Al-Qadisiyah Journal for Engineering Sciences

This study aimed to investigate the heat transfer behavior of an Al2O3-water nanofluid within a coil-agitated tank. The experiment utilized Al2O3-water nanofluids with varying volume concentrations, namely 0.2 vol%, 0.3 vol%, and 0.4 vol%. Two different cooling water flow rates, specifically 1.8 and 2.2 liters/min, were employed during the investigation. The propeller speed ranged from 2 to 12 (rps), and the temperature spanned from 30 to 80 °C. The findings revealed that the heat transfer coefficient of the nanofluids exceeded that of the base water. Moreover, it increased with higher volume concentrations, reaching its peak at 0.4 vol% with an average rise of approximately ±77.2%. Additionally, the heat transfer coefficient demonstrated an increase of about ±19.8% when the temperature was elevated to 80 °C and approximately ±11.9% when the propeller speed was raised to 12 rps. Comparing the two distinct flow rates, it was observed that the heat transfer coefficient rose with decreasing flow rate to 1.8 liters per minute, exhibiting an average enhancement of approximately ±13.6%.

Most industries struggle with corrosion. Corrosion inhibitors are needed in these sectors. Eco-friendly corrosion inhibitors should be effective even at low concentrations. In this work, the compound 2- Fluorophenyl-2, 5- dithiohydrazodicarbonamide (2F-TSC) was utilized as a corrosion inhibitor for copper in a 3.5% NaCl solution. The inhibitor efficiency was calculated by using a series of electrochemical methods like, open circuit potential (OCP), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). All tests have been done in a stagnant condition. The results show that the compound 2F-TSC looked to be of mixed type. Furthermore, the maximum inhibitor efficiency was reached at 99.2% at 10-2 M 2F-TSC and 5 h. The adsorption of 2F-TSC on the copper surface in 3.5% NaCl obeyed the Langmuir isotherm with a negative value of the standard Gibbs free energy of adsorption of -35.4 kJ/mol (chemisorption and physisorption). SEM, EDX, and AFM confirmed the presence of 2F-TSC on the surface of copper. The adsorption of the inhibitor molecules on the Cu (111) surface was further verified by a Monte Carlo simulation study. The results approved that the 2F-TSC can be utilized as a corrosion inhibitor for copper in an aggressive solution (3.5% NaCl).

An abdominal aortic aneurysm (AAA) is a life-threatening cardio-vascular condition. Current surgical intervention is based on the maximum diameter threshold of 5.5 cm. Over the past years, two indicators to predict potential rupture, the Rupture Potential Index (RPI) and Finite Element Analysis Rupture Index (FEARI), had been developed using finite element analysis (FEA), based on the predicted maximum wall stress and statistical or local wall strength. The purpose of this study is to develop a numerical model using the extended finite element method (XFEM) to understand the initiation/growth of potential rupture and predict its location in abdominal aortic aneurysm wall by involving the parameters of failure: the wall stress, wall strength, and strain, as well as, investigating the use of 3D-US AAA models instead of CT models. Failure analyses were conducted on numerical models of AAA derived from 3D-US and CT images for four elected patients to examine the initiation and growth of potential rupture under three different pressures of 120, 140, and 160 mmHg and three different wall strengths of 0.33, 1.34, and 2.36 MPa respectively. The majority of AAAs showed insignificant differences in stress distributions between 3D-US and CT models, except for one patient where the 3D-US model remarkably showed higher stress compared to the CT model. The location of rupture initiation was predicted reliably for both the models of AAA which have been independently verified with visual predictions by cardio-vascular surgeons. However, the predicted length of rupture and the potential penetration (full damage of the wall) varied between the models depending upon the applied pressure and the strength of the wall.

Traffic crashes are one of the main reasons for the deaths of many people and the loss of property. Therefore, it is important to conduct research and studies to reduce the risk of accidents and identify the causes that lead to their occurrence. The condition of the pavement is one of the main factors that lead to accidents, as several studies have been presented that show the impact of pavement defects such as rutting, roughness, and skid resistance on traffic safety. The purpose of this study was to identify and compile the most important research papers using the Web of Science (WOS), and then analyze the data using the VOSviewer program, as well as learn about most countries and journals that have published the related pavement condition of road crashes, as well as the authors and their collaboration. In addition to knowing the keywords that help researchers research this topic, to benefit from these studies, we must know the causes of accidents, analyze and treat them, and improve the performance of roads using modern analysis and maintenance methods that ensure traffic safety.

Due to its positive impact on human psychophysiological indicators, biophilic design can be implemented in various built environments. This design approach can be used when the connection to natural elements is limited and when the occupants feel stressed and uncomfortable in a specific space. Purposes: This research aims to investigate promoting Students’ well-being indicators through adapting biophilic design attributes in Salahaddin University dormitories Subjects: a cross-sectional field experiment conducted with 39 University students. Design: The participants experienced one of the two simulated rooms by using a virtual reality headset (VR). The first was a biophilic design room BDR based on the adopted BDAs, and the second was a non-biophilic design room NBDR. Besides, all participants performed a stress induction task SIT. Measures: Participants‘ physiological indicators were measured twice, one before and the other after the experiment. Measures included heart rate HR, Systolic blood pressure SBP, and diastolic blood pressure DBP. Result: Paired-sample T-test was used to compare the mean of physiological indicators. The P-values of physiological indicators were statistically significant (P<0.05). Conclusion: This study provided statistical evidence that BDAs can provide a restorative environment that positively affects human psychophysiology indicators, and NBDR provides a more stressful environment. VR is a powerful research tool if an empirical experiment and time/cost limit are allowed.

As a result of a large number of diseases due to environmental pollution resulting from emissions and the fast energy depletion. Many researchers resorted methods to produce a mixture that can be used as fuel and fight these issues. In this work, a mini review was concluded through previous studies to highlight and investigate the effect of using water ammonia solution on the characteristics of IC engines with special focus on gasoline engines. The main findings showed decreased engine performance because ammonia has a lower calorific value and energy density. also, most of the previous contributions highlighted a significant reduction in CO2 and CO emissions for all loads. Using ammonia solution increased NOx emissions slightly.

This paper presents an optimization model for the layout of a branching water distribution system. The goal is to minimize construction costs while meeting the system's demands. The study utilizes the general algebraic modeling system (GAMS) to optimize a non-looping water distribution system. The methodology involves determining the existence and diameter of connections between demand nodes. The optimization problem is formulated as a mixed-integer non-linear programming (MINLP) problem. A simplified layout is used to illustrate the constraints and validate the model. The explicit model implemented in GAMS yields optimal solutions and demonstrates the effectiveness of the approach. The results highlight the decisions on connection existence, flow, and pipe diameter, contributing to cost minimization. The findings from this study provide insights for optimizing the design of branching water distribution systems and reducing construction costs.

Numerical investigation of mixed convective in a vented square cavity with fin. The horizontal walls are adiabatic, while the left and right walls are at hot (T_h) and cold(T_c) temperatures, respectively. The fluid inlet to the cavity from the lower left open area(W_in), and exit from the upper right open area (W_out). In this study, a finite element scheme is employed. The analysis is done for specific Prandtl number (Pr=7), Reynolds number (50≤Re≤200), fin length (0.2≤L_f≤0.6), Richardson number (0.1≤Ri≤1), and the location of the fin (0.2≤h≤0.6). The finding indicates that the Nu_avg increases when high the location of the fin is, the increase at the maximum height of this fin location is estimated to be 17% due to an increase in the area of fluid flow on the hot wall caused by rising convective. The highest heat transfer occurs when the fin length is equal to 0.6 at the location(h=0.2).

The self-excited induction generator (SEIG) is widely applied in the wind energy conversion system (WECS) to enhance power generation. The power generation from WECS is varied in terms of varying wind speed. Hence, to improve the working of SEIG-based WECS, the multi-stage coati optimized proportional integral (CPI) fractional order proportional integral derivative (FOPID) controller is proposed in this work. The proposed coati optimized proportional integral - fractional order proportional integral derivative controls the SEIG’s grid side converter and generator side converter. The coati optimization algorithm optimizes the controller parameters of a proposed multi-state controller. The proposed CPI-FOPID controls both the voltage at the grid side converter and the current at a generator side converter. Moreover, the pitch angle of the wind turbine (WT) is controlled by the fuzzy-based tilt integral derivative (F-TID) controller. The proposed work will be implemented on the Matlab/Simulink platform, and the THD of 0.63% has proven the efficacy of the proposed methodology.

This paper presents a proposal for an authentication scheme for smart building systems and environments based on blockchain, its positive features, and fog computing. The most important feature that can be distinguished in the submitted proposal is its adoption of the principle of decentralization in contrast to traditional centralized documentation protocols, i.e. the proposed authentication system in which users and smart devices are implemented in a distributed and decentralized manner on the blockchain, that will provide a solution to a significant problem of low overall efficiency of the authentication process caused by a bottleneck in such important areas as computing capacity as well as centralized storage of a single authentication authority in the traditional model. There are also benefits from adding fog computing, and because it has higher computing and storage capabilities, it makes the data processing process more efficient, faster, more streamlined, and in line with the common necessities of the real-time IoT environment. The proposed scheme also provides solutions to protect the privacy of user data and increase the level of confidentiality, protection, and security, since a mysterious extractor was used to increase the confidentiality of the proposed model of the authentication system. Comparing a set of security schemes and conducting a security and performance analysis of the proposed scheme, the comparisons showed that the scheme can be characterized as having a good security level and an important efficiency level. The paper focused on specific aspects design of the authentication system, such as the registration and authentication process of all network entities, regardless of the specifics of the implementation of blockchain smart contracts.