Journal of Tropical Resources and Sustainable Science (JTRSS)
Journal of Tropical Resources and Sustainable Science (JTRSS) is published by Universiti Malaysia Kelantan (UMK) Press and managed by Faculty of Agro based Industry (FIAT). The editorial office is located at FIAT, UMK Jeli Campus. Experts from various academic backgrounds contribute ideas, time and expertise towards successful and quality publication of Journal of Tropical Resources and Sustainable Science. An Article Processing Charge (APC) of RM 500 will apply to all accepted articles submitted on or after 15th July 2025. Starting from 2026, JTRSS will publish four issues annually in March, June, September, and December.
Noise Level Study of Hair Dryer with Perforated Absorber
As user expectations for comfort and product quality increase, reducing noise from household appliances like hair dryers has become increasingly important. This study investigates the effectiveness of a perforated sound absorber in reducing noise emitted by a 2100W commercial hair dryer. The initial acoustic characterization was performed by measuring the overall sound power level (SWL) using a hemispherical microphone array, in accordance with ISO 3742. To identify the dominant noise source, Microflown Scan & Paint technology was employed, revealing the air inlet as the primary noise source. A perforated sound absorber was designed to be mounted at this location. Key design parameters–perforation diameter, panel thickness, perforation ratio, and air cavity depth–were optimized using sound absorption coefficient (SAC) simulations. The simulation model was validated through experimental measurements using a standard two-microphone impedance tube setup in accordance with ASTM E1050-98. The optimized design was fabricated via fused deposition modeling (FDM) using PLA and installed at the air inlet of the hair dryer. Subsequent SWL measurements indicated a noise reduction of 2.15 dB(A) compared to the hair dryer without the attachment, confirming the absorber’s potential for targeted noise control.
Copyright (c) 2026 Journal of Tropical Resources and Sustainable Science (JTRSS)
One-Dimensional Charring Rate Analysis from Malaysian Tropical Hardwoods: An Instrumental Measurement Approach
Timber is naturally combustible, which makes timber structures vulnerable to fire. Hence, maintaining a balance between structural strength and fire resistance is crucial to ensure safety and durability. When exposed to high temperatures, timber undergoes thermochemical decomposition through pyrolysis, ignition, and char formation, altering its chemical composition and physical structure. The formation of a charred outer layer serves as an insulator, reducing heat penetration and protecting the core. This process makes the charring rate a critical parameter in fire-resistant design, influencing the structural performance and safety of timber under fire exposure. Therefore, this study examines the relationship between char depth and charring rate in five Malaysian tropical hardwood species (Keranji, Resak, White Meranti, Kedondong, and Jelutong), with densities ranging from 450 kg/m³ to over 1000 kg/m³. The timber samples were tested under standard fire exposure ISO 834 (equivalent to BS 476: Part 20), using a large furnace under one-dimensional charring conditions for a duration of 60 minutes, during which internal temperatures were continuously recorded via embedded thermocouples. The experimental data revealed significant interspecies variation in charring rates, with denser species such as Keranji exhibiting slower char development than lower-density specimens like Jelutong. Charring rates were benchmarked against the Eurocode 5 (EC5)–recommended value of 0.5 mm/min, with most tested species performing favorably under the specified conditions. One-way ANOVA indicated statistically significant differences between species (p < 0.05), supported by coefficient of variations (COV) values that demonstrated the reliability and repeatability of the observed trends. These findings contribute to critical baseline data for structural fire design in tropical regions, thereby improving the accuracy of charring rate estimation for local timber species. The results support the development of more tailored, performance-based fire safety strategies aligned with international standards.
Growth and yield of hydroponic Pak choy (Brassica rapa subsp. chinensis L) under organic-derived nutrient sources from vetiver biochar and liquid pineapple waste
This study evaluated the potential of vetiver grass biochar and liquid pineapple waste as organic nutrient sources in the hydroponic cultivation of Pak choy (Brassica rapa subsp. chinensis L). Six treatments were tested: a synthetic AB fertilizer control (T1), and five organic alternatives, including 100% pineapple waste (T2), 100% biochar (T3), and various combinations of both (T4–T6). Growth parameters such as chlorophyll content, plant height, number of leaves per plant, and biomass were measured. The control (T1) consistently exhibited superior performance, with the highest chlorophyll content (40.87 ± 7.02), plant height (13.85 ± 1.57 cm), and yield (42.44 ± 6.05 g). Among the organic treatments, T5 (75% biochar + 25% pineapple waste) produced the best results, with elevated chlorophyll content (25.10 ± 2.19) and the highest yield (3.84 ± 0.47 g), indicating the effect of the nutrient-retentive properties of biochar combined with the nutrient-rich composition of pineapple waste. Pearson correlation analysis revealed strong positive relationships among all parameters, with yield highly correlated with the number of leaves per plant (r = 0.99), plant height (r = 0.99), and chlorophyll content (r = 0.94). These results highlight the relevance of vegetative traits as reliable indicators of crop productivity in hydroponic systems. While entirely replacing synthetic nutrients remains challenging, the T5 formulation presents a potential alternative for reducing chemical inputs. This study supports the advancement of sustainable nutrient management practices in soilless agriculture. Furthermore, although vetiver grass biochar combined with liquid pineapple waste shows promise, further research is needed to understand the long-term effects on optimizing organic nutrient sources ratios, pH buffering, comprehensive nutrient uptake, and the synergistic potential with other organic nutrient sources or fertilizer practices. Such understanding is crucial for guiding future research in sustainable farming practices.
A bibliometric analysis of fiber cement board research: Trends, development and future direction
Over the past decade, research on fiber cement board (FCB) materials has experienced significant growth, driven by the demand for sustainable and high-performance construction materials. This bibliometric analysis examines global research trends in FCB studies from 2021 to 2025 by systematically retrieving publications from Scopus using predefined search strings related to fiber cement boards. The study applied filters for peer-reviewed articles published in English and utilized the bibliometric tools VOSviewer to analyze citation networks, co-authorship patterns, keyword co-occurrence, and thematic evolution. This approach enabled the identification of influential publications and authors, as well as the detection of emerging areas of interest. A comprehensive database search revealed a growing focus on incorporating various fiber reinforcements, including synthetic and natural fibers, to enhance mechanical, thermal, and durable properties. Notably, research on hybrid fiber reinforcement and alternative binders has gained prominence due to their potential to improve sustainability and structural performance. The study revealed a rising publication trend, peaking at nearly 650 articles in 2024, with China leading in output (854 publications) and citations (10,373), while Australia demonstrated the highest impact (19.9 citations per paper). Highly cited authors such as Zaid, O. (691 citations) and Kaplan, G. (471 citations) have made significant contributions, with Construction and Building Materials emerging as the dominant journal. These quantified insights highlight key contributors, research influence, and thematic shifts toward AI integration, sustainability, and fiber innovation in FCB studies. The results highlight the importance of material innovation, emphasizing the role of fiber-modified cement composites in advancing environmentally friendly and resilient construction practices. This study serves as a crucial reference for shaping future research and industrial applications in sustainable building materials.
Computational analysis of resilient propagation algorithm variants for predicting harvester productivity
This study investigated the use of artificial neural networks (ANNs) to estimate the productivity of forestry harvesters operating in commercial eucalyptus plantations in Brazil. The dataset, collected from mechanised harvesting operations over continuous 24-hour shifts in the states of Espírito Santo and Bahia, included quantitative and categorical variables. Quantitative inputs comprised the mean individual tree volume and productivity. Categorical variables included terrain inclination, tree tortuosity and bifurcation, sub-forest presence, operator experience, and type of service supply. Four variants of the Resilient Propagation (Rprop) algorithm were evaluated: Rprop+, iRprop+, Rprop−, and iRprop−. A total of 200 ANN models (50 per variant) were trained using 70% of the data, with the remaining 30% reserved for validation. All networks employed min–max normalisation, sigmoid activation functions, and an eight-neuron hidden layer. Model performance was assessed using the correlation coefficient (R), root mean square error percentage (RMSE%), bias percentage, and variance. The Rprop+ variant achieved the best predictive performance, with R = 0.837, RMSE% = 18.380, bias% = –0.017, and variance = 9.867, proving high reliability in modelling harvester productivity and offering valuable support for planning and decision-making in mechanised forestry operations.
Pedro Henrique Guimarães Abrantes Lacerda
Evaluation of Lipid-Based Coatings on Postharvest Quality of Tomatoes during Ambient Storage
Tomatoes (Solanum lycopersicum) are susceptible to postharvest losses due to metabolic processes, physical injuries, and microbial spoilage. Edible coatings are a promising strategy to extend the shelf life of fresh fruits, including tomatoes, by providing a protective layer that controls the transfer of gases, moisture, aromas and volatile substances during storage. Thus, this study evaluated the effectiveness of lipid-based composite edible coatings in maintaining the postharvest quality of tomatoes stored at ambient conditions (24–26 °C, 65–75 % RH). Three coating emulsions were formulated in this study: F1 = coconut oil-lemongrass essential oil (CL), F2 = beeswax-coconut oil-lemongrass essential oil (BCL), and F3 = carboxymethylcellulose (CMC)-coconut oil-lemongrass essential oil (CCL). These coatings were applied to tomatoes at the turning stage and compared with uncoated samples over a 24-day period. Quality parameters, including weight loss, visual appearance, firmness, total soluble solids (TSS), and surface morphology, were evaluated at the end of the experiment. All coatings minimised moisture loss compared to the control, with F2 (BCL) showing the greatest reduction. Nonetheless, F3 (CCL) outperformed other coatings in preserving tomato firmness (525.07 ± 103.09 g) and TSS (4.50 ± 0.50 °Brix ), indicating enhanced control of the respiration and ripening. Microscopic analysis further revealed that F3 (CCL) formed a smooth, homogenous coating layer, with improved barrier features and no adverse sensory effects. Conversely, F2 (BCL) exhibited uneven coating distribution due to beeswax crystallisation, causing undesirable surface deposits and decreased firmness retention. These findings highlighted the potential of lipid-polysaccharide composite, particularly with CMC inclusion, to prolong the postharvest shelf life of tomatoes by reducing weight loss and retaining firmness and TSS content. Component compatibility is also crucial for structural integrity, functional properties, and consumer acceptability in edible coating applications.
Construction of Ecological Security Evaluation Index System for Hengshui Lake National Nature Reserve Based on the Pressure-State-Response Model
Ecological security is crucial for national security, human survival, and sustainable development. Thus, this study aims to establish an Ecological Security Evaluation Index System for Hengshui Lake National Nature Reserve in China based on the Pressure-State-Response (PSR) model. This reserve is a critical habitat for various wildlife species and provides essential ecosystem services to surrounding communities facing ecological issues, such as transitional development and accelerated urbanisation. The PSR model was chosen in this study because this tool provides a comprehensive and complex framework for assessing ecological security by considering three key components: Pressure, State, and Response. Three pressure components have been selected as indicators: Population, population density, and natural population growth rate. Meanwhile, eight condition parameters were included as the state indicator: Precipitation, precipitation pH, eutrophication, comprehensive water quality pollution index, chemical oxygen demand (COD), total phosphorus, fluoride, and permanganate index. Finally, the proportion of the tertiary industry, residents’ per capita disposable income, energy conservation and environmental protection expenditures, education expenditure, social security expenditures, and wetland environmental protection awareness were the response indicators considered in this study. The findings indicated that the ecological security evaluation index of Hengshui Lake between 2016 and 2022 increased from 0.203 to 0.756, whereas the ecological security level transitioned from unsafe to safe.
Impact of exogenous variables on paddy productivity modeling: an ARIMAX model perspective
Paddy productivity in Malaysia faces escalating difficulties in 2024–2025 due to increasing input costs, unpredictable weather patterns, and rising dependence on rice imports. These problems have intensified the necessity for precise forecasting instruments to inform food security policies and agricultural strategies. The present study examined the effectiveness of ARIMA and ARIMAX models in predicting yearly paddy productivity in the states in the northern region of Peninsular Malaysia, which were Kedah, Perak, Pulau Pinang, and Perlis, based on data from 1981 to 2022. The study investigated whether the inclusion of an exogenous factor, which was planted area, may improve forecasting accuracy beyond conventional univariate models. A systematic approach was employed involving stationarity assessment, model identification, residual diagnostics, and performance evaluation. The results indicated that ARIMAX modeling’s performance consistently surpassed that of ARIMA modeling, with Kedah achieving the best accuracy, closely followed by Perlis, Perak, and Pulau Pinang. The incorporation of exogenous variables markedly enhanced model responsiveness and accounted for structural changes in paddy production. The residuals from the final model for each state exhibited no indications of autocorrelation, hence confirming statistical validity. The study finds that ARIMAX modeling offers a dependable and comprehensible forecasting framework for paddy output and can function as an essential decision-support instrument for agricultural policies, particularly during times of supply instability. The methodology is versatile for many crops and geographies, facilitating extensive applications in agricultural forecasting and food security strategies.
Traditional Wisdom Sustainable Future: Gula Apong Processing Hut
Gula apong is a type of traditional sugar made from Nypa fruticans, a type of palm that can be found abundantly at coastal areas of Sarawak. Gula apong is processed and produced under a small hut known as langko, which is built in the N. fruticans forest. The current condition of existing langko is in a state of disrepair and neglect, marked by the absence of proper access roads, no clean water supply, no electricity, poor building structures, inadequate hygiene, and an inconvenient layout. The paper aims to improve the design of the gula apong langko to help sustain the gula apong industry with two main objectives: (1) to identify sustainable features for langko design and (2) to develop a new langko design incorporating these features while maintaining the original's essence. Fieldwork was conducted on seven langko structures located in Pusa, Asajaya, and Kuching. Data was collected through observation and site analysis to assess the physical condition, spatial layout, materials, and sustainability elements of langko structures. Non-structured interviews with local producers were also conducted to obtain more information on the langko conditions. From the study on the condition of the existing langko, the areas needing improvement include three main elements, including space planning, construction methods, and sustainable features. The new Langko design is divided into a semi-private area and a public area. The semi-private area is an enclosed space for the production of gula apong, while the public space can be used as a product display area or café. The semi-private area is built with enclosed walls to prevent contamination and ensure hygiene during the production of the gula apong. Water harvesting system, solar panel for lighting, transparent roofing for natural lighting, and sustainable local materials are among the features incorporated into the new design
Roles of Silver Particle Immobilised in Polysulfone Mixed Matrix Membrane on Flux Enhancement and Antibacterial Properties
A mixed matrix membrane immobilised with silver particles has been reported to possess antibacterial properties. Nevertheless, the presence of a foreign particle such as silver inside the membrane matrix could introduce a flux resistance that reduces the water permeation. Therefore, this study investigated the influence of silver particles on the membrane by varying the silver particle dosage. The silver immobilised mixed matrix membrane was analysed using scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), Brunauer, Emmett, and Teller (BET), and porosity tests to identify the effect of silver particles on membrane physicochemical properties. The membrane performance was evaluated by water flux and antibacterial tests. The water flux test revealed that adding silver particles in the membrane improved the water flux up to ~22 L/m2.h at 1.0 wt% silver content (PPAG1.0) compared to the pristine (PPAG0) membrane, which reported ~5 L/m2.h of flux. Further increase in silver dosage led to flux reduction, in which the membrane with 2.0 wt% (PPAG2.0) recorded ~8 L/m2.h flux. The antibacterial test indicated that the silver content in the membrane was directly proportional to the ability of a membrane to impede E. coli growth. The PPAG2.0 membrane exhibited the largest diameter of inhibition ring at 27.0 mm, while the pristine membrane did not inhibit E. coli growth. Hence, the optimum silver content in the membrane was identified at 1.0 wt% based on the PPAG1.0 membrane performance, exhibiting an inhibition diameter of 19.0 mm and ~22 L/m2.h flux.
Optimisation of Ecobrick Density and Strength as a Building Material to Reduce Plastic Waste
Bricks are an essential material in construction, but the production has considerable environmental and health impacts. Consequently, ecobricks have emerged as a potential sustainable alternative to conventional bricks. These environmentally friendly substitutes are made by filling recycled polyethylene terephthalate (PET) plastic bottles with compacted plastic waste to a specific density. In this study, the optimum density of plastic waste in PET bottles was optimised to produce ecobricks with suitable strength properties. This innovation aimed to use plastic bottles as a building material and offers a sustainable alternative for the construction industry. Seven samples with a density of 0 g/mL to 0.65 g/mL were empirically tested for compressive strength, impact resistance, flexural strength, and failure behaviour. The findings revealed that Sample E exhibited the best performance compared to other samples. This sample achieved a compressive strength of 17.54 N/mm2, demonstrating strong structural performance. In the drop test (1 m, 2 m, and 3 m), Sample E also showed no visible denting, with a measured density (0.45 g/mL) exceeding 0.33 g/mL. It also recorded flexural strengths of 4.65 N/mm2 at the neck, 6.59 N/mm2 at the body and 11.96 N/mm2 at the bottom. These results not only exceed the minimum compressive strength for bricks (5.2 N/mm2) required by the Malaysian Public Works Department but also fulfil the Global Ecobrick Alliance guideline for minimum density (0.33 g/mL) of an ecobrick. In summary, this study helps to reduce the amount of plastic disposed of in landfills by reusing plastic waste as functional building materials. Most importantly, these findings support the United Nations Sustainable Development Goals (SDGs), specifically SDG 9 (Industry, Innovation and Infrastructure) by promoting the sustainable development of infrastructure through innovative materials and SDG 13 (Climate Action) by reducing the impact on the environment through the reduction of plastic waste.
Development of raft foundation structural design tool for residential buildings
This study evaluates the structural and geotechnical aspects of raft foundation design for residential buildings, focusing on the influence of soil conditions on moments and shear forces. A comparative analysis between manual calculations and SAFE software revealed deviations due to variations in soil stiffness. Empirical correction factors (CFs) were developed using multiple linear regression to enhance manual design accuracy by incorporating subgrade modulus, raft thickness, and column spacing. These CF were integrated into a Visual Basic for Applications (VBA)-based spreadsheet-based design tool, ensuring compliance with Eurocode standards. The tool demonstrated quantifiable accuracy, achieving percentage errors below 10% for critical positive moment (Mmax) and maximum shear forces (Vmax), particularly in medium to hard soils. Slightly higher errors were observed in soft soils, as CFs were weighted more towards stiffer soils. Discrepancies are present across all soil types for negative moments (Mmin) due to the limitations in conventional slab method assumptions in capturing the location of hogging moments in raft foundations. This outcome indicated the need for further refinement of CFs, possibly through the integration of additional empirical data. As the scope of this study is limited to residential buildings, future work could expand the applicability of this tool to high-rise buildings, which require more complex load distributions and additional soil parameters for accurate soil behaviour modelling. Enhancements could include consideration for various soil types with differing bearing capacities and settlement characteristics under load. Additionally, incorporating differential settlement analysis would improve the representation of raft foundation behaviour and extend the applicability of this tool to more complex geotechnical conditions. Overall, the tool remains a practical and efficient solution for early-stage design and verification against the Finite Element Method (FEM) results.
Shear performance evaluation of Laran glulam beam-to-column T-Stub connector at different load positions
Glued laminated timber (glulam) structures are increasingly favoured due to sustainability, lightweight properties, and excellent strength-to-weight ratio. Therefore, understanding the relationship between loading position, shear performance, and bearing strength of this structure is crucial for optimising structural connections and preventing premature failure. This study investigated the shear performance of beam-to-column connections using plantation-grown Laran glulam. Shear tests were conducted at two load application points: 160 mm (near the support) and 600 mm (in the cantilever region) from the column face. The results indicated that a shorter loading position (160 mm) leads to significantly higher shear stress values, ranging from 3.42 N/mm² to 3.91 N/mm², with a mean of 3.62 N/mm². In contrast, a longer loading position (600 mm) resulted in lower shear stress values, ranging between 0.24 N/mm² and 0.37 N/mm², with a mean of 0.33 N/mm². These findings indicated that reducing the load distance intensified stress concentration and affected the structural integrity. Additionally, these findings provided valuable insights into stress distribution and failure mechanisms in glulam structures. Identifying critical load distances can minimise stress concentrations; thus, optimising the connection design as proposed in this study can aid in improving structural stability and durability. Finally, these findings can serve as a reference for engineering guidelines and design standards, aiding in the development of more reliable glulam structures for practical applications in sustainable construction.
The application of SCOR and DEMATEL models for assessing agricultural supply chain risks: a case study in the Mekong Delta
Agricultural products are major contributors to economic growth and food security in Vietnam. In the Mekong Delta region, agricultural products offer developmental benefits, but not without risks and challenges. Thus, this study identified risks, impacts, and the importance of the agricultural supply chain (ASC) in the Mekong Delta. The study combined qualitative and quantitative methods to review relevant domestic and international literature for data retrieval. Subsequently, the SCOR model was used to identify ASC risk factors, whereas the DEMATEL model was adopted to determine the importance of the identified risks. A total of 17 existing ASC risks in the Mekong Delta were identified in this study. Among the risks, “Planning for production, transportation, and delivery”, “Loss of agricultural products due to damage and quality degradation” and “Non-standard goods” were the most significant concerns in this study. In contrast, the respondents were less concerned about risks such as “Shortage of skilled labour and lack of access to experts” and “Purchasing cultivation seeds”. Meanwhile, “Shortage of skilled labour and lack of access to experts” and “Damaged machinery, production, and vehicles” were the highest rated impacts in this study. Finally, “Increased operating costs” was the most significantly affected risk factor for the respondents. In conclusion, these findings serve as a foundation for deeper investigations studies in ACS, particularly in Vietnam.
Physical Performance of Cross-Laminated Panels Made from Nypa fruticans
The increasing demand for renewable and sustainable construction materials has led to the exploration of underutilised tropical biomasses for engineered wood applications. Nypa fruticans (nipah palm), abundant in Southeast Asian mangrove ecosystems, possesses fibrous, lignified petioles suitable for composite panel production. Despite that, the application in cross-laminated panel (CLP) manufacturing remains largely unexplored. This study addresses the knowledge gap by evaluating the physical performance of CLP fabricated from N. fruticans, focusing on density, moisture content, thickness swelling, and water absorption. The panels were fabricated at three target densities (400, 600, and 800 kg/m³) using long fibre strips and a bio-based epoxy resin at a 3:1 resin-to-hardener ratio. Hot-pressing was conducted at 7 MPa for 15 minutes at 100 °C. The fabricated panels were tested according to JIS A 5908:2003 standards. Results revealed that increased panel density significantly reduced moisture content, with values decreasing from 15.84% at 400 kg/m³ to 13.65% at 800 kg/m³. While only the lowest-density group exceeded the JIS moisture content limit, thickness swelling across all groups remained within the acceptable range, showing improved stability with increasing density. Water absorption demonstrated the most significant density-dependent variation, with the 800 kg/m³ panel absorbing 20% less moisture than the 400 kg/m³ counterpart. Statistical analysis via ANOVA confirmed the influence of density on all measured parameters (p < 0.001), and Duncan’s post-hoc test highlighted significant group differences. In conclusion, N. fruticans is a promising sustainable raw material for CLP production, with the 800 kg/m³ configuration exhibiting optimal performance. These findings supported the viability of the Nipah palm in engineered panel applications and contributed to the diversification of tropical biomass resources in eco-friendly construction materials.
Biodiesel Production from Crude Jatropha Oil and Engine Performance
This study aimed to investigate the efficiency of converting crude Jatropha oil (CJO) into Jatropha biodiesel (JB) via the transesterification process, to optimize the operating conditions required for effective conversion, to determine the physicochemical properties of the resulting JB, and to evaluate diesel engine performance using various JB–diesel blends. Both one-step and two-step transesterification methods were explored in order to identify the most suitable approach for processing CJO. The findings revealed that only the two-step method produced satisfactory results, primarily due to the high free fatty acid (FFA) content present in the crude oil, which inhibits the effectiveness of a single-step alkaline transesterification process. Through systematic experimentation, optimal reaction conditions and variable ratios were determined, which yielded the highest biodiesel output of 84%. The optimum conditions consisted of a 0.02:1 ratio of acid catalyst to oil and a 1:1 ratio of alcohol to oil during the first step (lasting 1 hour), followed by a 0.03:1 ratio of base catalyst (NaOH) to oil and a 5:1 alcohol-to-oil ratio during the second step (lasting 2 hours). The produced JB was thoroughly characterized using Fourier Transform Infrared Spectroscopy (FT-IR), a bomb calorimeter, a density meter, and a flash point tester. The analyses established key fuel properties, with a calorific value of 35.23 MJ/kg, a density of 898 kg/m³, and a flash point of 165 °C, confirming that the biodiesel met essential quality requirements. Subsequently, blends of JB with mineral diesel at varying proportions were tested as fuel in a diesel engine to assess operational performance. Among all tested blends, the 20% JB blend demonstrated performance closely comparable to pure mineral diesel, achieving the lowest total and specific fuel consumption, while also delivering the highest engine speed, brake horsepower, and mechanical efficiency.
Exploring the features of plants threatening Malaysia's heritage buildings
Plants contribute to various functions in landscape design such as shade, ornamentation, food sources and etc. For heritage buildings, the functions of plants are identified as elements that can enhance the heritage value of a building. The presence of plants also harms the stability of heritage buildings. Certain plants have been identified to cause damage such as roof damage, wall cracks, plaster layer damage, stains on the paint layer, paint peeling, gutter and drain blockage, and wooden component damage. Therefore, the objective of this study is to identify the features of plants that threaten heritage buildings. This study used a qualitative research design involving observation and interviews. Observation methods were carried out on 112 masonry heritage buildings listed by the National Heritage Department (JWN). In-depth interviews were conducted with eight (8) registered conservators who possess extensive experience and are actively involved in heritage building conservation. The collected data were analyzed thematically to produce a list of characteristics of plants that contribute to the damage of heritage buildings. The study revealed eight (8) plant characteristics, namely compact canopy, shedding leaves excessively, bearing fruit, dense flowering, creeping root, adventitious root, weak wooded, and wide-crowned tree. This study aims to assist conservators, building occupants, maintenance contractors, and landscape architects in selecting suitable plants for landscaping and environmental design surrounding heritage buildings in Malaysia.
Copyright (c) 2025 Journal of Tropical Resources and Sustainable Science (JTRSS)
Agronomic Performance and Resistance Traits of Abaca Hybrid 7 ( Musa textilis Nee ) in the Field
The abaca ((Musa textilis Nee) industry is a vital contributor to employment and foreign exchange in the Philippines, but its productivity is increasingly threatened by viral diseases, particularly abaca bunchy top virus (ABTV). This study aimed to evaluate the agronomic performance and disease resistance of newly developed ABTV-resistant abaca hybrids under screenhouse and field conditions. Tissue-cultured plantlets were assessed for key agronomic traits, including pseudostem weight, length, and girth; dry fiber weight; percent fiber recovery; and sucker production. Disease resistance was evaluated through symptom observation and confirmed using ELISA and PCR diagnostics. Results indicated that the hybrids matured earlier (10–14 months) after planting. Notably, abaca hybrid Bandala (H7) outperformed Inosa with longer pseudostem (240–250 cm), larger middle girth, top girth size, and a larger base girth, and 16 suckers produced over 11.Similarly, Abaca Hybrid 2 (H2) exhibited a statistically significant difference compared to Bandala (H7) and Tinawagang Pula with fiber recovery of 1.05%, 0.8% and 0.6%, respectively. Additionally, hybrids exhibited complete resistance to ABTV, showing no symptoms and testing negative via PCR using the primer BBT1 and BBT2 that amplify the 348 bp fragment of DNA-R genome component.The absence of infection was confirmed by PCR using an internal control that detects the presence of Musa sequence. Hybrids also showed partial resistance to abaca mosaic and bract mosaic viruses under high disease pressure. These findings highlight the potential of virus-resistant abaca hybrids to improve yield, reduce disease losses, and support the long-term sustainability of abaca industry.
Domestic Tourist Perceptions of Social Carrying Capacity: Implications for Sustainable Tourism Management in Pangkor Island, Perak
Although economically advantageous, tourism growth can present considerable challenges to local communities and natural environments if not properly managed. This study examines domestic tourists' perceptions of Social Carrying Capacity (SCC) on Pangkor Island, Perak, a well-known tourism destination in Malaysia. A quantitative approach was used to collect data from 92 domestic tourists through structured questionnaires and the People at One Time (PAOT) visual assessment method to assess perceived crowding during peak periods. Most respondents (84.8%) indicated that their visit was for holidays and leisure. Results demonstrate a moderate level of satisfaction with infrastructure, especially in transport services (mean = 3.27). However, concerns were identified regarding cleanliness (mean = 3.01), crowding (mean = 2.25), and interaction with local communities (mean = 2.29). Findings from the PAOT showed that moderate crowding levels were deemed acceptable, with 39.1% of the respondents selecting Image C and 37.0% selecting Image D. The study emphasises the necessity of ongoing monitoring and increased community engagement, despite current SCC indicators being within acceptable thresholds, to ensure a balance between tourism development and the quality of life for residents. The findings provide valuable insights for policymakers and tourism planners focused on sustainable destination management in coastal and island contexts.
Synthesis of Mannich Eugenol Oxirane Morpholine compound as antifungal in vitro and in silico
The use of antifungal drugs increases along with the increase in fungal infections. This causes the fungus to be resistant to antifungal drugs, one of which is the azole class of drugs. This increase resistance poses a major threat to global health services. This research aims to synthesize eugenol-morpholine compound reacted with epichlorohydrin as antifungal drug in vitro and in silico. In silico testing uses the molecular docking method with the discovery studio application. Synthesis of eugenol-morpholine and synthesis of eugenol oxirane morpholine using the reflux method. Characterization of synthetic compounds using NMR. The synthesized compound was applied for in vitro testing on the Candida albicans fungus using the disc diffusion method. The results of in vitro and in silico research show that the compound eugenol oxirane morpholine has better antifungal activity compared to the compounds eugenol-morpholine and eugenol. The results of in silico research showed a cDOCKER value of -38.5537 kcal/mol and the in vitro results had an inhibition zone of 28.55 mm. The best compound as an antifungal drug candidate is the compound eugenol oxirane morpholine with the lowest cDOCKER value in in silico testing and a wide zone of inhibition in in vitro testing showing very strong activity.
Bioactivity of Mikania micrantha extract in controlling Erwinia chrysanthemi: a natural antibacterial approach
Crop losses caused by soft rot disease induced by Erwinia chrysanthemi pose a persistent threat to global agricultural productivity. Excessive use of synthetic chemical pesticides to control such bacterial diseases has raised serious environmental and health concerns due to their residual toxicity and ecological impact. As an alternative, plant-derived biopesticides have gained attention for their biodegradability, safety, and sustainability. This study aimed to evaluate the antibacterial activity of Mikania micrantha Kunth (sembung rambat) leaf extract against E. chrysanthemi and to determine the most effective concentration for bacterial inhibition. The antibacterial assay was performed using the Kirby–Bauer disc diffusion method with five treatments and four replications: three concentrations of M. micrantha leaf extract (25%, 50%, and 80%), a positive control (1% chloramphenicol), and a negative control (sterile distilled water). Data were analyzed using analysis of variance (ANOVA) and Duncan’s Multiple Range Test (DMRT) at a 95% confidence level.The results showed that M. micrantha extract exhibited moderate antibacterial activity, producing inhibition zones of 7.51 mm, 8.02 mm, and 8.40 mm for 25%, 50%, and 80% concentrations, respectively. Although inhibition increased with concentration, the differences among extract treatments were not statistically significant (p > 0.05). The positive control exhibited a much larger inhibition zone (30.95 mm), while the negative control showed none.These findings indicate that M. micrantha leaf extract possesses moderate antibacterial potential against E. chrysanthemi and may serve as a promising plant-based biocontrol agent for sustainable disease management.
Analysis of heavy metal content in emissions from shell, fiber, and empty fruit bunch biomass fuels
Riau Province is one of the largest palm oil producers in Indonesia, where palm oil mills use boilers as a primary component to generate steam energy for processing activities. At PT TH Indo Plantation, particularly at Pulai Palm Oil Mill, biomass fuels such as palm kernel shells, fibers, and empty fruit bunches are commonly used. Boiler operations are often associated with emissions that may pose environmental and health risks. This study aims to analyze the heavy metal content in emissions from these biomass fuels. The research employed quantitative methods, including proximate and ultimate analyses, as well as spatial modeling using AERMOD to observe emission dispersion. The results showed relatively low heavy metal content: 0.01% in palm kernel shells and empty fruit bunches, and 0.02% in fibers. AERMOD simulation indicated that the concentration of PM2.5-type particulate matter reached 3.31311 µg/m³, with dispersion extending up to 3 km from the source. Based on these findings, the use of shell, fiber, and empty fruit bunch fuels at Pulai Palm Oil Mill does not result in significant environmental impact related to heavy metal dispersion and may be considered relatively safe.
Assessing landslide susceptibility in Bukit Kwong dam, Kelantan, Malaysia using geospatial techniques and frequency ratio model
Landslides occurring at or near dam structures are among the predominant forms of geological hazards responsible for significant loss of life, property damage, and environmental degradation worldwide. To understand the risk, this study evaluates the landslide susceptibility in the nearly ageing Bukit Kwong Dam where ageing denotes to time-related deterioration occurring fifty years of operation using an integrated approach of Unmanned Aerial Vehicles (UAV), Geographic Information System (GIS) and frequency ratio model selected due to its simplicity and ability to provide numerical measure of the relative importance in the landslide occurrence. The proposed methodology involves the preparation of a landslide inventory, generation of multiple thematic maps representing factors influencing slope instability, including aspect, slope, plan curvature, profile curvature, elevation, land use, distance from river, Normalized Difference Vegetation Index (NDVI), rainfall, and distance from road. These thematic layers were subsequently integrated within a GIS environment using the frequency ratio technique to produce a Landslide Susceptibility Map (LSM). The LSM delineated five susceptibility classes, ranging from very low (48%), low (34%), moderate (12%), high (5%), and very high (1%). According to their high frequency values, slope, land use, plan and profile curvatures, and distance from river were identified as the most influential predisposing factors contributing to landslide occurrence. The performance and accuracy were evaluated using Area Under Curve (AUC), yielding a score of 0.85. The outcomes provide useful baseline information to identify landslide-prone areas for dam safety evaluations and slope management strategies in the region.
Landslide susceptibility Unmanned Aerial Vehicles Frequency ratio model Area under curve Malaysia
Geophysical investigation of subsurface structure using electrical resistivity imaging (ERI) and induced polarization (IP) methods in metaigneous terrains of Jeli, Kelantan
This study presents a geophysical investigation of subsurface structures within the metaigneous terrains of selected area located in Jeli, Kelantan using integrated Electrical Resistivity Imaging (ERI) and Induced Polarization (IP) methods. The study area is located within Universiti Malaysia Kelantan Jeli Campus, Jeli District, Kelantan, and lies within the Central Belt of Peninsular Malaysia. Geological mapping at this area revealed the presence of metaigneous rocks, offering critical insights into the lithological distribution and structural deformation history of the region. Geophysical surveys along selected profiles delineated variations in resistivity and chargeability, identifying key features such as fractured zones, weathered layers, and compact bedrock. High resistivity and moderate-to-high chargeability values correspond to intact metaigneous rock bodies, while lower values indicate weathered or altered zones. The integration of ERI and IP data with surface geological observations provides a comprehensive model of the subsurface, offering insights valuable for Rare Earth Element (REE) mineral exploration.
Geoheritage Potential of Limestone Caves at Felda Chiku 7, Gua Musang, Kelantan, Malaysia
This study aims to assess the geoheritage potential of Felda Chiku 7 in Gua Musang District, Kelantan. The study area hosts two limestone caves, which exhibit distinctive geological and geomorphological features, including karst landforms, speleothems, and speleogens. Geologically, the area is underlain by three primary lithologies — limestone, phyllite, and slate — that comprise the Gua Musang Formation. The geology of the study area is mainly composed of three lithologies: limestone, phyllite, and slate. The study integrated qualitative and quantitative assessments: the qualitative assessment was based on the author's fieldwork observations, whilst the quantitative assessment was based on the Modified Geosite Assessment Model (M-GAM) framework. The M-GAM frameworks integrate expert perceptions with visitors'/public perceptions, with the Main Values covering scientific, aesthetic, and protection values, and the Additional Values covering functional and touristic values. The qualitative assessment indicates the geodiversity of rocks (lithologies), geomorphology (speleothems and speleogens), landscape and fossil. In addition, the scopes are petrological, geomorphological and paleontological sites, and the scale is small. As for the quantitative assessment, the study shows that aesthetic values rank highest, followed by protection, scientific, functional, and tourism values. The M-GAM results indicate an intermediate overall geoheritage potential (28.4%), with exceptionally high scenic/aesthetic and protection scores, and low touristic readiness (restaurant/visitor infrastructure minimal)—consistent with local familiarity but limited public exposure. The findings demonstrate that Felda Chiku 7 holds substantial potential for future geoconservation and geotourism initiatives, provided that appropriate management strategies, interpretative programmes, and community engagement efforts are implemented to enhance accessibility and long-term protection of this natural asset.
Evaluation of groundwater sources using Electrical Resistivity Imaging (ERI) method in Felda Tersang 02, Raub, Pahang
This study employed the Electrical Resistivity Imaging (ERI) technique in the Felda Tersang 02 area of Raub, Pahang, to address the region's water supply issues. The study area is primarily composed of sandstone, slate, and dacite. Groundwater, critical for sustaining agricultural and industrial demands, is rapidly depleting due to unsustainable extraction. However, since the underlying geology and hydrogeology are complex, investigating and assessing groundwater sources can be challenging. By measuring the electrical resistivity of underlying materials, a geophysical technique called Electrical Resistivity Imaging (ERI) is used to map and evaluate groundwater sources. Each survey line is 200 m long with 41 takeouts spaced 5 m apart, using the Schlumberger and pole-dipole configurations. The study's findings will aid with groundwater resource management and provide a deeper understanding of the region's subsurface geology and hydrogeology. The 2D pseudosection results for all three survey lines reveal a significant accumulation of groundwater in a large geographical area. The identified low-resistivity range (0–100 Ωm) serves as a significant indicator of water-bearing formations, providing valuable insights into the area’s groundwater potential.
Roadside Trees Species Selection Model for Environmental Health and Public Safety in MalaysiaRoadside Trees Species Selection Model for Environmental Health and Public Safety in Malaysia
Selecting right tree species for roadside planting is crucial to balance environmental health with public safety concerns. Roadside trees as a part of urban green infrastructure have the potential to cope with some of these problems in urban environment and provide an array of services such as shade provision and aesthetic creation. Unfortunately, roadside trees are also acknowledged to render disservices. Damaged road surface, pedestrian walkway and underground utilities are a few instances of this. The wrong tree species planted at the wrong place can lead to significant environmental, social and economic consequences. The aim of this study is to develop roadside tree species selection model for reference to the local authorities. Two objectives are to determine additional attributes in urban roadside tree species selection and to examine the relationship between additional and similar attributes in landscape practices. This research employs mixed methods approaches consisting of both qualitative and quantitative approaches. An in-depth interview was conducted in four selected local authorities, namely Kuala Lumpur City Hall, Petaling Jaya City Council, Selayang Municipal Council, and Subang Jaya Municipal Council. The findings are validated by five registered landscape architects, revealing ten (10) additional attributes of root invasiveness and behavior, wood brittleness and branch drop risk, allergenic potential, growth rate and canopy management, compatibility with urban infrastructure, drought and pollution tolerance, fire resistance and flammability, wildlife attraction and pest management, aesthetic consistency and public perception, structural stability and wind resistance that influences the selection of roadside tree species in urban areas. These attributes were integrated into the roadside tree species selection model.
The Economic Value of Forest Ecosystem Services: Insights from Recreation and Ecotourism
Forests provide a variety of ecosystem services essential for human well-being, with recreation and ecotourism increasingly recognised as valuable non-market benefits. This study assesses the economic value of forest ecosystem services and visitors’ perceptions of recreational and conservation roles within two selected Eco Parks in Perak, Malaysia, namely Taman Eko-Rimba (TER) Lata Iskandar and TER Pasir Panjang. Using the Contingent Valuation Method (CVM), primary data were collected through structured surveys of 501 visitors (with a minimum of 250 respondents per site) to estimate their willingness to pay (WTP) for continued recreational access and enhanced conservation initiatives. The findings reveal that recreational and ecotourism services contribute significantly to the local economy through notable non-market values and individual WTP estimates. The OLS and Logistic regression models show mean WTP values of RM5.85 (OLS) and RM8.80 (Logit) for TER Lata Iskandar, and RM8.10 (OLS) and RM10.50 (Logit) for TER Pasir Panjang. Key significant determinants of WTP include income, education, visit frequency, visit duration, and repeat visitation, underscoring the influence of socio-economic capacity and behavioural factors on conservation support. Most visitors expressed strong support for conservation initiatives and recognised the importance of Eco Parks in providing environmental education, biodiversity protection, and community benefits. Positive visitor perceptions further reinforce the role of Eco Parks as essential assets for sustainable tourism and rural economic development. This study highlights the importance of integrating both economic valuation and public perception into forest management strategies to enhance conservation financing, improve visitor experiences, and support community livelihoods
Evaluation of heavy metal contamination and pollution indices in soil from selected dumpsites in Kelantan, Malaysia
Heavy metal contamination was one of the most important environmental issues, and the dumping of municipal waste at the dumpsites led to the contamination. Hence, this study focused on three dumpsites in Kelantan which were Beris Lalang Dumpsite, Kok Bedollah Dumpsite, and Bukit Che Ros Dumpsite. This study aimed to determine the concentration of selected heavy metals and to examine the soil quality using pollution indices. The soil samples were analysed using Atomic Absorption Spectroscopy (AAS). This study revealed the mean concentration of heavy metals in soil at Beris Lalang Dumpsite as following order, Cu (16.00 mgkg-1) > Cr (11.87 mgkg-1) > Zn (10.54 mgkg-1) > Mn (6.69 mgkg-1) > Pb (5.72 mgkg-1), while Kok Bedollah Dumpsite were Mn (64.86 mgkg-1) > Zn (31.28 mgkg-1) > Cu (18.92 mgkg-1) > Pb (18.59 mgkg-1) > Cr (3.52 mgkg-1) and Bukit Che Ros Dumpsite, were Zn (17.46 mgkg-1) > Cu (13.24 mgkg-1) > Cr (8.60 mgkg-1) > Mn (5.74 mgkg-1) > Pb (4.89 mgkg-1). Meanwhile for the pollution indices, the Igeo result showed that all stations were in class 0 except for one sampling point at Kok Bedollah Dumpsite. This is also supported by the Pollution Load Index (PLI) result for each dumpsite, which was also below 1, indicating that the areas were not polluted. If dumpsite management remains not managed correctly, this contamination may continue to have an impact on soil quality in the future. As a result, the data gained from this study was valuable in assisting authorities in managing dumpsites systematically to maintain the soil quality.
heavy metal, dumpsite, pollution indices, geo-accumulation index, pollution load index
Loop-Mediated Isothermal Amplification (LAMP) assay for rapid detection of Banana Bunchy Top Virus (BBTV) infecting Abaca (Musa textilis Nee) in the major abaca plantations in Caraga Region
This study evaluated the diagnostic efficacy of two methods for detecting Banana Bunchy Top Virus (BBTV) in abaca: conventional Polymerase Chain Reaction (PCR) and a novel colorimetric Loop-Mediated Isothermal Amplification (LAMP) assay. The study's purpose was to determine which method is more effective for field-based surveillance in the Philippines, a country with significant economic reliance on abaca production. A total of 243 leaf samples from key abaca-producing municipalities in the Caraga Region were collected and tested.The LAMP assay exhibited a significantly higher detection rate, identifying 85.2% of samples as positive compared to only 35.8% by conventional PCR (χ2 = 121.92, df = 1, p < 0.001). This diagnostic superiority was consistent across all four provinces surveyed, with the most pronounced difference in Surigao del Norte, where LAMP detected 86.04% of infections compared to a mere 2.33% by PCR. These findings reveal a substantial, previously hidden, reservoir of asymptomatic and low-titer BBTV infections that evade detection by traditional methods.The novelty of this study lies in its demonstration that LAMP is not only more sensitive but also uniquely suited for resource-limited settings due to its simple visual readout and lack of reliance on complex laboratory equipment. The results highlight that relying solely on symptom-based surveillance severely underestimates the true disease prevalence. The study concludes that adopting LAMP as a cornerstone of national surveillance efforts could provide a critical advantage in curbing the silent spread of BBTV, ensuring the sustainability of the abaca industry in the Philippines.