Journal of Studies in Science and Engineering

Cogging Torque Reduction of Brushless DC Motor: Investigating the Efficacy of Ra-dial Pole Shaping Technique with Novel Bump-Shaped Rotor Pole

Tanuj Jhankal — 2024-06-30

With the rising demand for high-performance motors in electrical vehicle applications, permanent magnet brushless DC motors are a promising solution due to their various attractive features. However, it has a significant drawback of high cogging torque, which deteriorates the overall motor performance. This negative impact is dominating in electric vehicles for low-speed applications. It is desirable to reduce the cogging torque to improve the performance of the radial flux brushless DC motor. The prime focus of this research is reducing cogging torque through the radial pole shaping technique with a bump-shaped rotor pole surface. This work also investigates the impact of the proposed approach on torque ripple and motor performance while cutting down the requirement for rare earth material. This paper uses two ratings: 1000 W, 510 rpm, and 250 W, 150 rpm motors. Two reference motors of proposed ratings were designed using radial-shaped permanent magnet poles. Finite element software is used for the simulation and modeling of the motors. A novel bump-shaped permanent magnet pole shape is introduced, and in-depth investigations have been carried out to evaluate the impact of the proposed pole shape on cogging torque. The validity of the analysis results is further substantiated by comparing the improved and reference model results. The comparison investigation indicates that the motor equipped with the proposed pole shape performs better than the reference motor.

Shear Reinforcement of Concrete Beams Using Iraqi Bamboo

Wrya Abdullah — 2024-06-30

Steel rebars require significant energy to produce and are prone to corrosion when exposed to ambient air. Therefore, Iraqi bamboo replaces steel stirrups and steel rebars in this research. Five reinforced concrete beams are tested using four-point load testing. The first beam was cast without stirrups to achieve shear failure and is labeled a control specimen. Three other beams had Iraqi bamboo instead of steel at the critical sections. The last beam had steel stirrups spaced at a distance half of the effective depth of the beam. It is found that the Iraqi bamboo can increase the load-carrying capacity of the beam by up to 15% if compared with the beam with no stirrups. Also, the ductility of the beam has increased by 17%. However, the maximum load-carrying capacity of the steel stirrup beam was larger than that of the bamboo stirrups by at least 21%. The main reason is the spacing of the stirrups, which is the main factor influencing the beams' behavior prone to shear failure.

Comparative Study of TLP250 and IR2132 Driver-Based Inverter for Induction Motor Driving

Timothy Hutton Yurico — 2024-06-30

As time progresses, electric motors are used for industrial or commercial purposes. The need for a motor that is robust, simple, and easy to maintain has been answered by creating an induction motor that can handle the purpose. At the beginning of its use, induction motors were more often used at constant speeds. Using an inverter becomes one of the solutions at hand to control the induction motor. Nowadays, most inverters are controlled by the SPWM (Sinusoidal Pulse Width Modulation) method. This method can adjust the output voltage and frequency by setting the carrier signal's frequency value and the reference signal's amplitude. A driver circuit is needed to implement an SPWM-based inverter. This driver circuit is needed to isolate the power circuit from the controller. Moreover, this circuit is also used to increase the microcontroller output signal to trigger the IGBT gate switch. The IR2132 and TLP250 drivers are often used in three-phase inverter applications. These drivers have advantages and disadvantages. This paper discusses the capabilities of these two drivers when applied to a three-phase inverter that functions as an induction motor drive. This inverter-controlled induction motor is advantageous because it can be rotated at a nominal speed and frequency.

Design of Storm Sewer System for Mass City Using Bentley SewerGEMS Software

Anwer Hazim Dawood — 2024-06-30

Erbil has been undergoing rapid urbanisation and population growth for the last ten years. The impervious surface areas increased, so the volume of runoff generated from stormwater increased. For this reason, the storm sewer system is faced with additional runoff from the urban areas, and the existing sewer system is inadequate. This study focuses on the storm sewer system design using SewerGEMS and AutoCAD Software in Mass City, which is located in the east of Erbil. The topographic map of the study area was created using Civil 3D software and the total station in surveying, and rainfall storm data were collected from Erbil Meteorology Station and the General Directorate of Water and Sewage. Geometric design and hydraulic modelling were done using AutoCAD and SewerGEMS, respectively. The results show hydraulic design parameters such as flow velocity, sewer pipe size, slopes, manholes, pipe profiles, hydraulic grade line, minimum depth of excavation, and the minimum number of drops. Such a model allowed the project to be accomplished in a short time, with high efficiency and low costs; the model effectively demonstrated its ability to improve design and analysis by examining hydraulic performance.

Development and Validation of a Diagnosis System for Lung Infection Using Hybrid Deep-Learning Techniques

Marwa A. Shames — 2024-06-30

A fast and accurate test is necessary to detect COVID-19. A computed tomography (CT) scan has shown diagnostic accuracy. CT scan processing using a deep learning architecture may improve illness diagnosis and treatment. We proposed a deep learning system for COVID-19 detection using CT images, including using and comparing transfer-learning, fine-tuning, and the embedding process. This paper presents the development of a COVID-19 case identification model using deep learning techniques. The suggested model utilized a modified visual geometry group (VGG16) architecture as the deep learning framework. The model was trained and validated using a chest CT image dataset. The SARS-COV-2 dataset contains 2482 CT scans of 210 patients from publicly available sources. The modified model demonstrated encouraging outcomes by greatly enhancing the sensitivity measure (95.82±1.75)%, which is an essential criterion for accurately detecting instances of COVID-19 infection. In addition, the model achieved higher values for the accuracy metric (91.67±1.68)%, the specificity meter (88.08±3.72)%, the precision metric (87.51±3.27)%, the F1 score (91.43±1.55)%, and the area under the curve (91.98±1.55)%. Deep learning effectively detects COVID-19 in chest CT scan images. Clinical practitioners may employ the suggested approach to study, identify, and effectively mitigate a greater number of pandemics.

Experimental Investigation of Single Slope Solar Still by Varying Water Depth and with External Reflector

Yuvaperiyasamy Mayilsamy — 2024-06-30

Solar distillation converts salt water into drinkable water, requiring minimal maintenance and energy-saving. However, the desalination process has drawbacks because the system's slow evaporation and condensation rate leads to low freshwater output. Consequently, this method is not widely utilized due to its limited productivity. To address this issue, the study's primary aim was to enhance the productivity of the single-slope solar still. This was achieved by altering the water depth from 3 cm to 6 cm and incorporating an external reflector. The experiments were conducted in Coimbatore, Tamil Nadu, India (11.0168° N, 76.9558° E), with a condensing cover inclined at 11 degrees. The research occurred on varying days between October and November 2023, with water depths ranging from 3 to 6 cm. A comprehensive analysis investigated the influence of different factors on daily production, such as ambient temperature, solar intensity, and inner and outer glass temperatures. The experimental results indicate that the solar still with a single basin, operating at a water depth of 3 cm, achieved the highest water productivity (2.68 L/day) and displayed the best efficiency (30.52%) compared to 4, 5, and 6cm depths. Furthermore, incorporating an external reflector into the solar system still demonstrated a notable elevation in temperature, resulting in a significant boost in water productivity of 3.085 liters per day. This improvement also led to an increase in efficiency of 35.1%.

Time and Cost Management in Water Resources Projects Utilizing the Earned Value Method

Ahmed Rasul Hussein — 2024-06-30

Today, the development of infrastructure and construction projects in developing countries is of paramount importance. Water projects, in particular, play a crucial role in advancing agriculture, industry, and the economy. The success of these projects hinges on the effective management of time, cost, and quality. The most critical indicator of a project's success is its completion within the forecasted time and budget leading up to its operation. This study aims to assess the impact of Earned Value Management (EVM) 's impact on managing project schedules and budgets in water resource projects. The earned value method was employed to ascertain if the project was ahead or behind schedule and whether the costs were within the budget or had overrun. The values of the Earned Value Index were analyzed at three stages of project implementation. Examining the Schedule Variance (SV) at various phases indicates that a lower percentage is more advantageous for the project. Initially, the SV was 40%, signaling a delay mainly due to the delayed start of operations in the injection gallery and access points. This improved to 25% in the second stage, with the commencement of previously lagging activities. The schedule variance decreased to 11.6% in the final stage, aligning closer to the project schedule's end. Additionally, the Schedule Performance Index (SPI) value, which reflects the efficiency of project management in terms of timeliness, improved from a weak start of 0.6 to 0.88 (with 1.0 indicating that project performance is on target).

Utilization of Oil Palm Empty Fruit Bunch (EFB) Waste as a Mixing Material for In-terlocking Brick Production

Lelly Marini — 2024-06-30

The choice of building materials has a considerable influence on the reliability of a building. Conventional bricks, despite their frequent use, pose a challenge due to their weight, as they affect the load-bearing capacity of the building, unlike interlocking bricks, which have holes at the top and bottom for reinforcement, potentially reducing the effects of earthquakes. In this study, interlocking bricks made from a mixture of empty oil palm fruit stalks and sand with different sand replacements (0%, 2.5%, 5%, 7.5%, 10%, and 12.5%) are investigated. The research results consistently show that the average density of EFB fiber composite bricks with a density of 1.48 grams/cm³ is lower than that of standard composite bricks. Although the compressive strength of these bricks is initially lower than that of standard bricks, it increases with the substitution of part of the sand with EFB fibers, although not significantly, with the highest compressive strength observed at a substitution rate of 12.5%, reaching 5.201 MPa. Water absorption rates ranged from 13.97% to 21.99%, which increases compared to standard bricks but still meets the requirements. With ongoing research and innovation, EFB-based interlocking bricks have the potential to address environmental challenges and support sustainable and environmentally friendly building practices.

Influence of Carbon Fibers on the Rutting Susceptibility of Sustainable HMA Mixtures with Untreated Recycled Concrete Aggregates

Nadheer Albayati — 2024-06-30

This paper focuses on achieving sustainability to reduce the detrimental effect on the environment and the economic aspects by including several ratios of coarse recycled concrete aggregates (RCA) (25, 50, 75, and 100%) in asphalt mixtures. The methodology included testing all raw materials, the wheel tracking test to assess mechanical performance, and the Marshall design approach to determine the appropriate asphalt content. The outcomes demonstrated no discernible difference between the volumetric characteristics of the asphalt mixtures containing RCA and the control mix. Marshall's stability rose by 14.2% when 50% of the mixture contained RCA compared to the control combination. All combinations containing RCA were performed inferiorly to the control mixture regarding rutting. 19.63% was the greatest increase in rut depth for combinations made entirely of recycled concrete aggregate. Several percentages of 0.2, 0.25, and 0.3% carbon fibers were added to the total weight of the asphalt mixture to enhance rutting performance. Marshall's stability and resistance to rutting have significantly increased, attributable to the carbon fibers; nonetheless, the volumetric properties of the asphalt mixture have only slightly altered. The combinations with 0.3% carbon fiber reinforcement and 50% RCA showed the largest gain in Marshall stability, up 34.6% above the control mixture. The same combination had the strongest resistance to rutting, which was —39.08% higher than the control mixture.

Teaching and Learning Optics: A Bibliometric Analysis with a Detailed Future Insight Overview

Antomi Saregar — 2024-06-30

Optics research has recently proven important for scientific, educational, and industrial applications. This study examines the increase and distribution of literature on learning and teaching optics. This analytical strategy uses quantitative and statistical methods to identify trends, evaluate quality, and monitor progress. From the 530 documents obtained using the Scopus database between 1944 and 2023, 464 were chosen. With a total of 49 documents, 2014 had the greatest substantial increase in the number of documents since 1944 till this data was collected. Writers from the United States contributed to 115 documents with 36% citations. They ranked first, followed by authors from Germany (37 documents and 12% citations) and China (36 documents), with citation rankings just below the top 10. Most publications appeared in Physics Education (15 documents; Q2 SJR 0.41). The International Journal of Science Education received the most citations for publications on teaching and learning optics (159 citations; Q1 SJR 1.15) and was ranked 1 in its category. The current core literature on teaching and learning optics shows that this area is quickly evolving but with insufficient international research collaboration. Research collaboration in this field must be strengthened to improve the worldwide response to teaching and learning optics. There is a need to broaden the scope of study regarding assessment instruments, technological engineering, learning approaches, learning methods, learning strategies, and learning media within the context of teaching and learning optics from elementary school to the university level.