bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling the hydraulic performance of an array of centrifugal pumps operating under a variable pressure in a hydro-pneumatic energy storage system
Authors: Cassar Andrea , Sant Tonio , Borg Andrew 
Published: December 2024

Abstract
The large pressure variation in hydro-pneumatic energy storage systems presents a major challenge for maintaining a high operating efficiency of the turbomachinery used in the hydro-electric energy conversion processes. This paper applies numerical modelling to compare the hydraulic performance of two pumping unit variants used for charging an offshore hydro-pneumatic energy storage (HPES) accumulator. The first unit consists of a single large centrifugal pump operated at variable speed while the second pumping unit is made up of an array of smaller, dynamically similar fixed-speed pumps. A number of series/parallel configurations for the latter option were derived in order to optimise the operational efficiency at various states of charge of a gas-charged accumulator, specifically between 80 and 200 bar. A comparative analysis of the operational hydraulic efficiencies for both pumping units shows that using an array of small fixed-speed pumps arranged in series/parallel configurations is more energy efficient than using a single large pump operated at variable speed.
Optimal Global Gravity Field Model for Calculation of local Gravity and Geoid in Indonesia
Authors: Ramdani Dadan , Pahlevi Arsauna , Muthia Harahap Rina 
Published: December 2024

Abstract
This study assesses the accuracy and reliability of 17 Global Gravity Models (GGMs) sourced from ICGEM for geoid and gravity anomaly calculations. Using 980 validation points for geoid calculations and 18 for gravity anomaly calculations, we evaluated the standard deviations of each GGM to determine their precision. The results indicate that the three GGMs with the lowest standard deviations for geoid calculations are SGG-UGM-2 (0.247 m), XGM2019e 2159 (0.205 m), and EGM2008 (0.191 m), while SGG-UGM-1 G exhibited the highest deviation at 10.711 m. For gravity anomaly calculations, XGM2019e 2159 (15.295 mGal), EGM2008 (14.517 mGal), and SGG-UGM-2 (14.396 mGal) demonstrated the highest accuracy. The findings underscore the importance of selecting appropriate GGMs for precise geodetic applications, with models like EGM2008 and XGM2019e 2159 offering superior performance due to their low standard deviations and high reliability. The spatial distribution of validation points further highlights the need for comprehensive evaluation across varied regions and terrains. This study provides critical insights for geodesists in choosing the most suitable GGMs for accurate geodetic results.
Assessing Multi-Hazard Risk through Spatial Analysis: A Geographic Information Systems for Susceptibility Mapping in Java Island, Indonesia
Authors: Meilano I , Virtriana R , Widyastuti R , Salim Z L , Lunardia H R , Arum F S , Maharani K A , Lendra N D 
Published: December 2024

Abstract
The geographic location and population make Java Island a disaster-prone area with various threats, including earthquakes, floods, landslides, and volcanic eruptions. Based on historical data, these four types of disasters caused a total of US$24,303,159,688 in economic losses in the last 50 years. In regard to the big loss, it is considered important to identify potential disaster risks to avoid more sustainable economic losses in the future. By utilizing developments in Geographic Information Systems (GIS) technology, potential disaster risk mapping could be carried out. The process begins with preparing a map of the potential risk of earthquakes, floods, landslides, and volcanic eruptions by referring to the regulatory document of the head of the National Disaster Management Agency (BNPB) Number 2 of 2012 and Indonesian National Standard (SNI). Afterwards, the potential risk map for each type of disaster will be combined to determine the hazard level of each disaster in 1 square kilometer-sized pixels. The merging process uses annual economic loss data over a period of 50 years as a weighting factor. Based on the data, the results show that 11.554% (15.092 square kilometers) of the area of Java Island falls into the high hazard level class, 77.642% (101.413 square kilometers) into the moderate hazard level class, and 10.804% (14.112 square kilometers) into the low hazard level class. The resulting multi-hazard map could be further used for various specific purposes, such as creating an early warning system or estimating direct losses due to disasters.
Analysis and Mapping of the Distribution of Groundwater Recharge Areas Using the Scoring Method (Case Study: Singgahan and Montong District, Tuban).
Authors: Purwanto Singgih , Susilo Adi , Naba Agus , Syaeful Bahri Ayi , Rachma Chafidha , Bhekti Pribadi Cherie , Navisa Siti 
Published: December 2024

Abstract
Tuban Regency, located in the northern part of East Java, borders the Java Sea to the north and is intersected by several rivers. The presence of numerous rivers and limestone or karst hills in regions like Singgahan and Montong Districts suggests significant potential for these areas to function as groundwater recharge zones. A groundwater recharge area is characterized by the vertical movement of groundwater, driven by the flow of water along the gradient of aquifers. Identifying and preserving these recharge zones in Singgahan and Montong is crucial to maintaining the groundwater supply, ensuring its availability in sufficient quantity and quality to meet the ongoing needs of ecosystems and human consumption. This study utilizes a scoring method to identify potential recharge areas, incorporating parameters such as land cover, soil type, rainfall, and slope inclination. In this method, each parameter is assigned a specific weight: slope inclination (20%), soil type (35%), rainfall (15%), and land cover (30%). The analysis revealed that the land cover in these districts primarily consists of plantations, with 6,840.63 hectares in August and 6,761.88 hectares in October. The slope inclination in Singgahan District is predominantly flat, covering 8,417.68 hectares. Both Singgahan and Montong Districts experience low rainfall, with 57% of the total area, equivalent to 12,670.89 hectares, falling into this category. The most prevalent soil type is Cambisol, which constitutes 33% of the area, or 7,463.46 hectares. Using the scoring method, it was determined that in August, Singgahan and Montong Districts possess high potential for recharge areas, with high-level recharge zones covering 1,314.70 hectares and medium-level recharge zones spanning 18,498.78 hectares. By October, the extent of high-level recharge zones had increased to 3,499.20 hectares, while medium-level recharge zones covered 16,942.45 hectares. These findings underscore the importance of managing these recharge areas to sustain groundwater resources effectively.
Lithology Prediction Using K-Nearest Neighbors (KNN) Algorithm Study Case In Upper Cibulakan Formation
Authors: Komara Eki , Faiz Nugraha Muhammad , Rafi Muhammad , Lestari Wien 
Published: December 2024

Abstract
Knowledge in the characterization and evaluation of hydrocarbon formations by identifying the type of lithology is an important step in oil and gas exploration. However, this method is not efficient enough because it requires a lot of time and effort. This study focuses on lithology predictions using log data input by applying one of the machine learning algorithms, namely K-Nearest Neighbors (KNN). This KNN algorithm can classify data based on K values to predict lithology. The Hyperparameter K value is determined based on the number of nearest neighbors calculated using the Euclidean distance principle. The K value in KNN needs to be optimized in order to find out the best K value to get high accuracy. The accuracy value of the model is obtained by comparing the results of the actual qualitative interpretation of lithology with the prediction results of lithology with KNN resulting precision, recall and F1 as representative of model accuracy. In the data train wells KP-24, KP-54 and KP-57 as well as test data, namely the KP-34 well, the value of k = 5 has the highest accuracy value of 89.9%. With the dominance of lithology in the predicted results, namely limestone, according to the information on the well data area, namely the Cibulakan Formation above and into the well, it reaches the Baturaja Formation. These results indicate that the lithology predicted by the KNN algorithm from the train data is already representative of the actual lithology data. Comparison of the results of qualitative interpretation with the results of machine learning predictions on the KP-34 well can predict thin or small layers and data labels in a relatively short time.
Building resilience in LNG marine terminal operations: a comprehensive socio-technical risk analysis utilizing the resilience assessment grid (RAG) method
Authors: Mahatrisna P I , Saut Gurning R O , Dinariyana A A B , Makapuan Rocky S J 
Published: December 2024

Abstract
In the face of rising global energy demand, LNG terminals play an essential role in the energy supply chain. However, the complexity of terminal operations, combined with the risk of catastrophic events, necessitates a robust resilience framework. This paper presents a comprehensive socio-technical resilience analysis that uses the Resilience Assessment Grid (RAG) methodology to measure resilience in LNG terminal operations. We examine the complex interplay of human elements, organizational culture, and technological systems in the terminal environment. Our approach uses the RAG methodology to identify vulnerabilities, assess the potential impact of disruptions, and assess the effectiveness of current safety and risk management practices. The results of this study show that the implementation of the safety concept at the LNG Marine Terminal is quite optimal, as indicated by the compliance figures for each resilience aspect, which exceed three as a benchmark. The highest score in the entire system is found in the ability to respond aspect, namely 4.38, which shows that the organization, in implementing this concept, still focuses on preventing and controlling accidents. This condition differs from the ability to monitor aspect, which has the lowest value, 3.97. However, this item cannot be called an inhibiting factor because its value exceeds the expected standard. In response, there is still room for improvement from existing achievements in the future.
Information Extraction from Automatic Identification System (AIS) Data for Identifying Shipping Line based on Maritime Mobile Service Identity (MMSI)
Authors: Ma’ruf M. , Ruslin R. , Hasanah Uswatun , Efendi E. , Arifin Willdan Aprizal , Handani Dhimas Widhi , Suasti Gede Bagus Dwi , Syamsudin Farih , Sinaga Johannes Valentino , Eryawan Billal Soebhi , Al-Kautsar Ken Cindha Bumi 
Published: December 2024

Abstract
Automatic Identification System (AIS) is a technology used to track the movement of ships through the transmission of ship data using Very High Frequency (VHF) waves. Ships around the world transmit their information, which is then captured by AIS receivers. This AIS data collected and stored at the ground station. This study uses the data on the number of ships categorized based the Maritime Mobile Service Identity (MMSI) in the southern Indonesian Archipelago Sea Route II (ALKI II), Madura strait, and its surroundings during one month period of March 2023. The AIS raw data processed using The Jupyter Notebook to generate the information such as MMSI, longitude, latitude, and navigation status. The information then plotted on QGIS to see the difference pattern of shipping lanes based on the ship’s MMSI number. The aim of this research is to demonstrate how AIS data processing and analysis can generate sufficient information for maritime spatial planning, including depicting maritime traffic density and traffic constellations, shipping lanes and navigation status, the hierarchical network of maritime routes, fishing zones, and spatial-temporal interactions between shipping activities. The findings from maritime spatial planning can offer valuable insights for law enforcement at sea and offer guidance for developing port infrastructure based on specific needs through the utilization of AIS data.
Utilization of sandblasting waste as additives to enhance mechanical performance of concrete mortar
Authors: Rizal Moh Najib , Sutrisno Wahyuniarsih , Wulandari Kiki Dwi 
Published: December 2024

Abstract
This research explains about the utilization of sandblasting waste, a byproduct of the shipping industry’s blasting process, as an additive in concrete mortar. The blasting process involves spraying silica sand to remove impurities from hull layers, resulting in waste that contains heavy metals like Fe2+, Mn4+, and Cr3+. Given its hazardous nature, alternative disposal methods are necessary to reduce landfill accumulation. By pre-treating this silica sand through cleaning and grinding, a new material, Ground Sandblasting Waste (GSW), with a particle size of approximately 390.4 nm and 94.75% SiO2 content, was produced. Concrete mortar specimens with dimensions 5 x 5 x 5 cm were prepared with GSW added in 1%-5% by weight of cement. Furthermore, this research also explores the combination of GSW with another additive named silica fume with a percentage of 6%. The compressive strength tests showed that adding 2% GSW and GSW-SF combinations, with proportions of 2% and 6% from the cement weight, greatly enhanced performance of mechanical the concrete mortar. This research highlights the potential for using pre-treated sandblasting waste to improve concrete performance and manage hazardous waste effectively in the shipping industry.
Development of Savonius Type Wind Turbine Model as A Source of Renewable Electrical Energy
Authors: Kusuma Cahya , Sutrisno Tri , Kusdiana Wawan , Aris Tri Ika R , Baidowi Ahmad 
Published: December 2024

Abstract
Wind turbines can be used as a renewable energy resource, especially in remote areas and outer islands where there is no electricity. Based on the calculations that have been carried out, it is found that the dimensions of the wind turbine model used in this research are a turbine height of 1 meter with a diameter of 0.5 meters. Meanwhile, the dimensions of the shaft used are 20mm. Model testing has been carried out in Juanda Surabaya, it is known that the generator power produced increases along with increasing wind speed which is also influenced by the rotation of the wind turbine. In the results of this research, the largest generator power was produced at a wind speed of 4.8 ms−1, which produced a generator power of 12.6 watts. Meanwhile, the lowest power is 0 watts because a wind speed of 0.4 m/s is not able to rotate the wind turbine. From the data collection results, it was also found that the SCC could only charge the battery if the minimum voltage reached 13 volts. So the new SCC can charge the battery at a wind speed of 3.7 m/s with a voltage output of 13.1 volts and a current strength of 0.5 amperes. This research will use a Savonius wind turbine with 2 rotor blades with dimensions of 1 meter high and 0.5 meter diameter. The research results show that power is obtained at a generator voltage starting from 13.1 volts which produces a current strength of 0.7 amperes. It is at this voltage that the new Solar/Wind Charge Control can charge the battery.
The influence of time steps and turbulence model in numerical predicting total resistance on Japan Bulk Carrier with and without pre-duct
Authors: Munazid A. , Ariana I M. , Utama I K. A. P. 
Published: December 2024

Abstract
As a numerical fluid dynamic simulation method, Computational Fluid Dynamic (CFD) must guarantee the accuracy of the simulation results carried out, where the accuracy of the simulation results depends on: numerical method, grid generation, mesh independence, grid type, turbulence model, etc. This paper explains the influence of turbulence model and time step on the resistance prediction results of the Japan Bulk Carrier (JBC) ships, with CFD simulations using the ANSYS CFX software package. The model is simulated with several turbulence models including: k-Epsilon (k-ε), k-Omega (k-ω) and Shear Stress Transport k-ω (SST k-ω), apart from that the turbulence model is simulated in several time steps. From the results of the CFD modelling carried out, the influence of the turbulence model and time step on the accuracy of predicting ship resistance from the JBC ship was analysed, by comparing the CFD modelling results with experimental results from National Maritime Research Institute (NMRI). In general, the turbulence model and time step influence modelling and mesh selection, the correct time step provides accurate and convergent modelling results.
Redesign the air ventilation system in the engine room 48 meter patrol ship
Authors: Kusuma C , Widayat M A , Kusdiana W , A T Ika R , Baidowi A 
Published: December 2024

Abstract
The patrol boat with a Length Overall of 48 meters has the main function as a coastal patrol boat. The air ventilation system installed on patrol ships currently reaches an average temperature of 320°K ∼ 345°K with an average speed of 0 ∼ 2.5 m/s and the airflow is not distributed throughout the engine room. The temperature in the engine room is above the ISO 8861:1998 standard where the maximum temperature is 318.15 K (45°C). Based on calculations according to ISO 8861, the total air capacity requirement is 10.806 m3s−1 or 38.901 m3/hour, while the currently installed air blower capacity only has an air capacity of 3.988 m3s−1 or 14.358 m3h−1. The existing air ventilation system consists of 2 air blowers that suck in outside air. Computing Fluid Dynamics (CFD) is used to calculate the temperature distribution of the engine room between the existing ventilation system and the ventilation system based on ISO 8861 calculations. Based on the CFD simulation results, a blower modification with a capacity of more than 10.806 m3s−1 is carried out so air can be distributed throughout the room at an average speed 2.5 ms−1 ∼ 8 ms−1 with engine temperature at a height of 1-2 meters is 303°K ∼ 315°K according to ISO 8861:1998 standards.
Boil of Gas Formation Rate Analysis in LNG Storage Tank on LNG Fuelled Harbor Tug Vessel
Authors: Ariana I M , Fathallah A Z M , Zaky H A , Akbar T A 
Published: December 2024

Abstract
To accelerate the achievement of the net zero emission program which also one of the contributors of the climate resilience aspect in the Sustainable Development Goals (SDG), the use of natural gas as ship fuel is one solution during the energy source transition period. Storing natural gas in the liquid phase (LNG) can reduce tank volume requirements by up to 600 times compared to the gas phase. However, the formation of BOG (Boil of Gas) can increase the pressure in the tank. In this research, the rate of BOG formation in tanks designed for LNG storage on Harbor Tug vessels was analysed using the CFD (Computational Fluid Dynamics) method. The simulation results of the BOG formation rate when the ship is not operated and at full speed are 0.61 m3/minute, - 0.43 m3/minute, respectively. The storage tank is able to withstand gas pressure for up to 50 days when the ship’s system is not operated.
Steel Scrap Prediction from Indonesian Ship Recycling: Ship Type Point of View
Authors: Mutmainnah W , Fauzi F , Mauliani D R , Kurniawan M A , Hendratna K K , Sunaryo  
Published: December 2024

Abstract
Hong Kong International Convention for the Safe and Environmentally Sound Recycling of Ships 2009 will entry into force on 26 Juni 2025, which is 24 month after Bangladesh and Liberia deposited their instrument to be a Contracted States to the Convention in 2023. As known widely, the output from the ship recycling activity is steel scrap that can be melted as a source of new steel. In Indonesia, the number of ship scrap is expected to be able to contribute to national steel industry. There are around 14.000 ships registered in Biro KlasiOikasi Indonesia. More than 2000 ships have been operated for more than 25 years. The aim of this study is for predicting the weight of the steel scrap by calculating the Light Displacement Tonnage (LDT) of potential ships to be recycled from available data based on 11 ship types that has higher total GT Total LDT estimation from ships more than 25 years is almost 2 million tons. This number would contribute positively to shipbuilding industry in Indonesia.
Improving the quality of urban ecosystem through ecological soundscape management
Authors: Beatrix K , Dahlan M Z , Koerniawan M D 
Published: December 2024

Abstract
In urban ecosystems, the interaction between humans and the environment is often dominated by noise from human activities, with the importance of natural sounds or the ecological soundscape being ignored. The ecological soundscape plays a crucial role in ecological interactions and the development of urban ecosystems by supporting biodiversity. Therefore, the impact of ecological soundscapes on enhancing sustainable ecosystems is aimed to be analyzed in this study. The influence of the ecological soundscape on the sustainability of living organisms in urban open spaces is evaluated, serving as an indicator for ecosystem improvement. Sound recordings were conducted at four strategic points. The dominant sound types are identified, and the role of the ecological soundscape in shaping soundscape patterns in urban open spaces is evaluated. Babakan Siliwangi Urban Forest was selected as the case study due to its significant benefits in improving the urban ecosystem. The results indicate that BSUF has not been fully taken over by the ecological soundscape. Natural sounds are masked by the constant human-made noise from traffic, indicating a decrease in biodiversity. Recommendations for enhancing the ecosystem through the ecological soundscape approach are provided, including noise reduction measures such as creating buffer zones with vegetation, expanding green spaces as habitats for wildlife contributing to natural sounds, and creating conditions supporting diverse flora and fauna. It is expected that these recommendations will lead to an enhancement of the ecological soundscape in urban areas and foster more sustainable and diverse ecosystems.
Integrating arborists and birds: Habitat management options for birds in the tropical urban green space
Authors: Mardiastuti A , Mulyani Y A 
Published: December 2024

Abstract
Tropical urban areas have been known as excellent habitats for birds. Trees in urban areas are essential in supporting birds’ lives; they must be managed appropriately. This paper aims to formulate habitat and tree maintenance management options that could benefit birds in tropical urban areas. Previous bird observations from three urban green spaces formulated management options. Managing urban birds’ habitat mainly involved managing trees producing food (fruits, seeds, insects, nectars) and providing bird cover (as resting, roosting, and breeding sites). Trees can be planted in clumps or rows, creating bird habitat patches and corridors. Trees producing small-sized seeds/fruits attract insects, and having nectars from flowers is preferred by birds. Tall trees with thick canopies are excellent as cover. As some birds nest in tree cavities, old-decayed trees must also be maintained, which might conflict with arborists’ intentions. Other conflicting matters are snags, parasitic/epiphytic plants, pests, and thick litter, which are excellent for birds but unwanted by arborists. Management options for arborists need to be integrated and synergized with avian ecologists to maintain/increase bird diversity and number in the tropical urban green space.