drive based on PID controller. The applications of Switched Reluctance Motors (SRMs) have being increased day by day, but this type of motors represents a highly nonlinear system, therefore there are a lot of difficulties in modeling and controlling them. We have proposed a non-linear mathematical model of a four phases 8/6 poles SRM then simulated it through Simulink/Matlab facilities. The whole control mechanism consists of a hysteresis current controller to minimize the torque ripple and a PID speed controller. The control design results are then validated in real-time by Simulink/Matlab software package.

In this paper, a Neural Network (NN) model system for self-organization fish school system is identified. Monitoring and data extraction from fish school video has been achieved by using image processing technique in order to generate the data suitable for parameter identification of NN model system. Data obtained have been used to identify the parameters of a model based on a black-box represented by nonlinear autoregressive exogenous model (NARX). The obtained results show that this system can be used for multi robot formation system.

In this paper, a design procedure which assumes general integer or noninteger order plant models ‘also can be unknown’ has been adopted to tune PID and fractional order PI (FOPI) controller. The design procedure depends on some specifications of frequency response of open loop system to ensure performance and robustness of step response of closed loop system. Firstly, the procedure is applied to integer order conventional PID (IOPID) controller, and then it has been extended to FOPI. Extensive simulation study has been made to investigate the performance of the obtained controllers, and also to compare between the two controllers. The simulation study has showed the validity and that the proposed controllers have good features in all of control demands, where it shows that these controllers have fast rise time with no overshoot and negligible steady state error. Also, it has showed that FOPI controller performs better than IOPID one.

The polyethylene terephthalate (PET) was prepared from PET flakes of empty local water drinking bottles and diagnosis by infrared spectroscopy (IR). The glass transition temperature, melting temperature Tm and heat capacity were indicated by differential scanning calorimeter (DSC). Part hundred ratios (phr,s) of (PET) were added to study its effect on concrete properties. Additives of (phr) impart performance such as increased cement dispersion, enabling drastically reduced water requirements. Enhance the mortar cubes performance; depend on the compatibility of cement with PET. Porosity of mortar cubes with cement, sand and added PET products were calculated. Maximum and minimum Compressive strength were calculated 58.76 MPa, and 24.0 MPa at phr 0.04 and 0.07 of PET with cement. And PET with cement and sand were calculated 16.5 MPa and 4 MPa at dosages 0.03 gm. and 0.08 gm. The relative dosages in calculating porosity percentages are (0.06, 0.1 and 0.3) gm.

In this study, a numerical investigation has been carried out for single phase flow behavior for thirty six internally finned tubes to demonstrate the effect of axial pitch to fin height ratio (p/e) for 0.8≤p/e≤6.345, helix angle of internal fins (β) for 30°≤β≤70°, apex angle of internal fins (α) for 0°≤α≤53.13°, internal fin height (e) for 0.6mm≤e≤1.0mm, internal tube diameter (di) with 14 mm and Reynolds number (Re) of single phase flow for 10000≤Re≤50000 on enhancement of forced convection heat transfer and reduction of friction factor by using ANSYS CFX program. It solves the three-dimensional Navier-Stokes equations for steady state turbulent with SST model and enhance wall treatment. The numerical analysis provided at fully developed velocity and temperature. Numerical results showed that the smallest axial pitch to fin height ratio (p/e) =0.8 and with apex angle α=10 degree provided enhancement of heat transfer of 2.8 to 3.55 times higher than of smooth tube. Finally, present numerical results are seen to be in good agreement with literature experimental correlations.

In this study the powder metallurgy technique was used to prepare the composite materials using the aluminum powder as the basis metal, with the additions of the 2, 4 and 6%Wt. of ZrO2-Cu coating and mixing it manually for 15 minutes at (30-32 oC). Then the mixture are compacted at pressure 320 MPa and sintering at 640oC in the atmosphere furnace with argon gas protection.
The physical properties include the green density, sintering density, porosity, and microstructure were examined for the prepared samples. X-ray analyzer was used to identify the phases changes in order to find the chemical reaction which it can be excepted occurred in the sintering samples. The result of X-Ray diffraction shows that there is new phase exist after sintering for all weight percentage.

The effect of pore fluid chemistry on the engineering properties of soil in Garmatt-Ali zone of Basrah was investigated. The tested soil is described as silty clay of low plasticity. The pore fluid was altered to include distilled water, raw sewage, and solutions of various salts such calcium carbonate, magnesium sulphate, and calcium chloride. Also, the solutions of salts were used with different concentration (0.25, 0.5, 0.75, 1.0 normality).
The prepared samples of soil were tested after different exposure periods.
The test program included determination of shear strength characteristics, consolidation characteristics, and Atterberg limits. The changes in shear strength, coefficient of permeability, void ratio – effective stress relationship, and Atterberg limits were recorded with the change in exposure period or the concentration of pore fluid solution.
Generally, it was found that there are reductions in the shear strength of soil when the pore fluid is changed from distilled water to solutions of salts or raw sewage. Also it was found that there is a change in the calculated values of permeability, upon changing the type of pore fluid. The coefficient of consolidation for polluted soil was found to be less than that for the reference samples with distilled water.

This study presents an attempt for establishment of sustainable development and management policies for utilization of Basrah coastal aquifer. The simulation/optimization approach is used with application to Um-Qasr aquifer in Basrah. In this research, 5 management schemes for sustainable use of a coastal aquifer exposed to seawater intrusion were developed and solved. The objective of the management models is to maximize the total amount of water pumped from the aquifer for beneficial use, and optimum location, numbers and redistribution of wells. Salt concentration of the pumped water from each of the pumping well was considered as a main constraint together with the minimum water head which is considered to control saltwater intrusion by heads balances with time. Solutions of the management schemes are based on a linkage between a simulation module SEAWAT and Simulated Annealing (SA) algorithm optimization module. The heads and concentrations, calculated by the simulation model based on pumping rates, are used in a SA optimization procedure to achieve an optimum solution. The five multi-objective management schemes were applied on Um-Qasr coastal aquifer. The results show that using simulation / optimization approach in Um-Qasr region can improve planning and management policies and can give better decision for aquifer utilization. The results show that the aquifer can safely increase its pumping rate by (175%) greater than its current abstraction according to the results of schemes 1.

The objective of the present paper is to evaluate the effects of the soil-structure interaction on the seismic evaluation in the building when a framed building is supported on raft foundation. Also the foundation-soil interaction effect has been considered by replacing it with equivalent springs. Nonlinear static pushover analyses of eight-storey reinforced concrete hospital building located at Delhi-India has been performed using the Capacity Spectrum Method of ATC-40. The deformations define the state of damage in the structure through three limit states of the NEHRP Guidelines and the FEMA-356 have been used to evaluate the performance level of the building for drift, the plastic hinge stage of the crack and shear under the condition of the fixed base and the effect of the soil-structure interaction. The performance of the building and individual components has been estimated for Design Basis Earthquake and Maximum Considered Earthquake. The weight of the slab was distributed as triangular and trapezoidal loads to the surrounding beams as per IS 456:2000. The weight of the brick masonry was distributed uniformly on the beams. The results show that the soil structure interaction has marked effect on the roof displacement, storey drift, design base shear, effective damping and crack pattern for beams and columns while there is a minor effect on the torsional behavior of the building. The building is more critical in the performance level when considering the soil flexibility.

The study investigates the behavior of reinforced concrete cylindrical shells under monotonically increasing loads. Three-dimensional models of six small-scale experimental shells with length-to-radius ratios ranging from short (0.84) to long (5.0) are implemented within the context of the finite element method, through use of the ANSYS computer code, and the nonlinear response is traced throughout the entire load range up to failure. Cracking occurs at working load levels, with subsequent reduction in shell stiffness. Increasing loads lead to failure modes varying from a beam failure in long shells, combined longitudinal and transverse cracking in intermediate length shells, and abrupt diagonal with limited transverse cracking in short shells. Ultimate load capacities range from 5.0 kPa to 60.0 kPa increasing with decreasing length-to-radius ratios.

A new photostabiliser, U.V. absorber 2, 4 – bis (4-ethylbenzoyl) resorcinol was prepared and characterized by different techniques such as spectroscopic method, elemental analysis, and moleculer weight determination. The absorber was examined for low-density polyethylene and compared with commercial U.V. absorber (Seesorb-100). The new photostabiliser, U.V. absorber showed higher ability to absorb U.V. light and more efficient for photostabilisation for low-density polyethylene, i.e, the optical properties were improved by using this photostabiliser.

This paper studies and compared the fatigue crack propagation rate da/dN for three kinds of ceramic wheel (model A, model B, and model C) made of Si3N4 ceramic with different additives used for gas turbine application. The stress intensity factor range was calculated using finite element method and then compared with analytical approximate approaches. Experimental fatigue test was carried out on the three specimens taken from the models. As a result, the types of additives effect on fatigue crack propagation rate. The model A has the highest da/dN values and model C exhibits the lower values of da/dN.

لقد فرضت الحروب على بعض الدول حالة من التسرع والاندفاع نحو
التخطيط الحضري العشوائي غير المدروس وذلك لسد النقص في العناصر
المعمارية والتكوينات الحضرية. وقد اكتسبت الاستدامة الحضرية مؤخرا
الى جانب الاستدامة البيئية والاقتصادية اهمية كبيرة في الدراسات العالمية
المعاصرة. ونظرا للمشاكل التي تعاني منها مدينة البصرة على مستوى
التشكيل المعماري والتلوث البيئي المدمر اضافة الى العجز الكبير في ايجاد
الحلول التصميمية المطلوبة للتأهيل العمراني للمدينة. كان ولابد من الحد
من المحاولات الفردية التي تتجه نحو مفاهيم غير واعية وتؤدي الى الشذوذ
وعدم الانسجام مع المحيط الخاص المميز للمدينة. فالتشكيل العمراني هو
سلسلة من التداخلات البصرية التي لا يمكن اعتراضها بمحاولات فردية
شخصية وغير مدروسة وعليه لابد من صياغة رؤى مشتركة يتفق عليها
المختصون في مجالات عديدة وعلى راسها البيئة. ومن هنا فان البحث يتجه
الى ايجاد مساحات بحثية يمكن ان تقدم حلولا تتسم بالموضوعية وملائمتها
للواقع لتكون اساسا للبنية المستقبلية للمدن المتضررة في إطار مفهوم
التنمية الحضرية المستدامة في المستقبل. وهنا فان البحث يهدف الى اختيار
أفضل الطرق في تشكيل مدينة البصرة الحديثة.

العمارة كتابة، وفق فهم أن الكتابة خلخلة وسط إبداعي وتحريك مياهه، -
يعيد نصها التفكيكي تشكيل أنظمتها بكسر التقاليد وإرتياد تشكلات تخالف الواقع،
تزيح الشكل عن تقليدية إنصياعه للوظيفة، نحو إنتاج فضاءات معمارية مشغولة
بتطوير خطابها الشكلي، ومن ثم الدعوة الى توظيفها، في أشكال تهب مستعمليها
مشاعر تخلق تجربة وتقدم فكرة، في جرأة خلق لم يقربه الإبداع من قبل، حيث
يضطرب الشكل المعماري ويتشتت ويتلوى، يربك صورتنا المألوفة عن الأبنية،
ويقدم وجوهاً أخرى ، تؤكد قدرة العمارة على تجديد خطابها الأبداعي ، مختلفاً عما
هو متوقع منه ، بما يثري خبرتنا البصرية بتجارب أخرى، تجدد حيوية التلقي، وتديم
لظاهرة العمارة بقائها ، كما في أعمال: )دانيال لبسكند وزهاء حديد وبيتر آيزنمان
وفرانك جيري وبرنارد تشومي(.

يؤخذ في المسكن المستدام بكافة تشكيلاته سواء على المستوى الحضري -
او المعماري تأثيرات البيئة المحيطة في عملية التصميم ، بدأ من توزيع الوظائف
السكنية او شكل المسكن او حتى المواد الانشائية المستخدمة في صياغته اضافة
للبعد التكنولوجي ، ناهيك عن الموقع وتأثيراته وكذلك الطاقة المستهلكة و تأثيراتها.
فالدراسة تذهب بالبحث والتحليل الى بناء استراتيجية شاملة للمشكلة الخاصة
بالمناخ القاسي للمنطقة ، و تأثيراه السلبي على التشكيل السكنى وذلك عبر تفعيل
الحلول المثالية لتلك المشاكل وفقا لمبادئ الاستدامة البيئية . فمفهوم المسكن
الصحي الجديد بصورته المقترحة يتناول المنافع التي يمكن ان يقدمها التشكيل البيئي
المستدام في تحسين ظروف مفهوم الارتياح الحراري داخل الفضاءات المعمارية .
ومن ثم تصميم شكل جديد من المساكن تحت مسمى انظمة التشكيل البيو مناخية
سلبية الطاقة . فذلك يتوجب ان تخضع افكاره لحكمة المعمار المصمم عبر المرور
على كل الاستراتيجيات الفاعلة والمفيدة والتي تساعد في خلق اقصى قدر من الراحة
المادية ويخفض بالتالي من التكاليف البيئية العالية.