Journals of Universiti Tun Hussein Onn Malaysia (UTHM)
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Analysis of MgFeCu-Layered Double Hydroxides with Different Interlamellar Anions for Efficient Removal of Dye in Wastewater Treatment
No full textSynthetic dyes, widely used in industries like textiles, leather, and paper, pose a significant global concern for water pollution due to their resistance to conventional wastewater treatment, causing toxic, carcinogenic, and mutagenic effects, endangering aquatic life and disrupting natural processes like photosynthesis. The study analyzes the adsorption of as-prepared MgFeCu-LDH with varied interlamellar anions (CO₃²⁻, SO₄²⁻, NO₃⁻) on dye wastewater, utilizing advanced techniques like Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) to identify LDH morphology and crystal structure, elucidating dye removal mechanisms. The methods and materials used in this study include synthesizing MgFeCu-Layered Double Hydroxides with various interlamellar anions using co-precipitation and involved weighing 50 mg of LDH and 30 ml of dye solution, equilibrating samples, and analyzing UV analysis and storage to determine the amount of adsorbed MO in the supernatants, followed by adsorption kinetic studies to evaluate the efficiency and mechanisms of dye removal from wastewater, focusing on pseudo-second-order kinetic models to determine the dominant adsorption processes. MgFeCu-SO₄ LDH removes dyes from wastewater in 150 minutes using a second-order process, providing a quick, cost-effective, and environmentally friendly solution. The findings provide important insights into the development of novel materials to address the persistent problem of synthetic dye contamination in aquatic systems, highlight the potential of LDH materials for wastewater treatment, as they offer a scalable approach to dye removal via tailored chemical and structural properties
Comparative Analysis of Distance Functions on DBSCAN Algorithm: Mapping Malnourished Toddlers in Medan City, Indonesia
Full text linkMedan City is one of Indonesia\u27s largest cities and faces fundamental challenges in addressing malnourished toddlers. It had a stunting prevalence of 19.9% in 2022. The high rates necessitate a practical approach to identifying and managing high-risk areas. This study aims to map districts in Medan City based on the spatial data of public health center locations and malnutrition data for toddlers, using the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm. DBSCAN is a popular clustering algorithm because of its ability to group data based on density and detect outliers as noise. However, using the Euclidean distance function in DBSCAN may not be appropriate for all geospatial cases. The novelty lies in comparing five distance functions (Euclidean, Manhattan, Minkowski, Cosine, Chebyshev) within DBSCAN to determine which produces the most meaningful clustering in a geospatial health context. The study shows that DBSCAN with the Chebyshev distance function cannot effectively map the malnutrition problem in toddlers, as indicated by a Silhouette index (SI) value below 0.25. The clustering quality using Minkowski and Cosine distance functions in DBSCAN is not superior to that of the classical DBSCAN, with all three producing weak and unclear structures. The most effective mapping results come from using the Manhattan distance function in DBSCAN, which yields an SI value of 0.51045, two clusters, and optimal parameters of Minpts = 6–9 and ε = 6.98–7.8. The first cluster includes two districts (Medan Labuhan and Marelan), while the remaining districts form the second cluster. The analysis of different distance functions provides new insights into how selecting the appropriate distance measure can influence clustering quality in a geospatial context with DBSCAN. The similarity of the clusters is expected to inform decision-making in addressing toddler malnutrition issues in Medan City
Use of Tyre Pyrolysis Products as Recycled Raw Materials for the Production of Composite Suspension Fuel
Full text linkComposite suspension fuel (CSF) is a viable alternative not only to solid coal but also to fuel oil and diesel fuel. The issue with combined systems is the low stability and heterogeneity of the distribution of solid particles, which causes an increase in the viscosity of dispersed systems. Studies have shown that it is possible to use pyrocarbon, which is made from used car tyres, as a fuel for boats. Systems based on pyrocarbon without additives have high viscosity values. To regulate the rheological properties and stabilize the CSF, additives such as dispersants, plasticisers, and stabilisers are used. Research has been done into how dispersants affect the properties of composite suspension fuel (CSF). They used additives like carboxymethylcellulose (CMC), sodium lignosulfonate (LSTNa), naphthalene formaldehyde (NF), the condensation product of β-naphthalene sulfonic acid and formaldehyde (C-3), and humic acids. Studies of the flow of CSF based on pyrocarbon are in line with studies of the surface of pyrocarbon using electrokinetic methods. It is estimated that the surface of unmodified pyrocarbon has a positive charge at a pH of 2-10. The addition of reagents causes a change in the surface charge of the pyrocarbon and surface recharging. The best results have been obtained in CSF formulations with additives containing a sulfur group, such as C-3, NF, and LSTNa in a mass concentration of 2%. The resulting suspensions have an apparent viscosity of no more than 0.8 Pa·s, which makes it possible to use the obtained CSF as a liquid fuel suspension with a solid phase concentration of up to 60% by mass
Human-Metaverse Interaction in TVET: Research Trends and Future Directions
Full text linkTechnical and Vocational Education and Training (TVET) is swiftly advancing to integrate digital and immersive technologies, equipping learners for prospective employment markets. The metaverse, a shared virtual environment facilitating real-time interactions between individuals and digital entities, is an emerging technology impacting TVET. As Metaverse applications proliferate, they are anticipated to transform training techniques, skill acquisition, and workforce preparedness in Technical and Vocational Education and Training (TVET). A comprehensive analysis of prior studies on Human-Metaverse Interaction (HMI) is essential for grasping these implications. This study performs a bibliometric analysis of HMI, pinpointing essential topics, authors, publications, and trends within this domain. Primary bibliographic data is obtained from the Scopus database using keyword searches and quantitatively examined using bibliometric approaches in VOSviewer software. The analysis examines publication volume, thematic content, national connections, and keyword frequencies to delineate the intellectual framework of HMI research. Research findings reveal an increasing emphasis on virtual reality, augmented reality, and metaverse-related classifications, while highlighting deficiencies in domains like human-robot interaction and social virtual reality. This study offers significant insights for TVET educators and professionals, emphasizing how breakthroughs in HMI research might influence curriculum design, pedagogical approaches, and workforce readiness for a metaverse-oriented future
Effectiveness of E-Module and Learning Style on Self-Regulation Learning Model to Increase the Occupational Safety and Health Knowledge for Mechanical Education Students
Full text linkVocational education is designed with learning that is relevant to the industrial sector. In learning activities, teaching materials are essential to support learning goals. The study aimed to identify the effectiveness of the E-module and learning style on application learning to increase the occupational safety and health knowledge for vocational education. This research is quantitative on variables bound between variables. The population of the study are all students of the education machine engineering faculty that have taken the Health and Safety course in the academic year 2023/2024. The methods used to collect the data needed in the research are R and D, which include developing instruments; lesson plans, practice questions, and quizzes; pre-test and post-test questions, learning style questionnaires, and E-module. The research results show that the E-module increases the effective health and safety work learning achievements, and with that, the style of learning lacking learning effectiveness in improving health and safety work depends on methods and the use of the E-module. Simultaneously, E-module and learning-style learning achievements effectively increase health and safety, especially for the visual learning style; the effectiveness of the E-module has a good outcome. Furthermore, the use of E-module and learning style development is needed.
Women\u27s Leadership and Career Motivation in the Construction Industry: Challenges and Barriers
Full text linkThe construction industry is one of the sectors with high employment risks and is closely associated with challenging careers. "Dirty, Difficult, and Dangerous" or 3D describes the work situation on construction sites, making these jobs both difficult and risky. This environment creates problems such as negative organizational culture, difficulty maintaining positions within organizations, hazardous workplace conditions, gender stereotypes, and the overall image of the construction industry, which often deters women from pursuing careers in this field. This study aims to examine the challenges and barriers faced by women in leadership roles in the construction industry and how these factors impact their career motivation. The study focuses on three main objectives: identifying the challenges women leaders face in enhancing career motivation, identifying the obstacles to women\u27s leadership, and understanding the relationship between these challenges and obstacles in the construction industry. To achieve these objectives, this study employs a literature review and quantitative methods, involving female leaders working in Grade 7 (G7) construction companies who hold positions such as site supervisors, site engineers, architects, safety supervisors, and surveyors. Conducted in the construction area of Johor Bahru, the study surveyed 172 women leaders. Descriptive and inferential analyses were used to measure the variables set in the study. The findings indicate that the primary challenges for women in leadership are organizational culture, maintaining positions within organizations, and gender stereotypes. Additionally, significant barriers include career balance and skill competence. This study serves as a reference for understanding the obstacles and challenges that women leaders face in the construction industry, providing insight into how these barriers can be overcome to enhance women\u27s leadership and career motivation in this demanding field
Integrating Circular Economy Through Refuse, Rethink and Reduce in Vocational Education for Sustainable Development
Full text linkAdvancements in sustainable development have expanded into vocational education, highlighting the teaching of circular economy as pivotal in realizing the global vision for Sustainable Development Goals. However, there is no specific tool used to study the smarter product consumption and manufacturing in circular economy management, especially in refuse, rethink, and reduce constructs, as detailed in the 9R circular economy framework, has prompted the current study to conduct a preliminary study throughout the instrument\u27s development and validation. The determination of content validity occurs at two levels; instrument development, and instrument validation. This study aims to obtain item-level content validity index (I-CVI) and scale-level content validity index (S-CVI) for instrument to evaluate smarter product use and manufacture in teaching circular economy. Findings from the first research question indicated that there was agreement on 39 of 44 items (I-CVI at least 0.83), while 5 items did not meet the CVI cutoff value from the six experts who validated the instrument, were subject to revision. The instrument\u27s overall item-level content validity index (I-CVI) for all three constructs is 40.00. The second research question revealed an S-CVI value (on average) of 0.91 for the entire session, with an S-CVI (Universal Agreement) of 0.57. In conclusion, the completed 39-item instrument demonstrates content validity and holds potential for enhancing evaluation efforts on smarter product use and manufacture (refuse, rethink, and reduce) in teaching circular economy for vocational education
Multi-Additive Optimization of Fine-grained Soil Using Taguchi-Grey Relational Analysis Approach
Full text linkThis article presents a novel integrated statistical approach for the multi-additive optimization of the fine-grained soil specimens reinforced with polymeric fibers. Eggshell powder (3%-9%), polypropylene fiber (0.05%-0.15%) and sodium chloride (2%-6%) were mixed in the silty soil to test the strength and durability characteristics of the stabilized soil for various construction purposes. The soil specimens having different mix proportions, as allotted through L9 (3^3) standard orthogonal array table, were subjected to various laboratory experiments and the obtained responses were further analyzed through Taguchi method integrated with Grey Relational Analysis (GRA) approach. This novel hybrid technique was used to integrate the multiple responses into a single response. The results of the study positively affirm the efficacy of the Taguchi-GRA integrated approach in geotechnical engineering
Light Intensity Optimization of a Microcontroller-Based Solar Tracking Panel
Full text linkThis paper is on the light intensity optimization of a microcontroller-based solar tracking panel system, addressing the limited efficiency of fixed solar panels in capturing solar energy. This project aims to improve fixed solar panels by using a tracking system that always follows the sun\u27s direction using a microcontroller. An automated tracking system for solar panels usually has two types: single-axis and dual-axis. This project studies the light intensity gained from the solar panel based on the tilt angle of the solar panel according to the sun\u27s movement. The gyroscope is used to gather data on the tilt angle to analyze and compare it to a fixed solar panel at an optimal angle. A DC multimeter measures the voltage and current obtained from the solar panel, and a DC motor moves the panel every 1 hour. At the end of this work, a complete automatic solar tracking system with high efficiency was successfully developed. There is an increase of 9.195% in the efficiency of the power gained by applying the solar tracker system. Therefore, a solar tracker can help improve the efficiency of collecting renewable energy of solar
Thermodynamic Analysis of Flammability and Ecological Safety Levels of Liquefied Petroleum Gas and R134a Refrigerant Mixtures for Refrigeration Applications
Full text linkThe flammability of hydrocarbons such as propane, butane, and liquefied petroleum gas (LPG) affects their wide acceptance as working fluids in air-conditioning, refrigeration, and heat pump systems. Mixing LPG with non-flammable R134a will produce a mixture with lower flammability. Therefore, this paper investigated the physical properties, flammability levels, and global warming potentials of LPG and R134a mixtures. The results obtained revealed that the mixtures of LPG and R134a exhibit low critical pressures and higher critical temperatures that are reasonably higher than the ambient temperature, which are beneficial to the cooling effect per unit volume of the refrigeration system. The mixture’s boiling point temperature and global warming potential (GWP) reduce as its flammability increases, which will require a diligent trade-off among these three properties of the mixture. The percentages of LPG in the mixture that produced satisfactory GWPs with respect to the EU’s F-gas regulation and those that falls into the safety class of mild flammable range from 45 to 100% and 5 to 90%, respectively. Conclusively, this study reveals that novel ecologically acceptable refrigerants with reduced flammability could be obtained from the mixtures of LPG and R134a refrigerants within the range of 45 to 90% content of LPG