University of Indonesia

This article explores the foundational theories that underlie the development of learning machines and identifies a core epistemological problem within prevailing conceptions of language, mind, and technology. These domains, which frequently inform the design of learning systems, are typically grounded in representationalist assumptions. In contrast, this article advances a distinct framework through the theory of a-ppropriation , which refers to the mind-body capacity to appropriate—or manipulate—the essence of reality into personal perspectives and actions. Within this framework, human understanding is conceived as a direct engagement with the essence of reality, unmediated by representational structures, and expressed within comprehensible, articulable, and utilizable forms such as language, art, and technology. Accordingly, the learning machine is not understood as a mirror of human cognition, but as an embodiment of appropriation: a system designed to interpret data and prompts directly by locating their equivalent and parallel forms within both the data center and user input. As a result, the machine generates responses within a mode of “personal understanding.” In other words, it does not rely on representational modeling or conventional machine learning systems based on binary syllogism, but instead functions as an agentic machine —capable of interpreting novel data and prompts beyond its initial training parameters.

The increasing global demand for sustainable aviation fuels has driven extensive research on developing efficient heterogeneous catalysts. This study investigates the effect of different surface functionalization methods of mesoporous SBA-15 on its catalytic activity for the production of a C16 precursor of bio-aviation fuel. The SBA-15 surfaces were modified by two acid functionalization routes, namely sulfonation and sulfation, to enhance its surface acidity and catalytic activity. Sulfonation was carried out using 3-mercaptopropyltrimethoxysilane (MPTMS) followed by oxidation to obtain the SO3H–SBA-15 catalyst containing sulfonic acid groups (–SO3H), while sulfation using ammonium sulfate as a precursor produced the SO4–SBA-15 catalyst containing sulfate groups (SO42-). Both catalysts were characterized using NH3-TPD and acid-base titration to quantify the total acidity. The catalytic performance was evaluated through hydroxyalkylation-alkylation (HAA) reaction between 2-methylfuran (2-MF) and methyl isobutyl ketone (MIBK) to synthesize a C16 bio-aviation fuel precursor, 5,5′-(4-methylpentane-2,2-diyl) bis(2-methylfuran) abbreviated as MPM. The results revealed that both modification methods effectively increased the total acid of SBA-15. However, the sulfated SBA-15 catalyst exhibited superior catalytic activity and stronger acid strength than the sulfonated one due to formation of more acid sites on its surface. Therefore, the sulfation route was identified as a more effective strategy for developing highly active solid acid catalysts. This research demonstrates the superior properties of sulfated mesoporous SBA-15 as a promising and sustainable heterogenous catalyst for converting biomass-derived platform chemicals into advanced C16 bio-aviation fuel precursors.

This study examines how halal supply chain management influences supply chain performance in food and logistics settings where product integrity, food safety, and sustainability are increasingly scrutinized. The review is motivated by fragmented empirical findings and limited synthesis on how digital technologies shape the performance effects of halal practices. A systematic literature review was conducted by searching the Scopus database for English journal articles in business, management, and accounting published between 2014 and 2025. From an initial pool of 9,780 records, stepwise screening with the keywords supply chain management, halal supply chain management, supply chain performance, and halal product yielded nine studies for synthesis and bibliometric mapping with VosViewer. The findings indicate that strict physical segregation, end to end traceability, robust certification and labelling, organisational capabilities, and knowledge management enhance efficiency, flexibility, halal compliance, and market trust, leading to stronger operational and sustainable performance. The review also highlights opportunities for technologies such as blockchain, the Internet of Things, artificial intelligence, and immersive virtual environments to improve transparency and reduce contamination and data fraud risks. These insights call for cross industry empirical testing of mediating mechanisms and infrastructure readiness to support more adaptive halal supply chains.

ZnO nanoparticles synthesized through Pogostemon cablin Benth (PCB) leaf extract demonstrate significant potential as active UV-protection agents in sunscreen cosmetic product. This research employs an environmentally sustainable approach by utilizing secondary metabolites present in PCB leaf extract, including flavonoids, alkaloids, and tannins compounds. These bioactive compounds function as natural bases sources and capping agents for hydrolysis process. The effect of adding PCB leaf extract concentration variations (5, 7, 9 %) has been studied on the results of ZnO nanoparticles bandgap values of 3.26, 3.17, and 3.12 eV, respectively. Morphological characteristics transformed from hexagonal wurtzite structures to spherical which is caused by the active role of functional groups in PCB leaf extract. The ZnO nanoparticles exhibited an average particle size distribution of 79.5 nm accompanied by exceptional homogeneity levels at −29 mV. For PCB leaf extract at 5, 7, and 9 % concentrations produced SPF values for ZnO nanoparticles measuring 19.33, 33.48, and 47.66, respectively. PCB leaf extract enables controlled ZnO nanoparticles size, enhanced UV absorption, and significantly improved for sun protection factor (SPF). • ZnO nanoparticles was synthesized using Pagostemon cablin Benth (PCB) leaf extract as a natural hidrolysis process. • ZnO nanoparticles was characterized by FTIR, XRD, PSA, SEM-EDX. • PCB leaf extract has a significant effect on the UV-protection properties of ZnO nanoparticles. • The SPF value of ZnO nanoparticles synthesized with PCB extract concentration (9 %) was 47.66.