Basrah Journal for Engineering Sciences

The purpose of this research is to control a quarter car suspension system and also to reduce the fluctuated movement caused by passing the vehicle over road bump using modified PID (Proportional Integral and Derivative) controller. The proposed controller deals with dual loop feedback signals instead of single feedback signal as in the conventional PID controller. The structure of the modified PID controller was created by moving the proportional and derivative actions in the feedback path while remaining the integral action in the forward path. Thus, high accuracy results were obtained. Firstly, modelling and simulation of linear passive suspension system for a quarter car system was performed using Matlab – Simulink software. Then the linear suspension system was activated and simulated by using an active hydraulic actuator to generate the necessary force which can be regulated and controlled by the proposed controller. The performance of whole system has been enhanced with a modified PID controller.

In this study, glass-filled epoxy functionally graded material (FGM) was prepared by adopting the hand lay-up method. The vertical gravity casting was used to produce a continuous variation in elastic properties. A 30 % volume fraction of glass ingredients that have mean diameter 90 µm was spread in epoxy resin (ρ = 1050 kg/m3). The mechanical properties of FGM were evaluated according to ASTM D638. Experimental results showed that a gradually relationship between Young’s modulus and volume fraction of glass particles, where the value of Young’s modulus at high concentration of glass particles was greater than that at low concentration, while the value of Poisson’s ratio at high concentration of glass particles was lower than that at low concentration. The manufacture of this FG beam is particularly important and useful in order to benefit from it in the field of various fracture tests under dynamic or cyclic loads.

In this research, a two – dimensional numerical investigation is conducted to show the ability of the jet-ejector to prepare the air – methane mixture at different equivalence ratio. The basic dimensions (diameters ratio, throat length, angle α, and angle θ) of the jet-ejector are taken into account on calculating the equivalence ratio. The results showed that the ratio of the diameters has a higher effect than other parameters on preparing a mixture for equivalent ratios including both rich and lean mixture. The rest of the factors did not have a significant effect on the value of the equivalence ratio, and only had a role in preparing an equivalence ratio for rich mixture type.

The Atmospheric Water Generator (AWG) is an environmental water recovery that easily dehumidifies water vapor moisture from the air. This article presents an experiment to construct an AWG model using solar energy as a source of power. An experimental and numerical study for a device of (AWG) is performed. The experimental work is performed at Basrah city, located in the south of Iraq, during August and September of 2019 and March of 2020. The theoretical results are calculated by EES and the numerical study has been conducted by the (ANSYS19/CFD/ FLUENT) program. The experimental device is tested for different days with different climate conditions. The Maximum water production obtained is 3.4 L/day from all the testing days, for different hours of operation when the relative humidity in the range of (45 – 95 %) and the temperature range from 17 °C to 45 °C. The results shown that, the water production rate is increased with increasing humidity, temperatures, hours of operation, and model size.

The panel absorbed solar radiation and majority of this radiation is transform into a heat, and it is usually wasted and useless. At higher cell temperature, the current out of the cell has an unnoticeable rise, but the voltage value will drop significantly, resulting in a reduction in maximum power produced. The cooling method is therefore beneficial to keep the panel at the operation temperature. A simulation model is developed using COMSOL Multiphysics software version 3.5 software to investigate the enhancement in performance of a PV water cooling module (PVW module) based on a passive and simple cooling technique using a wetted cotton porous wick attached on the PV panel's back side and compare with uncooled PV panel (PVREF module). Unsteady, laminar and 2-D, the flow in the proposed modules is assumed. The input parameters were taken from a real weather condition was perform in Najaf-Iraq. The effect of variation of mass flow rate is also studied in the present work. Good agreement was obtained for PVREF module with previously researches.

Several governments around the world announced new strategies regarding their construction industry. These strategies focus on reducing construction projects' time, cost and improving their impact on the environment. To achieving these goals within the proposed time scale, these authorities advise their stakeholders to start to implement different methods in project delivery such as Building Information Modeling (BIM), Integrated Project Delivery (IPD), Geographic Information System (GIS), and many more. All these new technologies and methods will reduce human errors in the project lifecycle which will lead to reducing project waste. In addition, this will pave the road to automation in construction. Automation will help to mitigate the huge number of clashes and mistakes. Iraq an oil-depended country suffering from economic crises due to the considerable reduction in oil prices. This struggle must enforce the government to use this opportunity to solve current project problems such as project delays and budgets overrun and rethink how to reduce construction project time and cost. However, the applicability and understanding of these new methods and technologies need to be explored first among the Iraqi construction industry. This paper will investigate the understanding of automation in construction among different disciplines working with different experiences in the Iraq construction industry. The method of survey was used to sightsee their view regarding automation in construction understanding, benefits, and the challenges. The results reveal that there a positive view in terms of understating the meaning of automation in construction. In addition, several benefits are identified as the most effective gains if these new methods are implemented. Furthermore, more than a few challenges also have been acknowledged that need to be considered to increase the successfulness of implementing automation in construction.

Performance a double slope of the solar still Integrated With or without parabolic trough collector is investigated experimentally. To improve the output of a double slope solar still, a number of initiatives have been undertaken, using wax as a phase change material (PCM) with a parabolic trough collector. A parabolic trough collector (PTC) transfers incident solar energy to the solar still through a water tube connected to a heat exchanger embedded in used microcrystalline wax. Experiments were carried out after orienting the basin to the south and holding the water depth in the basin at 20 mm. According to the results obtained, the solar stills with parabolic trough collector have higher temperatures and productivity than solar stills without parabolic trough collector, as well as the ability to store latent heat energy in solar still, allowing fresh water to condense even after sunset. In addition, the parabolic trough collector with phase change material in the double slope solar improves productivity by 37.3 % and 42 %, respectively.

A large number of RC structures or at least some of their members need strengthening or rehabilitation. Among the typical failure modes, the shear failure is more dangerous and less predictable, because of usually brittle behavior and sudden collapse. Therefore, there are necessities for upgrading the shear capacity and the local ductility of reinforced concrete beams. In this study, four different techniques of concrete jacketing were used to improve the behaviors of the shear deficiencies beams. The four techniques used in this study to enhance the behavior of the beams were by using a Self-Compacted Fiber Reinforced Concrete jacket without stirrups (S.-J. + Steel Fiber), a concrete jacket of Self Compacted Concrete with stirrups (S.-J. + Stirrups), a concrete jacket of ferrocement jacket (S.-J. + Ferrocement), and a concrete jacket of ferrocement jacket with external steel reinforcing bars (S.-J. + Ferrocement + R). These techniques contributed to enhancing the load-carrying capacity and delaying the appearance of the first crack in tested beams compared with the control beam by a percentage of (35, 59, 30, 6) % and (18, 35, 81, 80) %, respectively. The specimen (S.-J. + Stirrups) showed the best performance in comparison with the other used strengthening techniques used in this study in terms of stiffness and the ultimate load-carrying capacity. The ferrocement jacket (S.-J. + Ferrocement) was found to be the most suitable jacketing system used to enhance the shear capacity in terms of cracking load.