Tikrit Journal of Engineering Sciences

The Automation design and implementation of any industrial system are very complex pieces of technology. Many systems and components work simultaneously to fulfil a significant operation and control of the system process. The existing evaporative cooler system panel is based on the conventional relay system and has many drawbacks. It takes time and is difficult for people to reach; it could endanger human life and damage machinery. It operates entirely manually and has little to no remote capabilities. Any harm or failure to the electrical panel, the motors, or the instrumentation results in a system shutdown and a loss of power production without giving the control room any prior notice. An automated control system is the natural next step for such a system to eradicate these problems. The Proposal is to implement an automation system designed and implemented by using S7- 1215C Siemens CPU for controlling and WinCC RT advanced as HMI and SCADA approach for monitoring. The programming software is Totally integrated Automation (TIA) Portal V15 software and is used for monitoring the configuration file. Programming style is the ladder while web-server capabilities are initialized for using the wireless protocol with mobile device App S7 for operating and monitoring the system. This paper proposed an innovative automation design and implementation for the gas turbine evaporative cooler system at Erbil/Perdawd combined cycle power plant. The experimental results show that the proposed embedded automation control system is very flexible and simple for controlling and monitoring the evaporative cooler.

An experimental study of four colors of ordinary dye (white, yellow, tibny, blue) of the external wall of the apartment building was carried out in the current work, to find out the range of its effect on the heating load in the winter season comparing with dark color of cement wall at 24hr. In the southern wall was made two opening, the dimensions of the opening were 1 meter high and 0.3-meter width. Two types of walls are built in the two opening. The first wall was made of bricks and was covered with a layer of cement (Ficus) 1 cm in thickness, while the second wall was also built of bricks covered with cement (Ficus) with a thickness of 1 cm and was painted with different colors. The results showed that the heating load is not affected by the change of the facade color of the buildings where the difference in the external and internal temperatures of the colored wall compared to the black wall was approximately equal during winter season during minimum temperature surface at night.

Geographical Information systems (GIS) has been widely utilized in engineering applications because it has been considered as a very powerful, important, strong, and necessary tool, especially in the study of soil erosion. In the present study, Remote Sensing and GIS have been utilized to determine the values and mapping the spatial distribution of rainfall erosivity (R) for the Harir River Basin. The area of study is 350.03 km2, and it is located between (36° 20' 00" N to 36° 40' 00" N) latitude and (44° 10' 00" E to 44° 30' 00" E) longitude and the elevation of Harir River Basin is ranged from 366 m to 1823 m. The digital elevation model for Harir River Basin with 30 m resolution has been used. The (IDW) method has been utilized in order to interpolate and generate the spatial distribution of the average annual rainfall stations data. The average annual rainfall data from 2000 to 2021 for five meteorological stations (Harir, Khalifan, Shaqlawa, Rawanduz and Soran) were used. The results have been demonstrated that the average annual rainfall from 2000 to 2021 for Harir River Basin is ranged from 619.013 mm to 774. 173 mm. Additionally, three equations have been utilized in order to determine the values of rainfall erosivity of Harir River Basin. The results have been demonstrated that the average rainfall erosivity for Harir River Basin is ranged from 1528.42 (MJ.mm/ha/h/year) to 2100.00 (MJ.mm/ha/h/year). As well as the results have been demonstrated that 100% of the area of study is under class of low rainfall erosivity.

Scientific research is an important reason that indicates the progress of countries and the general scientific level. This study aims to research and verify some of the causes and obstacles that the Iraqi authors face and prevent them or lead rejection of their manuscripts from publishing in high-impact journals. Information was collected by questionnaires surveyed and some phone interviews with chief- editors of Iraqi journals subjected to the Scopus classification. The results showed that there are many reasons behind the rejection of research in high-impact journals، these reasons include several causes such as poor quality of the English language، which is known as a language of publication in Iraq for the science field، as well as the lack of experience and the inefficiency of the authors' responses on the evaluators' comments.، these were the main three reason which obstructing the publishing process of Iraqi researchers.

Many investments and commitments have recently been set to use renewable energy source, overcome energy crisis and align with climate target. Solar power development and deployment make investment in power generation sustainability. The goal of this study is harvesting energy by rotating solar panel toward the sun direction. Astronomical formula is derivate to calculate the sun altitude and azimuth depending on given latitude, longitude coordination. The photovoltaic (PV) panels rotate horizontally and track the sun direction in 9 positions regarding to their actual time and calculated azimuth angle. Partial shaded effectiveness that produces between the adjacent panels due to PV panel’s inclination is calculate accordingly. The total increment of power production from fix to tracked panel structure is 17.3% per day. The extra power generation is distributed over the period between solar noon times.

In this research, two subjects are presented. The first one was, studying the effect of the ellipticity ratio on the bearing performance characteristics (flow rate, load number, power absorbed, and stiffness coefficients), where three different values of the ellipticity ratio (0.5, 1, and 1.5) were studied and the conventional bearing was considered as a reference for comparison with the elliptical bearing of different values of ellipticity ratio to demonstrate the effect of ellipticity ratio on the bearing performance, while the other aspect was, studying the effect of aspect ratio on the elliptical bearing performance. Three different values of aspect ratio (0.5, 1, and 1.5) were studied. This was achieved within the range (0.1 - 0.8) for the eccentricity ratio. The finite difference method was used to solve Reynold’s equation numerically to obtain the pressure distribution on the bearing surface and then the bearing characteristics were computed. The computer program (Matlab R2015a) was used for solving the equations used in this study. From the results, it was observed that increasing the ellipticity ratio gives an increase in the flow rate values and a decrease in the (load number, power losses, Krr, Kss, |Krs| and Ksr) values, while, increasing the aspect ratio gives an increase in the (flow rate, power losses, Krr, Kss, |Krs| and Ksr) values and a decrease in the load number values. It was also observed that the elliptical bearing has a (higher flow rate, lower load capacity, and less power losses), than the conventional bearing. In addition, the elliptical bearing has higher principle stiffness coefficients (Krr and Kss) in the region (n<0.41) and (n<0.66), respectively, and lower cross-coupling stiffness coefficients (Krs and Ksr), than the conventional bearing.

Gypseous soils are considered problematic soils because the soil cavities happen during receiving the water or this type of soil and solving gypsum materials and contract in a soil volume. In this study, three types of gypseous soils are used; soil1, soil2, and soil3 with gypsum content (28.71%, 43.6%, and 54.88%) respectively, petroleum products (engine oil, fuel oil, and kerosene) are added to the soils with percentages (3%, 6%, 9%, and 12%) for each product. The result showed that specific gravity, liquid limit, optimum moisture content (O.M.C), and maximum dry density decreased with an increased percentage of product for all types of products. The direct shear (dry and soaked case) results show that increasing the (angle of internal friction and the soil cohesion) for soil1, soil2, and soil3 by adding engine oil and fuel oil. Still, when the soils were treated with kerosene, the angle of internal friction increased while cohesion decreased. The collapse potential for the treated soils increases with increasing gypsum content for all petroleum products. The collapse potential (CP) for (soil1) decreased by 47% when using 6% of the engine oil, 48.8% when using 9% of the fuel oil, and 55% when using 9% of the kerosene. The same percentage of the petroleum products (engine oil, fuel oil, and kerosene) decrease the collapse potential for (soil2), (47%, 46%, and 50%) respectively and decrease the collapse potential for (soil 3), (51%, 47.7%, and 52%) respectively. In the unconfined compressive test applied on (soil1) using maximum density, the results show that the soil strength increased (26% and 10%) when using 6% and engine oil and fuel oil, respectively, while the soil strength decreased by 29% when treated with 9% of kerosene.

In the recent period, developed countries have resorted to using smart grids more widely as a solution to the problems of shortage of electric power, because it is the most environmentally friendly due to its reliance on renewable energy sources and does not require expensive maintenance due to the proximity of its stations to the feeding areas. However, these networks faced problems in sharing the required power between the inverters of the user stations, as well as regulating their frequency when connected to the main network to fill the shortage of electrical energy. This paper aims to achieve the actual sharing of power (Active and Reactive) supply to the varying load between the smart grid inverters by designing a PID (Proportional, Integral, Derivative) controller. PID controller gain tuning by PSO (particle swarm optimization) algorithm which is based on PWM (Pulse Width Modulation) scaler that feeds the Microgrid inverter switches. Frequency control can be achieved when connecting Microgrid with the main grid by using PLL (Phase Locked Loop) to generate a controlled reference signal for the PID controller.

Civil structures were designed to carry a variety of loading during their service life, including fire hazards. As a result, providing fire safety to structural members is one of the most important tasks in civil infrastructure design. Steel structural members are subject to fire-induced damage or collapse due to their high heat conductivity and quick loss of strength and stiffness qualities. Furthermore, the failure in steel beams under the combined effects of bending, shear, and fire loading is poorly understood in the literature. A present study consists of experimental investigations on the fire response of steel beams under bending and shear dominant loading. The specimens have a constant length of 1250 mm. The total depth of the specimens was changed according to the section chosen: 4 in, 6 in, and 8 in (10 cm, 15 cm, and 20 cm). The results of tests show that beams can fail suddenly due to a high drop in yield and ultimate strength of the steel beam. the increase in temperature degree reduced greatly the yield and ultimate flexural strength of the steel beams with different sizes (for all groups). This reduction reached at some times to 50% for the ultimate strength capacity of the specimen. Shear strength is also affected greatly by fire exposure and the reduction reached to about 38%. Furthermore, the design strength capacity can only tolerate loads at low temperatures. This reduction in strength was noted under flexural and shear dominant loading. Moreover, the design strength capacity can withstand against loading at low-temperature degrees only.

This paper presents the steps of designing, controlling, and implementing a 3kW Gallium-Nitride (GaN)-based bridgeless totem-pole power factor corrector (PFC) for single-phase 230V rectifier applications. The bridgeless design of such a converter combined with zero-recovery switching loss of GaN transistors enables more efficient design operation compared to traditional Si-based solutions. Thermally efficient design with forced-air cooling for the switching devices increased the power density beyond 100W/inch3 while keeping the power switches temperatures less than the thermal limits. Continuous Conduction Mode (CCM) was adopted in this work for better converter stability and was analyzed thoroughly along with the losses breakdown for each part of the converter. The digital control model of the converter was discussed in detail accompanied by the hardware design steps for the converter. Experimental results proved a maximum efficiency of 98.9% during 2.4kW operation and 98.6% during 3kW (full load) operation with minimum Total Harmonics Distortion (THD) of AC input current of 2.78% at rated current (13A) when converting the AC input voltage (230V) to 400 VDC.