Al-Qadisiyah Journal for Engineering Sciences

Al-Qadisiyah Journal for Engineering Sciences (QJES), E-ISSN: (2411-7773), P-ISSN: (1998-4456), was established in 2008. The Journal, in its current form, is intended to contribute to the state of the art in all engineering research fields. The Journal is a peer-reviewed journal published by The University of Al-Qadisiyah, the College of Engineering. The journal is published quarterly (March, June, September, and December). The QJES has been indexed by Scopus recently, starting in December 2023.

Traditional image segmentation algorithms have many drawbacks, such as over-segmentation and image distortion due to reflected light. The Watershed algorithm is one of the most popular image segmentation algorithms. Over-segmentation errors caused by overlapping targets in the image, as well as noise and glare, must be removed. In this article, we apply image processing using the watershed algorithm and propose to improve the algorithm based on principal component analysis. PCA is a popular technique for analyzing large datasets with many advantages per observation. PCA improves data interpretability while maximizing information content, enabling visualization of multidimensional data by finding image component gradients in a new space called the principle component that is unaffected by noise and reflected light. In contrast, the components mainly containing noise will eliminate with negligible information. This paper introduces three primary steps. The process involves applying the watershed algorithm to the image in the first phase, using the proposed approach (applying the watershed algorithm and suggesting an improvement based on principal component analysis) to the image in the second step, and comparing the outcomes of the two previous processes. Test results show that the suggested technique can achieve accurate and durable target shapes.

Ballistic protection of vehicles has become an important endeavor, as it concerns how occupants can possess a comfortable feeling together with a high level of protection during a shooting incident. In recent years, numerous forms of armor have employed several kinds of distinct materials to produce a new generation of panels to address the crucial issues in the structure of armor, such as how to provide high protection with reduced density combined with further increasing the stacking and bond strength between the layers of the panel. This study attempts to use a different approach represented by engineering design to combine with the high impact resistance and low weight, as well as high bonding between the laminate of the structure. The structure of the suggested armor consists of five main layers made of different materials: FRP composite materials, then two perforated layers of steel, followed by one perforated layer of rubber, and finally, one layer of aluminum. These layers were tested via 9 mm caliber to specify the ability of each layer to absorb the energy of the projectile and then the configuration of the layers depending on the function of each layer. However, the results offer a significant ballistic performance with reasonably reduced mass and excellent bonding strength between the layers of the structure.

From ancient Greece till the present, the golden ratio has been considered one of the most significant criteria of beauty in art and architecture. Architectural forms are part of the visual language that is bound by the rules of geometry and proportion. This study aims to identify the extent to which contemporary mosques in the city of Erbil utilize the golden ratio in the aesthetics of their facades. The research attempts to answer the question: was the golden ratio implemented in designing the facade of contemporary mosques in Erbil? The study adopted a mixed quantitative and qualitative analysis method. To achieve the study\'s aim and answer its questions, six mosques built in the last decade in Erbil were selected. Qualitatively, survey and documentation followed. Quantitatively, Phi matrix software, AutoCAD, and graphic software were applied as a mathematical approach. The study concluded that only one case used the golden ratio in the design of its façade by 100%, while it did not exceed 75% in most other mosques. The study draws the attention of designers and architects in the field of mosque architecture to the adoption of the golden ratio in the designs of mosque facades because of its role in achieving the aesthetic aspect.

The integration of nanofluid effects and channel shape effects in a heat sink, which exhibits both variable and constant cross-section, has gained significant traction as an efficient cooling method for thermal devices, particularly microelectronic devices. This research presents an experimental and numerical analysis to compare the performance of microchannel heat sink designs (straight, zigzag, wavy, and circular cavities). In addition, the study dealt with the use of pure water and nanofluid (CuO-H2O) with volumetric concentrations of (0.01, 0.02, and 0.03) as coolants. COMSOL Multiphysics was used for numerical analysis to simulate and solve the problem of fluid and heat flow in 3D. The bottom wall of the four microchannels is subjected to a steady heat flux of 170 kW/m2. The simulations were only performed within the laminar domain, encompassing a spectrum of Reynolds numbers ranging from 50 to 150. The influence on the microchannel\'s wall temperature, thermal resistance, pressure drop, and friction factor is exhibited. According to the findings, the wavy and zigzag microchannel heat sink cooled by nanofluid displays higher performance in terms of heat transmission and dissipation in comparison to the heat sink that was cooled by distilled water. as evidenced by a 12% increase in mussel number at volume concentrations of 0.03%.

Urbanization has led to the damage of infrastructure due to floods and water accumulation on roads and sidewalks. To address this problem, pervious concrete was designed to drain water smoothly. However, pervious concrete has certain drawbacks, such as brittleness and poor tensile strength. To overcome these shortcomings, it is reinforced with fiber. Polypropylene fibers are commonly used for this purpose. On the other hand, managing waste plastic is a major problem as it has a significant environmental impact and requires large areas for landfills. Waste rope fibers (WRF) are among these wastes. There have been very limited investigations on the use of WRF in pervious concrete. Therefore, this study aims to investigate the effect of polypropylene (PP) fibers and waste rope fibers (WRF) on the mechanical and structural properties of pervious concrete. PP and WRF fibers were added in proportions of 0.25%, 0.5%, and 0.75% by volume of concrete. A range of tests (compressive strength, tensile strength, density, permeability, load-deflection behavior, and ductility) were conducted to evaluate the resulting concrete. The results indicated that although the permeability was decreased by adding fibers, the fibers significantly improved the mechanical and structural properties of pervious concrete. The highest values for compressive strength, splitting tensile strength, and ultimate load were 83.4%, 72.4%, and 89.62% for PP fibers-based mixtures, while they were 49.9%, 41.9%, and 102.83% for mixtures made with WRF at an addition rate of 0.5% for both types of fibers. The results also demonstrated that the existence of fibers improved the ductility of the concrete, which means that WRF can be used successfully in producing eco-friendly pervious concrete with better performance than the control specimen.

This work introduces seven various polymer samples blended in a twin-screw extruder with flame retardants (FR), and an additive, which is a 1% Stabiliser, to investigate thermoplastic polymer melting, thermal decomposition, and melting moderates. The reduction method is used to analyze its melting points, physics and chemical properties, and thermal decomposition. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) tests are known as thermal analysis tests. It was established that halogenated flame retardants have little effect on reducing the rate of gas escape from polymer melt which affects the viscosity, as it was found. Thus, the APP and FR245 in Polymer help in some polymer leftovers. All samples were treated with flame retardants and no clay, melted completely, at the end of the test some samples did change. All these results investigated by (the XRD) test either, Scanning Electron Microscopic (SEM) or Digital images have been used also applied Limiting oxygen index (LOI) test, in the previous work for the same samples of polymers to verify the results and record a more precise outcome to draw the relationship between melting and dripping behavior via the following studies due to the furnace test which is modulated and calibrated. As a result, the addition of clay together with conventional flame retardants enhances the overall thermal stability forming the polymer. The compatibles help in improving the dispersion of the clay in polymer and reduce the rate of gas escape from polymer melt affecting the viscosity.

Density, as a spatial concept, can be used to predict and manage how land is used. It also plays a role in determining how much capacity is present within a given area. Due to the rapidly growing population in the Kurdistan region for local increase and attendants coming from other governorates, one of the major issues is housing. Over the past ten years, the Kurdistan Investment Board has started the construction of numerous residential complexes by investor companies. This study\'s objective is to evaluate the housing projects carried out by the investor sector to assess the population and housing density and land use balance and evaluate the relation of green area with neighbourhood components. For the current study, five residential complexes were invested in (Zeitun City, Italian I Village, Global City, Aynda II, and Andazyaran city). Since the data are numerical, the applied methodology is quantitative. According to the findings, the net population density of Andazyaran city is higher than the Iraqi standard however the gross population density of Andazyaran city is over moderate levels of single-family housing standards. Gross accommodation density is showing same problems including Aynda II, While Zeitun City\'s land use balance is below average, Global City and Aynda II are in line with Iraqi standards. Indicators show low commitments regarding density parameters of more than one-third of cases to updated housing standards while the remaining complexes follow density indicators limitations with not more than middle level.

Air-conditioning systems (ACs) are essential in hot and humid climates to ensure acceptable ambient air quality as well as thermal comfort for buildings users. It is essential to improve refrigeration system performance without increasing the effects of global warming potential (GWP) and ozone depletion potential (ODP). The main objective of this study is to evaluate the performance of an air conditioning system that operates with a liquid suction heat exchanger (LSHX) through implementing refrigerants with zero OPD and low GWP (i.e., R134a and R1234yf). Liquid suction heat exchanger (LSHX) was added to an automobile air conditioning system (AACS).When Liquid suction heat exchanger was added to the cycle, primary results indicated that an enhancement in the cycle coefficient performance (COP) by 25.2 %and 17.3% for R134a and R1234yf respectively, and decreasing in mass flow rate of the refrigerants used (m ̇_r). Also increasing in refrigeration effect (RE) by 4.2% and 2.3% for R134a and R1234yf respectively. Presence of LSHX caused increasing in heat rejected by condenser (Qcond.) according to increasing in sub-cooling degree and decreasing in compressor work (Wcomp.), increasing in condenser exergy destruction (X. des. cond.) and thermostatic expansion device (TXV) exergy destruction, but decreasing in compressor and evaporator. Summary of previous experimental and numerical studies is presented as well.

Recently, simple cycles have played an essential role in generating electricity in Iraq. However, these devices suffer from low thermal efficiency and low power output. In the present work, a theoretical study was conducted with the aim of improving the performance of (the AL-Amara power plant 125 MW). The current work consists of three parts: The first part focuses on the impact of ambient temperature on the performance of simple circuits, including mass flow, power output, thermal efficiency, and other parameters. In the second part, modifications from simple to combined cycles are implanted. The third part examines the benefits of using solar systems to produce more steam to feed heat recovery steam generators, which hope to generate more electricity and reduce emissions. For a simple gas turbine installation, the results show that the mass flow rate decreases almost (10.8%) as the ambient temperature increases from (15-50) °C. However, the reduction in air mass flow significantly reduced power output and thermal efficiency (22.6% and 13.2%, respectively). In the second part, the application of the combined mode shows significant improvements in power output and thermal efficiency (32.5% and 32.3%, respectively). The specific fuel consumption dropped by nearly 32.19%. Finally, in the third part, the collected results show that there is an acceptable increase in the amount of steam generated by the solar system (21.02 kg/s) when using the solar system. The overall performance of the integrated cycle shows that the power output and thermal efficiency are almost improved (11.28% and 10% respectively)

The aim of this research was to increase the engine car efficiency by adding an innovative material called hybrid MWCNT/Al2O3 nanofluids. A volume ratio instance for investigations is 0.05 MWCNT mixed with 0.05 Al2O3 in distilled water (DW). The experimental temperature setup was in the range from 50 °C to 70 °C. The results demonstrate that as temperatures increase, specific heat and thermal conductivity increase significantly, while viscosity and density gradually decrease. At 70 °C, the highest thermal conductivity of 1.143 W/m.K was achieved in the presence of hybrid MWCNT/Al2O3 nanofluids. Furthermore, it was found that the correlation coefficient for thermal conductivity is 97.06% R2.