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Takaras River is a river basin that is vulnerable to pollution, particularly from the mercury usage in small-scale gold mining. This study aims to identify water quality based on mercury (Hg)and pH levels in the Takaras River. Samples were taken at two locations using a purposive sampling method. Results showed indications of mercury use on former gold mining land around the Takaras River altought the mercury content level was below 0.075 µg/L or 0.00075 mg/L in sample 1 and 2. Based on the test results, the acidity level (pH) in the two water samples from Takaras River is 3.86 and 3.84 in sample 1 and 2, compared to the maximum pH quality standard of 6-9 for Class II water, it is concluded that the scale of acidity in Takaras River is very low, indicating that the water quality in the Takaras River is highly acidic, abnormal, and shows signs of serious pollution. The implications of low pH levels in the Takaras River can cause damage to the Takaras River ecosystem, a decline in soil quality and fertility, and an increase in heavy metal toxicity in the environment surrounding the river.

Ballast water plays a crucial role in maintaining ship stability during shipping, but it also carries environmental and human health risks due to the heavy metals it carries. This study aims to examine the health risks posed by exposure to heavy metals in ballast water and to assess the effectiveness of management practices implemented in the maritime industry. Using a literature review method, this study examines various scientific sources related to the content of heavy metals such as lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) in ballast water, as well as their impacts on human health and marine ecosystems. The results indicate that heavy metals in ballast water can cause long-term toxic effects such as neurological disorders, kidney damage, and respiratory and reproductive disorders. The greatest risk is experienced by maritime workers who are directly exposed through inhalation or skin contact during the ballast water sampling and processing process. To minimize these risks, strict work safety protocols, improved ballast water treatment technology, and regular monitoring of heavy metal levels are required. Thus, this study emphasizes the importance of strengthening ballast water management policies and practices that are oriented towards human health and environmental sustainability.  

This study investigates the role of artificial intelligence (AI) in enhancing language learning, with a focus on five key applications: automatic text analysis, personalized learning, adaptive feedback, language error detection, and automatic translation. The study addresses the challenge of integrating AI effectively in educational contexts while balancing technological potential with pedagogical guidance. The objective is to provide a comprehensive understanding of how AI tools contribute to more adaptive, efficient, and engaging language learning experiences. A systematic literature review method was employed, selecting and critically analyzing studies published between 2020 and 2025 that examined AI-assisted language learning strategies. The findings indicate that automatic text analysis supports comprehension monitoring and guided learning, while personalized learning adapts content to individual learner needs, enhancing motivation and retention. Adaptive feedback delivers immediate, targeted guidance that fosters accuracy and self-regulated learning, and language error detection tools enable learners to identify and correct grammatical and lexical mistakes, promoting metalinguistic awareness. Automatic translation broadens access to authentic texts and cross-cultural materials, supporting comprehension and independent learning. Synthesizing these findings highlights the transformative potential of AI to improve learning outcomes while also revealing challenges such as tool reliability, ethical considerations, and the need for teacher oversight. The study concludes that AI, when thoughtfully integrated, complements instruction, enhances learner engagement, and supports differentiated and data-driven teaching strategies, providing valuable insights for language educators and guiding future research on AI-enabled language learning.

Sanskrit verbs constitute a compelling object within linguistic research because of their semantic and structural complexity, which has not yet been widely explored. A proper understanding of Sanskrit verb usage can help prevent errors, especially among Hindus who use the language in cultural or religious contexts. Therefore, this research aims at analyzing the structure and semantic role of Sanskrit event verbs through the Natural Semantic Metalanguage approach. The data sources were from three chapters of the Bhagavad Gita (Chapters IX, X, and XI). The data were gathered using documentation and systematic note-taking techniques, and subsequently analyzed through qualitative methods by implementing the Natural Semantic Metalanguage approach conducted by Wierzbicka, supported by the semantic macroroles theory by van Valin and Lapolla. From this research, five Sanskrit event verbs were found in those chapters, namely cyavanti “to fall down”, pravartate “to develop”, vepamānaḥ “to tremble”, abhivijvalanti “to blaze”, and pratapanti “burns”. Further analysis showed that these event verbs can be classified into MOVE and HAPPEN types. In addition, the semantic macroroles of the Sanskrit event verb arguments found can be identified in the form of AGENT, PATIENT, EXPERIENCER, SOURCE, and THEME.

Acid mine drainage (AMD) is characterized by low pH and high concentrations of heavy metals such as iron (Fe) and manganese (Mn) that exceed environmental quality standards, thus requiring effective treatment to prevent environmental pollution. This study aims to evaluate the ability of a mixture of activated carbon derived from pineapple leaves mixed with coal to increase pH and reduce Fe, Mn, and Total Suspended Solids (TSS) levels in acid mine drainage at PT Alreksa Bara Mitra. The process to make activated carbon involved preparation, carbonization, and activation processes on the pineapple leaves and coal separately. The following step is to mix but pineapple leaves and coal the has been activated. The treatment was conducted using an adsorption method with variations in adsorbent mass of 4 g, 8 g, and 12 g and a contact time of 30 minutes. The parameters analyzed included pH, Fe, Mn, and TSS before and after treatment, and the results were compared with the quality standards stipulated in Minister of Environment and Forestry Regulation No. 05/2022. The results showed that the characteristics of the activated carbon mixture met the SNI 06-3730-1995 standard. Increasing the adsorbent mass contributed to the rise in pH from 5.5 to near the acceptable range of 6–9 and significantly reduced Fe, Mn, and TSS concentrations below the permitted limits.The findings indicate that the mixture of pineapple leaf- and coal-based activated carbon is an effective, economical, and environmentally friendly alternative adsorbent for acid mine drainage treatment.

MMP is a metal manufacturing company engaged in casting, forging, and machining processes with a three-shift work system, including night shifts that may increase mental and physical workload due to disruptions in workers’ biological rhythms. This study aims to analyze the mental and physical workload of die casting machine operators during the night shift and to propose improvement measures using the Fault Tree Analysis (FTA) method. The study involved 23 operators, with mental workload assessed using NASA-TLX and physical workload measured using CVL. The results indicate that mental workload falls into high to very high categories, with WWL values ranging from 46.6 to 97.3, where 12 operators experienced very high mental workload. The dominant contributing dimensions were effort, physical demand, and temporal demand. Meanwhile, physical workload ranged from 19.48% to 36.36% CVL, with most operators not experiencing fatigue. Although physical workload remains within acceptable limits, the high mental workload indicates the need for improvements. FTA analysis identified key contributing factors, including work methods, work systems, ergonomics, machine conditions, and the work environment. Proposed improvements include job rotation, improvements in work methods and task distribution, adjustments to the work system, enhanced machine maintenance, and ergonomics-based workplace improvements.

PT UVW uses jigs in the vacuum metalizing process that require washing, which is currently done manually, resulting in inefficiency and risks to operators, thus, jig washer machine was created in order to reduce the risk for operators and increasing efficiency, which based on horizontal mixer. This study analyses the effect of agitator design on fluid flow patterns in a jig washing machine to obtain an optimal design. Two agitator design alternatives were developed and tested using Computational Fluid Dynamics (CFD) simulations at rotational speeds of 70, 75, and 100 rpm, followed by prototype fabrication and performance testing. Simulation results show that the second design produces a higher fluid velocity (20.4 m/s) and a more turbulent and uniform flow pattern compared to the first design (1.7 m/s). Field tests confirmed that the second design achieves higher washing effectiveness (97.14%) with reduced water consumption and shorter washing time. The optimally designed agitator washing machine increases productivity by six times compared to manual washing and reduces operator exposure to hazardous chemicals. This study recommends the second agitator design for improving washing efficiency and effectiveness.

Tegal Regency is a region in Central Java Province. Geographically, Tegal Regency is situated on a highly advantaged path. This regency, with its capital in Slawi, boasts a diverse range of economic centers spread across several regions. Dominated by small and medium-sized industries, the community can be empowered and participate in improving their well-being through job creation. Small and Medium Industry centers are highly diverse. One area we highlight in this article is the potential of metal and machinery SMEs, which are crucial commodities in the local economy. The metal industry is located around Talang District. The metal and machinery sector holds significant promise due to the potential for increased manufacturing demand, which can boost the local economy. In this study, we used field research and interviews to understand how the SME economy operates. By highlighting this, we hope that the government will focus on SMEs, particularly in the metal and machinery sector, by providing incentives for training and improving product quality and human resources. Based on the above description, local economic growth is highly possible with the support of adequate facilities and infrastructure.

Jamu is a traditional medicine still widely consumed by the public, but it has the potential to be contaminated with the heavy metals lead (Pb) and cadmium (Cd), which are toxic and can cause health problems, particularly to the liver and kidneys. Heavy metal contamination can originate from raw materials grown in polluted environments and from processing, storage, and packaging that do not meet quality standards, particularly for products that have not undergone official supervision. This study aims to analyze the content of lead and cadmium metals in registered and unregistered herbal medicine products. The analysis was carried out using the Atomic Absorption Spectrophotometry (AAS) method after sample preparation through wet digestion using strong acid. Six herbal medicine dosage forms were analyzed, namely powder, chopped, pills, capsules, cream, and shake parem. Method validation included tests for linearity, precision, limit of detection, and limit of quantification to ensure the reliability of the analysis results. The results showed that all registered herbal medicine samples met the safety requirements for Pb and Cd. In contrast, several unregistered herbal medicine preparations, especially powder, chopped, and cream, did not meet the safety requirements for Cd, while the Pb levels in all samples met the safety requirements for Pb. These findings indicate that unregistered herbal medicines carry a higher risk of heavy metal contamination. Therefore, strengthening quality control, selecting safe raw materials, and increasing compliance with regulations are necessary to ensure the safety of herbal medicine consumption and protect public health.

This study aims to analyze the effect of Tungsten Inert Gas (TIG) welding parameter variations on the mechanical and metallurgical properties of AISI 304 austenitic stainless steel, which is widely used in construction and industrial applications due to its excellent corrosion resistance and joint strength. The research focuses on identifying the optimal welding current to minimize welding defects and enhance joint structural integrity. Welding current was varied at three levels, namely 100 A, 125 A, and 135 A, while other parameters such as welding speed, argon shielding gas flow rate, and electrode type were kept constant. Mechanical properties were evaluated through Micro-Vickers hardness testing conducted in the weld metal, Heat Affected Zone (HAZ), and base metal, as well as tensile testing to determine ultimate tensile strength and elongation. In addition, non-destructive testing using the dye penetrant method was performed to detect surface welding discontinuities. Metallographic analysis was carried out using optical microscopy following an etching process to observe grain morphology, grain size, and the formation of microstructural phases. The results are expected to demonstrate a correlation between increased heat input due to higher welding current and changes in mechanical properties and microstructure, particularly in the HAZ. This study provides practical guidance for determining optimal TIG welding parameters for AISI 304 to achieve high tensile strength, homogeneous hardness distribution, and a stable microstructure resistant to intergranular corrosion.

The increasing consumption of plastic, particularly single-use packaging, has led to a significant rise in household plastic waste, which poses a potential threat to environmental sustainability. One type of waste that remains underutilized is metallic plastic packaging. This Community Service activity aimed to enhance community knowledge and skills in processing metallic plastic packaging waste into handicraft products with functional value and economic potential. The activity was conducted in collaboration with the Family Welfare and Empowerment Group (PKK) of Ngringo Village, Karanganyar, involving 15 participants. The methods employed included a preliminary survey, educational outreach, hands-on practical training, and continuous mentoring. The effectiveness of the program was evaluated using pre-test and post-test assessments analyzed through the normalized gain (N-gain) method. The results demonstrated an improvement in participants’ knowledge and skills following the training, with an average N-gain value of 0.68, which falls within the moderate-to-high category. These findings indicate that the metallic plastic packaging waste processing training was effective in enhancing community capacity. Furthermore, the activity not only contributed to reducing plastic waste generation but also promoted the implementation of circular economy principles.

Permanent tooth loss is a common oral health problem experienced by patients. This condition can be caused by pathological conditions such as tooth decay, leading to tooth extraction. Rehabilitation treatment for partial posterior tooth loss aims to restore masticatory function, maintain occlusal relationships and periodontal health, and improve aesthetics. A 34-year-old man came with a complaint that his lower right posterior tooth had been extracted and wanted a permanent dentures to replace his missing tooth. The intraoral and periapical radiograph examination revealed that 46 was missing, and 47 had enamel caries. The diagnosis for 46 was determined to be partial edentulous. The treatment plan was a PFM fixed-fixed bridge with a sanitary pontic for 46, a rigid connector, and a full crown retainer for 45 and 47. In this case, the choice of PFM bridge is based on several considerations, i.e., high chewing loads, relatively low cost, and high long-term success. The PFM bridge has been the primary choice for posterior tooth rehabilitation, due to its durability and cost-effectiveness.

The objective of this study is to comprehensively examine and analyze the influence of microstructure on the mechanical properties of metallic materials. Microstructure is known to play a crucial role in determining the mechanical behavior of metals; therefore, a thorough understanding of this relationship is essential for the development of engineering materials. This study adopts a systematic literature review approach, employing descriptive analysis and meta-analysis of recent scientific publications obtained from various reputable academic databases. The analysis results indicate that microstructure is a significant determinant of the mechanical characteristics of metallic materials, including strength, ductility, and resistance to deformation. The most influential microstructural parameters include grain size, phase distribution, crystallographic orientation, dislocation density, and the presence and characteristics of precipitates. Among these parameters, grain size has been shown to be the most dominant factor. The Hall–Petch strengthening mechanism demonstrates that grain refinement can increase the tensile strength of materials by approximately 200 to 300 percent. In addition, materials with multi-phase microstructures, such as dual-phase steels and TRIP steels, exhibit an excellent combination of strength and ductility compared to single-phase materials. Based on the meta-analysis results, each metallic material system exhibits a trade-off between strength and ductility, whereby an increase in strength is generally accompanied by a reduction in ductility. These findings indicate that achieving an optimal combination of mechanical properties for specific application requirements necessitates a comprehensive and integrated microstructural engineering approach.

This study aims to evaluate the level of heavy metal pollution and the potential ecological and human health risks in the waters of Selangan, Bontang City. The research focuses on analyzing the concentrations of iron (Fe) and mercury (Hg) in sediment, considering that both elements are toxic, persistent, and capable of bioaccumulating within the food chain. The study was conducted over six months, from January to June 2023, at four sampling stations representing the environmental conditions of Selangan waters. The methodology included sediment sampling, sample preparation through drying and grinding, and laboratory analysis using Inductively Coupled Plasma–Optical Emission Spectrometry (ICP-OES) to determine Fe concentrations. The results were then compared with quality standards established by the Washington Annotated Code 173-204-320 and Indonesia’s National Agency of Drug and Food Control (BPOM) Regulation No. 5 of 2018. The findings indicate the presence of heavy metal contamination across all sampling stations. Fe concentrations ranged from 2.35 mg to 6.308 mg, significantly exceeding the permissible limit of 0.3 mg/L. Meanwhile, Hg concentrations ranged from 0.015 mg to 0.028 mg, also surpassing the standard threshold of 0.001 mg/L. These results clearly demonstrate heavy metal pollution in the Selangan waters, posing potential threats to marine ecosystem health and coastal communities. Regular monitoring and mitigation measures are urgently recommended to prevent further environmental degradation.

Waste management has become a critical issue in achieving sustainable development, particularly in urban areas such as Medan City, where the volume of waste continues to increase each year. This study aims to analyze the optimization of economically valuable waste utilization through recycling activities to support the Sustainable Development Goals (SDGs), using a literature-based approach. The method employed is a literature review by collecting, examining, and comparing previous research from national and international journals related to recycling practices, circular economy principles, and urban waste management. The findings indicate that the utilization of economically valuable waste—such as plastic, paper, metal, and organic materials—can generate economic benefits for communities while improving overall waste management efficiency. The reviewed studies also highlight several key factors influencing recycling success, including government policies, the availability of recycling facilities, public awareness, and collaboration with recycling industries. Optimizing waste utilization has been shown to contribute significantly to various SDGs targets, including waste reduction, improved community welfare, and environmental protection. Therefore, strengthening the recycling ecosystem through multi-stakeholder collaboration is essential for Medan City in promoting sustainable urban development.

This study explores the development of digital and storynomic-based tourism in Kamasan Tourism Village, Klungkung Regency, Bali. Kamasan is historically known as the center of classical Balinese wayang painting and traditional metal crafts such as gold, silver, and brass. Using a qualitative descriptive method through observation, interviews, and document studies, this research identifies the village’s cultural potential and formulates a sustainable tourism development model. The SWOT analysis reveals that Kamasan’s main strengths lie in its rich cultural heritage, community participation, and diverse local crafts, while weaknesses include limited digital promotion, lack of facilities, and low involvement of younger generations. Opportunities arise from the growing trend of cultural and educational tourism and strong government support for digitalization through the Anugerah Desa Wisata Indonesia (ADWI) program. The integration of storynomic tourism and digital media—such as e-brochures, promotional videos, and virtual tours can enhance destination competitiveness, strengthen local identity, and improve community welfare. This research emphasizes that combining cultural storytelling with digital innovation is a strategic approach to creating sustainable and engaging tourism experiences in Kamasan Village.  

This study examines the impact of industrial activities in Bontang City, a major center for natural gas processing and fertilizer production, which potentially increases heavy metal contamination in coastal waters. Specifically, the research focuses on the accumulation of lead (Pb) and copper (Cu) in Anadara granosa, a benthic bivalve selected as a bioindicator due to its capacity to accumulate pollutants. The study aims to analyze Pb and Cu concentrations in Anadara granosa tissues collected from the waters of Selangan Hamlet, Bontang City, as an indicator of local environmental quality. The research was conducted over a six-month period, involving shellfish and water sampling from four observation stations. Heavy metal analysis was performed using Atomic Absorption Spectrophotometry, and the results were evaluated against relevant environmental quality standards, including Government Regulation of the Republic of Indonesia Number 22 of 2021. The findings revealed the presence of Pb and Cu at all sampling stations, with varying concentrations. The highest Pb and Cu levels were recorded at the South Station, while the lowest concentrations were observed at the East and North Stations. Overall, the measured concentrations of both metals significantly exceeded established safety limits, indicating serious risks to aquatic ecosystems and human health. These results confirm Anadara granosa as an effective bioindicator of heavy metal pollution and highlight the urgent need for further studies and mitigation efforts.

The danger of cadmium contamination in water sources remains a crucial environmental issue due to its persistent nature and high toxicity level, which poses serious risks to human health and ecosystems. Cadmium is a non-biodegradable heavy metal that can accumulate in living organisms over time. The presence of these toxic Cd²⁺ ions is known to trigger damage to vital organs such as the liver and kidneys; therefore, reducing their concentration in aquatic environments is of paramount importance for environmental protection and public health safety. Among various treatment methods, adsorption is considered one of the most effective and economical techniques for removing heavy metal ions from contaminated water. In this study, the capability of mesoporous silica MCM-48-NH₂ as an adsorbent for Cd²⁺ ions was systematically evaluated. The adsorption performance was examined by investigating several important parameters, including contact time, solution acidity level (pH), and initial Cd²⁺ concentration. Furthermore, the adsorption mechanism and interaction between Cd²⁺ ions and the adsorbent surface were analyzed using Langmuir and Freundlich isotherm models. The results demonstrate that the adsorption process of Cd²⁺ ions onto MCM-48-NH₂ tends to follow the Langmuir isotherm model, indicating monolayer adsorption behavior, with a maximum adsorption capacity of 0.66 mmol g⁻¹.

In general, school students buy snacks in the school canteen or street vendors (PKL) around the school. 2 The types of food sold are varied, ranging from healthy snacks to unhealthy snacks so that they can attract students to consume school snacks. Healthy snacks are foods that have sufficient and balanced nutrition and do not contain (contaminated) elements that can harm or damage health. This community service activity aims to educate healthy eating patterns to prevent food and drinks containing microbial contamination at Mariana Catholic High School, Medan. The method used is an educational approach through health counseling, interactive discussions, and demonstrations of hygienic practices, especially correct handwashing techniques and the importance of maintaining personal hygiene and the school environment. This activity was attended by 40 students as participants. The evaluation of the activity focused on one main indicator, namely student participation in hygienic behavior practices as a form of direct application of the material that has been given. The results of the activity showed that all participants (100%) followed the demonstrated hygienic practices, which indicates a very high level of participation and enthusiasm. These findings indicate that educational methods accompanied by hands-on practice are effective in increasing understanding and encouraging the adoption of clean and healthy living behaviors. Community service activities at Mariana Catholic High School in Medan have been shown to increase students' knowledge about the dangers of microbial contamination and the development of hygienic behaviors in daily life. Structured and ongoing education is an effective preventive measure to create a healthy and clean school environment.

Soil contamination by hydrocarbons, pesticides, heavy metals, and complex pollutants is rapidly increasing and degrading essential ecosystem functions. Physical or chemical treatments offer faster results, yet they are often costly, energy-intensive, and risk disrupting soil biological integrity without fully eliminating pollution sources. Microorganism-based bioremediation provides a more sustainable alternative by utilizing microbial metabolism to degrade or immobilize pollutants into less toxic and less mobile forms. This article presents a structured literature review on the roles and applications of microorganisms for bioremediation of contaminated soils, covering comparisons between single isolates and microbial consortia, dominant biological mechanisms, and ecological challenges in field application. A Systematic Literature Review approach was applied, using narrative synthesis and thematic clustering of national and international journals published between 2020 and 2025. The review indicates that single microbial isolates are commonly selected for specific pollutant targets, whereas microbial consortia are preferred for mixed or persistent contaminants due to metabolic synergy that enhances microbial adaptability and stepwise pollutant breakdown in highly polluted soils. Adaptive mechanisms such as EPS production and biofilm formation contribute to microbial resilience under stress and help retain contaminants within the soil matrix. Key challenges identified include inoculum stability under extreme conditions and limited microbial access to pollutants trapped in micro-soil pores. The findings highlight that microbial selection strategies must be tailored to pollutant characteristics and soil environmental conditions, while also emphasizing the potential of biofilm-based systems and organic carriers to support broader field implementation of microbial bioremediation.