Reduction of fluid resistance using the rheological characteristics of a polymer-surfactant solvent is research that contains many aspects, such as the theory of the drag reduction process, historical journey, and ongoing current research development. Many studies have been conducted, but it is challenging to know all existing and new research threads. The present investigation was conducted using literature studies regarding drag reducing agents. This research will also discuss the characteristics of flowing fluids and their effects on the velocity profile with friction factor of flowing fluids in smooth circular straight pipe geometries based on experimental, theoretical approaches. It concludes with aspects of research conducted around reducing drag using drag reducing agents, ideas about innovations, structuring overlook in testing, and modification of the fluid flow state.

Various combinations of ship propulsion systems have been developed with low-carbon-emission technologies to meet regulations and policies related to climate change, one of which is the combined gas turbine and steam turbine integrated electric drive system (COGES), which is claimed to be a promising ship propulsion system for the future. The objective of this paper is to perform a techno-economic and environmental assessment of the COGES propulsion system applied to liquefied natural gas (LNG) carriers. A propulsion system design for a 7500 m³ LNG carrier was evaluated through the thermodynamics approach of the energy system. Subsequently, carbon emissions and environmental impact analyses were carried out through a life cycle assessment based on the power and fuel input of the system. Afterwards, a techno-economic analysis was carried out by considering the use of boil-off gas for fuel and additional income from carbon emission incentives. The proposed propulsion system design produces 1832 kilowatts of power for a service speed of 12 knots with the total efficiency of the system in the range of 30.1%. The results of the environmental evaluation resulted an overall environmental impact of 10.01 mPts/s. The results of the economic evaluation resulted in a positive net present value and a logical payback period for investment within 8 years of operation. The impact of this result shows that the COGES has a promising technological commercial application as an environmentally friendly propulsion system. Last, for the economy of the propulsion system, the COGES design has a positive net present value, an internal rate return in the range of 12–18%, and a payback period between 6 and 8 years, depending on the charter rate of the LNG carrier.

The rapid expansion of maritime transportation has significantly impacted air quality due to increased ship emissions. This study aims to develop a ship emission monitoring system utilizing Automatic Identification System (AIS) big data, with Tanjung Priok Port in Indonesia (ID TPP) as the case study. The system is designed to monitor and analyze ship emissions based on historical AIS data, providing actionable insights to mitigate environmental impacts. By integrating various data processing techniques, including data preprocessing, database development, sailing time and speed calculation, and emission estimation, this research provides a comprehensive framework for a ship emission monitoring system. The system can be implemented in ports through the development of an interactive web-based dashboard, enhancing the decision-making capabilities of port authorities and other stakeholders. The results demonstrate the system’s potential for effectively monitoring emissions and promoting sustainable maritime operations .

Anchor Handling Tug Supply (AHTS) vessels play a critical role in supporting offshore oil and gas operations, making them vulnerable to accidents. An appropriate method is therefore required to minimize risks and ensure safe and efficient operations. This study aims to identify high-risk operational activities of AHTS vessels and to develop a fuzzy logic-based risk assessment model for their operations. Conventional risk assessment approaches tend to be subjective and are often characterized by a high degree of uncertainty, highlighting the need for a more adaptable and precise approach. The adoption of fuzzy logic offers a potential solution to address uncertainty; however, its less intuitive representation of risk assessment poses challenges for non-expert users. To overcome this limitation, a fuzzy logic-based risk assessment system was developed using Python programming. The results indicate that three operational activities pose high levels of risk. Fuzzy logic yields more accurate and elevated risk values compared to conventional methods. Furthermore, the developed model was successfully implemented as an interactive web application, which represents a unique feature not commonly addressed in previous studies. This implementation enables users to analyze risk levels more easily and supports faster, more intuitive, and more effective decision-making in risk assessment processes.

Pusat Logistik Berikat (PLB) or Bonded Logistics Center has been listed as a part of the Indonesia Economy Policy Volume II under the government of President Joko Widodo, as regulated in Government Regulation (PP) Number 85 Year 2015. PLB operations are expected to make national logistics activities more efficient, increase the availability of goods/raw materials needed by industries, increase local/foreign investment, and assist in the development of Indonesia as a logistics hub in the Asia Pacific region. The existence of PLB for automotive manufacturing industry is believed to have a special impact both in supporting the availability of automotive components and in increasing the competitiveness of exports of national automotive products. Especially with the regulation stipulated in Presidential Regulation Number 55 Year 2019, concerning the acceleration of the battery-based electric motor vehicle program. This paper aims to provide an analysis of the existence of PLB and its impact on national automotive manufacturing industry. The study was conducted by applying a dynamic system simulation to test the hypothesis of the PLB impact. Simulation model is a dynamic system approach using the Vensim®PLE8.0.4 program. The simulation results show the efficiency that can be obtained with the PLB. The ease of customs facilities obtained from PLB as well as the reduction in custom clearance time have a significant positive impact on the national automotive manufacturing industry.

Flow control is an important topic because of its contribution in energy saving in piping system. The choice of control technique of flow is no less important to be applied in the right case. One of the impacts of this application is the efficiency of degradation time which can occur at any time. Therefore, the purpose of this study is to reveal the degradation time of two types of flow control. The research applied a piping system with a horizontal position. For the working fluid, it uses a mixture of nata de coco fibers for active control and spiral pipes for passive control with the slurries as the working fluid. Both pipes used were the three lobes spiral pipe and the pentagon spiral pipe with the average size P/Di 7. The results revealed that the active control had a variation of the drag reduction value with the increasing time indicating that degradation occurred while the passive control had a constant value. The results of this study are very important to determine the type of flow control that will be used according to the case handled and the results to be obtained.