University of Thi-Qar Journal for Engineering Sciences

In the present paper, a numerical study has been investigated by using computational fluid dynamics (CFD) to analyze pressure, head, head coefficient, pressure coefficient, input power, and volume fraction of cavitation at three cases of simulation in which each one has constant parameters; however, with modifying number of blades which is changed from five to sixteen. The constant parameters are rotating speed, volume flow rate, mass flow rate, outlet diameter, suction specific speed Nss, Reynolds number and NPSHr. These parameters have been fixed to have the same conditions for each case. The shear stress transport (SST) turbulence model has been used to inspect a steady state incompressible flow through centrifugal pump numerically. The simulation has done by using ANSYS®, Vista CPDTM Release 15.0. The results are plotted and discussed to describe and find a relation among cavitation, pump behavior, and variation of blade numbers at constant conditions. The results show a strong relation among increasing blade numbers, centrifugal pump performance and reducing pump cavitation.

The research aims to study and simulation weld joint type Double –Fillet Tee Joint ,It was studied stress concentration along the weld area and calculate the required weld size under effect variable loads (1,2,4)kN by using Finite Element Method through a program Solidwork Simulation 2013.It has been identified weld size (4mm) as the value of fixed for all loads, this value is proposed from welding of scientists as the default value ranging (4-10)mm and used a feature (Edge Weld Check Plot) in solidwork program .It has compared the theoretical results with the analytical results ,the ratio of error was less than (2%) .It has simulation by draw 3D solid model and convert it to shell model with loads and fixture .The results showed that the maximum value of the stress is (10)N / mm2 under load (4)kN and less thickness necessary for the welding connection is 0.132 mm under load (1)kN The more load on joint weld will increases weld size required without afailure.The research supplies recommendations for precision of solidwork simulation to be used as design device calculate the joints.

Automatic voltage regulator is used to fix the output signal by correcting the voltage of the exciter and track the generator’s voltage. The improvement of automatic voltage regulator (AVR) response will reflected on the power system performance. In this paper two intelligent techniques fuzzy logic (FL) and Particle swarm optimization (PSO) are used to enhance the response of the Fourth order AVR system based on the merging between them and then the control action summed and coupled with PID controller action. Fuzzy controller has many benefits in design of AVR compared with conventional controllers, but the response of the AVR system still insufficient, therefore, the PSO and Fuzzy are used together for this purpose to produce Fuzzy-Swarm-PID controller (FSPID).Usually the cognitive (C1) and social acceleration (C2) are taken as a constant values in PSO algorithm, but here the Fuzzy logic system is used to get these accelerations to enhance the response.

A two-dimensional model was developed to simulate the unsteady state flow of groundwater in the upper part of Dibdibba sandy unconfined aquifer in Safwan-Zubair area, south of Iraq,in order to assess the hydraulic characteristics in this aquifer by the comparison of the observed head and calculated head, as well as the use of this model to predict the groundwater head in case of changing weather conditions. The suggested conceptual model, which is advocated to simulate the flow regime of aquifer, is fixed for one layer, i.e. the activity of the deeper aquifer is negligible. Seven cases were considered during sensitivity analysis. The results of sensitivity analysis showed that the increment of the initial values of hydraulic conductivity (K) and specific yield (Sy) more than 100% can lead to a noticeable increment in the level of groundwater.The unsteady state calibration results were evaluated by comparing the temporal variation in simulated heads with those of observed ones at thirteen observed wells.According to the calibration process, the hydraulic characteristics of the upper aquifer have been redistributed; the hydraulic conductivity in the study area was between (15-150) m/day, while the specific yield was between (0.125-0.45).

Digital signal processing techniques used widely to cancel undesired parts of the signals, like that interference with other frequency range. Electromagnetic signals can be interference with human body signals such as Electrocardio signal Electroencephalogram and Electromyography. These interferences can be affect on the diagnosis signal during the examination and when these happen with different frequencies,such as (EMG) noise, devices that have high vibration which give fault data or effect the final result. Filtering of signals interference is very useful in the diagnosis of biomedical cases, as instant as the ECG signal that represent weak signal. This work treat problems of all kinds of interference with ECG signal and reduce it based on the development of digital Finite Impulse Response (FIR)filter for ECG signal which has the frequency between (5Hz to 100 Hz)using fdtool by MATLAB instead of classical filters that often unaccurate. It is hard to get pure signal from human body without any interferences specially with that range of frequencies. In this paper the ECG signal has been presented from human body with its frequency spectrums before filtering then filtered from unwanted frequencies and show the elimination of the disturbance interference from this signal

Vertically aligned copper (Cu) nanorod arrays fabricated by glancing angle deposition (GLAD) technique was used to study the heat transfer by natural convection in micro systems. These nanorods were deposited on Cu thin film surface, which was coated on Si (100) wafer substrates. For comparison, planar Cu thin film samples were also produced by normal incidence deposition. This study focuses on investigating experimentally the heat transfer by natural convection from the sample(nanostructured plate) to the surrounding air. Newton's law of cooling has been utilized to calculate the free-convection heat transfer coefficient for Cu nanorods as well as Cu thin film. Compered to Cu thin film samples, it has been found that the heat transfer coefficient values of Cu nanorods are higher due to the enhanced heat transfer-surface area, which causes a significant reduction in thermal resistance. These nanostructured surfaces offer an effective method of device cooling such as for small electronic devices, micro-reactors and air conditioning.

The intersection is the most important part in the road system .The intersection may be at the same level which named " AT GRADE INTERSECTION" where all the vehicles are at the same level, or at different level which called "GRADE SEPERATION" The choosed intersection "Al –Qithara Intersection" is one of the important intersections in the city therefore it was selected to evaluate traffic movements in this intersection. The filed measurements was conducted to collect the traffic data to find out the possible remedies to improve the traffic operation in the intersection. Two suggestions were submitted to improve the intersection performance. The first one depends on departure the traffic movements while the second suggestion includes the use of traffic signals. The main conclusion that in spite of the presence of al-Qithara Bridge the intersection is congested with many conflict points. The study recommended that the traffic movement should be modified and the intersection should be modified to signalized intersection.

The knowledge theses focus on study the acting concepts in architecture failed and what its can do from general and detail according its quality nature which serve knowledge riches of architectural field and all that secret important to go for study belief concept and its act and impact by architectural field how can the general knowledge real and thoughtfully theoretical characters for it limited.This research aims to define the general basic for knowledge view for belief concept which achieved by limit the general knowledge view about him , and abstracted him related with architectural field as a dual then go to designation anther dual that be as a reflect for last dual and to architectural field which represent architectural knowledge model and depend on concepts (type/value) then operate the similar between them and the theoretical vocabularies that derive and explore the check for the detail theoretical indicators for them. Then submit the final conclusions and recommendations.