Tikrit Journal of Engineering Sciences

This paper presents a simulation and hardware implementation of a closed loop control of a separately excited D.C. motor using a self-tuning PID controller. The PID controller design is based on using the Field Programmable Analog Array (FPAA) technology. Parameters tuning of the PID controller is achieved by using the genetic algorithm (GA). The FPAA controller based technology gives the advantage of low power, no quantization noise, high bandwidth and high speed response. The practical results show that a self-tuning controller can outperform a hand-tuned solution and demonstrate adaptability to plant drift; also it gives very acceptable results in the reduction of overshoot, stability time and the steady-state transient response of the controlled plant.

This paper presents a new method to calculate the network reliability based on the use of flooding routing algorithm. Tie Set (TS) method is one of probabilistic reliability method, is combined with flooding technique to generate an efficient new method to estimate reliability. The proposed method can be generalized to be active with others reliability methods such as Cut Set, and Enumeration methods. TS method depends on two factors: finding the TS paths and the inclusion-exclusion expansion equations. A modified flooding algorithm is used to generate the group of TS paths which is then used to find the reliability. It will be demonstrated by a case experiment the simplicity and effectiveness of the flooding technique to generate paths between a pair of nodes in a graphical representation of a communication network.

The navigation of a mobile robot in an unknown environment has always been a very challenging task. In order to achieve safe and autonomous navigation, the mobile robot needs to sense the surrounding environment and plans a collision-free path. This paper focuses on designing and implementing a mobile robot which has the ability of navigating smoothly in an unknown environment, avoiding collisions, without having to stop in front of obstacles, detecting leakage of combustible gases and transmitting a message of detection results to the civil defense unit automatically through the Internet to the E-mail. This design uses the implementation of artificial neural network (ANN) on a new technology represented by Field Programmable Analog Array (FPAA) for controlling the motion of the robot. The robot with the proposed controller is tested and has completed the required objective successfully.

Position location in cellular networks has become increasingly important in recent years due to emerging of location-based services. Numerous applications use position location such as emergency calls, network optimization to resource management and improve the performance of handover in cellular network.U plink Time Difference of Arrival (U- TDOA) technique in cellular networks is dealt with this technique based on estimating the time difference between the received signal to the base stations of a certain subscriber using the Generalized Cross Correlation method. Chan’s method is used in solving the resulting hyperbolic equations for finding the Position Location (PL) of a certain subscriber. Chan’s method give accurate results, compared with other techniques .in this paper we concern on the some factors (increase sample, increase power without and with interference cancellation) for improved U-TDOA Accuracy.

A modified Sierpinski Gasket fractal antenna for multiband application is proposed in this paper. The modified ground plane and the microstrip feed are used to obtain the wider bandwidth at the resonance frequency. The antenna is designed and printed on two layers FR-4 substrate (εr=4.4 and h=1.6 mm) to cover the UMTS and 2.4/5.2 WLAN. The radiation pattern of the proposed antenna is similar to an omnidirectional. The proposed antenna has maximum gain of 1.88, 1.6, 4.31 dB at 2, 2.4, 5.2 GHz, respectively The properties of the antenna such as return losses, radiation pattern, input resistance and gain are determined via numerical CST Microwave Studio 2010 software.

With increasing the usage of mobile communication devices and internet network information, the entry of private telecommunications companies in Iraq has been started since 2003. These companies began to build up cellular towers to accomplish the telecommunication works but they ignore the safety conditions imposed for the health and environment that are considered in a random way. These negative health effects which may cause a health risk for life beings and environmental pollution. The aim of this work is to determine the safe and unsafe ranges and discuss damage caused by radiation emitted from Asia cell base stations in Shirqat city and discuses the best ways in which can minimize its exposure level to avoid its negative health effects. Practical measurements of power density around base stations have been accomplished by using a radiation survey meter type (Radio frequency EMF Strength Meter 480846) in two ways. The first way of measurements has been accomplished at a height of 2 meters above ground for different distances (0-300) meters. The second way is at a distance of 150 meters for different levels from (2-15) meters above ground level. The maximum measured power density is about (3) mW/m2. Results indicate that the levels of power density are far below the RF radiation exposure of USSR safety standards levels. And that means these cellular base stations don’t cause negative the health effect for life being if the exposure is within the acceptable international standard levels.

In this paper, by using the symmetrical properties of the discrete Hartley transform (DHT), an improved radix-2 fast Hartley transform (FHT) algorithm with arithmetic complexity comparable to that of the real-valued fast Fourier transform (RFFT) is developed. It has a simple and regular butterfly structure and possesses the in-place computation property. Furthermore, using the same principles, the development can be extended to more efficient radix-based FHT algorithms. An example for the improved radix-4 FHT algorithm is given to show the validity of the presented method. The arithmetic complexity for the new algorithms are computed and then compared with the existing FHT algorithms. The results of these comparisons have shown that the developed algorithms reduce the number of multiplications and additions considerably.

Accelerated development and use of decision-making technology, including the analytical hierarchy process (AHP) which has a high reliability to solve most of the uncertainty problems and meet their practical requirements, which enabled it to be used in a number of engineering and administrative applications. Statistical design of experiments technology is considered essential keys to deal with random data. Their important features enables us to combine them in a appropriate scenario to predict the prospects and rates of random factors and determine the extent of their impact on the delay for the implementation of a project. This research verified and reach the possibility of using these two techniques in the development of mutual influence between each of random factors, a very high correlation has been proved among such factors, where the correlation coefficient between them is equal to the value (1), a mathematical models that govern random factors effects was built by using of Statistical analysis of variance (Anova) and multiple linear regression to find mathematical models that found to be had a high resolution through R2 and F tests which gave (R2 = 1, F > = 1.18E +32) results. These models are used to build a scenario to predict the expectations of potential for the disposal of these factors during the annual monthly plan, and treatment to avoid random effects on the implementation of the project and the planned completion time.

Three laboratory scale units are designed and constructed in order to perform the present work. These units are capable of working under different hydraulic retention time (HRT) (16-32hrs), recycle ratio (0.25–1.5), and temperature (20 -35 ̊C). The results show that BOD5, COD, NO3-1, PO4-3 removal is increased with increasing HRT and recycle ratio under different temperatures. The maximum removal efficiency of COD and BOD5 is 97.16 % and 97.99 % respectively under 24 hrs retention time, 1.5 recycle ratio and 20 ̊C. However, the maximum removal efficiency of NO3-1 (83 %) was obtained under the same mentioned condition except temperature which was 35 ̊C. The maximum removal efficiency of PO4-3 (76.59 %) is obtained at 32hrs HRT, 1.25 recycle ratio, and 20 ̊C. It is obvious from the results of the present work that BOD5, COD, and NO3-1 removal increased with increasing temperature while; PO4-3 removal is decreased with increasing temperature.

In this research study the effectiveness of removing heavy metal ions from aqueous solutions using sand in the area of Syrian villages and Alpedrosia. Aqueous solutions were used for each of the anthropogenic ions chromium and lead concentrations in (5-100) mg / l .and at pH = 4.5 and constant temperature T = 30oC was to determine the concentration of lead and chromium ions remaining in solution The results showed that the contact time between the ion solution is artificial and community sandy studied and the 24-hour enough “to reach a concentration equilibrium. It was found that removal majority of the ions of lead and chromium being staged on the sandy be within 6 hours the first time to seek, and that the increase in ions adsorbed slightly up to 24 hours, And conclude that the sand Alpedrosia very effective adsorption better than the sand villages, and that the selective media sand studied for ions lead better than Bcward chrome and matches the equation curve adsorption of ions chromium and lead on the sandy Alpedrosia and villages with the equivalent to the Longmuir’s theory.

In this research, the ability of effective microorganisms (EM) to remove nitrate from groundwater had been studied. Many samples were taken and tested from several wells in Tikrit University. The tests showed that the samples of groundwater contained a few nitrate concentrations (less than 1 mg/l) so that the wastewater was a synthetic solution by adding potassium nitrate (KNO3) to the groundwater as a nitrate source within the range of (50–150) mg/l. the ratios of EM were used in the experiments ranged between (1:250) to (1:5000). While the hydraulic retention times 24 and 48 were used in the experiments. The result showed that the removal efficiency of nitrate was increased by increasing the ratio of EM in the processing unit and the maximum nitrate removal was 82% when the nitrate concentration and EM ratio were 150 mg/l and (1:250) respectively and HRT was 48 hr.

This research included the study of influence of sawdust addition on the properties of mortar and ferrocement slabs and study the influence of treatment sawdust on the static and dynamic properties of the Sawdust Ferrocement Slabs (SFS). In the present work, addition a different sawdust percentage ranged between (10% to 50%) of the volume of fine aggregate to cement mortar and superplasticizer was used to increase compressive strength and workability of cement mortar. The tests include, samples of cubes and prisms were tested for compressive strength and modulus of rupture and calculated the thermal conductivity for Sawdust Cement Mortar (SCM). The results show a significant improvement in the properties of cement mortar in terms of thermal insulation, the values of thermal conductivity ranged between (0.54 to 0.31) W/(m.K) ) to the ratio mixes respectively. While for the ferrocement mix without any sawdust ratio up to 0.65 W/(m.K) and this mean an improvement in the performance of mixtures of thermal insulation by 17% to 52%. The best sawdust ratio for the compressive strength is 30% where the value of thermal conductivity then is 0.38 W/(m.K) and the value of compressive strength of (29 Mpa). Also, Sawdust Ferrocement Slabs (SFS) (treated and untreated) were cast and tested under static and dynamic loads effect. The results show a good improvement in the mechanical properties of (SFS) under these loads.