Vol. 57 No. 4 (2025)

The nickel industry in Indonesia generates massive volumes of ferronickel slag that may harm the environment. This research evaluates the feasibility of utilizing coal fly ash and slag from a ferronickel smelter in Obi Island in Indonesia to synthesize geopolymer, an environmentally friendly cementitious material. Compressive strength of geopolymer mortars was measured as a function of slag particle size (coarse and fine), fly ash mass fraction in the dry aluminosilicate binder precursor blends (0.4 and 0.8), and thermal curing period (24 and 48 hours). Mortar specimens were produced by…

Driver fatigue is the primary factor contributing to traffic accidents globally. To address this challenge, the electroencephalogram (EEG) has been proven reliable for assessing sleepiness, fatigue, and performance levels. Although alertness monitoring through EEG analysis has shown progress, its use is affected by complicated methods of collecting data and labelling more than two classes. Based on previous research, the original form of EEG signals or power spectral density (PSD) has been extensively applied to detect driver fatigue. This method needs a large, deep neural network to produce…

The demand for adaptable and efficient soft robotic grippers has grown due to their potential applications in industries such as food handling, manufacturing, and logistics. This study explores a Kirigami-based soft robotic gripper, designed to handle a wide range of objects with minimal risk of damage. The gripper utilizes a Kirigami-inspired structure combined with Liquid Silicone Rubber (LSR CN-251), chosen for its flexibility, durability, and food-safe properties. Finite element analysis was conducted to analyze the gripper’s mechanical performance under tensile forces ranging from 0.1 N…

Zeolites are widely applied in various fields owing to their outstanding properties. However, our understanding on the nature of zeolite synthesis is not completed yet due to its high dimensional parameters. Machine learning has the ability to unravel fundamental relationships between complex parameters and predict the possible outcomes; thus, it can potentially reveal the nature of zeolite synthesis. This mini review highlights the current use of machine learning to comprehend the black box issue in zeolite synthesis. Conventional syntheses of zeolite were also elaborated to showcase the gap…

Rice is the main commodity processed into rice, as a staple food for the people of Indonesia. Pests and diseases can cause decreased production to crop failure. The method used by farmers is pest control by spraying chemical pesticides. However, chemical pesticides have serious impacts on plants, increased immunity for pests, increased chemical residues in crops that threaten human health, and environmental pollution. The objective of this study is to design an integrated high-tech trap that is effective, efficient, cost-effective, durable, safe, environmentally friendly (zero-emission), and…

Construction waste poses a significant environmental and economic challenge in Indonesia’s rapidly expanding construction sector. This research develops a financing model for managing construction waste throughout the project life cycle, emphasizing the integration of cost components and waste management strategies. Data were collected through surveys, structured interviews, and observations from 80 construction projects across Indonesia. The analysis revealed that while reinforcement, bricks, and split stone have high recycling potential, actual reuse remains limited due to poor planning and…

In this study, polylactic acid (PLA) was proposed as a material for producing bioplastics due to the desirable properties, including high processability, low cost, and good transparency. However, the degradation of PLA as a bioplastic remains a significant challenge. To address this problem, PLA was modified by blending with a bio-filler, in the form of calcium carbonate (CaCO3) prepared from eggshell powder (ESP). The CaCO3 filler in form of ESP was incorporated into PLA using the solution casting method. The parameter being varied was the ESP loading, ranging from 0 wt% to 20 wt%. The…

Cardiovascular diseases are the leading cause of mortality worldwide. An increasing number of studies have applied artificial intelligence (AI) to identify anomalies and classify electrocardiograms (ECGs), supporting early detection and diagnosis. This study proposes and evaluates the classification of ECG signals based on time-series data and features extracted via fast Fourier transform (FFT) and discrete cosine transform (DCT), implemented on resource-limited microcontroller units (MCUs) for selected AI models. Two models, the artificial neural network (ANN) and the convolutional neural…

This paper presents the design and implementation of a solar-powered automatic shrimp feeder utilizing IoT technology to enhance efficiency and precision in aquaculture. The core of the system is the DC motor operated feeder mechanism, and is capable of user defined customization like feeding scheduling, speed control, real time system monitoring etc. from distance through IoT integration via a smartphone. The motor speed can be adjusted to 1000, 1500, and 2000 rpm as per the requirement. Additionally, system can also monitor other water quality parameters like water temperature, pH and DO…

Indonesia is the global leader in palm oil production, but it deals with significant challenges in managing palm oil mill waste, particularly palm kernel shells (PKS). This study investigated palm kernel shell (PKS) as a precursor for synthesizing magnetic activated carbon (MAC) to enhance its performance as an adsorbent for liquid waste treatment. The precursor was delignified using alkali liquor and magnetized by incorporating Fe²⁺ and Fe³⁺ ions, followed by chemical activation (ZnCl₂) through an intermediate pyrolysis process. The performances of delignified and non-delignified MAC (DMAC…