Tikrit Journal of Engineering Sciences

Journal Information
ISSN / EISSN : 1813-162X / 2312-7589
Published by: Tikrit University (10.25130)
Total articles ≅ 551
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Jawdat K. Al-Tirkity, Akram H. Al-Taay
Tikrit Journal of Engineering Sciences, Volume 19, pp 14-22; https://doi.org/10.25130/tjes.19.1.02

Abstract:
This study aims to demonstrate the effects of geogrid reinforcement on the bearing capacity of strip footing under eccentric loading. Numerical analysis using finite element program called (PLAXIS 2D Professional v.8.2) are presented. The effect of each of the depth ratio of the topmost layer of geogrid (u/B), the vertical distance ratio between consecutive layers (h/B), number of geogrid layers (N), and the effective depth ratio of reinforcement (d/B) on the bearing capacity were studied, where (B) is the footing width. Also, the combined effect of load eccentricity ratio (e/B), depth of embedment ratio of footing ( f D /B) and the angle of internal friction ( ) on the ultimate bearing capacity were investigated.
Abdulrahman A. Ibrahim
Tikrit Journal of Engineering Sciences, Volume 20, pp 38-58; https://doi.org/10.25130/tjes.20.3.12

Abstract:
As for maintenance important role had to be take practical measures to implement the maintenance work to ensure all the way continuing operations efficiently and prevent interruptions sudden and at the lowest possible cost, for the purpose of achieving this goal must adopt sophisticated methods guarantee us the perfect application for maintenance work and that the manner in Quality Management. In this research study the reality of the Division maintenance at the university (how the assignment of work, administrative structure, how the decision-making, documentation, …. etc.) and through theoretical study of quality management and maintenance and through field visits and interviews and look at how Division maintenance was reached a new administrative regime can be applied to achieve better performance through conversion administrative system from the Division of maintenance to the maintenance department and the distribution of tasks and the establishment of unit quality and other units new help to organize and develop the performance and was also preparing form is used to adjust the cost of the stomach and form to adjust training methods workers, have also been preparing a flowchart illustrates the stages of decision-making starts identifying the problem and ending the assessment of the resolution and corrected in case of an error.
Abdul-Kareem Z. Mansoor, Thair A. Salih, Fawaz S. Abdullah
Tikrit Journal of Engineering Sciences, Volume 20, pp 1-9; https://doi.org/10.25130/tjes.20.1.01

Abstract:
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.
Ali H. Ali, Ahmed K. Ibrahim
Tikrit Journal of Engineering Sciences, Volume 21, pp 55-62; https://doi.org/10.25130/tjes.21.3.07

Abstract:
This research work includes an experimental investigation to study the mechanical properties ofreactive powder concrete (RPC) exposed to acidic solutions. A comparative study was conductedon concrete mixes, control mix without exposure and mixes exposed to acidic solutions. RPC wasexposed to two acids (Sulfuric acid and Nitric acid) with concentration of (1.0)% for each acid. Theacidic solutions were used to study acidic rain effect and durability of RPC. Compressive strengthtest was used to study the effect of acid rain on RPC after exposure to the acid in a duration (48)hours. This exposure was done: after demolding and after (3 and 7) days curing. The maximum lossin compressive strength for Sulfuric acid and Nitric acid was (11.7 and 19.7)% respectively for afterdemolding exposure as compared with the control mix.For durability of RPC the specimens exposed to acidic solutions tested in duration (40, 50, and 60)days, to determine the compressive strength, splitting tensile strength, flexural tensile strength, andweight loss. Test results showed that RPC resistance to Sulfuric acid more than Nitric acid. Themaximum loss in compressive strength, and loss in weight were (6.20 and 2.69)% in Sulfuric acidand (22.60 and 1.32)% in Nitric acid environment respectively at (60) days as compared with thecontrol mix. The loss in splitting tensile strength and flexural tensile strength were (17.1 and 13.3)%for Sulfuric acid and (25.7 and 25.0)% for Nitric acid exposure respectively at (40) days ascompared with the control mix.
Israa I. Khaleel
Tikrit Journal of Engineering Sciences, Volume 22, pp 40-46; https://doi.org/10.25130/tjes.22.2.06

Abstract:
Transient stability analysis is considered one of the most important subject related to any power system, where the study aim is to estimate whether the system will stay stable in the event of abnormal cases. Fuzzy Logic is used to estimate the value of added braking resistance required to bring the system to its normal state. This method has been applied with experimental system having five buses.
Khalid Khaleel Mohammed, Mohammed Idrees Dawod
Tikrit Journal of Engineering Sciences, Volume 23, pp 21-28; https://doi.org/10.25130/tjes.23.2.03

Abstract:
A 13 bit Sigma-Delta ADC for a signal band of 40K Hz is designed in MATLAB Simulink and then implemented using Xilinx system generator tool. The first order Sigma-Delta modulator is designed to work at a signal band of 40 KHz at an oversampling ratio (OSR) of 256 with a sampling frequency of 20.48 MHz. The proposed decimation filter design is consists of a second order Cascaded Integrator Comb filter (CIC) followed by two finite impulse response (FIR) filters. This architecture reduces the need for multiplication which is need very large area. This architecture implements a decimation ratio of 256 and allows a maximum resolution of 13 bits in the output of the filter. The decimation filter was designed and tested in Xilinx system generator tool which reduces the design cycle by directly generating efficient VHDL code. The results obtained show that the overall Sigma-Delta ADC is able to achieve an ENOB (Effective Number Of Bit) of 13.71 bits and SNR of 84.3 dB.
Tikrit Journal of Engineering Sciences, Volume 24, pp 1-10; https://doi.org/10.25130/tjes.24.2.01

Abstract:
An experimental study on a passive solar distiller in the Tikrit city on (latitude line"34 36onorth, longitude line "45 43o east), and purpose of that study to raise the efficiency andproductivity of the solar distiller. And then design the monoclinic solar distiller and add reflectorplate and a solar concentrate. The Practical tests were conducted at a rate of every half-hourfrom the beginning of February to the beginning of the month of June. The study began bycomparing the solar distiller that contain the concentrates and without contain it. Then study theinfluence of adding coal and chemical solutions, like blue Thymol solution and bluebromophenol solution to see the additions effect on the productivity and efficiency of distiller,and also The study was conducted to see the effect of the water depth on the productivity ofdistiller with take four water depths within the basin are (2,1.5,1,0.5) cm of water. The tests wereconducted in weather conditions close. and the results of the study, That distilled added hisconcentrates improved its productivity by 46% and efficiency increases 43% with non-use ofconcentrates, and coal increased efficiency by 36% and productivity improved up to 38%, theaddition of blue Thymol solution increases the efficiency by 19% and productivity by 16%, aswell as bromophenol solution increase productivity by 23% and improve efficiency by 25%,when comparing the additions found that the best one is coal. Through the study of the depth ofthe water show that increases productivity and efficiency by reducing the depth of the water inthe basin distiller.
Hasan Abdulrazaq Al-Sanjary,
Tikrit Journal of Engineering Sciences, Volume 27, pp 113-132; https://doi.org/10.25130/tjes.27.3.12

Abstract:
The increasing costs of providing a residential unit is the main reason behind the residents well of minimizing the area of the plot which forms the big burden within the total cost. This change of the dimensions and area of the residential plot is expected to influence the functional plan of the residential unit . It is necessary to study this expected effect in creating some diversities on the functional pattern of the residential unit as a matter of fact ,which is known to be well-established with the bigger areas of the residential unit. These patterns could form new adaptations for living style towards the change in proportions and dimensions of the residential plot. Although some specialized studies have provided diverse functional patterns for functional organization following the variations of residential plot dimensions, the research points out that there is no full competence of the functional view created from the real effect of such variations, therefore the research problem is set to be" there is no clear theoretical imagination of the effects of minimizing the dimensions of residential plot on the spatial organization plans of actual residential units. The aim of the research is to limit the spatial organizations expected to emerge in actual residential units because of the variations of the dimensions of a residential plot and its ability to provide more economically appropriate models within the minimum areas the residential plot. The research hypothesizes that minimizing the width and the area of the residential plot leads to spatial organizations which form new adaptations of social needs for residents.. These six models represent the reliable areas and proportions adopted in dividing the city within applied partitions. The research the smaller residential plots, which were evaluated according to a scale to correspond with achieving the social needs within the concept of affordable residential unit.
, Nada Abdullah Younis
Tikrit Journal of Engineering Sciences, Volume 29, pp 46-58; https://doi.org/10.25130/tjes.29.1.5

Abstract:
This work introduces a new way to assess the condition of highways and classify them as congested or uncongested highways. This was done by recording a video and sorting the number of lane change orders instead of finding the traffic density, delay, and flow rate. Then extracting data from the video and performing a microscopic simulation for it to study the driver's behavior and create the statistical model. Thus, obtaining the mathematical relationships and coefficients that illustrate that process, after verifying the reliability and calibration of these variables. This research aims to facilitate the highway assessment process, as an alternative or supplementary method of highway evaluation by the Highway Capacity Manual 2010. It is adequate to record a video and count the number of vehicles that change their lanes and then compare them with the results that have been determined in the search to judge the highway is congested or not. The study area was achieved by choosing five segments of multilane arterial roads (six lanes divided) on the left coast of Mosul city. These segments were selected to be as similar as possible in the geometric configuration as well as like traffic flow. After that, cameras were installed according to criteria to record traffic movement and for a time not less than ten hours for each segment, and on the workdays for traffic movement. Then, the videos were uploaded using the Goodvision traffic data recognition program. These outputs were converted to be entered into the PTV-VISSIM traffic simulation program in addition to the other geometric information needed by the program to complete the analysis process and find traffic flow parameters. In the extraction process, the normal distribution and the uniform nature of the data representation of the observed event on the segments were examined using the Z-test and the K-S test, the results were normal and significant. Then the results were verified and the traffic parameters such as density and flow rate were checked to ensure the nature of the traffic flow. The process was also verified using the vehicle motion graphic representation method (Vehicle Trajectory), which is the initial examination to estimate the new variable. A new variable has been extracted, which is one of the traffic movement variables, which depends on the percentage of complete and proper lane change completion within the parameters imposed by the simulation program, it’s the Lane Change Occupancy factor (LnChOc.). Then the statistical model was derived using SPSS for the new variable. It describes traffic conditions on highways and the results are verified and calibrated in more than one way. It’s a simple statistical model was obtained to estimate the traffic movement from this variable and vice versa from the following equation:, Which gave results for critical traffic on multi-lane roads in the Mosul city as follows: - Ø Ø Ø
Tikrit Journal of Engineering Sciences, Volume 29, pp 59-74; https://doi.org/10.25130/tjes.29.1.6

Abstract:
This study investigates the flow of a semicircular labyrinth weir in an open channel by experimental and numerical methods. The experiments were carried out in a channel with a length of 3.5m and width of 0.25m and 0.3m height under five different flow rates. Five different discharge values over the weir were used. In each experiment, flow rate and flow depth were measured. Numerical processes solved using mathematical equations of fluid flow through the computational fluid dynamics using ANSYS FLUENT code. The Volume of Fluid (VOF) model is designed for the case of water and air-immiscible faces. Standard k-epsilon turbulence models were tested. A mass balance result indicates that the maximum error between the inlet and outlet discharges of the main channel does not exceed 12% for discharge values of 4.31 L/sec. The results indicate that by increasing the discharge flow rate, the percentage of error decreased to 0.4% for discharge, 14.6 L/sec. The findings show that the free water surface profile obtained from the numerical model compared to experimental values complies well with the experimental results.
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