bluuebunny/crossref_metadata_2025_split huggingface dataset:
Age-old transformation of oil hydrocarbons in polluted Grey-Brown Soil in the Absheron Peninsula
Authors: Wei X , Bocharnikova E A , Matichenkov V V , Demin D V 
Published: December 2021

Abstract
Oil production, transportation and refining are a source of the extensive environmental pollution. The study of oil pollutants allows the identification of their behavior pattern necessary in order to elaborate efficient decontamination technologies. The Absheron oil field is one of the most long-term exploited deposit in the world. Today this area is a unique place to investigate the long-lasting natural oil transformation processes. Grey-Brown Soils contaminated with crude oil 100 and 40 years ago and currently were investigated. Hexane-extractable fraction of oil compounds was examined by chemical methods, gas chromatography and mass spectrometry. In the process of natural degradation, molecular weight of oil hydrocarbons and degree of oxidation significantly increased, while the contents of carbon and hydrogen slightly decreased with time. The results obtained have shown the accumulation of high-molecular weight aromatic molecules with high degree of unsaturation in the upper layer of the soil contaminated 100 years ago. These aromatic structures exhibit the great resistance to decomposition and may be carcinogenic, thus posing a risk to human health. The contamination with oil resulted in altering soil properties. More pronounced change was observed in the soil carbon, including the soil contaminated 100 years ago. Over time after contamination, the soil alkalinity enhanced, whereas soil pH did not change. Our study evidences that oil pollutants continue to be present and the soil properties have not recovered even 100 years after pollution. Reclamation of these areas requires the application of special technologies.
Distribution of the Initial Fluid Composition in an Oil-Gas-Condensate Reservoir with Incomplete Gravity Segregation
Authors: Kusochkova E V , Indrupskiy I M , Kuryakov V N 
Published: December 2021

Abstract
It is known that initial composition of the hydrocarbon fluid in a petroleum reservoir changes significantly with depth due to the influence of gravity and geothermal gradient. Classical models of these phenomena are based on the assumption of equilibrium (quasiequilibrium) distribution of component concentrations in the gravity field with the presence of stationary thermodiffusional flux. However, there are typical situations in gas condensate reservoirs when the quasi-equilibrium conditions are not met. For example, this is true if immobile residual oil exists in the reservoir or for deep tight formations where gravity segregation is not completed. For such cases, modified models are required. They are proposed in this paper to take into account the non-equilibrium conditions of the initial fluid composition distribution in gas condensate (or oil-gas-condensate) reservoirs.
Silicon substances for restoration of oil-contaminated areas
Authors: Zhang P , Matichenkov V V , Bocharnikova E A , Sevostianov S M 
Published: December 2021

Abstract
Numerous investigations demonstrate that active forms of silicon (Si) enhance the plant tolerance against abiotic stresses by several mechanisms, including increasing the antioxidant activities and minimizing oxidative damage. Soil contamination with oil and oil products relates to abiotic stress that detrimentally affects soil microbial population and plant growth. Considering the crucial role of microorganisms and plants in bioremediation of oil-polluted areas, Si substances can be beneficial to acceleration of soil reclamation. In greenhouse experiment, wheat was grown in Grey Forest Soil contaminated with used motor oil. The effect of fumed silica and monosilicic acid on soil enzymatic activity and plant growth was studied. Both Si substances provided increasing the plant biomass and the activities of catalase and dehydrogenase. As regards the plant growth, the effect of Si was more pronounced in polluted soil, while the enzyme activity was higher affected in unpolluted soil. The activities of catalase and dehydrogenase were closely correlated to the water-soluble Si in soil (R=0.91-0.92). Silicon substances with high content of, plant-and microorganism-available Si might be promising for involvement in bioremediation technology for oil-contaminated soil.
Attenuation of long period multiple using F-k filter and surface-related multiple elimination methods on 2D broadband seismic data from Morowali Waters, Sulawesi
Authors: Situmeang G L , Manik H M , Nainggolan T B , Susilohadi  
Published: December 2021

Abstract
Wide range frequency bandwidth on seismic data is a necessity due to its close relation to resolution and depth of target. High-frequency seismic waves provide high-resolution imaging that defines thin bed layers in shallow sediment, while low-frequency seismic waves can penetrate into deeper target depth. As a result of broadband seismic technology, its wide range of frequency bandwidth is a suitable geophysical exploration method in the oil and gas industry. A major obstacle that is frequently found in marine seismic data acquisition is the existence of multiples. Short period multiple and reverberation are commonly attenuated by the predictive deconvolution method on prestack data. Advanced methods are needed to suppress long period multiple in marine seismic data. The 2D broadband marine seismic data from deep Morowali Waters, Sulawesi, contains both short and long period multiples. The predictive deconvolution, which is applied to the processing sequences, successfully eliminates short period multiple on prestack data. The combination of F-k filter and Surface Related Multiple Elimination (SRME) methods are successful in attenuating long period multiple of the 2D broadband marine seismic data. The Prestack Time Migration section shows fine resolution of seismic images.
Algorithm design for wind prediction in Berakit Bay, Bintan Island using Long Short-Term Memory (LSTM) method
Authors: Pratama D R , Jaya I , Iqbal M 
Published: December 2021

Abstract
Wind speed is a crucial parameter alongside coastal areas, especially Indonesia. Above average wind speed can cause harmful effects on human activities. This study uses wind speed data from Berakit Bay, Bintan Island is a potential location for coastal community settlement, fisheries, and tourist activities. The wind parameter then predicted using the Long Short-Term Memory or LSTM algorithm. This algorithm is able to study long-term dependencies by converting simple nervous system designs into specialized blocks containing cells. It is suitable to be applied to long-term wind predictions where the wind speed at this time is very influential with the wind speed in the future. In preparing the LSTM, the data preprocessing and the architecture used will determine the prediction results. In this study, four different architectures were made in order to determine the most optimal architecture. The results show that the LSTM architecture is able to obtain a relatively good RMSE value of 1.87 and an accuracy of 39.40% with the use of two LSTM layers, 256 units in the first layer and 128 in the second layer. The LSTM algorithm in predicting wind can also be applied to other areas in Indonesia.
Prediction and classification of suspended sediment and zooplankton signals from acoustic Doppler current profiler backscatter data using artificial neural networks
Authors: Dwinovantyo A , Solikin S , Manik H M , Prartono T , Susilohadi  
Published: December 2021

Abstract
Characterization of each underwater object has its challenges, especially for small objects. The process of quantifying acoustic signals for these small objects can be done using high-frequency hydroacoustic instruments such as an acoustic Doppler current profiler (ADCP) combined with the artificial intelligence (AI) technique. This paper presents an artificial neural network (ANN) methodology for classifying an object from acoustic and environmental data in the water column. In particular, the methodology was tuned for the recognition of suspended sediments and zooplankton. Suspended sediment concentration and zooplankton abundance, which extracted from ADCP acoustic data, were used as input in the backpropagation method along with other environmental data such as effects of tides, currents, and vertical velocity. The classifier used an optimal number of neurons in the hidden layer and a feature selection based on a genetic algorithm. The ANN method was also used to estimate the suspended sediment concentration in the future. This study provided new implications for predicting and classifying suspended sediment and zooplankton using the ADCP instrument. The proposed methodology allowed us to identify the objects with an accuracy of more than 95%.
Exploring bioactive pigments from marine bacterial isolate from the Indonesian seas
Authors: Brotosudarmo T H P 
Published: December 2021

Abstract
Marine microbes offer a significant source for biodiscovery due to their rich biodiversity and genetic capacity. Particularly, microbial pigments of marine origin are getting more attention in current research due to their widely perceived application as natural food colorants, antioxidant, antimicrobial, and many more. In the past five years, our research group has successfully characterised various bioactive pigments isolated from marine bacteria, including Erythrobacter flavus strain KJ5 that produces unique sulphur-containing carotenoids, Pseudoalteromonas rubra strain PS1 and SB14 that contain antimicrobial prodiginine, and Seonamhaeicola algicola strain CCI for high content of zeaxanthin. This paper describes the challenges we encountered in conducting research in exploring bioactive pigments especially with focus on carotenoid research, reviewed critically on strategy we developed for isolation of isolate as well as identification and elucidation of the pigments, and consideration for future research.
The coral reef health at surrounding blue swimming crab fishery sites in Mandangin Island, East Java, Indonesia
Authors: Ardiansah I , Hidayat S A , Mutmainah D F D , Siahaan M C B , Firdaus M R , Subhan B , Madduppa H 
Published: December 2021

Abstract
Blue swimming crab fishery activities very often do not put into account the environmental condition. Coral reef, as one of the blue swimming crab habitats, can be affected by these activities. This study aims to determine the effect of blue swimming crab fisheries on coral health in Mandangin Island, East Java, Indonesia. Data collection points are determined based on the results of interviews by participatory mapping. Water quality data includes visibility, temperature, salinity, pH, DO, current velocity. Collecting coral reef data were using Line Intercept Transect (LIT), while for reef fish Underwater Visual Census (UVC) were used. The coral health index was determined based on the relevance between benthic components and fish components. The average of Mandangin Island’s water quality is in accordance with the quality standards of the Indonesian Minister of Environment Decree No.51 of 2004. Hard coral cover and fish biomass are classified as low, but the value of resilience is high. The coral reef health index value on Mandangin Island is 3.
Harmful algal blooms and their impact on fish mortalities in Lampung Bay: an overview
Authors: Sidabutar T , Cappenberg H , Srimariana E S , Muawanah A , Wouthuyzen S 
Published: December 2021

AbstractThe first disaster caused by harmful algal blooms in Lampung Bay was reported in 1991, where mass mortality of cultivated shrimp occurred in the brackish water ponds due to aTrichodesmiumbloom. After this incident, the phenomenon reoccured in the following years continuously. Around nine species bloom makers in this bay are namelyPyrodiniumsp.,Noctilucasp.,Phaeocystissp.,Dinophysissp.,Trichodesmiumsp.,Ceratiumsp.,Prorocentrumsp.,Pseudonitzhiasp., andCochlodiniumsp. The most frequent causative species, such as greenNoctilucaandTrichodesmium, co-occurring during blooms and causing fish mortalities in the fish farming floating nets (KJA). Two species are known as the most potentially harmful species, namelyPyrodiniumsp. andCochlodiniumsp.Cochlodiniumblooms happened at the end of 2012, and since then, this species has continuously reappeared in the following years. The outbreak ofCochlodiniumsp. still appeared in 2017 and 2018, but no fish-killing occurred. Phytoplankton bloom events occur at specific locations, mainly at fish farming floating nets on the west side of the bay, next to Hurun Cove. This paper discusses the occurrence of algal blooms in Lampung Bay and the triggering factors for increasing phytoplankton populations that cause harmful algal blooms.
Enhancing reef fish diversity using artificial reef-building: A case study of coral reef rehabilitation on Nyamuk Island, Anambas Islands
Authors: Prabowo B , Rikardi N , Setiawan M A , Santoso P , Yonvitner  , Arafat D , Subhan B , Afandy A 
Published: December 2021

Abstract
CCMRS-IPB conducted coral reef rehabilitation at damaged coral reefs around Nyamuk Island. Those artificial reef buildings for rehabilitation gave shelter spaces for reef fish. This research aims to calculate the effect of coral reef-building, which enhances rugosity to the reef fish diversity around the rehabilitation sites. The study was conducted on Nyamuk Island in the Anambas Islands. Reef fish were sampled annually from 2014 to 2019 using the underwater visual census. The Diversity index and non-Metric Multidimensional Scaling were built to discover reef fish diversity, and reef fish species were affected the most. Yearly data shows an escalation number of reef fish abundance and richness at the end of 2019. The major reef fish group is found to have constant diversity throughout the year compared to other functional groups. The target reef fish group came to this rehabilitation ecosystem primarily attracted by nourishment availability. There is a shift in the reef fish diversity from the early year to the project end. Generally, major reef fish groups will be refuged first around the rehabilitation sites, especially territorial types. Target fish groups from herbivorous and carnivorous types will mostly come along after their food availability and location to get around.
Morphometric and genetic identification of a newly record pygmy seahorse Hippocampus denise in the Kepulauan Seribu reefs, Indonesia
Authors: Sunuddin A , von Juterzenka K , Sani L M I , Madduppa H 
Published: December 2021

Abstract
The study was conducted to describe the seahorse species based on morphological and molecular characters. The pygmy seahorse in Panggang Island in Kepualuan Seribu was discovered in October 2011. The species was allegedly identified as Hippocampus denise (Family: Syngnathidae) described by Lourie and Randall which published in 2003. The high similarity is based on small morphometric, orange-like color and its association with sea fan Annella sp. Their habitat is fairly shallow at a depth between 13-24 meters compared with their sister species observed in Bali, Nusa Tenggara, and Sulawesi. The phylogenetic analysis constructed with several sequence data of Hippocampus spp. from Genbank shows that sample collected from Panggang Island is in the same clade with Hippocampus denise with 100% bootstrap value. BLAST analysis result also showed a high maximum similar identity (>99%) with the species Hippocampus denise. The seahorse specimen described in this study has a common typology of habitat with Hippocampus denise. This study shows that genetic analysis to determine the Hippocampus denise can be carried out to support species recognition, especially for cryptic species such as Hippocampus spp. There are variations in morphometric and habitat depth levels, indicating local adaptation of pygmy seahorses to the Kepulauan Seribu reefs.
Olive ridley (Lepidochelys olivacea) laying eggs habitat mapping in Penimbangan Beach, Bali Island
Authors: Natih N M N , Pasaribu R A , Hakim M A G Al , Budi P S , Tasirileleu G F 
Published: December 2021

Abstract
Penimbangan beach is one of the tourist destinations located in Buleleng Regency, Bali Province, Indonesia. This beach is also a nesting place for one of the sea turtle species in Indonesia, which is olive ridley (Lepidochelys olivacea). The problem that exists on the island of Bali today is most of the land in coastal areas were experienced land degradation. This land degradation occurs due to human activities or natural factors, it harms the turtle nesting habitat around the coastal area of Bali Island. Conservation of nesting turtle habitat is needed through spatial analysis using Geographic Information Systems (GIS). This study uses the parameters of sand particle, beach slope, width beach, humidity, and temperature parameter to determine the suitability of the turtle nesting habitat. Penimbangan beach area which is very suitable for turtle nesting locations has an area of 163,45 m2, suitable for laying eggs 4.886,44 m2, and not suitable for laying eggs 10.201,64 m2. The map of the suitability for laying turtle eggs is dominated by areas that are not suitable because the width of the beach is not too long and the humidity is still relatively high.
Carbon stock estimation and mapping of mangrove forest using ALOS-2 PALSAR-2 in Benoa Bay Bali, Indonesia
Authors: Mahasani I G A I , Osawa T , Adnyana I W S , Suardana A A M A P , Chonnaniyah  
Published: December 2021

AbstractMangrove forests in tropics coastlines area play an essential role in carbon fixation and carbon storage. Mangrove forests in coastal areas are very effective and efficient in reducing the concentration of carbon dioxide (CO2) in the atmosphere because mangroves can absorb CO2through photosynthesis by diffusion through stomata and then store carbon in the form of biomass. With the lack of efforts to manage mangrove forests, it needs to be developed so that forest functions can be utilized sustainably. This paper describes examining the use of remote sensing data, particularly dual-polarization ALOS-2 PALSAR-2 data, with the primary objective to estimate the carbon stock of mangrove forests in Benoa Bay, Bali. The carbon stock was estimated by analyzing HV Polarization, Above Ground Biomass (AGB), and ground biomass (BGB). The total carbon stock was obtained by multiplying the total biomass with the organic carbon value of 0.47. The potential carbon stock in the mangrove Benoa Bay area is 209,027.28 ton C to absorb carbon dioxide (CO2) of 767,130.11 ton CO2Sequestration same with 3.87X1011bottles in 2015 and 204.422,59 ton C to absorb carbon dioxide (CO2) of 750.230,93 ton CO2Sequestration same with 3.79x1011bottles in 2020.
Coastal vulnerability mapping due to tsunami using Geographic Information System in Buleleng Regency, Bali Province
Authors: Suhita N P A R , Siregar V P , Lumban-Gaol J 
Published: December 2021

Abstract
Bali is one of the areas vulnerable to disasters because of its geographical position, which is flanked by two earthquake sources in the form of a subduction zone and back-arc thrust zone, which can cause a tsunami in Bali region. This research aims to identify and map the level of coastal vulnerability to the tsunami in Buleleng Regency, Bali Province. The mapping was carried out using Geographic Information System (GIS). This study used secondary data and field data. The parameters used in analyzing the level of tsunami vulnerability were land elevation, slope, landuse, distance from the beach, and distance from the river. The level of vulnerability was grouped into five classes, namely very safe (35,466.9 ha), safe (70,485.0 ha), moderately vulnerable (17,645.0 ha), vulnerable (6,903.3 ha), and very vulnerable (438.9 ha) located in the Districts of Gerokgak, Seririt, Buleleng, and Sawan which are close to the river.
Light propagation, coefficient attenuation, and the depth of one optical depth in different water types
Authors: Nababan B , Ulfah D , Panjaitan J P 
Published: December 2021

AbstractThe ocean color satellite can only sense a water column up to one optical depth. However, literatur regarding the depth of one optical depth is very limited to none. This study aimed to determine light propagation, attenuation coefficient (Kd), and the depth of one optical depth in different water types. We used in situ data of downwelling irradiance (Ed) with depths taken using the instrument of submersible marine environmental radiometer (MER) in the northeastern gulf of mexico (NEGOM) in April 2000. We also used SeaWiFS data such as water leaving radience (Lw), remote sensing refectance (Rrs), and chlorophyll-a concentration (Chla). The results showed that the light propagation pattern generally decreased with increasing depth. The reduction in light intensity with depth was very strong in the red wavelengths, lower in the green wavelengths, and the lowest in the blue wavelengths. In contrast,Kdvalues were generally found the lowest at the blue wavelengths, slightly increase at the purple and green wavelengths, and the highest at the red wavelengths. The depth of one optical depth in the case-1 waters was found as deep as 39.79 m (λ=475 nm), followed by intermediate water of 31.79 m (λ=475 nm), and in the case-2 waters of 16.08 m (λ=490 nm). BothKd(490) in situ and modelled results showed a good correlation (r=0.83-0.84) and R2values of 0.68-0.71.
Mapping of shallow water bathymetry and reef geomorphology using Sentinel-2 satellite imagery in Genteng Besar and Genteng Kecil Island, Kepulauan Seribu
Authors: Agus S B , Siregar V P , Susilo S B , Sangadji M S , Tasirileleu G F , Budi P S 
Published: December 2021

Abstract
Information on seafloor characteristics is one of the essential variables in coastal management and marine ecosystems. Application methods in remote sensing technology to study about characteristics of shallow waters have continuously been done. This research consists of two parts: an estimation of depth using Sentinel 2B satellite imagery with the Lyzenga algorithm and geomorphological classification of the benthic area using the Benthic Terrain Modeler (BTM) approach. BTM is a method to analyze benthic habitat and shallow water geomorphology. Integrated Depth data were analyzed using BTM to obtain bathymetric position index (BPI), slope, and classification of reef geomorphological structures. The resulting BPI value range is directly proportional to the given spatial area (scale factor). The slope is ranged between 0.01° – 19.24°, while optimum depth estimation is applicable until 10-meter. The values of BPI and slope were used as variables to classify the geomorphology of shallow water benthic areas based on the previous classification dictionary. Six geomorphological classes resulting from this study are Back Reef, Deep Depression, Depression, Lower Bank Shelf, Mid-Slope Ridges, and Reef Crest.