International Journal of Integrated Engineering
The International Journal of Integrated Engineering (IJIE) is a single blind peer reviewed journal which publishes 3 times a year since 2009 (April, August and December). The journal is dedicated to various issues focusing on 3 different fields which are: Civil and Environmental Engineering. Original contributions for civil and environmental engineering related practices will be publishing under this category and as the nucleus of the journal contents. The journal publishes a wide range of research and application papers which describe laboratory and numerical investigations or report on full scale projects. Electrical and Electronic Engineering. It stands as a international medium for the publication of original papers concerned with the electrical and electronic engineering. The journal aims to present to the international community important results of work in this field, whether in the form of research, development, application or design. Mechanical, Materials and Manufacturing Engineering. It is a platform for the publication and dissemination of original work which contributes to the understanding of the main disciplines underpinning the mechanical, materials and manufacturing engineering. Original contributions giving insight into engineering practices related to mechanical, materials and manufacturing engineering form the core of the journal contents. More details
Open access licenses Open Access is by licensing the content with a Creative Commons (CC) license. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
7-level of Asymmetric MLI with Reduced Number of Switching Devices Structure for High Power-Density Achievement Using Pareto-Front Method
In order to obtain high power density utilizing the Pareto-Front technique, this study presents the performance of the suggested 7-level asymmetric multilevel inverter (AMLI) topology employing a reduced number of switching devices (RNSD) structure. In order to decrease total harmonic distortion (THD), AMLI topology primarily produces greater levels of output voltage without changing the structure. For a 7-level AMLI, a 5-level RNSD structure is suggested as the circuit configuration. The suggested circuit construction will be operated using the sinusoidal pulse width modulation (SPWM) switching strategy. In actuality, because SPWM generates the switching scheme using a sine wave as a reference, its THDs are smaller than those of PWM. In accordance with IEEE Std 519-1992, the LC passive filter is taken into consideration. It demonstrates that the THD of the 7-level AMLI is the lowest in simulation, at 0.8%, compared to 4.4% in experimental data. The Pareto-Front method comparison results showed that, despite the switching frequency changing from 2 kHz to 500 kHz, the proposed 7-level AMLI with RNSD structure is still able to achieve high efficiency at 98.52% and high power-density of 4.46 kW/dm3 at 75 kHz when compared to the 7-level cascaded H-bridge structure.
Issue on Electrical and Electronic Engineering
Copyright (c) 2025 International Journal of Integrated Engineering https://creativecommons.org/licenses/by-nc-sa/4.0
Assessing Solid Waste Management Practices of Shoreline Cottages in First Class Municipality Public Beach Resorts: A Quantitative Analysis in South Cebu, Philippines
Beach resorts are vital to the tourism industry, providing relaxation and recreation for both locals and visitors. However, the enjoyment they offer often comes at a cost to the environment, particularly in the form of solid waste. This study takes a closer look at how shoreline cottages in public beach resorts located in South Cebu, Philippines, manage their waste. Guided by the principles of the Ecological Solid Waste Management Act of 2000, the research assessed current waste generation patterns and evaluated management practices in two first-class municipalities: Argao and Dalaguete. Using a quantitative and descriptive approach, data were gathered from 68 participants, comprising business owners, resort staff, and local government officials, through surveys, interviews, and actual waste sampling. The findings reveal a noticeable difference in the amount of waste produced on busy versus unbusy days, with recyclable materials being the most common type of waste generated. While awareness of proper waste disposal is generally high, issues remain in waste segregation and consistent policy enforcement. Importantly, the study found strong correlations between the local government's waste management efforts and those of the resorts, particularly in areas like segregation, disposal, and compliance with penalties. The results highlight the need for a more integrated and collaborative approach to waste management—one that strengthens existing practices, improves compliance, and supports sustainable tourism.
Issue on Civil and Environmental Engineering
Liquid Disintegration Regime of Plain Orifice, Swirl, and Effervescent Atomization: A Review
Liquid atomization is a process in which bulk liquid disintegrates into sprays. Numerous liquid atomization mechanism theories have been developed to describe the disintegration process. The disintegration process of bulk liquid into sprays can be characterized using the liquid disintegration regime map. This map illustrates stages of liquid disintegration for a liquid atomization mechanism and is a helpful tool in understanding the underlying physics of a specific liquid atomization regime. However, a liquid disintegration regime map for a type of atomization, namely swirl effervescent atomization, is hardly available and is hypothesized in this paper. Swirl effervescent atomization has broad advantages within the hybrid category, and it is crucial to map the liquid disintegration regime for this type of liquid atomization. The first stage towards mapping the liquid disintegration regime is to review the liquid disintegration mechanisms. This article reviews the liquid disintegration regime of the plain orifice, swirl, and effervescent atomization considering their relation to swirl effervescent atomization.
Issue on Mechanical, Materials and Manufacturing Engineering
Enhancing Security Using ECDSA-Based Hardware Security Module with DS28E38 Secure Data Authentication IC
The increasing integration of technology across diverse sectors such as manufacturing, logistics, healthcare, and smart infrastructure has enhanced operational efficiency and introduced significant cybersecurity vulnerabilities due to open networks and automatic technology. This research addresses these risks by developing a verification system using the integrated circuit (IC) security DS28E38, which employs Elliptic Curve Cryptography (ECC) to keep data integrity. The key innovation lies in combining physically unclonable function (PUF)-based authentication with the Elliptic Curve Digital Signature Algorithm (ECDSA), providing a resilient mechanism for device identity verification and protection against cyber threats. The research also includes a comprehensive performance evaluation, considering metrics such as time efficiency, memory utilization, power consumption, and resilience against simulated cyberattacks, demonstrating that the proposed system significantly enhances cybersecurity while preserving operational performance.
Impact of Autonomous Vehicles on Control Delay & Safety: A Case Study of Signalized Tight Diamond Interchange at Executive Towers Business Bay, Dubai
Autonomous Vehicles (AVs) promise to transform urban mobility by improving traffic flow and safety, but their actual impact under varied traffic and geometric conditions remains uncertain, warranting further study. This study evaluates the impacts of AVs on the operational and safety performance of a signalized tight diamond interchange at Executive Towers Business Bay, Dubai, under mixed traffic conditions. Three AV driving logics: aggressive, normal and cautious, were gradually introduced, replacing conventional cars while maintaining a constant mix of 2% heavy vehicles and 1% buses. A calibrated and validated traffic model was developed in PTV VISSIM using site-specific geometric and operational data, with maximum queue length used as the measure of effectiveness (MOE). Thirteen scenarios were simulated to evaluate varying AV penetration levels. Delay outputs were extracted from VISSIM, while vehicle trajectory files were analyzed in the Surrogate Safety Assessment Model (SSAM) using TTC thresholds of 1.5 and 1.0 seconds. Calibration yielded optimal values for VISSIM’s car-following parameters: average standstill distance (1.35 m), additive part of safety (0.75 m), and multiplicative part of safety (1.50 m). Results showed that at a demand level exceeding 5,000 veh/hr, AV-Aggressive at 100% penetration reduced average delay by 7.5% and total conflicts by 48.6% compared to conventional vehicles. In contrast, AV-Cautious increased delay by 90.6% and conflicts by 69.2%. AV-Normal caused a modest 3.5% increase in delay but reduced conflicts by 26.7%. Overall, Scenario 13, 100% AV-Aggressive—demonstrated the best operational and safety performance. These results highlight the critical role of AV driving logic in shaping interchange performance, with aggressive AV behavior at full penetration offering the most substantial improvements in delay reduction and conflict mitigation. This suggests that future AV integration strategies should consider behavior modeling as a key factor in optimizing traffic operations and safety in complex urban environments.
Thermophysiological Comfort Assessment of Football Jersey Fabrics used in Hot and Humid Weather
Optimizing thermophysiological comfort is crucial for enhancing athletic performances and well-being during intense exercise in hot and humid climates. This study assessed the comfort properties of four commercially available 100% polyester microfibre fabrics used in football jerseys: mini mesh (MM), polar eyelet (PE), eyelet (EY), and interlock (IT). Fabric assessments were conducted to evaluate thermal resistance, water vapour resistance, water vapour permeability, air permeability, and moisture management properties. Among the fabrics, the PE fabric demonstrated to give the most superior thermophysiological properties, with the lowest thermal resistance (0.009 m²K/W), the lowest water vapour resistance (0.44 m²Pa/W), and the highest water vapour permeability (237.7 g/m²/day) and air permeability (2149.2 mm/s). These values are attributed to the fabric’s porous, open-knit structure that enhances heat and moisture dissipation, resulting in improved breathability and wearer comfort. Statistical analysis confirmed significant differences among the fabric structures, reinforcing the influence of fabric design on comfort performance. The findings suggest that, among the fabrics, the PE fabric performs better as sportswear for tropical climates like Malaysia.
Monitoring Water Quality Parameters in Shrimp Aquaculture
In shrimp aquaculture, maintaining optimal water quality is essential for ensuring the health and growth of shrimp. This study focuses on the real-time monitoring of water quality parameters, using a multi-sensor system that measures temperature, salinity, dissolved oxygen (DO), pH, total dissolved solids (TDS), and turbidity. With the use of a solar panel for electricity, the multi-sensor system is capable in monitoring the water quality of a shrimp pond over two consecutive days. Based on the measurement data, the measured range is 6.5 – 9.0 for pH, 19 – 31.5°C for temperature, 9.0 – 25.0 ppt for salinity and 2.0 – 12.0 NTU for turbidity. The range of these parameters is ideal for shrimp aquaculture. Nevertheless, the TDS and DO do not meet the ideal range. TDS should be less than 1500 ppm, with a measured range of 1800 to 3400 ppm. Feed inputs and the buildup of metabolic waste may be the cause of this high TDS value. In the meantime, DO measures in the range of 2.5 to 22.0 ppm, with the lowest DO occurring late at night and falling below the DO limit of 5 ppm. By using mechanical aeration late at night to raise the DO level, this DO shortage can be resolved. The findings demonstrate that in order to guarantee accurate control of crucial parameters, ongoing real-time monitoring of sensor technology is required. Shrimp aquaculture may become much more sustainable and efficient by implementing automated systems for water quality regulation, which also lowers the risks related to environmental variations.
Nurfatihah Che Abd Nurfatihah Che Abd Rashid
Sediment Deposition Analysis using InfoWorks ICM for Segamat River, Muar River Basin
Various environment-related issues within a river system associated with urbanization will lead to urban channel and river bank erosion and sedimentation problems such as floods, water quality degradation and disruption to the ecosystem. Apart from the development, river dredging activities and sand mining will also cause instability problems to the river morphology. In view of its negative impacts to the river system, an assessment on the river morphology for Segamat River, Johor has been conducted. The study aimed to examine the processes of erosion and deposition of river morphology and propose strategic measures to minimize the effects of erosion and sedimentation along the river. Sediment transport modelling has been carried out for 10-, 50-, 100- and 1000-year Average Recurrence Interval (ARI) storm events based on the runoff hydrograph using InfoWorks Integrated Catchment Modelling (ICM) coupled with a sediment-transport module. The Ackers-White sediment transport equation was selected in the model due to its applicability across a wide range of particle sizes and flow conditions, offering reliable predictions for the study reach. The simulation results highlight the large variability in channel morphology along river reach, where the sediment transport model predicts more sediment deposition at the middle reach of Segamat River. The findings underpin an Erosion and Sedimentation Control Plan (ESCP) that spatially targets dredging moratoria, buffer-zone restoration, and adaptive sand-extraction scheduling to restore morphodynamic equilibrium and reduce flood risk.
Defining Action Plans to Reduce Defects in a Paper Production Line Using Statistical Process Control and Fuzzy Analytical Hierarchy Procedure
Defect prevention in products is essential to improve production efficiency and improve product quality in accordance with consumer expectations. Action plants to prevent defects in a paper factory were tried to be found in this research. The action plan was obtained using Statistical Process Control to control production to comply with specific limits, and Fuzzy Analytical Hierarchy Procedure used to find the priority of the problem. The data collected showed that the primary defects were in the form of wrapping alignment and folding sheets. Analysis showed that wrapper properties and the length of time the wrapper roll on the floor caused the problems. To overcome the causes of the problems, three action plans need to be taken: training, creating SOPs, and creating maintenance checklists.
Embedding the Real-Time AES-128 Encryption into Programmable Logic Controllers for Secure Modbus TCP/IP Communications in Industrial Control Systems
This study presents a practical implementation of AES-128 encryption for Modbus TCP/IP communications in industrial control systems. The proposed method advances beyond theoretical approaches by providing a deployable, hardware-independent structured control programming solution embbed on Siemens S7-1200 and Rockwell CompactLogix PLCs. Experimental evaluation shows an average encryption latency of 41.08 μs, with end-to-end communication delays maintained between 5–35 ms. An optimized key management mechanism reduces expansion overhead by 63% compared with conventional designs. Robustness is demonstrated through more than 12,000 test cycles with consistent timing performance (σ < 3 μs) and full interoperability with unmodified Modbus TCP devices. Wireshark analysis further confirms effective prevention of man-in-the-middle attacks without hardware modifications. The results indicate that the proposed scheme provides a certifiable and efficient security layer, thereby offering a feasible migration pathway for securing legacy infrastructures in Industry 4.0, SCADA, and industrial IoT environments.
ANN Based Approach For Simultaneous Detection of Groundwater Pollution Origin and Release Characteristics
Present study aims at simultaneously identifying the three essential features of groundwater pollution source identification (GPSI) problem viz. the pollutant source location i.e. the distance between origin and observation point (x), duration of the pollutant release (T0) and its concentration strength i.e. the pollutant release flux history (C0). Four Artificial Neural Network (ANN) models were developed, the three models, viz. ANN1, ANN2, ANN3 identified the three source parameters individually; while the fourth model ANN4 aimed at identifying the source parameters x, C0 and T0 simultaneously. The model input comprised multiple sets of concentration breakthrough curves (BTCs) at 50 discrete ‘x’ for 10 different T0 and 10 varying C0 values. Employing the governing partial differential equation of pollutant transport in groundwater, 383130 patterns of BTCs were generated for training and testing of ANN models. Model performance was evaluated using standard statistical measures to recognize the optimal ANN architecture. A network with architecture 14-15-3 was found to be optimum for ANN4 and resulted in a average absolute relative error (AARE) of 9.17, 19.96, 16.75 for identifying x, C0 and T0 respectively. Single output ANN models performed better than the multiple output ANN model. While comparing for individual source parameters as target variables, both the models (single and multiple outputs) could efficiently identify the source location. Whereas, the release concentration and duration of pollutant release estimation by single output model performed better than the multiple output model. The proposed ANN based solution of the GPSI problem illustrated here, has a practical application in formulating strategies for regulating and penalizing the agencies accountable for the groundwater pollution.
Synthesis and Characterization of Electrode with Pd-Ni/C Catalyst and Performance Test of MEA for Applications in Proton Exchange Membrane Fuel Cell (PEMFC)
The implementation of Pd-Ni/C catalysts in PEMFCs is still quite limited, even though Pd and Ni alloys hold considerable promise as an alternative to decrease reliance on Pt/C. The PdNi/C metal alloy functions as a catalyst on the anode side for the hydrogen oxidation process in PEMFCs. The catalyst was synthesized by incorporating NiCl₂·6H₂O into Pd/C with a catalyst loading of 0.5 mg/cm². Electrodes were prepared with varying Pd to Ni weight ratios in carbon (3:1, 1:1, and 1:3), and were compared against Pd/C and Ni/C electrodes, while a Pt/C catalyst was used on the cathode side. The Membrane Electrode Assembly (MEA) was constructed by combining the anode containing the Pd-Ni/C catalyst, and the cathode containing the Pt/C catalyst using a Nafion 212 membrane. XRD characterization showed a carbon peak at 2θ = 26.4° and a palladium peak at 2θ = 41°, both with low intensity. XRD spectrum of Pd-Ni/C electrode showing amorphous crystal peaks. The highest catalytic activity of the electrode was achieved by the electrode with Pd:Ni = 3:1 with an ECSA value of 1.539 m²/g and conductivity value of 3.98 × 10-2 S/cm. The highest OCV value was obtained with the MEA using a Pd/C catalyst at ambient temperature, reaching 0.88 V, which was not significantly different from the 0.8 V value of the Pd:Ni= 3:1 catalyst. The maximum power density of MEA with Pd:Ni= 3:1 catalyst at the anode was 4.88 mW/cm² at a current density of 10 mA/cm². This research indicates that the MEA with the Pd:Ni = 3:1 catalyst at anode achieves optimal performance at an operating temperature of 25°C, contributing to high efficiency in PEMFC applications.
Application of Artificial Intelligence in Short-Term Load Forecasting at Low-Voltage Substations
This study presents a Short-Term Load Forecasting (STLF) process in Vietnam. A total of 13 features, including 9 electricity-related features and 4 time-related features, are extracted to predict the Total Active Power (TAP) of a three-phase low-voltage transformer station. The Mutual Information (MI) analysis results show that the Active Power (AP) features in the three phases have a significantly higher importance level than the other features in predicting TAP. Two algorithms, including Deep Neural Network (DNN) and Artificial Neural Network (ANN), are used to predict TAP. In addition to the two models using all 13 features, two corresponding models using only 3 AP features are also trained for comparison. Results show that, with 17 047 data points, models using 3 AP features have a suitable level of complexity for better results than similar models using all 13 features. The DNN model with 3 features yields the best results, with MAE, RMSE, and R2 values of 1.9089, 4.2880, and 0.9971, respectively. In future research, the number of data points will be improved to explore better features, and other features could also be considered.
Flexural Behaviour of CFS Gapped Built-up Channel Beam with Web and Flange Stiffeners
This study investigates the structural performance of cold-formed steel (CFS) gapped built-up beams with flange and web stiffeners, focusing on load-carrying capacity and deflection characteristics. Experimental tests and finite element (FE) analysis were conducted to evaluate the influence of varying stiffener configurations and gap sizes on beam behavior under four point bending. Results indicate that beams with flange stiffeners exhibit higher load-carrying capacity and greater resistance to deflection compared to those with web stiffeners, due to improved stability against bending stresses. Increasing gap between the back to back channel from 25 to 100 mm was found to affect load distribution and deflection, with moderate gaps (50 mm) yielding optimal performance. The FE model showed good correlation with experimental results, though deflection under ultimate loads was slightly underpredicted, highlighting the impact of real-world imperfections. These findings provide valuable insights for designing optimized CFS gapped beams with enhanced structural efficiency by providing flange and web stiffeners for practical applications.
Human-Centered Design and Development of an Adjustable Crutch: Enhancing Usability and Functionality for Physical Disabilities
Crutches are becoming more and more critical as the number of physically disabled individuals in a nation rises. The need for multidimensional and multivariate crutches to assist people with disabilities is more significant today. Before making a variant of the standard crutch, a proper study must be done to construct a stable crutch for high load-carrying capacity. Additionally, various crutch models are also available. A new challenge is the development of an entirely new crutch model. Numerous types of analysis were carried out in this research to create a reliable and effective product, including market analysis, quality function deployment, functional structure development, Kano model development, specification and design analysis, materials and manufacturing processes, and cost analysis. All facets of product development, such as consumer requirements, assembly schematics, and recycling practices, were explored in the study. The most intriguing additions were the product’s capacity to fold and the seating tool facility. A load analysis was conducted to meet this requirement, utilizing data from a survey of disabled persons employed in the business regarding the equipment required for people with physical challenges, especially when selecting materials. Another unique feature of our product is an adjustment system that helps the user to adjust its height. These features are new and thus make our product more memorable compared to existing products on the market. Ultimately, the product was developed and utilized successfully through the research.
Turbidity Trends in 20 Water Treatment Plants Across Sabah, Malaysia: Implications for Sustainable Water Resource Management
Water Treatment Plants (WTPs) play a vital role in ensuring safe drinking water by removing contaminants, with turbidity serving as a key indicator of raw water quality. However, turbidity levels in raw water sources are increasingly influenced by extreme weather events and anthropogenic activities, presenting challenges for effective water treatment. This study aims to assess turbidity trends and identify contributing factors in WTPs across Sabah, Malaysia, to support more sustainable water management practices. Turbidity data from the WTPs, spanning 1 to 8 years, were analysed, supplemented by time-lapse satellite imagery to assess upstream catchment conditions wherever possible. Data were categorised into four administrative divisions - West Coast, Kudat, Interior, and Tawau divisions - and examined for temporal and spatial variations. The analysis revealed frequent turbidity spikes, particularly in the Tawau and Interior divisions, with some WTPs, such as Kalabakan and Beaufort I & II, recording levels exceeding 1000 Nephelometric Turbidity Units (NTU), which is the operational shutdown threshold used by WTPs to prevent treatment failure and equipment damage. Kalabakan recorded a peak turbidity of 2,264 NTU, while Beaufort I and II reached 2,528 NTU, more than twice the downtime threshold. These elevated levels were closely linked to extensive land clearing and agricultural activities. The study underscores the importance of integrated water resource management, including erosion control, reforestation, and stricter land-use regulations. To improve operational resilience, real-time turbidity monitoring and predictive modelling are recommended to enhance WTP resilience and ensure a sustainable water supply in tropical regions amidst intensifying environmental pressures.
Long-term Continuous Monitoring of Dissolved Oxygen Concentration Based on Multi-Spectral Sensors and Machine Learning
Dissolved oxygen (DO) is a crucial indicator of water quality and requires continuous monitoring across various applications. Although optical sensors are widely used for DO measurement, their large-scale deployment for long-term monitoring remains challenging due to high costs and the need for periodic replacement of sensing probes. This study presents a novel non-contact DO monitoring system that integrates a low-cost multispectral sensor with an optimized machine learning framework, offering a practical solution for long-term, continuous monitoring. A compact spectroscopic sensing unit was developed to continuously acquire absorbance data from water samples across 18 wavebands ranging from 410 to 940 nm. Multiple machine learning models were trained under different configurations, and several waveband selection algorithms were applied to identify the optimal predictive model. The neural network regression model utilizing four wavebands (460, 585, 680, and 760 nm) achieved the best result with a coefficient of determination and a root mean square error of 0.99 and 0.22 mg/L, respectively. These findings demonstrate the high accuracy and practical potential of the proposed system for long-term DO monitoring in aquaculture and environmental applications.
Experimental and Numerical Study on the Impact of Air Gaps Between Layers on the Ballistic Performance of Steel-Rubber Laminated Composites
Laminated steel–rubber composites are widely recognized for their capability to absorb and dissipate impact energy, making them promising candidates for ballistic protection. Despite their potential, the specific role of internal air gaps in influencing ballistic resistance has not been thoroughly explored. This research focuses on assessing how different air gap configurations affect the protective performance of these layered composites. A series of ballistic tests were carried out using 9 mm caliber hemispherical projectiles, supported by finite element simulations to replicate and validate the observed behaviors. Tests were conducted on specimens with varying air gaps between layers, including a configuration without any gap. The lowest penetration depth was observed in the specimen with no air gap, registering 6.502 mm in the experimental data and 6.885 mm in the simulation. Conversely, the highest penetration was recorded in the 3 mm air gap setup, reaching 10.357 mm and 10.092 mm for experimental and simulation results, respectively. Interestingly, the 2 mm air gap condition exhibited a notable rise in projectile kinetic energy, peaking at 547.6 J at 9.175 × 10⁻⁵ seconds, which then stabilized. These findings indicate that although greater air gaps allow deeper projectile intrusion, they effectively prevent back plate damage by concentrating stress absorption on the front layers. Overall, the study demonstrates that air gap design plays a critical role in controlling energy distribution and enhancing the impact resistance of steel–rubber composites.
Finite Element Model for Pull-Out Test of Reinforcement Embedded in Confined Concrete
A finite element (FE) model was developed to simulate the pull-out test of steel rebar embedded in concrete confined with pre-tensioned steel straps. The model treated both the concrete and steel rebars as refined solid elements, enabling explicit representation of their deformations. A surface-to-surface contact model was employed at the concrete-rebar interface to ensure accurate load transfer. The importance of using a confined concrete model capable of accurately simulating nonlinear behavior under high confining pressures was emphasized in the modelling process. For this purpose, the concrete damaged-plasticity (CDP) model was adopted. Multiple pull-out tests were simulated using this approach, and comparisons with experimental data demonstrated that the proposed FE model accurately reproduced bond stress-slip responses. Additionally, the model successfully captured different failure modes, including splitting failure in specimens without confinement and pull-out failure in confined specimens.
Experimental Investigation on Combustion, Performance, Emissions, and Vibrations in a Diesel-Hydrogen Dual-Fuel Engine with an On-Demand Hydrogen Generation System
The study addresses the challenge of onboard hydrogen storage in transportation by proposing an innovative solution involving an on-demand hydrogen generation system. This system operates via a chemical reaction between aluminum sulphate (Al₂(SO₄)₃) and sodium borohydride (NaBH₄), producing hydrogen gas in real-time. The research examines the performance of a Variable Compression Ratio (VCR) diesel engine running in a dual-fuel mode, where hydrogen is supplied from the reactor. Engine behaviour was systematically analyzed under varying operating conditions, including compression ratios of 16, 17, and 18, and engine loads ranging from no load up to 12 kg, increasing in 3 kg steps. Additionally, the hydrogen flow rate was adjusted between 0 and 15 liters per minute. The results indicate that the engine achieved its best performance, in terms of efficiency, combustion, emissions, and vibration characteristics, at a compression ratio of 18 and a hydrogen flow rate of 15 liters per minute. These findings offer valuable insights for the advancement of on-demand hydrogen reactors, highlighting their potential for integration with VCR diesel engines to promote cleaner and more sustainable transport solutions.
Raw Hard Clam as Adsorbent to Remove Phosphate in Water: Removal Prediction, Kinetic and Isotherm Model Study
Phosphorus pollution from various sources like agriculture, untreated industry, and domestic wastewater is a significant cause of water contamination. It can trigger eutrophication, marked by an excessive supply of nutrients that fuel the rapid growth of algae and aquatic plants. This, in turn, can lead to harmful algal blooms, severely reducing oxygen levels in the water and affecting marine life, including fish and other creatures suffering from the lack of oxygen. The purpose of this study is to evaluate how effectively raw hard clam shells remove phosphate from synthetic wastewater through batch experimental testing. Batch experiments were conducted using raw hard clam shells (particle sizes 1.18 to 2.36 mm) mixed in an orbital shaker at 170 rpm using potassium dihydrogen phosphate solution, 100 mL at a particular time, until an equilibrium state. The batch experiment data evaluating phosphate removal from raw hard clam shells had the highest removal effectiveness of 99.6%. The kinetic study proves that the predominant adsorption mechanism between the adsorbent and adsorbate involves chemisorption, where electron sharing occurs, forming chemical bonds. The adsorption isotherm data showed suitability for the Langmuir model, indicating that adsorption happens at particular binding sites in monolayer adsorption on the adsorbent surface. Additionally, the data can be used to understand the prediction contour of mass of adsorbent required and removal efficiency under various beginning concentrations from research using batch experiments. The significant potential of this study is that the Raw Hard Clam Shells adsorbent is a sustainable and eco-friendly material for tackling phosphate pollution in future wastewater treatment.
Sheikh Muhammad Fadhlullah Baktal Sheikh Farhan Bakatal
Environmental Impacts of Commercial Haulage Operations on Air Quality in Nigeria
The operation of large haulage vehicle parks in Nigeria significantly contributes to ambient air pollution, posing serious environmental and health risks. This study investigates the adverse environmental consequences of air pollutants released by haulage vehicles in a major highway park connecting Osun state to other parts of Nigeria. Focusing on Oke Ese, Ilesha, Nigeria, the research identifies primary pollutants, measures concentrations, and analyzes air quality impacts. Total Suspended Particulates (TSP) and X-ray Fluorescence (XRF) analyses were conducted across various sample sites, including the truck park and surrounding residential areas. Findings reveal that Total Suspended Particulate (TSP) concentrations range from 83.14 μg/m3 to 720.59 μg/m3, exceeding Nigerian air quality standards and posing health risks to nearby residents. Average ambient sampling values were 404.86 μg/m3, significantly higher than the FEPA standard of 250 μg/m3. Source Sampling and residential sampling averages were 990.2μg/m3 and 235.29 μg/m3, respectively. XRF analysis detected high levels of magnesium in truck exhaust, with a maximum value of 189.25106 ×106 (µg/m³), far exceeding the US National Ambient Air Quality Standard (NAAQS) of 100 µg/m³. The study concludes that stricter emission regulations and alternative energy solutions are necessary to mitigate environmental and public health impacts. Achieving recommended air quality guidelines could save millions of lives globally, emphasizing the importance of addressing air pollution. The research underscores the need for urgent action to protect the health and well-being of communities surrounding haulage vehicle parks in Nigeria.
Wave Labyrinth Weir: A New Shape Spillway to Minimize the Effect of the Vertex Angle
Increasing the discharge capacity of spillway structures is essential for efficient water management and flood control. This can be achieved in various ways, one of which is by lengthening the spillway crest. Labyrinth weirs, which provide a longer crest length compared to linear weirs within the same channel width, are commonly designed in trapezoidal, triangular, or rectangular forms. However, the convergence of the weir walls at sharp vertex angles tends to reduce discharge capacity. To address this limitation, a new wave labyrinth weir design—free of sharp corners—was proposed in this study to minimize the adverse effects of vertex angles. The shape of the wave labyrinth weir was derived from the cosine wave equation. The influence of the vertex angle was evaluated based on the discharge coefficient (Cd) at various upstream heads. The experimental investigation was conducted under free-flow conditions in a rectangular flume measuring 4.80 meters in length, 50 centimeters in width, and 40 centimeters in depth. Two physical models were fabricated using acrylic: a basic triangular labyrinth weir and the proposed wave labyrinth weir. Both models shared the same crest length (L = 87 cm) and height (P = 10 cm). Flow measurements were obtained through point gauge readings and the Thomson weir method. The results showed that the maximum discharge coefficient (Cd max) for the wave labyrinth weir reached 0.88, compared to 0.82 for the triangular labyrinth weir. This confirms that the wave labyrinth weir effectively reduces the negative impact of vertex angles on discharge performance. In addition, the wave configuration contributed to smoother nappe flow and reduced turbulence, suggesting greater flow stability compared to the conventional design.
Inventory Management Policies for Maintenance Spare Parts: Integration of Analytic Hierarchy Process and Multicriteria ABC Classification in the Plastics Industry
This study establishes supply management policies for maintenance spare parts in a plastics transformation company, using a methodology applicable to any industry managing spare parts inventories. It addresses the challenges of excessive inventory levels and the lack of objective rules for defining stock quantities and parameters by applying a multicriteria approach based on AHP and ABC classification, incorporating expert judgment through the Delphi method. The classification assigned the highest weight to criticality (0.683), followed by supply (0.2) and maintenance (0.117), ensuring a balanced evaluation. Demand analysis revealed that 69% of spare parts exhibit erratic demand, 39% have no recorded demand, and only 145 out of 3,842 items show stable demand, allowing the application of double exponential smoothing forecasting techniques. Based on these findings, a periodic inventory review system was implemented with demand-adjusted policies: (R, S) with safety stock (IS) for class A and B items with stable demand and adjusted IS levels or stock elimination for erratic demand items when justified. This strategy led to a 30% reduction in excess stock and a 15% increase in spare parts availability, optimizing costs and operational efficiency. Additionally, the study highlights the importance of establishing shared indicators between logistics and maintenance, maintaining accurate demand records, and centralizing spare parts storage to enhance decision-making and minimize downtime. These findings contribute to improving inventory management and reducing operational disruptions in industrial environments.
Climate Change Impacts on Future Rainfall in Padas River Basin, Sabah, Malaysia using Statistical Downscaling Method
The objective of this study was to assess the influence of climate change on the rainfall across the Padas River Basin, Sabah, Malaysia. Observed rainfall data (1985-2014) and downscaled climate model outputs (2025-2100) from four of the most suitable Global Climate Models (GCMs) (CMCC-CM2, IPSL-CM6A, MIROC6 and MRI-ESM2) were employed. The projected rainfall trend was analysed based on the 10th (P10), 50th (P50) and 90th (P90) percentiles to assess low, median, and high rainfall scenarios, allowing a more comprehensive understanding of uncertainty and risk in future rainfall patterns. The projection suggest an overal increase in rainfall for all months in the future, attributable to a lengthened wet season during the study period. Compared with the historical baseline, the highest monthly increase is projected in May (+60.3 mm), followed by Nov (+46.8 mm), while Feb shows the smallest increment (+5.5%). The projected increase in monthly rainfall between May and November may elevate future flood risks. Annual rainfall is expected to rise by approximately 5.4% (2025-2050) and 7.4% (2051-2100), with the highest intensity concentrated near coastal areas. Under SSP2–4.5 and SSP5-8.5, the mean annual rainfall is projected less than 3,625 mm and 4,030 mm, respectively. All four (4) models indicate a similar spatial rainfall pattern, with the northeastern part of the basin receiving more rainfall. In the long-term P90 scenario, coastal areas are projected to experience higher rainfall with cumulative rainfall less than 300,000 mm over the 76 years period. Meanwhile, the long-term P50 scenario shows results consistent with historical monthly data. These findings are essential for water management and long-term sustainability of water resources under changing climatic conditions.
Application of a Mathematical Model in Creating a Hard Alloy Tool That Combines Strength and Plasticity
The article discusses the use of a mathematical model in creating a hard alloy tool that combines strength and plasticity, the development of a multi-component alloy composition using methods of planning experiments and processing test results in materials science, the preparation of a multi-component metalloceramic material from local raw materials, and their physical and mechanical properties and their role in materials science. The results of research on the use of a mathematical model in creating a hard alloy tool that combines strength and plasticity are presented. Using the steep ascent method to optimize the composition, a powder composition was determined that provided a level of stability and served as the basis for further research. An alloy with a polydisperse composition is able to embody the required properties. It is assumed that large grains of the phase provide plasticity, and small grains provide high wear resistance of the alloy.
Evaluating the Potential of Green Roofs Incorporating Coconut Waste for Climate Change Adaptation
Climate change is a pressing global issue demanding urgent attention due to its widespread impacts. Green roofs present a promising solution by improving stormwater management, enhancing thermal regulation, and promoting sustainability. Yet, their adoption in Malaysian buildings remains limited. The lack of recycled waste utilization also reflects a missed opportunity for sustainable innovation. Coconut waste, abundantly available in Malaysia, remains unexploited despite its potential as a green infrastructure component. Hence, experimental investigations were conducted using three roof models: a conventional roof, a green roof constructed with commercial materials, and a green roof incorporating recycled waste. In the recycled waste-based green roof, coconut shells were used as the drainage layer, while coconut fibers served as the filter layer. Results showed that the recycled waste green roof outperformed the commercial green roof, reducing peak flow by up to 46%, compared to 19–31% for the commercial green roof. It also enhanced stormwater quality, achieving a 45% reduction in biochemical oxygen demand (BOD), while the commercial green roof achieved only 5%. Additionally, vegetated roofs helped lower temperatures, with reductions ranging from 6.45% to 11.48% for the commercial green roof and from 14.75% to 16.13% for the recycled waste green roof, compared to the conventional roof. These findings highlight the potential of green roofs, particularly those utilizing recycled waste materials, as a sustainable solution for urban climate adaptation. Increased adoption of such systems can help to address environmental challenges while promoting the circular use of waste materials.
Simulation of Sustainability and Energy Efficiency of NH3/CH4 Co-firing Flames in Swirl Combustors
Ammonia has emerged as a promising candidate due to its carbon-free and renewable nature. As a green energy carrier, ammonia can significantly reduce greenhouse gas emissions, but its utilization as a fuel faces challenges, including lower laminar flame speed, lower adiabatic flame temperature, higher ignition energy, narrower flammability limits, and increased nitrogen oxide emissions. To investigate their sustainability and energy efficiency, the study aims to simulate NH3/CH4 co-firing flames in a swirl combustor. The research focuses on premixed NH3/CH4/air reactants with varying methane fractions (0%, 25%, 50%, 75%, and 100%) at standard atmospheric pressure. The study simulates the steady flow field using ANSYS Fluent and the RNG k-ε model and uses the results for unsteady simulations. Through the simulation, it indicates a trade-off between CO2 and NOx emissions. High CO2 emissions correspond to the complete combustion of methane, while low CO2 emissions indicate incomplete combustion, resulting in unburned methane. From the simulation results, 25% of methane fraction, with its highest energy efficiency and temperature, emerges as the most sustainable despite producing unwanted NOx emissions. Overall, 25% of methane fraction results are identified as the optimal mixture for energy production, highlighting the need for balancing efficiency and emission controls in sustainable combustion processes.
Investigation on the Deposition of Conductive Ink on Multiple Substrates with Different Substrate Surface Energy and Ink Surface Tension Properties
Conductive ink is a transformative material that enables the printing of electronic circuits on a variety of substrates, revolutionizing the field of printed electronics. This study addresses the limitation of existing mathematical models for conductive ink deposition, which primarily assume ink deposition solely on generic substrates and printing on the fly, thus lacking adaptability for diverse applications. The objective is to integrate substrate surface energy and ink surface tension into mathematical model thus improve the precision of ink track width estimation. Employing a syringe deposition system, data analysis was conducted to develop an improved mathematical model that predicts ink deposition on various substrates while establishing optimal printing parameters. Experimental results indicated significant discrepancies in line widths, with initial measurements exceeding 2 mm and percentage errors surpassing 150%. By incorporating SSE, the improved model achieved line widths between 0.72 mm and 0.92 mm, significantly reducing the maximum error to 15.82%. The findings emphasize the crucial influence of substrate surface energy and ink surface tension on ink spreading and adhesion, particularly on substrates with varying porosity and absorbency.
Integrating Forensic Analysis and Sustainable Design for Slope Stabilization: A Case Study Using Waste Tire-Filled Gabion Structure (WTFGS)
This study presents a forensic investigation and geotechnical modelling of a landslide disaster and associated slope failure that adversely affected nearby infrastructure. The investigation involved geological mapping and geotechnical investigation through borehole drilling, followed by laboratory testing to characterise the physical index and engineering properties of the soil. Slope stability analyses were performed using SLOPE/W to show the stability analysis (Factor of Safety - FOS) for both the current failed slope condition and a proposed remediation design that incorporates sustainable materials. The proposed solution utilised a waste tire-filled gabion structure (WTFGS) as a sustainable slope retaining technique. Results indicated that the FOS for the existing slope was 0.979, classifying it as unstable. However, with the implementation design of WTFGS, the FOS improved to 1.580, indicating a stable slope in accordance with standard guidelines. These findings demonstrate that using waste materials to replace conventional materials is a practical remediation technique and a sustainable solution for slope stabilisation in new construction and slope repair applications. The integrated methodology strengthens failure assessment and supports the development of effective, sustainable slope stabilization solutions.
Forensic Investigation, Landslide Disaster, Slope Stability Analysis, Slope Remediation, Factor of Safety (FOS), Waste Tire-Filled Gabion Structure (WTFGS)
Comparison of Myocardial Mechanical Metrics in Electromechanical Model vs. Fluid-Electromechanical Model
The development of multiphysics heart model has grown tremendously over the past decade. In this paper, we compare two multiphysics approaches: electromechanics and fluid-electromechanics, in simulating left ventricular mechanics and the output of mechanical metrics. Cardiac electromechanical (EM) model refers to the approach of simulating heart mechanical deformation, triggered by cardiac action potential, while the generated ventricular pressure is determined by a penalty function and applied uniformly across the endocardium. Fluid-electromechanics (Fluid-EM) approach relies on similar action potential wave to trigger mechanical deformation but the ventricular pressure is determined by solving the Navier-Stokes equations within the ventricular cavity. Thus, Fluid-EM is more accurate as it models the blood-ventricular interaction, producing more realistic loading on the endocardium and enabling analysis of blood flow dynamics. Due to its complexity, the Fluid-EM approach is more computationally demanding than the EM approach. We assessed several mechanical metrics within the ventricle namely stresses and strains to assess regional differences in the heart by implementing both approach in a heart geometry extracted from a healthy patient. Differences in the mechanical metrics were noted indicating both models were loaded differently due to differences in modelling the blood. This suggests that in greater differences can be expected should there be more regional differences in the myocardium such as in infarct cases.
Implementation of Digital Twin for Investigation of Delayed Building Construction
During 2020-2022, a significant portion of the national budget was redirected to the healthcare sector for the handling of COVID-19 and economic recovery in Indonesia. This policy has resulted in delays in infrastructure development both nationally and locally. One example is the construction of a government office in Bandung. If construction resumes, investigating the level of damage to structural elements becomes crucial. In this research, the investigation of the level of damage was conducted by constructing a Digital Twin in the form of a 3D building model using the Terrestrial Lasser Scanner (TLS) BLK360, Cyclone Register 360 software, and Autodesk Recap Pro. The visual investigation results on the 3D model show the presence of 31 elements, with 39% mild damage and 61% moderate damage out of the total detected damage on columns, beams, and slabs. On the structural element, tests were conducted, with the assistance of the Non-Destructive Test (NDT) equipment, and the examination of the nominal moment capacity strength of the structural elements showed that several elements have experienced damage and a reduction in nominal moment capacity after 3 years construction delayed. On the column there was an increase in nominal moment capacity by 47 kNm and shear strength difference of 5.394 kN. On the Beam, there was a decrease in negative nominal moment capacity, where the value of M_(n^- ) actual = 187,067 kNm while the M_(n^- ) planned = 241,389 kNm. On floor slab there was a decrease in the nominal moment capacity in the x-direction M_n actual = 22,984 kNm while the M_n planned = 28,932 kNm. In the y-direction M_n actual = 24,167 kNm while the M_n planned = 22,594 kNm. Based on the investigation results, the delayed building construction can be resumed by repairing and strengthening the damaged structural elements using grouting, epoxy injection, and Fiber-Reinforced Plastic (FRP) methods.