Publication Search

Indonesia, as a tropical country, is exposed to high levels of ultraviolet (UV) radiation, increasing the risk of skin damage. Sunscreen is widely used as a protective measure indicated by the Sun Protection Factor (SPF) value. This study aimed to evaluate the effect of active ingredient variations on SPF values and other influencing factors. A literature review with a descriptive-comparative approach was conducted using research articles published between 2021 and 2026 from Google Scholar, PubMed, ScienceDirect, and Elsevier. A total of seven eligible articles were analyzed. The results showed that the type of active ingredients, concentration, combination of ingredients, and dosage form significantly influence SPF values. Natural ingredients generally produce low to moderate SPF values, while combinations of active ingredients result in significantly higher SPF due to synergistic effects. Increasing the concentration of active ingredients also leads to higher SPF values. Additionally, dosage forms such as creams, serums, sunscreen powder and foundations affect sunscreen effectiveness through their film-forming ability on the skin. In conclusion, the combination of active ingredients and higher concentrations provides more optimal protection against UV radiation.

This research investigates intelligent cooling system design for main ship engines operating in tropical waters, integrating advanced machinery engineering with human factors to address thermal management challenges affecting engine performance, reliability, and crew operational effectiveness. Tropical maritime environments impose severe cooling demands through elevated seawater temperatures (28-32°C), high ambient conditions (28-35°C), and accelerated biofouling, reducing conventional cooling system effectiveness by 15-25% while increasing maintenance burdens and operational risks. Through qualitative analysis involving marine engineers, chief engineers with tropical operational experience, cooling system manufacturers, naval architects, automation specialists, and maritime training institutions, this study examines how intelligent cooling systems incorporating variable-speed pumps, adaptive control algorithms, predictive maintenance, and crew-centered interfaces can optimize thermal management while supporting effective human-machine collaboration. Results demonstrate that intelligent systems can reduce cooling energy consumption by 20-35%, improve temperature stability by 50-65%, extend maintenance intervals by 40-80%, and enhance crew situational awareness through intuitive monitoring interfaces, while requiring comprehensive training programs developing technical understanding and operational competencies. Key implementation challenges include control system complexity, sensor reliability in harsh marine environments, integration with existing engine management platforms, crew competency development requirements, and lifecycle cost justification. Findings reveal that successful intelligent cooling system implementation requires holistic sociotechnical approach addressing machinery engineering optimization, automation technology deployment, and human capability development through coordinated design and training strategies. This research contributes to marine engineering literature by providing integrated frameworks for intelligent system design incorporating machinery performance, automation capabilities, and human factors supporting operational excellence in tropical maritime operations.

The increasing demand for housing in tropical regions requires building materials that are fast to apply, environmentally friendly, and resilient to extreme climate conditions as well as disaster risks. Conventional interlocking bricks are often chosen for their ease of construction, yet they still face challenges such as moisture and early cracking. This study proposes the innovation of the Hybrid Living Green Brick, a combination of lightweight bricks made from rice husk ash and fly ash waste (FRCB) with a biological layer of cyanobacteria. FRCB improves compressive strength by approximately 30% with the addition of 5% rice husk ash, achieving 65 kg/cm², thereby meeting Class 50 requirements (≥50 kg/cm²) according to SNI-15-2094-2000. The incorporation of 3% cyanobacteria provides an additional though not significant strength improvement, while still within the Class 50 category. It also reduces brick weight by 4.3%, with further optimization potential through cyanobacteria integration, and lowers carbon emissions from the firing process. Cyanobacteria induce the formation of CaCO₃ layers that seal pores, reduce water absorption by an average of 10%, and provide self-healing properties for microcracks. Preliminary observations indicate that FRCB offers stable mechanical performance, while biological activity was observed on the 7th day with the formation of pale-white mineral layers continuing until the 28th day. This hybrid innovation shows potential to support sustainable and disaster-resilient tropical construction by combining the mechanical strength of waste-based materials with the biological durability of cyanobacteria against extreme climates. Despite challenges related to moisture control and production standardization, the Hybrid Living Green Brick concept opens new pathways for developing environmentally friendly construction materials that are more adaptive to disaster-prone tropical conditions.

Rainfall is a crucial factor in the stability of the Earth's ecosystem and has a significant impact on agriculture, forestry, energy, and water management. However, increasingly unstable climate change makes rainfall patterns difficult to predict accurately using traditional methods. The city of Medan, the capital of North Sumatra Province, has a tropical rainforest climate with an average annual rainfall of approximately ±2200 mm and an average temperature of 27°C. Significant weather fluctuations in this area can trigger flooding when rainfall increases and cause water shortages when rainfall decreases (BMKG, 2021). Therefore, a prediction approach that can manage non-linear and dynamic data is needed. Artificial Neural Networks (ANN) are one of the reliable machine learning methods for detecting data patterns. By using the backpropagation algorithm, the model can gradually reduce prediction errors, making it widely used in weather forecasting applications. In this regard, this study uses ANN with the backpropagation method to forecast monthly rainfall in Medan City by utilizing data from 2022–2024 as training and testing data.

The advancement of automotive technology has accelerated the adoption of renewable‑energy‑based electric vehicles, including the integration of solar panels on electric scooters. Indonesia’s tropical climate provides abundant solar energy potential; however, the limited surface area of scooters often restricts panel placement to the footrest section. This study aims to evaluate the impact of using a 10 mm clear acrylic cover on the performance of a 50 Wp monocrystalline solar panel in an electric scooter battery‑charging system. An experimental method was employed by comparing the panel’s performance under two conditions: without a cover and with the acrylic cover installed. Key parameters observed included voltage, current, and charging power, recorded using a data logger. Tests were conducted for 30 minutes under varying solar radiation intensities. The results indicate that the acrylic cover reduces the panel’s output power, from 55 W to 45 W at a solar radiation intensity of approximately 1100 W/m². These findings suggest that the use of an acrylic cover must be carefully considered to maintain optimal charging system performance.

The advancement of automotive technology has accelerated the adoption of renewable‑energy‑based electric vehicles, including the integration of solar panels on electric scooters. Indonesia’s tropical climate provides abundant solar energy potential; however, the limited surface area of scooters often restricts panel placement to the footrest section. This study aims to evaluate the impact of using a 10 mm clear acrylic cover on the performance of a 50 Wp monocrystalline solar panel in an electric scooter battery‑charging system. An experimental method was employed by comparing the panel’s performance under two conditions: without a cover and with the acrylic cover installed. Key parameters observed included voltage, current, and charging power, recorded using a data logger. Tests were conducted for 30 minutes under varying solar radiation intensities. The results indicate that the acrylic cover reduces the panel’s output power, from 55 W to 45 W at a solar radiation intensity of approximately 1100 W/m². These findings suggest that the use of an acrylic cover must be carefully considered to maintain optimal charging system performance.

L House is a house design that is shaped like the letter "L". This distinctive configuration offers flexibility in spatial arrangement and creates an interesting interaction between interior and exterior areas. L House by 022Studio is a work that combines modern aesthetics with traditional values and sustainability. Through a descriptive criticism method involving interviews with architects, literature studies, and analysis of design elements, this study aims to reveal the strengths and challenges in the application of modern design in a tropical context. L House successfully integrates space with nature through the use of local materials, flexible spatial layouts, and building orientations that optimize natural lighting and ventilation. In addition, this design also makes a significant contribution to the development of modern architecture in Indonesia by demonstrating that modern buildings can be adapted to local cultural and environmental contexts. L House is a good example of sustainable architecture that can inspire similar projects in the future.

Sea cucumbers (Holothuroidea) are marine organisms of high ecological and economic value, yet their populations in many tropical regions have declined due to exploitation pressures. This study aimed to analyze the density and distribution patterns of sea cucumbers in the coastal waters of Tuhaha, Saparua Island, Central Maluku Regency. A quantitative descriptive survey was conducted using 1 × 1 m quadrat transects along eight transect lines perpendicular to the shoreline. Density was calculated based on the number of individuals per unit area, while distribution patterns were determined using Morisita’s index. Four species of sea cucumbers were identified, namely Holothuria scabra, Holothuria atra, Bohadschia vitiensis, and Bohadschia marmorata, with a total of 33 individuals and an overall density of 0.19 ind/m². Species H. scabra exhibited the highest density (0.11 ind/m²), whereas H. atra and B. vitiensis had the lowest (0.01 ind/m²). The population distribution was aggregated (Id = 6.11), indicating a strong association with specific microhabitats, particularly muddy-sand substrates. Environmental parameters (temperature 30°C, salinity 30 ‰, pH 6.90) remained within the optimal tolerance range for sea cucumbers. These findings indicate that Tuhaha waters continue to support Holothuroidea populations; however, the aggregated distribution pattern reflects vulnerability to overexploitation. Therefore, ecosystem-based management through habitat conservation, catch restrictions, and the integration of aquaculture and restocking is essential to ensure the sustainability of sea cucumber resources in Central Maluku.

Tulungagung Regency has the potential for culinary tourism that can be developed, one of which is traditional culinary. Although the Tulungagung Regency Government has presented a "Halal Culinary Area" and a "Pinka Culinary Tourism Area", the area has not fully provided an interesting visual and functional experience. Therefore, it is necessary to design a space that facilitates traditional culinary MSMEs as well as an educational and recreational place. This design carries the theme of contemporary tropical architecture by considering local climatic conditions, through the application of wide openings, cross ventilation, wide trellises, and the use of natural materials, as well as expressive styles with the shape of a rooster roof and the basic shape of an elliptical building as a symbol of adaptation to climate change and the economy in the business environment. The facilities in this design include traditional restaurants, educational bales, wiyata offices, prayer rooms, playgrounds and other supporting facilities that can attract the interest of the community and introduce traditional Tulungagung culinary.

As a high-value crop, potatoes necessitate balanced nutrient management for optimal growth and yield. This research aimed to assess how varying applications of NPK 20-20-10 fertilizer influenced potato growth, yield, tuber quality, agronomic efficiency, and economic viability within tropical climates. The experimental setup involved a randomized complete block design, incorporating four replications across seven distinct treatments: a control, a standard inorganic fertilization regimen, and NPK 20-20-10 applied at 0.50, 0.75, 1.00, 1.25, and 1.50 times the suggested dosage. The findings indicated that applying NPK 20-20-10 significantly enhanced several parameters, including plant height, branch count, tuber count, tuber weight, and overall yield components, when contrasted with the control group. Notably, the 1.25 times recommended dose demonstrated superior performance, leading to a 34.9% increase in tuber number and a 68.6% rise in tuber weight compared to the control. Agronomic effectiveness scores surpassed 100 for dosages ranging from 0.75 to 1.50, with the 1.25 dose registering the peak value. Economic evaluations confirmed the profitability of all NPK treatments, and the 1.25 dose yielded the most favorable R/C ratio and a net profit of IDR 29,053,400. Consequently, the recommended application for potato cultivation is 675 kg/ha of NPK 20-20-10, distributed in three equal parts at planting, four weeks post-planting, and six weeks post-planting. Thus, these results underscore that NPK 20-20-10, when applied at 1.25 times the recommended rate, presents an agronomically effective and economically sound strategy for sustainable potato farming in tropical settings.

This literature study evaluates the accuracy of the Slope Mass Rating (SMR) method for coal mine slope stability in Indonesia through a systematic descriptive synthesis of 25 empirical studies from 2020 to 2025. The objectives of the study were to identify the level of SMR prediction accuracy, factors affecting the method's performance, and modifications required for local Indonesian conditions. The research method involved a systematic search with inclusion criteria for empirical studies reporting SMR and/or Safety Factor (SF) values ​​for coal mines and associated slopes in Indonesia. Quantitative analysis showed a range of reported SMR values ​​between 41 and 96 with a median of 72, while SF values ​​ranged from 1.137 to 4.09 for normal operational conditions. The synthesis results indicated that SMR provides a consistent stability classification for initial slope design and failure mode identification (planar, wedge, toppling), with historical validation showing a correlation of up to 91.23% between SMR-based hazard zoning and actual field events in some cases. Key limitations include dependence on discontinuity data quality, sensitivity to groundwater conditions and tropical weathering, and variation in the interpretation of adjustment factors F1-F4. Modifications such as NAAF23 and integration with numerical modeling have been shown to improve prediction reliability. It is recommended that coal mining practitioners combine SMR with kinematic analysis and limit equilibrium modeling as standard operating procedures, and develop adjustment factors specific to Indonesian geological conditions. Further research should focus on standardizing parameter reporting and cross-site quantitative validation to enable more robust statistical meta-analyses.  

This study formulates a design concept for the Beach Tourism Resort Area in Botubarani Village by applying tropical architecture that responds to coastal climatic conditions while enhancing the quality of visitor experiences. The research integrates principles of thermal comfort, environmental sustainability, and the ecological potential of coastal environments as the basis for creating climate-adaptive and environmentally responsive tourism areas. The methodology includes site analysis, field observation, climatological assessment, and a literature review related to tropical architecture and coastal tourism design. The collected data were used to determine building orientation, mass layout patterns, visitor capacity, materials, vegetation, and utility systems appropriate for humid tropical climates. The findings show that the site’s position between the sea and the mountains, combined with full-day sun exposure, requires design strategies that maximize cross-ventilation, utilize sloped roofs, provide natural shading, and apply local materials such as wood, bamboo, and red brick. The large spatial needs based on visitor capacity projections are accommodated through a flexible cluster layout that supports visual and functional connectivity between buildings while incorporating green open spaces to enhance microclimate comfort. The utility system is designed using sustainability principles through greywater–blackwater separation, infiltration wells, and recycling-based waste management. This study confirms that the application of tropical architecture in coastal tourism areas can improve thermal comfort, energy efficiency, and environmental sustainability. These findings guide developing tropical tourism area designs that are more adaptive to climate change and more responsive to visitor needs.

This study examines and provides a descriptive analysis of Omah Pulung, a residential house located in Banyumanik, Semarang City, Central Java. The focus of the research is directed at the application of a minimalist architectural style that emphasizes simplicity of form, spatial efficiency, and aesthetic aspects that are in harmony with the characteristics of the building. The principles of minimalist architecture are applied through the selection of simple but functional materials, optimal natural lighting arrangements, and air circulation systems that are suitable for Indonesia's tropical climate. The research method uses a qualitative approach with observation, documentation, and descriptive analysis techniques to explore the physical and functional characteristics of the house. The results of the study show that Omah Pulung successfully represents the principle of minimalism through simple geometric shapes, efficient use of space, and natural lighting that supports the comfort of residents. In addition, good air circulation strengthens the adaptation of the house to tropical climatic conditions so that healthy and sustainable housing is created. This research contributes to the understanding of the application of minimalist architecture in the local context, as well as a reference for the development of residential design that is environmentally friendly and according to the needs of urban communities in Indonesia.

Millions of people suffer from malaria, one of the most serious parasitic diseases that threatens human life and causes high rates of morbidity and mortality, particularly in tropical and subtropical regions. Traditional diagnostic methods, such as blood smear examination, which can be performed using a microscope, face many challenges due to the inaccuracy of manual analysis and the reliance on individual skills. Therefore, the use of machine learning or deep learning algorithms to automate malaria detection offers promising solutions to improve accuracy, reduce diagnosis time, and enhance scalability. In this paper, a multi-class convolutional neural network (CNN)-based model is designed to classify cells infected with Plasmodium falciparum (P. falciparum) and Plasmodium vivax (P. vivax) and uninfected cells from blood smears, as most severe cases and deaths are caused by P. falciparum and P. vivax. This is achieved by building and training a CNN from scratch, rather than using transfer learning from pre-trained models. The proposed network was trained and tested on the Kaggle dataset, which consists of 27,558 images of infected and uninfected individuals. These images were divided into 13,779 images of uninfected individuals, 6,890 images of individuals with P. falciparum malaria, and 6,889 images of individuals with P. vivax malaria. The images were preprocessed using several operations, including blurring, denoising, and morphological processing. The proposed model achieved the best evaluation accuracy when compared with other deep learning algorithms, with an accuracy rate of 96.5%, a sensitivity rate of 95%, a specificity rate of 97.6%, and an F1-score rate of 96.5%. These results demonstrate the effectiveness of the proposed model as a tool to assist clinicians in malaria diagnosis, reducing reliance on manual analysis.

Leaves of Etlingera walang (Blume) RMSm have been empirically used in traditional medicine to relieve stomach disorders and are known to contain secondary metabolites with potential antimicrobial properties. Salmonella typhi infection can cause typhoid fever with symptoms such as diarrhea and abdominal pain, while Candida tropicalis is a fungus that can infect the gastrointestinal tract and lead to digestive disturbances. This study aimed to evaluate the antibacterial and antifungal activities of the ethanolic extract of E. walang leaves against S. typhi and C. tropicalis. The antimicrobial assay was carried out using the disk diffusion method at extract concentrations of 25%, 50%, and 100%, with chloramphenicol and ketoconazole as positive controls, and DMSO as the negative control. Phytochemical screening revealed the presence of alkaloids, flavonoids, saponins, and tannins. However, the results showed that the extract did not produce inhibition zones against either test microorganism. Extract evaluation indicated a moisture content of 12.23%, total ash 13.39% (above the standard), acid-insoluble ash 1.25%, total plate count 1.8 × 10 ⁴ , and mold and yeast count 1.0 × 10 ³. The findings suggest that although the ethanolic extract of E. walang leaves contains secondary metabolites and is traditionally used for stomach ailments, it does not exhibit antimicrobial activity against S. typhi or C. tropicalis.

Fungal infections are a common health problem in tropical regions, including Indonesia, since humid conditions support microbial growth. Candida tropicalis is a pathogenic species frequently identified as the cause of both superficial and systemic candidiasis. The rising resistance to synthetic antifungal agents such as fluconazole and ketoconazole highlights the need for safer and more effective alternative therapies. Propolis, a resinous substance produced by Trigona sp. bees from various plant sources, contains flavonoids, phenolics, and terpenoids with important biological activities, including antimicrobial and antifungal effects. This study aimed to evaluate the effectiveness of ethanol extract of propolis from Balikpapan against the growth of Candida tropicalis using the disk diffusion method. Phytochemical screening revealed the presence of alkaloids, flavonoids, phenolics, tannins, and terpenoids in the extract. Antifungal activity testing showed that concentrations of 80%, 90%, and 100% significantly inhibited fungal growth, with the largest inhibition zone of 27.93 mm observed at 100% concentration. Statistical analysis using ANOVA confirmed significant differences among treatments. Thus, ethanol extract of Trigona sp. propolis from Balikpapan demonstrates strong potential as a natural antifungal agent. These findings support the use of propolis as a natural-based therapeutic alternative for fungal infections and contribute to the development of herbal pharmaceutical products.

Oil palm (Elaeis guineensis) is a major tropical commodity in Southeast Asia that plays an important role in the global economy, especially as a raw material for the food, cosmetics, and bioenergy industries. West Kalimantan Province is one of the regions with the largest oil palm plantations in Indonesia, where its area increased from 1,166,282 Ha in 2020 to 1,449,274 Ha in 2022. Landak Regency contributes 119,326 Ha, but its productivity is still relatively low with a total production of 184,592 tons or around 1.54 tons/Ha. PTPN IV Ngabang in Landak Regency as one of the largest palm oil companies in the area also faces the problem of low productivity, thus hindering harvest rotation and the achievement of daily targets. This study aims to describe the productivity of oil palm harvester labor and find out what factors affect the productivity of oil palm harvester labor in PTPN IV, Ngabang District, Landak Regency. The method uses qualitative as an approach in finding answers with a sample of 78 respondents. The variables in this case study are labor productivity (Y) and independent/independent variables (X), namely age, working period, family dependents, mileage, and education. The data analysis technique used in this case study is analysis on multiple linear regression. The results of the study concluded that the productivity of oil palm harvesters in PTPN IV Ngabang averaged 1200,71 kg/day. Simultaneously, age, family dependents, working period, mileage, and education affect the productivity of oil palm harvester labor at PTPN IV Ngabang. Partially, the factor that greatly affects the productivity of the oil palm harvester workforce at PTPN IV Ngabang is the age factor of the worker and working period. Meanwhile, the factors of family dependents, distance traveled and labor education partially did not have a significant effect.

This design project is motivated by the low public interest in sports and the limited availability of sports facilities, creating a need for a sports hall that is both effective and efficient in enhancing the community’s quality of life. However, the mere provision of a sports facility is not sufficient; considerations such as building orientation, opening design, and airflow circulation are essential to create an optimal environment for sports activities. Therefore, the tropical architecture approach serves as the primary design basis for the sports hall in Asahan Regency. The aim of this design is to support a healthy lifestyle and improve the quality of life of the local community through comfortable and safe sports activities. The design method adopts a qualitative approach, with data collected through interviews and field observations to understand the needs and preferences of the community. The design also reflects local identity through a mass transformation inspired by the shell form, symbolizing the city of Asahan. The shell structure system is known for its slenderness, making it lightweight and efficient, while its curvature ensures even load distribution. This approach can serve as a model for future sports facility developments in Asahan Regency. This sports hall is expected to become a central hub for athletes in Asahan, providing optimal training facilities to improve their performance. With a modern building and complete facilities, the community can engage in sports activities more comfortably and safely, thus increasing public interest in sports and enhancing overall well-being. This design also aims to promote awareness of the importance of a healthy lifestyle through an effective and efficient sports center.

Sibolga City, located along the seashore and endowed with abundant natural beauty, holds significant potential for development as a marine tourism destination. Beyond its coastal appeal, the city offers opportunities for diverse recreational areas such as camping grounds, botanical gardens, culinary centers, and Mancakrida zones. To support these initiatives, this research investigates the sources of activities and spatial programs that can be realized through the construction of cottages and integrated recreational facilities. Given Sibolga’s hot tropical climate, the application of Tropical Architecture is essential to address environmental challenges including solar exposure, rainfall intensity, air humidity, and wind orientation. This study aims to harness Sibolga’s environmental assets by proposing sustainable cottage designs and recreational spaces that align with the principles of Tropical Architecture. The research contributes to the development of commercial residential models that are harmoniously integrated with nature, promoting economic sustainability and ecological balance. Methodologically, the study involves interviews, site surveys, and comparative analyses to derive contextual design solutions. The final output is a conceptual design for cottages and recreational areas that reflect climate-responsive architecture and support Sibolga’s tourism growth. This research not only enhances architectural knowledge in tropical settings but also offers practical insights for urban planners and stakeholders seeking to revitalize Sibolga City as a vibrant, nature-integrated tourism hub.

Taro flour (Colocasia esculenta L. Schott) is a local food ingredient with significant potential to be developed as an alternative carbohydrate source. Its high starch content, dietary fiber, and functional properties make taro flour a promising candidate for use in various food formulations. Moreover, the widespread availability of taro in tropical regions supports its sustainable utilization. However, the development and application of taro flour face several challenges, such as high levels of antinutritional compounds (particularly oxalates), variability in characteristics among cultivars, limited processing technology, and low consumer acceptance. Therefore, innovation in processing techniques is needed, including pre-treatment methods to reduce antinutrient content, starch modification to enhance functionality, and composite formulation with other food ingredients to expand product applications. This article aims to establish a comprehensive conceptual framework for the innovative development of taro flour, focusing on processing technology, functional value, and commercialization potential. Through this approach, the development of taro-based products is expected to increase added value, support local food diversification, and strengthen national food security.