KUFA JOURNAL OF ENGINEERING

This paper presents two reconfigurable microstrip antennas with different sizes of the patch elements for Cogniative Radio (CR) network. The desired resonant frequencies can be controlled by using smart tunable permittivity materials. The switching among these frequencies depending on the CR requierments. A wide tunability range  of switching frequencies covers the bands of Wi-Fi and Wi-Max standards are obtained. This rang of frequencies begin from 1.5 till 5.5 GHz. Variable permittivity concept with respect to (as a function of) external source has been assummed for switching through this study. The two geometry structures for the planner array antenna are investigated and simulated using COMSOL sofware.

A two dimensional mathematical model is developed to simulate a groundwater flow regime of the upper part of Quaternary Deposites, in the Teeb area, Missan province. The optimum management of groundwater flow is developed by a linking simulation-optimization model. In this study, MODFLOW, 98 packages are used to simulate the groundwater flow system in unconfined aquifer. This model is integrated with an optimization model (Modular Groundwater optimizer) which is based on the simulated annealying (SA). Fixed well location case was undertaken by running the model with adopted calibrated parameters. The optimum value of pumping rate estimated through this study is (108320 m3/day), this value is compared with another previous work which based on genetic algorithm GA for the same area. The results of comparison showed that the optimum value obtained by SA is higher than the one obtained from GA by 18.35% for the same piezometric head draw down that indicate, the SA gives higher value than GA in this study.

The flow of the wind near an absorber of a trough collector is analyzed. Since this absorber loss useful heat into the ambient, it is necessary to reduce that heat. The common strategy of reduction is the use of a vacuum tube. The maintaining of vacuum is difficult due to air leak or glass fracture led to find another replacement for this strategy. The idea of the present work is to put a half circular disc in front of the receiver in order to reduce the air velocity near the tube and reduce the heat transfer process. The flow is analyzed in the area to find the streamlines of flow and the behavior of air for a different air velocities and trough orientations. The analysis is done by using COMSOL Multiphysics program V4.4. The data show that the overall air velocity is reduced near the receiver as predicted.

The cracking due to restrained shrinkage at early ages of concrete is one of the shortcomings of concrete, which may reduce its sustainability. Staged nonlinear static analysis adopted by SAP2000 software is used to analyze one-way slabs applied to restrained shrinkage. Staged nonlinear static analysis has been improved using the concept of cracked element and the proposed model showed good correlation with test results. Creep strain calculated by CEB-FIP cannot be used correctly with shrinkage at early ages of concrete (first three months), and a modification factor has been suggested in the present research. The modification factor is dependent on the steel ratio. Shrinkage relaxed due to creep has been found slightly affected by the steel ratio, which may be considered constant and equals to 60% approximately. Steel reinforcement will control crack width by reducing the restrained length of shortened concrete due to shrinkage, which is equal to the distance between multiple cracks.

The quality of the geometric design of the road network shall be enhanced when a new access management is applied to get the most optimized route that may be chosen by the road user. Herein Utaifeyah district in Baghdad City is selected, transportation network map is generated for the area, points of problems or incidents like traffic congestion points are located and taken into consideration. The work includes data collection of the traffic volumes within the network from the study area, and then applying optimization study for the alternatives that uses microscopic traffic simulation.
The results shows that when the access management scenarios were proposed, and the corridor analysis of the related transportation network was applied, the quality of transportation style of the Utaifeya district shall be improved, the access ratio to the district has increased to 216%, and the emissions of the harmful matters from vehicles have been decreased by 30%.

There is a need to increase the speed of the power converters for many applications. Nevertheless, one of the limiting factors for power device performance is the parasitic inductances as the switching speed becomes higher. These parasitic inductances act as reaction elements that affect the switching process, and generate high voltage spikes across the PCB. In other words, the advantages of low parasitic inductances in PCB are offered best switching performance for high efficiency and minimizing conduction losses.
In this paper the effect of the parasitic inductances for a synchronous buck converter has been analyzed. MATLAB simulations have been developed to show their effects on the performance of the synchronous buck converter. Furthermore, another MATLAB simulation has been built to show the thermal consideration. This simulation could predict the air cooling budget that the PCBs might need to reduce their operating temperatures.

Two-dimensional mathematical models are developed to simulate the flow regime of the upper part of Quaternary Deposits by two approaches finite difference and finite element. 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. The models are calibrated using trial and error procedure in two stages, steady state followed by unsteady state. Calibrated value of hydraulic conductivity and specific yield using MODFLOW (finite difference) and MICROFEM (finite element) simulations for both steady and unsteady states ranged (1-10) m/day while the specific yield ranges between (0.1- 0.4). For steady state condition, the mean absolute errors are 0.249 and 0.133 for MODFLOW and MICROFEM respectively. For unsteady state condition, the mean absolute errors are 0.025 and 0.02 for MODFLOW and MICROFEM respectively. The results of MODFLOW and MICROFEM shows that the flow in the study area from northeast to southwest.

The location of the jump downstream the hydraulic structures outlets is an important parameter taken into considerations within the construction of the downstream protection works. One of the ways of moving the jump into a closer distance from the outlets is to raise the tail water level. In this research, a flow partitioning structure, FPS, designed, carried out, and installed downstream a sluice gate to apportion the cross sectional area of the flow and, then, increase the resistance of the friction force by increasing the walls of flow. The FPS shaped as a sectioned triangular prism consists of sets of 2.6cm×2.6cm iron square-section pipes formed with direction of the flow. The FPS with a vertical front face consisting of 16×11, rows × columns, of pipes extended 10cm downstream and held by a 0.5cm, thickness, iron bars and welded together to prevent any egression of the pipes from the FPS. This combination of the pipes and bars made a width of 29.6cm and height of 42.6cm to fit, approximately, the flume cross sectional area dimensions. The downstream face made with an inclination of 45o to prevent the free fall of the water.
The system (which consists of a sluice gate, FPS, and rising weir) installed in a horizontal flume of 0.3m width, 0.45m depth, and 15m length. The system operated with flow rates ranged from 11.11 to 36.24l/s with different gate openings in 27 tests. In each test, the hydraulic jump formed downstream the sluice gate and the FPS once placed downstream the jump and once removed, in the same test, with maintaining the same flow conditions, and measurements are taken to investigate the effect of the FPS on the jump.
The results show that the additional friction resistance by the FPS increased the tail water level and forced the hydraulic jump towards the sluice gate, in which the FPS produced a converging distance ranged from 0.64m to 5.34m. This convergence of the jump lowered the head losses of the flow before the jump and then increased Froude Number, Fr, and produced higher y2/y1 value. The increased value of y2/y1 increased the energy dissipation of the jump, in which the jump produced energy dissipation ranged from 8.47 to 85.38% with the existence of the FPS instead of 5.91 to 66.14% without it, with same flow conditions. In spite of the considerable increase in the tail water level downstream the FPS, there was no significant differences of the dissipated energy with and without the FPS for the whole system, in which the energy dissipation ranged from 14.05 to 55.91% with the FPS and ranged from 13.57 to 55.09% without it.

Drip Irrigation Method is the best method that has been used in the world among the other irrigation methods because of its good and high uniformity. This method distributes water to the field using a pipe network and transforms it to the plant by emitters. In spite of the advantages of drip irrigation method, the system has many problems, such as the impact of soil type, silt and discharges distribution. To achieve the goals of using a drip irrigation system, it must be designed and operated properly so that rates and location of delivery of water to the root zone is suitable for crop requirements. Generally, the criterion for drip irrigation system operation is based on soil texture. Soil wetting is one of the most important parameters to determine the deep percolation rate and the efficiency of the system. Knowledge of soil wetting pattern and its movement plays a large role in deciding depth and spacing of pipes, design of irrigation scheduling and improving the efficiency of the drip irrigation system.
The objective of this study is to develop an approach to operate the drip irrigation system in sandy and clay soils by a computerized method regarding the type of crops, its consumptive use, type of soil, frequency of irrigation and water distribution in the network .The study adopts two approaches as follows: The field work approach and the theoretical approach. In the field work approach, soil analysis of the physical and chemical properties of the soil which affect the soil quality as well as its suitability for growing plants are determined. For the theoretical approach the well known software CROPWAT is used for the calculation of crop water requirements and irrigation requirements depending on soil, climate and crop data. Measurements of the consumptive use, discharge, velocities, wetted soil width, wetted soil depth, frequency of irrigation for the two types of soil with silt content calculated. The designed discharge was found to be higher in clay soil than sand soil because it saves the water for a long time through a small area as it is little porous. Increasing silt rate for each type of soil, cause to increases the amount of irrigation water requirement. As the wetted soil width depends on emitter discharge and soil type, it will be increase with soils in high silty clay compared with the low silt and bigger as compared to sandy soils.

Removal of noise from an image is an essential part of image processing systems. In this paper a hybrid denoising algorithm which combines spatial domain Wiener filter and thresholding function in the wavelet and framelet domain is done. In this work three algorithms are proposed. The first hybrid denoising algorithm using Wiener filter with 2-level discrete wavelet transform (DWT), the second algorithm its using Wiener filter with 2-level framelet transform (FLT) and the third hybrid denoising algorithm its combines wiener filter with 1-level wavelet transform then apply framelet transform on LL of wavelet transform. The Wiener filter is applied on the low frequency subband of the decomposed noisy image. This stage will tend to cancel or at least attenuate any residual low frequency noise component. Then thresholding detail high frequency subbands using thresholding function. This approach can be used for grayscale and color images. The simulation results show that the performance of the first proposed hybrid denoising algorithm with discrete wavelet transform (db5 type) is superior to that of the second and third proposed algorithms and to that of the conventional denoising approach at most of the test noisy image with Gaussian noise and Slat & pepper noise while the third proposed denoising algorithm with hybrid wavelet & framelet transform is superior to that of the other proposed algorithms at noisy images with speckle noise.