Yanbu Journal of Engineering and Science (YJES)
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202 research outputs found
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UTILIZATION OF WASTE CRUMBED RUBBER TIRE AS FINE CONCRETE AGGREGATE
No full textThe use of solid wastes is not a new concept in concrete industries, but still in its early stages in the growing countries. There is a need to realize the value of recycling the crumbed rubber tires accumulated every year in Saudi Arabia and its use in concrete mixes. The objectives of the paper are to investigate the feasibility of incorporating tire crumb rubber as a replacement for natural mineral aggregates in concrete, study the influence of curing time on the compressive strength, and the engineering properties of concrete mix design with and without crumbed rubber. An important consideration has been acknowledged the development of rubberized concrete products which are feasible in terms of production and have some market potential. Three different concrete groups were prepared and tested in terms of compression. The mechanical test results demonstrated that the use of crumb rubber reduced all types of compressive strength. The different crumb rubber sizes have some influence on the mix and can be considered as structural light and moderate weight concrete
Application of Energy-Saving for an inverter feeds three-phase induction motor
No full textThree-phase induction motors are the most prevalent AC motors used in many applications. Operation of these motors at load power less than that of the motor full-load power leads to significant power losses and reduces the motor’s efficiency. To mitigate these losses and increase the efficiency of the three-phase induction motors at light loading conditions, energy-saving techniques should be utilized. This paper investigates a voltage control technique applied to light-loaded induction motors to save the energy using an inverter. The light load selected in this paper is a fan load of power load less than the motor full load power. Theoretical analysis, computed characteristics, and experimental verifications are presented to show the effectiveness of the proposed energy-saving technique
SIMPLIFIED METHOD FOR DETERMINING THE RESISTANCE TO GROUND OF POWER TRANSMISSION TOWERS
No full textThe resistance to ground of towers in power transmission lines with ground wires is calculated using difference equations and using the concept of characteristic impedance of a two-port network. The simplicity and elegance of the latter approach is clearly demonstrated, and with practically feasible network terminations is valid for any length of line
Modeling and Simulation Study of a Novel Bat Sand Vertical Axial-Wind Turbine
No full textA wind turbine with a vertical axis offers a high potential for energy production. Numerous operational and design aspects, such as aspect ratio, blade number, climatic conditions, dust effect, rain impact, humidity, and other geometrical forms, affect the performance of vertical axial-wind turbines. In this work, CFD was used to analyze the flow characteristics across the blades of a unique v ertical-axis wind turbine. The tests were conducted at various airflow velocities, including 2 m/s, 4 m/s, 6 m/s, and 8 m/s. Utilizing numerical simulation, the pressure contours and streamlines were drawn. Due to the direct influence of the dynamic pressure on the front surface of the turbine blades,t he highest pressure was observed on the front side of the blades. Maximum vortices were found on the rear side of the turbine blades, whilst minimal vortices were observed on the front side. Likewise, the lowest pressure was measured on the side of the turbine blades. At airflow velocities of 8 m/s and 2 m/s, the highest and minimum pressure values measured were 7.3 kPa and 2.63 kPa, respectively. Additionally, streamlines were identifi- ed
Experimental and Theoretical Study to Increase the Solar-Organic Rankine Cycle Efficiency
No full textUnder conditions of high climate temperature and environmental pollution, scientists are turning to the use of new and renewable energy. The solar Organic Rankin Cycle (ORC) is greatest technology for converting low or medium-temperature energy sources into electricity. For the purpose of generating steam from solar energy to power the organic Rankin cycle a system consists of solar pond, flat plate collector and parabolic dish was designed, implemented, and tested to use in organic Rankin cycle (ORC). The novelty in the present work is the use of the solar pond as storage of heat that does not lose because the salinity gradient middle layer in the pond does not allow heat to pass through it, as well as the use of reheating to enhance the thermodynamic efficiency. Also, an analytical model has been made to enhance the output power and efficiency of the solar thermal ORC according to some organic control criteria. A Cycle of solar thermal power plants (ORC) is simulated with four refrigerants, R144a, R125, R124 and R245fa of working fluid\u27s performance. The cycle net-specific work can be verified at the highest efficiency as a function of turbine extraction numbers, over-temperature, and evaporation temperature. Superheated steam was obtained at a temperature of 327 °C to be used in the Rankin cycle of the solar energy system which is generated in this work. The maximum output power improvement is 9% when using the working fluid R125 for R124,5. 5% for R245fa, and approximately 2.8 for R144a. And the thermal efficiency of ORC is higher with R123 compared to 144a by about 2.2%. Furthermore, it also concluded that both inlet and outlet temperatures of a turbine are very important factors that affect the operational performance of organic Rankin cycle power generation systems
Transitioning to Alternative Fuels: A Study on the Feasibility of Synthetic Fuels in Saudi Arabia’s Road Transport Sector
No full textResearchers are exploring alternative fuels to transition away from conventional fuels, driven by the need to reduce carbon emissions and dependence on fossil fuels. The transportation sector is a significant consumer of fuels, making it a crucial area for alternative fuel adoption. This study is an expansion on earlier works by recognizing the potential for synfuels derived from fossil fuels to compete with fuels derived from renewable sources. Study illustrating possible transition scenarios in the road transport sector to replace gasoline and diesel in fossil fuel-dependent economies, including Saudi Arabia. The study highlights the potential of alternative fuels like ethanol and hydrogen to meet demand due to of technology developments that increase efficiency and reduce the costs. The findings demonstrate that by 2050, synthetic fuel production will significantly lower the crude oil consumption and CO2 emissions. This study, a first for the region, assesses the implementation of synthetic fuels produced from fossil fuels. Study shows that significant modification in policies and their execution is required, and alternative fuels can be cost-competitive with conventional fuels if Saudi Arabia’s strict CO2 reduction targets are met. The study provides a preliminary assessment of the system implementation and underscores the need for strict regulations to drive the transition to alternative fuels
NON LINEAR SIMULATION MODEL OF ENGINE RESPONSE DUE TO PISTON-SLAP
No full textPiston slap is a transient impact phenomenon existing in the reciprocating engine. It comprises a major cause of the complex transient vibration of the engine. In order to correlate the piston-slap impact with the slap-induced vibration and consequently find out an effective approach for the engine dynamic behavior simulation for improved prediction of engine vibration response, an investigation for theoretical modeling is proposed. The piston-slap phenomenon is discussed from the viewpoint of engine mechanics. Based upon this, a nonlinear model is developed to simulate the slap-induced vibration response. Using numerical integration procedure, the cylinder liner vibration response and its correlation with the piston-slap are reasonably evaluated
A NOVEL BIM-ENABLED SOFTWARE-BASED SOLUTION FOR MITIGATING CONSTRUCTION RISK MANAGEMENT
No full textThis paper presents a novel Software-based solution to mitigate the most prevalent construction risks with systematic implementation of Building Information Modeling Software at the lifecycle stages of the project and provides practical recommendations for industry practitioners. The construction industry has a complex and uncertain process presenting different opportunities and challenges at various project phases. Incorporating traditional risk management methods with BIM helps identify and manage risks effectively. This research paper presents a systematic approach to implementing BIM throughout the lifecycle of an eight-story building project, from feasibility to construction, to manage major risks in each phase. The paper addresses a gap in the literature by identifying and mitigating prominent risks in the construction industry of Pakistan through BIM modeling, based on a review of 180 common risks and detailed interviews. The research methodology involved surveys and data analysis to identify and prioritize the most significant risks and suitable BIM mitigation measures. The study suggests that BIM’s collaboration software resolves communication issues while Clash Detection mitigates Design-related risks before the start of construction. Simulation of Planned vs. Actual Progress and accurate Quantity Estimates achieved by BIM’s estimation software contribute to the successful completion of the project. BIM and its tools have the potential to revolutionize the construction process if used as a structured risk management tool throughout the project lifecycle. The paper advises designing out most project risks in the Planning and Design phase while reserving monitoring and control for later stages as early identification and management of risks is critical for success
A comprehensive Analysis of the Application of GIS and RS Technologies in Flood Prediction and Risk Assessment, with a Focus on Wadi Baysh Dam in the Jazan region. KSA
No full textThis study uses GIS spatial analysis and open-source data based on flood hazards formulas to provide a thorough analysis and forecast of floods using Geographic Information Systems (GIS) and Remote Sensing (RS). The Wadi Baysh Dam overflowed with water in 2016 as a result of the torrential downpour that hit the dam, its streams, and the surrounding surroundings results the increasing the storage capacity. In terms of water reserves, it is the dam that is thought to be the biggest in the Kingdom. Some settlements in Baysh, which are under siege since their highways are blocked off, suffered greatly as a result of flooding. However the storage capacity of Wadi Baysh Dam around 200 million cubic meters of water. In order to identify the actual Wadi Baysh flood-vulnerable area, this study combined data from remote sensing, the Geographic Information System (GIS) technique, and an Analytical Hierarchy Process (AHP) computation. The investigation was carried out to determine the viability of using remote sensing open-source data,basemap of the study area andArcGIS10.4 software in Wadi Baysh risk management. Slope (10%), height (15%), drainage density (20%), distance to stream (20%), rainfall intensity (25%), and land cover (10%) all have a proportion of relative weight that determines how flooding is analyzed. As a result of the most recent GIS analysis (weighted overlay approach), five zones are identified within the extracted flood region based on the categories of hazard. There are ten blocks in all—five in a high-risk area and five in a moderately dangerous one. The paper looks at the flood risk in Wadi Baysh using a combination and integration betweenremote sensing opensources data and GIS models. High precipitation and runoff in the dam’s downstream sections will be the main cause of difficulties, causing a great deal of death and destruction to agricultural and urban areas. Eventually, a control room connected to the GIS model and remote sensing devices will be needed in this valley to implement an efficient warning system and flood hazard management system
Production and evaluation of activated carbon from Saudi Arabian Acacia Tortilis tree bark by microwave and low temperature activation process
No full textIn the present work, activated carbon was prepared from Acacia Tortilis tree bark, utilizing phosphoric acid chemical activation, and microwave irradiation (AC-MWI). Activated carbon was also prepared by conventional phosphoric acid chemical activation and low temperature carbonization (AC-CA). Characterization of the activated carbons were performed by proximate analysis adopting ASTM standard procedures. BET-specific surface area, total ash content, bulk density, moisture content, pH, pore volume and iod- ine number were determined. Comparison of characteristics for both carbons, with the characteristics of AC available in the literature and commercially available in the market was performed. Comparison showed that activated carbon produced from Acacia Tortilis tree bark is well comparable with the reported characteristics of AC in literature and commercially available in market. It was found that AC-MWI has higher BET-specific sur- face area than AC-CA (836 m2/g and 687 m2/g respectively). Results depict that there is a n increase of 22.3% in microspores component and 21.7% BET- specific surface area obta- ined in AC-MWI as compared to AC-CA. Similarly, the corresponding pore volume obtai- ned (4.97 cm3/g and 4.07 cm3/g respectively) demonstrating better values as compared to the commercial ACs (\u3c1 cm3/g). Additionally, it was found that AC can be produced by mi crowave irradiation in about 48.5% less time when compared to conventional low temper ature heating. The adsorption study of produced ACs was performed using methylene blu e as a contaminant. Study showed that MB removal rate initially increased with increase in contact time, which decreased with time until steady state was reached. Adsorption da ta of MB was fitted to Freundlich, Langmuir and Temkin adsorption isotherm models. All models show reasonable correlation, however, Freundlich isotherm is best to describe the MB adsorption on AC-MWI based on correlation coefficient R2 value (0.9985). The resu- Its revealed the feasibility of microwave heating for preparation of high surface area acti- vated carbons from Acacia Tortilis tree bark