Publication Search

Self-Compacting Concrete (SCC) requires a high cement content, which contributes to increased carbon emissions; therefore, this study evaluates the effect of partial cement substitution with fly ash (5%, 10%, and 15%) and the addition of Polyethylene Terephthalate (PET) waste (0.5% and 0.7%) on the mechanical properties of SCC with a target strength of f’c 30 MPa. The research employed laboratory experimental methods, including fresh concrete tests (slump flow, L-box, and V-funnel) and hardened concrete tests (compressive, tensile, and flexural strength) at 7 and 28 days. The results indicate that fly ash substitution enhances compressive strength, with the highest value of 49.59 MPa achieved at 5% fly ash at 28 days, exceeding normal concrete (34.73 MPa). The addition of PET tends to reduce compressive strength due to increased porosity; however, it significantly improves flexural strength, as the combination of 5% fly ash and 0.5% PET achieved 4.7 MPa compared to 2.9 MPa for normal concrete. Overall, the combination of fly ash and PET waste shows potential for application in structural elements requiring high flexural performance.

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.

The coal mining industry requires accurate stockpile volume measurements for inventory and production reporting. Conventional methods have limitations in accuracy, efficiency, and safety. This study compares the accuracy and efficiency of coal stockpile volume measurements using a Terrestrial Laser Scanner (TLS) Leica MS60 and an Unmanned Aerial Vehicle (UAV) DJI Matrice 4E, validated by the ASTM D6172-98 standard. Conducted on five Run of Mine (ROM) coal stockpiles covering 13,500 m² at PT XYZ, Lahat, South Sumatra, the TLS method used 43 scan positions, while the UAV employed 430 aerial images with specific flight parameters. Data were processed using Leica Infinity, Surpac, and Agisoft Metashape. The results showed volumes of 94,076 m³ (TLS) and 94,965 m³ (UAV), with a difference of 889 m³ (0.95%). Volume deviations ranged from 0.48% to 1.89%, with an average of 1.42%, all within the ASTM tolerance (<2%). Time efficiency analysis revealed that the UAV method required 200 minutes (3.33 hours), saving 63.3% (approximately 6.17 hours) compared to the TLS method (570 minutes). The largest efficiency gain occurred during field data acquisition, with an 85% reduction in time. This study confirms UAV photogrammetry as a valid, accurate, and efficient alternative for coal stockpile volume measurement in mining.

This research aims to design and develop a prototype wave power plant that utilizes the vertical motion of a buoy as a source of mechanical energy, which is then converted into electrical energy using a recoil starter mechanism. The system is designed to be installed at the stern of a prototype ship. The vertical movement of the buoy caused by ocean waves is transmitted to the recoil starter through a drive rope, producing a stable one-way rotational motion. This rotation is further transmitted to a gearbox to increase rotational speed before driving a DC generator. The electrical energy generated is stored in a 12 VDC battery, supported by a buck–booster converter to stabilize the output voltage. This study employs an experimental engineering approach to evaluate system performance based on empirical test data. The main components of the system include a buoy as a wave energy collector, a recoil starter as the initial rotating mechanism, a DC generator as the electrical energy producer, a buck–booster converter as a voltage regulator, a 12 VDC battery as an energy storage unit, and a monitoring system based on an ESP32 microcontroller integrated with a PZEM-017 sensor. Experimental results show that the recoil starter operates effectively in driving the generator under both no- load and buoy-loaded conditions. Increases in generator rotational speed are directly proportional to increases in output voltage and current. The PZEM-017 sensor demonstrates a high level of measurement accuracy, approaching 100% when compared with a multimeter. Overall, the proposed wave power generation system functions reliably and shows potential for further development as a small-scale alternative renewable energy source.

This research is motivated by the importance tank cleaning process on tankers to prevent cargo contamination, maintain cargo quality, and ensure crew safety. MT. Marina Prosperity, a chemical/oil tanker, uses the Butterworth system as the primary method for tank cleaning at every cargo change. However, in practice, technical and operational constraints are still found that affect the results of tank cleaning. The research method used is descriptive qualitative with data collection techniques through direct observation on the ship, interviews with the Chief Officer and Boatswain, and documentation studies in the form of log books and SOPs. Data were analyzed by focusing on three aspects, namely work efficiency, work safety, and operational procedures for using Butterworth. The results show that the use of Butterworth can increase time and energy efficiency compared to manual methods, with an average cleaning time of 2–4 hours per tank depending on the type of cargo. From a safety aspect, Butterworth reduces the need for crew to enter the tank, thereby reducing the risk of exposure to chemicals and hazardous atmospheres. However, work effectiveness and safety are greatly influenced by the condition of the equipment, the stability of water pressure, and the crew's discipline in implementing the SOP. On several occasions, steps such as nozzle cleaning, manual mopping, and safety meetings were not consistently performed, resulting in residual load in certain areas. With routine equipment maintenance, close supervision, and ongoing crew training, Butterworth can be optimized to produce more effective, safe, and standards-compliant tank cleaning process.

The increasing demand for electrical energy and the limited availability of fossil fuels have driven the development of renewable energy sources, including marine current energy, which remains underutilized in coastal and remote maritime regions. This study presents the design and realization of a small-scale marine current power generation prototype using a horizontal axis propeller turbine with a NACA S814 blade profile and analyzes the effect of turbine rotational speed on electrical power output. The system converts marine current kinetic energy into mechanical energy through turbine rotation and subsequently into DC electrical energy using a generator, which is stabilized by a Buck–Boost Converter and Maximum Power Point Tracking (MPPT) for charging a 12 VDC battery. Real-time monitoring of electrical and mechanical parameters is implemented using an Internet of Things (IoT)–based system comprising an ESP32 microcontroller, a PZEM-017 sensor, and an RPM sensor. Experimental results demonstrate a positive correlation between water flow rate, turbine rotational speed, and generator output voltage. The system begins operating at a minimum flow rate of 35.2 L/s at 56 RPM, producing 0.2 V, while optimal performance is achieved at 45.3 L/s and 516 RPM, generating up to 13.3 V. These results indicate that the proposed prototype is a viable alternative renewable energy source for marine applications.

Time delays and cost overruns remain major problems in building construction projects, particularly in concrete structural works that dominate project duration and cost. This study aims to evaluate the application of re-engineering in concrete structural work methods on the time and cost performance of multi-storey building projects. A quantitative approach using a case study method was employed through comparative analysis between the existing method and alternative methods. The analyzed alternatives include ready-mix concrete with Sika Viscocrete 8007 admixture and semi-system formwork as Alternative I, ready-mix concrete with system formwork as Alternative II, and ready-mix concrete with Sika Viscocrete 8007 admixture combined with system formwork as Alternative III. The results show that all alternatives perform better than the existing method with a duration of 243 days. Alternative I reduced the duration to 208 days with cost efficiency of IDR 55,781,730 or 0.214 percent. Alternative II reduced the duration to 203 days with cost efficiency of IDR 187,553,261 or 0.724 percent. Alternative III achieved the best performance with a duration of 168 days, accelerating 75 days and providing the highest cost efficiency of IDR 243,334,991 or 0.941 percent. The study concludes that re-engineering effectively improves project time and cost performance, with Alternative III as the optimal method.

Submarine pipelines are vital infrastructures in aviation fuel distribution, carrying high risks of operational disruption, safety issues, and environmental pollution. In 2025, the aviation fuel receiving submarine pipeline at Integrated Terminal Ampenan was deformed due to mechanical pulling by MT Anargya I, causing system shutdown. This incident created risks of seawater intrusion, marine pollution, and potential fuel shortages at Lombok International Airport. This study evaluates the effectiveness of applying a double-ended draining method combined with an oil bubble trap as a fast, safe, and sustainable solution for submarine pipeline repair. Using a case study and descriptive-analytical approach based on the Continuous Improvement Program (CIP), the research analyzed quality, cost, delivery, safety, environmental, and workforce aspects. The results showed the method effectively drained aviation fuel without seawater contamination, prevented marine spills, maintained fuel quality within specifications, and completed repairs before critical stock levels were reached. Additionally, it provided significant cost savings compared to emergency supply operations and achieved zero safety incidents and environmental pollution. The integration of double-ended draining and oil bubble trap proved to be an effective, adaptive innovation with strong potential for replication and standardization in other aviation fuel submarine pipeline systems.

Indonesia is in an earthquake-prone region, therefore, designing building constructions that can withstand seismic loads is crucial in civil engineering. Reinforced concrete shear walls are one of the vertical structural fundamentals that are effectively used in multi-story buildings to withstand lateral forces due to earthquake and wind loads. Structures that use shear walls can increase stiffness and reduce horizontal deviations (deflections) of buildings, which contribute to the stability and safety of structures based on the SNI 1726:2019 standard. This study aims to analyze the effect of shear wall configurations on deviation and torsion requirements in multi-story building planning. The study object is a 6-story reinforced concrete building model in a specific earthquake zone. The design and modeling were performed using structural analysis software, taking into account columns, beams, slabs, and shear walls. The analysis results show that optimal placement of shear walls at the building edges significantly reduces horizontal drift, torsion, and shear forces, and improves the structural performance level compared to structures without shear walls or those with less effective placement. Structures with shear walls have optimal stiffness in absorbing lateral forces, making them more resistant to damage from the planned earthquake.

Healthcare is an integral part of health development in Indonesia, which aims to optimally improve public health. Hospitals, as healthcare facilities, are required to provide quality, safe, and patient-centered services. Service quality is a key indicator of service success, as good service impacts patient satisfaction. One of the most important services in hospitals is obstetrics, which directly relates to maternal and infant health, making patient satisfaction a crucial aspect. Midwives, as professional healthcare workers, play a strategic role in providing comprehensive, sustainable, and patient-centered midwifery care. This study aims to analyze the influence of healthcare facilities and midwife performance on patient satisfaction through service quality. The method used is a quantitative study with an analytical approach and a cross-sectional design. The results of the multiple linear regression test indicate that midwife performance has a more dominant influence on service quality than healthcare facilities. Meanwhile, regarding patient satisfaction, service quality is the most dominant factor, followed by midwife performance and healthcare facilities. The conclusion of this study is that service quality reflects the overall patient experience and is a key factor in improving patient satisfaction.

Fertilization serves as a fundamental component of crop cultivation, wherein the application of mineral nutrients is crucial for plant nourishment, facilitating various physiological processes critical for growth and development. The objective of this study is to establish an optimal recommended dosage that enhances cabbage growth and yield. The experimental design employed in this study was a randomized block design with four replications. The treatments consist of seven fertilization levels, as follows: No fertilization with nitrogen (N), phosphorus (P), or potassium (K) (P0), reference fertilization (P1), 0.5 dose of unbalanced compound fertilizers (P2), 0.75 dose of unbalanced compound fertilizers (P3), 1.0 dose of unbalanced compound fertilizers (P4), 1.25 dose of unbalanced compound fertilizers (P5), and 1.5 dose of unbalanced compound fertilizers (P6). The experiment indicated that the application of unbalanced compound fertilizers enhances cabbage plant growth, as evidenced by increased plant height and leaf number compared to the control treatment. Additionally, fertilization improves yield components relative to untreated plants. The application of 0.5 doses of unbalanced compound fertilizers proves agronomically effective, yielding the highest relative agronomic effectiveness at 169%, meaning a 1.69-fold increase in yield. Economically, the same dosage is also highly beneficial, achieving the highest R/C ratio of 2.35 and generating a profit of Rp. 14,365,150. The study results confirm that unbalanced compound fertilizers were both agronomically effective and economically advantageous. The recommended dosage for cabbage cultivation is 134 kg/ha, applied in two stages: 50% at 1 WAT (weeks after transplanting) and the remaining 50% at 4 WAT.

The food and beverage industry in Indonesia is growing rapidly through digital marketing, particularly through the role of influencers in influencing consumer preferences and purchase intentions. Several influencers are no longer merely collaborating with brands, but are also becoming business owners by leveraging their personal branding and follower base. However, when promoting their own products, the effectiveness of these strategies on purchase intentions is not always consistent. This study aims to examine the influence of the Theory of Planned Behaviour on purchase intention and analyse the role of Parasocial Relationship through influencer authenticity and influencer trustworthiness in regional cuisine at RM Padang Payakumbuah. The research uses a quantitative approach with data from 182 respondents in the Special Region of Yogyakarta, analysed using PLS-SEM. The results show that attitude and influencer authenticity do not have a significant effect on purchase intention, while subjective norm and perceived behavioural control have a significant effect. Furthermore, influencer trustworthiness strengthens the relationship between perceived behavioural control and purchase intention. These findings emphasise the importance of social recommendations, ease of purchase access, and building trust towards influencers.

This study aims to analyze the influence of workforce agility, job satisfaction, and job engagement on employee adaptive performance at PT. MMT Buana Logistik. The dynamic logistics industry requires employees who have high adaptability to technological changes and operational demands. This type of research is quantitative causality with an explanatory approach. The population in this study were all employees of PT. MMT Buana Logistik, totaling 49 people, with the sampling technique used saturated sampling (census). Data were collected through questionnaires with a 5-point Likert scale. Data analysis techniques used included instrument testing (validity and reliability), testing of classical assumptions (normality, multicollinearity, and heteroscedasticity), and multiple linear regression analysis. Hypothesis testing was carried out through t-tests (partial), F-tests (simultaneous) and coefficient of determination (R2). The results showed that workforce agility, job satisfaction, and job engagement partially and simultaneously have a positive and significant influence on employee adaptive performance. These findings imply the importance of managing work flexibility, fulfilling employee satisfaction, and increasing work engagement to build adaptive human resources to support company competitiveness in the logistics industry.  

This study investigates the impact of TikTok Live, viral content, and Fear of Missing Out (FOMO) on the purchasing decisions of Gen Z consumers in Jombang City for food and drink products. Social media, particularly TikTok, has rapidly expanded and functions as a potent digital marketing instrument. It influences consumer behavior through live broadcasting and the dissemination of viral content. The objective is to examine the influence of these three factors on purchasing decisions. This study employs a quantitative methodology. The data was obtained from surveys administered to 60 Gen Z participants who purchased food or beverages following exposure to TikTok advertising. Samples were selected by purposive sampling. Data were examined using multiple linear regression with SPSS software. Findings indicate that TikTok Live exerts a favorable and substantial impact on purchasing decisions. Viral material exerts no substantial impact. FOMO exerts a detrimental and substantial impact. The results indicate that TikTok live streaming effectively enhances consumer purchases, especially within the food industry.  

Investment decisions in pharmaceutical manufacturing companies listed on the Indonesia Stock Exchange (IDX) are influenced by fundamental analysis and stock price fluctuations. Stock prices reflect market perceptions shaped by profitability, liquidity, and capital structure. This study examines the effects of Return on Assets (ROA), Current Ratio (CR), and Debt-to-Equity Ratio (DER) on stock prices, both partially and simultaneously. Using a quantitative approach, the study analyzes secondary data from audited financial statements and stock prices of 12 pharmaceutical companies during 2022–2024, totaling 36 observations. Panel data regression with EViews 12 is applied. Results show that ROA and DER have positive and significant effects on stock prices, while CR has a negative but insignificant effect. Simultaneously, all three variables significantly influence stock prices, with an adjusted R² of 73%, indicating strong explanatory power. Profitability (ROA) is the most influential factor, followed by capital structure (DER), while liquidity (CR) shows no significant impact.

The rapid development of Artificial Intelligence (AI) has brought significant changes to the criminal justice system, particularly in criminal investigations and evidentiary processes, while simultaneously raising complex legal and ethical challenges. Objective: This study aims to analyze the legal implications of the use of AI in criminal investigations, focusing on its benefits, risks, and challenges related to the admissibility of AI-based evidence, as well as the need for regulatory frameworks that ensure fairness, transparency, and accountability. Methods: This research employs a normative qualitative approach through the analysis of legal regulations, a review of legal and technological literature, and a comparative approach across jurisdictions, complemented by case studies of AI applications in law enforcement practices. Results: The findings indicate that AI enhances investigative efficiency through data analysis, crime prediction, and digital forensics; however, it also poses risks such as algorithmic bias, human rights violations, and issues concerning the reliability and transparency of evidence. Furthermore, differences across legal systems result in the absence of uniform standards for the admissibility of AI-based evidence. Therefore, adaptive regulatory frameworks grounded in the principles of fairness, transparency, and accountability are required, along with strengthened human oversight to ensure that the use of AI aligns with the principles of justice and human rights protection.

Communication within the family, especially between parents and children, is an important foundation for the development of a child's personality, emotions, and social skills. The purpose of this writing is to identify the types of parental communication styles, analyze the factors that influence them, examine their impact on child development, and provide practical recommendations to improve the effectiveness of communication patterns within the family. The method used in writing this paper is a literature study. The discussion results show that there are three main types of parental communication styles: permissive, authoritarian, and democratic. The permissive style tends to give the child unlimited freedom, the authoritarian style emphasizes control and obedience, while the democratic style encourages openness and mutual respect. The choice of communication style is influenced by various factors such as educational background, culture, past experiences, and the socio-economic conditions of parents. Each communication style has a different impact on the emotional, social, and cognitive development of children. The democratic style is considered the most effective in optimally supporting child development. This article provides recommendations to parents to increase knowledge about dialogical-based parenting, practice assertive communication skills, give children space to express their opinions, and build a family culture that is open and mutually respectful.

This reseach aims to analyze the role of an innovative deep learning-based instructional model in enhancing students’ conceptual understanding, critical thinking skills, and active engagement during classroom learning processes. The rapid development of educational technology currently demands continuous innovation in instructional practices, particularly to improve teacher quality and professionalism in addressing the challenges of the 21st century. To achieve this objective, this research employed a qualitative method with a literature review approach. Data were collected through a systematic review of various national journals, international journals, books, and relevant scholarly sources published within the last ten years. The findings indicate that the implementation of a deep learning-based instructional model can significantly enhance teachers’ creativity in designing instructional strategies, strengthen the effectiveness of the learning process, and improve the quality of teacher-student interaction. Furthermore, this approach encourages teachers to become more adaptive to digital technological advancements and more responsive to the diversity of students’ needs and learning styles. Therefore, the deep learning-based instructional model can serve as a strategic and sustainable solution for improving teachers’ professional practices in the modern education era.

This study aims to develop a Puzzle Book learning media for the topic of angle measurement and to examine its validity, practicality, and effectiveness for third-grade elementary school students. The research employed a Research and Development (R&D) approach using the ADDIE model and involved 26 third-grade students as participants. Data were collected through expert validation sheets, student response questionnaires, and learning achievement tests, which were analyzed using descriptive quantitative and qualitative methods. The results showed that the Puzzle Book obtained a validity score of 98.0% from media experts and 100% from material experts, both categorized as highly valid. Student responses reached 100%, indicating that the media is highly practical and engaging. Furthermore, the analysis of learning outcomes revealed a gain score of 0.9187 in the high category, demonstrating that the Puzzle Book effectively improves students’ problem-solving abilities in angle measurement. Overall, the Puzzle Book learning media is highly feasible, practical, and effective for classroom implementation, as its interactive design and alignment with third-grade learning characteristics help students understand angle concepts more concretely, enjoyably, and meaningfully.

Adolescence is a transitional period marked by rapid biological, psychological, and social changes, which often lead to various problems for individuals, particularly at the high school level. This study aims to analyze the role of guidance and counseling services in addressing these issues using a literature review approach. The method employed is a systematic literature review of relevant scientific publications from 2020 to 2026. The data collection process was carried out through the search, selection, and evaluation of literature related to student issues and guidance and counseling services in schools. The research findings indicate that students face various challenges, such as difficulties in learning, low academic ability, academic stress and anxiety, as well as social-emotional issues influenced by internal and external factors. Guidance and counseling services play a role in supporting students to self-reflect, overcome problems, and optimize their potential through preventive, curative, and developmental approaches. The success of these services is also supported by the role of counselors, collaboration with other teachers, and parental participation. However, in practice, there are still a number of obstacles, such as limited human resources, a lack of coordination, and an incomplete understanding of the functions of these services. Therefore, efforts are needed to improve implementation and cooperation so that guidance and counseling services can operate more efficiently.