Journals of Universiti Tun Hussein Onn Malaysia (UTHM)
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Addressing Competency Gaps in Aviation Maintenance Education: Lessons from the Philippine Experience
No full textThis study investigates competency gaps in the Aircraft Maintenance Technology (AMT) program of the Philippine State College of Aeronautics (PhilSCA), assessing how well the curriculum aligns with international aviation standards, including the International Civil Aviation Organization’s (ICAO) Annex 1 on personnel licensing, the European Union Aviation Safety Agency’s (EASA) Part 66 on aircraft maintenance licensing, and the Philippine Civil Aviation Regulations (PCAR) Part 3 governing approved training organizations. Employing a convergent mixed-methods design, the study collected data from 85 purposively selected participants, including graduates, industry professionals, and educators, between January and March 2024. Data collection involved surveys, semi-structured interviews, and curriculum document analysis to evaluate training effectiveness and graduate readiness. Results show strong curriculum alignment in foundational topics such as propulsion systems and safety documentation. However, significant gaps were identified in advanced diagnostics, avionics systems, composite materials, and essential soft skills such as communication and teamwork. Graduates who completed On-the-Job Training (OJT) in airline environments demonstrated higher job readiness than those trained in more minor Maintenance, Repair, and Overhaul (MRO) facilities. The study underscores the need to adopt competency-based education (CBE), standardize OJT placements, and deepen industry-academic partnerships. Recommendations include integrating certification pathways, expanding practical training, and establishing continuous curriculum review processes. By analyzing the Philippine experience, this study offers actionable insights for developing countries. These findings inform scalable reforms toward a globally aligned aviation workforce
Modelling and Forecasting of Crude Oil Price Return Volatility from 2006-2023: An Application of the Garch Models
No full textThe volatility dynamics of Nigerian crude oil prices from 2006 to 2023 were investigated in this work using the generalized autoregressive conditional heteroskedasticity (GARCH) modeling technique. Strong evidence of time-varying conditional heteroskedasticity in the dataset was found using diagnostic tests. The model information criteria showed that the dependencies were well represented by the parsimonious GARCH (1,1) formulation. Based on maximum log-likelihood and information criterion values, exponential GARCH (EGARCH) showed the best in-sample fit. The projection predicts prices beginning at a very high level in 2024 and then rapidly falling, with a steep downward slope in the expected price trajectory. The model predicts that by the end of 2025, crude oil prices will be significantly lower than they were at the start of the projection period. Overall, our empirical findings give good support for using EGARCH techniques to forecast volatility in Nigerian crude oil returns. As a result, practitioners now have access to efficient prediction tools that have been verified using rigorous statistical approaches to help them estimate future price risk
Sustainable Paper Production Using Treated Pineapple Leaf Fiber and Wastepaper Composites
No full textFibers extracted from plants offer alternatives to commercial materials to produce paper which are increasingly valuable in sustainable product development. This study investigates the potential of pineapple leaf fibers (PALF) as an alternative to synthetic fibers in composite with wastepaper for recycle paper fabrication to reduce the agricultural waste. The study focuses on the extraction and characterization by emphasizing the effects of alkaline treatment using sodium hydroxide (NaOH) on the physical and mechanical properties of the PALF. Wastepaper was then combined with treated PALF in varying ratios i.e. 1:1, 1:2, and 2:1 to create the composite paper. The properties of the synthesized PALF were evaluated in term of moisture content and tensile strength. While the morphological characteristics was evaluated using Scanning Electron Microscopy (SEM) and functional group determination by Fourier Transform Infrared Spectroscopy (FTIR). Results indicate that NaOH treatment significantly enhances the mechanical properties of PALF by improving fiber strength and reducing moisture content with the 1:2 ratio demonstrating the highest tensile strength (9234.596 Pa). Compared to the 1:1 ratio which exhibited a tensile strength of 6946.375 Pa, the 1:2 ratio resulted in a 32.9% increase in tensile strength. Similarly, when compared to the 2:1 ratio (5311.917 Pa), the 1:2 ratio showed an impressive 73.9% enhancement in tensile strength. These findings suggest that increasing the proportion of wastepaper relative to pineapple leaf fiber (PALF) enhances fiber bonding and mechanical strength, likely due to better fiber interlocking and reinforcement. With its high tensile strength and improved durability, this composite paper can be utilized in packaging materials, stationery and biodegradable wrapping papers. This study highlights the viability of PALF in the development of eco-friendly composite materials, contributing to waste reduction and promoting the use of renewable resources in material science
Characterization of The Properties of South Lampung Clay as Lightweight Expanded Clay Aggregate
No full textBloating properties are essential to determine clay\u27s ability to expand and form pore structures for lightweight expanded clay (LECA) applications. South Lampung clay was taken from four different places: TN, TB1, TB2, and TJ. The clay was dried at 110oC until the water content was 7%, then ground using a ball mill to 200 mesh. The clay was formed into balls with a diameter of 10 mm and then heated at 1,050oC for 15 minutes. The chemical composition was analyzed by X-ray fluorescence. X-ray diffraction was used to analyze the crystal structure formed. Topography was analyzed using FESEM. The bloating coefficient (Cb) was calculated by comparing the volume before and after heating. Based on SiO2, TN and TB1 meet the self-bloating standard with 52.28 and 56.82% content, respectively. However, based on Al2O3, only TB1 meets the minimum standard with a value of 17.46%. Based on the total flux being below 10%, all clay has the potential for self-bloating. The type of clay is kaolinite with feldspar and kaolin phases. The bloated clay was found in TB1 and TJ with values of 1.08 and 1.46. Additives are needed to increase an expansion. This study can be developed to obtain the composition of local clay, which can be applied to various fields
An Innovative Water Reaction Turbine of the Ultra Z-Blade Designed for Water Conditions of Low-Head and Ultra-Low Flow
No full textIn comparison to conventional fossil fuels like coal and gas, hydropower offers many advantages. This is because it does not discharge harmful gases into the atmosphere, which contributes to air pollution. Nevertheless, there will be negative ecological effects in the area around a hydropower energy-producing plant if it is built. Hydropower is significantly less dangerous than pico-hydro systems, which only require a trickle of water to generate electricity through the rotation of a turbine. The reaction-type turbine is the topic of this study because it can be rotated by a relatively small amount of water. Cross pipe turbines (CPTs), split reaction turbines (SRTs), and Z-blade turbines (ZBTs) are all examples of older turbine designs that prioritized pressure above flow. There has been little progress made so far to compensate for the low head and ultra-low flow water segment. In order to tap into low head and ultra-flow water resources, this work attempts to address this by developing an ultra z-blade turbine for pico-hydro producing systems with two types of pipes measuring 0.75 inches and 2.0 inches in diameter. The concepts of mass, momentum, and energy conservation are used to generate the equations. The performance of the newly developed U-ZBT is compared to that of the well-established CPT, SRT, and ZBT via an experimental method. As a result, a 0.75-inch pipe size performed better than a 2.0-inch pipe size at a maximum speed of 130 rpm and a water flow rate of 1.77 L/sec
Design of High Efficiency Class E Power Amplifier Utilizing 0.18-µm RF CMOS Technology for 5G Network
Full text linkThe design of high-efficiency class E power amplifiers faces challenges due to low transistor breakdown voltages, high parasitic capacitances, and limited quality of on-chip passive components, which reduce power efficiency and linearity. Existing solutions offer moderate efficiencies but often require complex trade-offs that are not ideal for high-frequency applications. This research aims to optimize a class E power amplifier design to achieve higher efficiency and output power for 5G newtork, addressing these limitations while maintaining performance suitable for modern wireless communication systems. This paper proposed a high efficiency class E PA for 5G network. The proposed PA is implemented using the 0.18-µm RF CMOS process technology, and the circuit is designed and simulated using Cadence software. The proposed PA consists of a power stage and a driver stage. The power stage and the driver share a single source. The simulation results show that at input power of 0 dBm and supply voltage of 1.8 V, the proposed PA demonstrates a maximum peak power added efficiency (PAE) of 55 %. Meanwhile, a maximum output power (Pout) of 13.1 dBm is delivered by the proposed PA. Since the PA exhibits a stability factor (K value > 1), it is unconditionally stable. In addition, the PA achieves s-parameter of S11, S22 and S21 performances of -13.8 dB, -29.3 dB and 19.7dB, respectively. Furthermore, the layout of the proposed PA is 1.82 mm2 including the pads.
Performance Evaluation of Different Classification Algorithms Applied for Identifying Maternal Nutritional Status by Anthropometric Measurements
No full textPregnancy significantly influences infant quality and development. Maternal monitoring, indicated by body mass index (BMI) and mid-upper arm circumference (MUAC) measurements, reflects a country\u27s socioeconomic development. Improper measurements heighten the risk of chronic energy deficiency (CED) in pregnant women and low birth weight (LBW) in infants. This study leverages artificial intelligence (AI) to enhance the detection process. Specifically, it evaluates the prediction performance of various classification methods: Decision Tree (DT), K-Nearest Neighbors (KNN), Logistic Regression (LR), Naive Bayes (NB), Random Forest (RF), and Support Vector Machine (SVM). Using interviews in Jombang District, Indonesia, these methods were expected to identify maternal nutritional status. The model design was divided into two stages: MUAC estimation generated binary classes, and BMI estimation generated multiple classes. The evaluation of these methods included various performance metrics: Accuracy (Acc), G-means, Sensitivity (Sens), Specificity (Spec), Positive Predictive Value (PPV), and Negative Predictive Value (NPV). Based on the results, all methods are proposed for both classifications, except KNN on multiple classification. KNN achieved significant scores in all matrices with p<0.01. KNN\u27s performance is impacted by data imbalance. The study revealed a strong correlation (0.92 coefficient) between BMI and MUAC variables. The application of ML algorithms in detecting maternal nutritional status can significantly enhance the effectiveness and efficiency of health facilities, especially in areas with inadequate resources and medical personnel. However, exploring diverse ML algorithms is recommended to find optimal approaches for more varied data and to contribute solutions for sustainable development in the country.
Characterization of Clays from Adamawa State, Nigeria, for 3D Printing Applications
No full textThe Sustainable Development Goal 6 aims to ensure availability and management of sustainable water and sanitation, and this is particularly poignant for rural communities that rely heavily on sources such as streams, rivers, hand dug wells and in rare cases boreholes. In Nigeria, only a fraction of the population use improved drinking water sources and sanitation facilities. This makes access to safe and clean drinking-water in the rural areas of Nigeria practically impossible, leading to several health complications. This plays a significant role in diarrhoea related cases in Nigeria, in both adults and children. This research assessed the viability of locally sourced clay from Adamawa State as candidate material for 3D ceramic printed water filter. The assessment involves testing the physical, microstructural and mineralogical properties of the local materials obtained from different areas of the State. A prototype water filer was developed following geometric designs in Autodesk Fusion 360, and trial mix designs of composite materials using 3D printing extrusion process. The result indicates that the clays satisfied minimum plasticity requirements and exhibited satisfactory extrusion property. Heavy metals were not detected in all the clay materials, and composition displayed high amounts of silica and alumina content. The application of 3D printing technology will go a long way towards improving state-of-the-art and refinining the process as well as provide real time opportunity for correcting and editing flaws detected at each stage of prototype development as oppose to the traditional pottery process.
Development of a Mobile Application for Building Maintenance by Implementing Augmented Reality Technology
No full textBuilding maintenance procedures are currently inefficient, which emphasizes the need for more creative and efficient solutions. In order to improve maintenance operations, the present study aims to develop a functional testing of a mobile application that combines Building Information Modelling (BIM) and Augmented Reality (AR). The development process was tested using Autodesk Revit to produce 3D models that included comprehensive equipment and building material specifications. Subsequently, the AR component of the application was developed using Unity Hub in conjunction with the Vuforia Software Development Kit (SDK). Alpha and Beta testing were deployed and tested in Android devices comprising two key phases. The application showed 100% operational stability with all features functioning as intended throughout alpha testing, which comprised internal evaluations to confirm functionality, stability, and usability. The System Usability Scale (SUS), which consists of 10 Likert-scale questions assessing user confidence, ease of interaction, and perceived usefulness, was used in beta testing to gather end-user input. Beta testing confirmed the system’s effectiveness, with an average SUS score of 72.5 and 90% of users reporting that the application is easy to learn and use. The study demonstrates that integrating AR with BIM in a mobile application fundamentally enhances building maintenance by streamlining processes. This study offers a solid foundation for further research and development and shows how combining AR and BIM might enhance conventional building maintenance
A Comprehensive Review of Network and Communication in IoT Systems
No full textThe Internet of Things (IoT) represents a transformative domain in technology, integrating devices equipped with sensors, software, and connectivity to enable data exchange and automation. This paper discusses IoT networks and their communication protocols, highlighting applications across smart homes, industrial settings, and agriculture. It explores core technologies such as Wi-Fi, Bluetooth, Cellular (4G/5G), and LoRa, emphasizing their advantages and limitations. The layered IoT architecture, from perception to application, is reviewed, detailing its impact on system performance. Challenges related to energy consumption, security, and scalability are also addressed. Key findings underscore the importance of tailored communication solutions and integrated protocols for optimized IoT performance