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.
Quality of Bay Leaf Extract (Syzygium polyanthum) Using Various Solvents as a Natural Preservative in Jerky
Sustainable food preservation is essential in strengthening food security in the agro-complex sector. Bay leaves (Syzygium polyanthum) are a local spice from Indonesia that contains bioactive compounds, including flavonoids and eugenol, with potent antioxidant and antimicrobial activities. This study aims to evaluate the quality of bay leaf extract using different solvents to determine the most effective solvent for developing natural preservatives for beef jerky products. The experiment used a completely randomized design (CRD) with five solvent treatments: distilled water (T1), methanol (T2), ethanol (T3), petroleum ether (T4), and n-hexane (T5). The parameters tested in this study were Total Dissolved Solids (TDS), pH, color value (L*a*b*), and Fourier Transform Infrared Spectroscopy (FTIR). The results showed that the type of solvent had a significant effect (p<0.01) on all parameters. Ethanol produced extracts with the highest TDS value (942.75±35.2 mg/L), slightly acidic pH (6.40±0.42), and the lightest color intensity (L*=39.98 ±1.85). The yellowness value (b* = 4.14 ± 0.49) also indicated higher concentrations of flavonoids and other phenolic compounds. FTIR analysis confirmed the presence of hydroxyl (3231 cm⁻¹) and aromatic (1650 cm⁻¹) functional group peaks in the ethanol extract, indicating its superior ability to extract antioxidant-rich compounds. In addition, a more explicit spectral definition in the fingerprint region further indicates a richer bioactive molecular composition compared to other solvents. This study concludes that ethanol is the most efficient solvent for producing high-quality bay leaf extracts, with excellent potential as natural preservatives to improve oxidative stability and extend the shelf life of beef jerky. This study provides valuable insight into the development of preservation systems using natural ingredients, especially for meat products that require safer, more sustainable preservation methods. This innovation supports sustainable food processing and promotes safer preservation practices, contributing to achieving national food security by using local biological resources.
Copyright (c) 2026 Journal of Tropical Resources and Sustainable Science (JTRSS)
Variation in growth of candidate lactic acid bacteria isolated from ‘dadih’ under varying total solids concentration and incubation times
Dadih is a traditional fermented milk from West Sumatra, Indonesia, which is made by naturally fermenting fresh milk inside bamboo tubes. While this traditional method gives dadih its unique flavor and texture, producing it on a larger scale consistently requires the use of controlled starter cultures. This study, therefore, aimed to have the optimal combination of total solids concentration and incubation time for milk fermented by lactic acid bacteria (LAB) starters isolated by dadih. Five individual LAB starters STARTER 11, STARTER 21, STARTER 25, STARTER 29, and STARTER 41 were tested in four different milk-based media: plain cow's milk (as a control), evaporated cow's milk, cow's milk added with 5.0% cream milk powder, and cow's milk added with 10% skim milk powder and 8.0% cream milk powder. Each medium was homogenized, pasteurized at 85 ℃ for 30 m, inoculated with a 3.0% LAB starter, and incubated for 24, 30, 36, 42, and 48 h. The outcome showed that the total solids concentration had a substantial effect on pH (p = 0.032) and curd formation (p = 0.041), but not on titratable acidity (p = 0.117). In the study, the control treatment using plain cow's milk had the lowest pH (4.66 ± 0.02) and the highest titratable acidity (0.45 ± 0.00), suggesting that LAB thrived best under these conditions and produced a stable, well-formed curd. By contrast, milk has a higher total solids content. Specifically, cow's milk with 10% skim milk powder and 8.0% cream milk powder has fermented more slowly, having weaker acidification and softer curd, likely due to reduced bacterial activity. Extending the incubation period to 48 h substantially increases acid production and curd firmness, resulting in the best coagulation consistency. Overall, plain cow's milk devoid of solids has a longer incubation time, creating the most favorable environment for LAB, which results in optimal acidification and a stable, firm curd.
Critical success factors (CSF) in implementing smart solid waste management in Banda Hilir, Melaka
Smart Solid Waste Management (SSWM) employs advanced technologies to enhance the efficiency, environmental sustainability, and regulatory compliance of waste management systems. However, its adoption in Malaysia remains limited, largely due to inadequate stakeholder awareness and insufficient community engagement. This study investigates the core features, implementation barriers, and critical success factors (CSFs) of SSWM in Banda Hilir, Melaka, offering empirical insights to address existing adoption challenges. A quantitative approach was employed, using convenience sampling of 293 respondents from key institutional stakeholders, including the Melaka Solid Waste Corporation (SWCorp Melaka), Melaka City Council, and SWM Environment Sdn. Bhd. Descriptive statistical analysis identified low-carbon technologies (mean=4.42), multi-stakeholder collaboration (mean=4.35), and intelligent routing systems (mean=4.26) as the most critical features. Key barriers to implementation included financial constraints (mean=3.93), high initial investment costs (mean=3.82), and technological limitations within current waste systems (mean=3.42). These barriers align with four critical success factors (CSFs) which are financial support (mean=4.48), stakeholder acceptance (mean=4.12), stakeholder awareness (mean=4.11), and the availability of adequate facilities and technology (mean=4.06). The findings offer evidence-based policy recommendations to support the wider adoption of SSWM, contributing to sustainable urban development and aligning with Malaysia’s environmental sustainability objectives.
Practices and challenges in Pijanga (Glossogobius giuris H.) fishing across Lake Mainit, Philippines
Lake Mainit is the fourth-largest Lake in the Philippines, playing a crucial role in the lives of local fishermen who rely on Pijanga fishing as their primary source of income. This study examines the livelihood practices and challenges of fishermen, using semi-structured questionnaires administered to 90 respondents. The data collected were tabulated in frequency and percentages. Point-biserial and Spearman's rho correlation tests were utilized to determine the significant relationship between practices and socio-demographic variables using Jamovi, an open statistical software. The findings showed that their primary way of catching fish is by using a modified cast net at 65.56% followed by Gillnets and spears at 36.67% and 12.22%, respectively. Most of the challenges they encountered were related to natural disasters (83.33%), adverse weather conditions (57.78%), and problems with boat or fishing equipment (35.56%). Moreover, there was no significant correlation between age of the respondents and the variables of full-time fishermen (p=0.210), catch per kilo per fishing (p=0.904), percentage sold of Pijanga (p=0.559), and percentage of consumed Pijanga (p=0.651). Fishermen believed that pijanga fishing is a sustainable practice at 77.78% and they are aware of the prohibition of catching small fish (91.11%), prohibition of using small nets (71.11%), and banning of dynamite fishing (10%). Despite this, 51% of the respondents also believed the possibility of pijanga fishing ban in the lake. Pijanga fishing faces a range of challenges, including adverse weather, pollution, and regulatory constraints. Fishermen view pijanga fishing vital to their livelihood and community well-being. Addressing these challenges requires strong cooperation between local authorities, environmental groups, and other stakeholders to ensure the long-term health and sustainability of the Lake.
Fostering public awareness and wetland conservation through biodiversity education at Paya Indah Wetlands, Malaysia
Paya Indah Wetlands (PIW) in Dengkil, Selangor, managed by PERHILITAN, is a biodiversity-rich reserve that serves as a sanctuary for wildlife, including the endangered saltwater crocodile (Crocodylus porosus) and the river hippopotamus (Hippopotamus amphibius), while promoting conservation, education, and ecotourism. This study evaluated the effectiveness of Communication, Education, and Public Awareness (CEPA) activities in enhancing visitor awareness of wetland and wildlife conservation. Using a mixed-method approach, data were collected from 18 January to 24 April 2025 through questionnaires, interviews, focus group discussions, and field observations involving 261 visitors aged 18 and above. Results indicate that visitors highly valued PIW’s conservation and educational roles, with average ratings ranging from 4.52 to 4.58. They appreciated the site's biodiversity (M = 4.45), strongly supported ecosystem protection (M = 4.53), and felt safe during their visit (M = 4.49). These findings suggest that CEPA efforts at PIW effectively enhance public perception and environmental awareness, offering a strong baseline for targeted improvements in future education and outreach initiatives.
Herpetofaunal richness in Sungai Sedim Forest Eco Park: strengthening the park’s ecotourism value
The Sungai Sedim Forest Eco Park, located within compartment 16 of the Gunung Inas Forest Reserve in Kedah, was surveyed to document the diversity of herpetofauna and update existing species records. Given the rapid growth of ecotourism in Sungai Sedim Forest Eco Park, a robust and current ecological baseline is required to ensure sustainable management and the development of tourism products that emphasize biodiversity. Using the visual encounter survey (VES) and pitfall trapping methods, the survey was carried out throughout five sampling sessions from July to October 2022. A total of 45 species, comprising 169 individuals, were successfully recorded by the study. Among the recorded species, Hylarana labialis was the most abundant, with 17 individuals, followed by Leptobrachium hendricksoni with 16 individuals, Amolops larutensis with 15 individuals, Limnonectes blythii and Odorrana hosii with 14 individuals each, and for reptile Gonocephalus grandis with 10 individuals and Cyrtodactylus consobrinus and Cyrtodactylus quadrivirgatus with eight individuals each. Clear, shallow streams and freshwater swamp forests are associated with the abundance of Hylarana labialis. Furthermore, the survey highlights the ecological richness of the area, with the remaining individuals representing a variety of species, each with fewer than 10 individuals recorded. Diversity indices revealed a consistently high level of species diversity, with Simpson’s Index (1-D) ranging from 0.8166 to 0.9282, and Shannon-Wiener Index (H’) ranging from 1.851 to 2.81. Pielou’s Species Evenness (J’), which ranged from 0.7549 to 0.917, indicates moderate to highly uniform species distribution across sessions. At the same time, the species accumulation curve did not reach the asymptote. The findings from the herpetofauna survey in Sungai Sedim Forest Eco Park strongly affirm the ecological value of the area and provide a scientific basis for expanding its ecotourism focus beyond adventure-based activities. The richness, diversity, and even distribution of species observed suggest a stable and relatively undisturbed habitat, positioning Sungai Sedim Forest Eco Park as an excellent location for conservation-oriented ecotourism.
Exploring anti-Herpes Simplex Virus agents from Malaysian medicinal plant biodiversity: Asplenium nidus L. and Phaleria macrocarpa (Scheff.) Boerl.
Plant-derived compounds offer promising alternatives for antiviral drug development due to their structure and bioactivity. This study explores the potential of two Malaysian medicinal plants, namely Asplenium nidus L. and Phaleria macrocarpa (Scheff.) Boerl. as sources of anti-herpes simplex virus type-1 (HSV-1). The paper examines the various extracts and fractions from these plants for their phytochemicals, in vitro cytotoxicity and antiviral activity. The variability in phytochemical profiles is addressed and correlated with the mode of antiviral action in infected host cells. Asplenium nidus root aqueous extract contains alkaloids, flavone aglycone, terpenoids, saponin, tannin and steroids. Asplenium nidus extracts/fractions are considered as non-cytotoxic, with the 50% cytotoxic concentration (CC50) in the range of 0.78+0.15 to 47.01+1.56 mg/mL. The effective concentration (EC50) of extracts/fractions toward the virus was within 0.056+0.007 to 0.743+0.39 mg/mL and the selective indices (SI) were within 14 to 63.25 which exceed 10, suggesting promising antiviral properties. P. macrocarpa fruit extracts/fractions are considered as non-cytotoxic, with the CC50 in the range of 0.40+0.02 to 1450 ± 2.0 mg/mL. The EC50 values were within 0.10+0.02 to 18 ± 1.2 mg/mL. As for the SI values were within 8 to 80.6 mg/mL with only three fraction/extracts worthy as antiviral agents, including P. macrocarpa fruit aqueous extract, fruit methanol extract and, aqueous protein extract P. macrocarpa fruit. The aqueous protein extract P. macrocarpa fruit contains proteins, sugar, flavonoid, polyphenol, and xanthone. Asplenium nidus root aqueous extract and aqueous protein extract P. macrocarpa fruit both exhibit multiple modes of action indicated by virus inhibition percentage exceeding 50% supported by statistical analysis with p<0.05. These include preventing virus attachment and penetration into cells, virucidal activity and reducing viral progeny to inhibit reinfection. These findings underscore the potential of tropical medicinal plants in contributing to the development of novel antiviral therapeutics.
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.
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.
Morphological delimitation of Durio dulcis Becc. and Durio graveolens Becc. based on comparative leaf traits
This study presents a comparative analysis of leaf morphology in Durio dulcis and Durio graveolens. A total of 12 accessions were analysed using 35 leaf morphological parameters, including leaf organisation, structure, and surface characteristics. The leaf specimens were obtained from the MARDI gene bank in Jerangau, Terengganu, and examined using standardised botanical methodologies. Cluster analysis using the unweighted pair group method with arithmetic mean (UPGMA) method based on Gower’s similarity coefficient demonstrated clear interspecific separation, indicating clear morphological differentiation between the two species. Although both species exhibited similar characteristics, including simple leaf type, petiolate attachment, and entire margins, significant variations were observed in petiole width (broader in D. graveolens), leaf sizes (larger in D. graveolens), apex and base morphology, leaf shape variability, venation clarity, and trichome distribution (denser abaxial indumentum in D. graveolens). Fourteen morphological characteristics were identified as key diagnostic markers for species delimitation, including petiole width (upper and base), leaf length and width, apex angle and shape, and venation clarity. These findings highlight the significance of detailed leaf morphology in Durio classification and provide vital baseline data for conservation, phylogenetic analysis, and future crop enhancement research.
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.
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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.