bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation on the determination of available phosphorus using blue molybdate in Organosols
Authors: Garin Raihan , Simanjuntak Fransisca , Darmawan  , Sumawinata Basuki 
Published: July 2022

Abstract
Bray and Olsen methods have widely been used for measuring available phosphorous (P) in soil. Those methods have been known resulting good correlation between available P in soil and crops, especially for corn. Correlation between P uptake by plant and P concentration in Bray extractant ranges from 0.74 to 0.94; the method is, therefore, recommended for neutral and acid soils (pH ≤ 7.0). Meanwhile for Olsen method, correlation could span from 0.73 to 0.96 for alkaline soils. Both, however, have been observed to potentially result in false-high available P in Organosols. This might be due to dark color of Bray and Olsen extracts that reacting with blue molybdate and resulting in high values of absorbance during spectrophotometric measurement. In the case for Organosols, dissolved organic substance originates dark color of the extract. Therefore, organic substance should be eliminated prior to the measurement. This research explored an improvement for available P measurement in Organosols by treating the extract with H2O2 and an activated charcoal. This treatment the Olsen extracts has resulted in a notable available P gap, i.e. 102.7 ppm of treated extracts compared to 1207.7 ppm of untreated one.
Tropical peatlands in North Kalimantan: characteristics, extent, and estimates of carbon stock
Authors: Sukarman  , Gani Rachmat Abdul 
Published: July 2022

Abstract
North Kalimantan Province has the third largest tropical peatlands in Kalimantan Island. Despite this, a detailed data on the characteristics, extent, and carbon stock of tropical peatlands in North Kalimantan is currently not available. Therefore, BBSDLP has carried out a semi-detailed peatlands mapping on Nunukan and Tana Tidung Regencies and Tarakan City, North Kalimantan Province. Peat soil mapping refers to SNI 7925:2019, scale of 1:50,000. The study found that peatlands in North Kalimantan covered about 216.944 ha, with the majority extent in Tana Tidung Regency (71.512 ha), followed by Nunukan Regency (142.198 ha) and Tarakan City (3.233 ha). Peatlands in this area occupied fluvio-marine (B) and peat (G) landforms, with hemic and sapric decomposition levels, and a depth of 50 - < 700 cm (shallow to extra very deep). Substratum layer, i.e. mineral soils, comprised of clay to sandy clay soil texture. According to the Indonesian Soil Classification system, peat soil in the research area was categorized as Organosol Saprik, Organosol Hemik and Organosol Fibrik. Estimated carbon stock was about 328.80 M tons C, with an average of 1.516 tons ha−1. With this large figure, the results emphasize the importance of peatlands for land use and spatial planning.
The perspective of oil palm production in swampland as a result of soil properties diversity: Review of survey results in Kalimantan and Sumatra
Authors: Wakhid N , Mawardi  , Hairani A , Noor M 
Published: July 2022

Abstract
Currently, oil palm plantation has expanded into marginal lands, including swamp agroecosystems. Rapid development of oil palm plantation is due to increasing demand for raw materials of bioenergy. Utilization of swamplands for oil palm development is hindered by unfavorable physical, chemical, and soil fertility properties and vital environmental issues. However, many research demonstrate the potential and appropriate agronomic suitability for oil palm cultivation. This paper presents findings on surveys conducted on Kalimantan and Sumatra swamps. Land evaluation from six swampland sites showed that at the average, 36% of swamplands were categorized as moderately suitable (S2). Meanwhile, 37% of those were marginally suitable (S3), with the rest was not suitable (N). The evaluation indicated severe issues associated with unsuitable class (N), including shallow (<50 cm) pyrite, thick layer (>3 m) of peat and high level of inundation (>2 m) with a prolonged (3-6 months) overflow. In addition to these, acidity, peat maturity and nutrient status also serve as the limiting factors. Actual oil palm productivity in swamps remains low due to suboptimal cultivation technology and land and environmental management. It is, therefore, necessary to increase entrepreneurs and farmers’ capacity to improve management and cultivation systems. Land selection for site development should respect the following requirements: pyrite depth >100 cm, peat thickness >3 m with sapric maturity level, mixed peat and mineral soils, soil pH ranging from 5.0 to 6.0 and base saturation around 30%.
Response of four oil palm varieties to low frond desiccation in the main nursery with water stress conditions on peat
Authors: Muhayat  , Rauf A , Mukhlis  , Winarna  
Published: July 2022

Abstract
Oil palm is an important commodities for plantation sub-sector in Indonesia. The limitation of mineral soils for agriculture directs utilization of peatland for oil palm plantation. The major problem of peatland plantations is Low Frond Desiccation (LFD) due to fluctuation of groundwater. This study observed the responses of oil palm in the main nursery to water stress as well as the changes in physical and physiological properties of plants. This research using factorial randomized block design, replicated three times with two factors (four oil palm varieties and five watering stoppage) to determine plant responses to watering stoppage. The results showed that watering stoppage can increase the LFD incidence, decrease leaf chlorophyll, water content and plant height. The highest incidence and LFD intensity was at 5 weeks watering stoppage with the highest LFD intensity value of 45.67%. LFD started at 2 weeks watering stoppage with LFD intensity ranging from Dumpy variety 17.69%, DxP 540 variety 28.58%, Langkat variety 29,46%, Yangambi variety 38.89%. The oil palm varieties having the highest LFD intensity at 5 weeks watering stoppage were found in the Yangambi variety and the lowest was in the Dumpy variety.
Management and development of oil palm cultivation in swamplands in perspective of limitation and sustainability
Authors: Annisa Wahida , Susilawati Ani , Noor Muhammad 
Published: July 2022

Abstract
Development of oil palm plantations in swamps in the last ten years has progressed rapidly as a result of limited availability of fertile lands. Due to the nature of the environment, productivity over swamp land is quite different from other ecosystems. Studies reported that average productivity of oil palm in swamps ranges from 0.8-1.2 tons fresh fruit bunch (FFB)/ha/month (equivalently 9-10 t FFB/ha). Economic analysis shows that this productivity level does not provide a benefit to the farmers. It was reported, however, that with the intervention and introduction of good management and technology, productivity of swamp land can reach 25-27 t FFB/ha and on peat soil it can reach 19 t FFB/ha. Socio-economic factors such as capital, knowledge, technology, labor, physical infrastructure or other facilities significantly affect palm oil productivity. Identification of economic, socio-political, and ecological aspects drive a concept of sustainable development for oil palm plantation. This paper reviews results related to this development in the perspective of limiting issues related to sustainability. Development of oil palm plantations expects high productivity and stability, yet promoting equality and local wisdom towards sustainable environment. Good management of soil and water is the key for oil palm farming in swamp lands. There are four properties of sustainable agroecosystems, namely productivity, stability, sustainability and equity.
Comparison of Bio- and Ferric Leaching for Beneficiation of Bulk Copper-Nickel Sulfidic Concentrate
Authors: Panyushkina A E , Fomchenko N V , Muravyov M I 
Published: July 2022

Abstract
Processing of sulfidic raw materials, including bulk concentrates of nonferrous metals, is a problem of current importance in metallurgy and waste recycling. In this study, leaching with a chemical ferric iron reagent was compared to two bio-approaches to process a bulk copper-nickel concentrate: (1) ferric leaching with a solution obtained by microbial oxidation and (2) stirred-tank bioleaching using an active acidophilic microbial community. The results of both the chemical and bio-processes indicated nickel dissolution, while copper was accumulated in leach residues. After short-term high-temperature leaching with the chemical or bio- solution (Fe3+, 10 g/L), the nickel content in solids decreased by 0.7 and 2.6%, respectively, while the copper content slightly increased (by 1.5–3.2%). Bioleaching at 40°C was characterized by a considerably higher efficacy of the process: nickel leaching reached 86.7%, and the copper content increased by ~5% in the bioleach residue. Based on these results, ferric leaching can be considered an inefficient method for selective nickel removal, while bioleaching may be a promising cost-effective approach characterized by relatively low environmental hazards to obtain a high-grade copper product. Moreover, ferric leaching with the bio-solution can improve the grade of monometallic sulfidic concentrates due to additional selective nickel extraction.
Feasibility of Using Tabagwang Waste Shells as Catalyst in the Production of Biodiesel from Yellow Grease
Authors: Columbres Kim V. , Pasion Junel S. , Salvador John Paulo P. , Calaycay John Patrick T. , Ulit John Carlo G. , Caranto Cristina M. , Retumban Joseph D. 
Published: July 2022

Abstract
Heterogeneous catalytic transesterification of yellow grease, commonly known as used cooking oil, utilizing the calcium oxide derived from waste shells of Jagora asperata, locally known as tabagwang, was carried out to produce biodiesel. Waste tabagwang shells were prepared and calcined at 900°C for 4 hours under static air to obtain CaO. The prepared CaO was used as a catalyst in the transesterification of used cooking oil. Reaction conditions such as temperature (45°C and 60°C), catalyst loading (2% and 10%), and methanol-to-oil molar ratio (6:1 and 9:1) were considered to evaluate the feasibility of the catalyst in terms of percent yield. For the given set of parameters, the largest yield of 4.85 mL biodiesel, corresponding to 9.70%, was obtained at temperature of 45°C, catalyst loading of 2%, and methanol-to-oil ratio of 9:1. Using a two-level factorial design, an optimum yield of 10.06% was calculated with the following conditions: temperature, 47.06°C; catalyst loading, 2.03%; methanol-to-oil molar ratio, 8.93:1.
Whether the Darrieus Rotor with Straight-Blades or Curved-blades is the Best, in Terms of Aerodynamic Efficiency
Authors: Abusannuga Hashem , Özkaymak Mehmet 
Published: July 2022

Abstract
An essential part of any wind turbine system is the rotor because it is the component that is in direct contact with wind and converts its kinetic energy into mechanical power. Then, it can either use this mechanical power directly to run some machinery, or you can use it to run an electricity generator and get electricity. One such turbine which is ideal for small-scale applications is the Darrieus wind turbine. This turbine has two blade configurations, straight or curved. This study aims to figure out the influences of these two blade configurations on the aerodynamic performance of the wind turbine. The engineering geometric shape of a parabolic Darrieus rotor was selected with certain dimensions, in this study it called P-D, and then a straight blade Darrieus rotor was extracted from it, in this study it called S-D1, similar to that of a parabolic in terms of rotor diameter and rotor height values, number of blades, blade section length and its type. Thus, a geometric similarity was obtained between the two rotors in terms of height to diameter ratio value and solidity value. Another rotor called S-D2 was also extracted and it is similar to P-D in terms of blade length, which means that the parabolic blade is straightened. There is also a similarity in solidity, and therefore it can be said that the masses of the rotors P-D and S-D2 are equal. This is the methodology that was followed to make the comparison in terms of aerodynamic. This analysis is done by developing a computer program that is based on mathematical model called multi-stream tube which modified to apply on both configurations of Darrieus turbine. The straight-bladed configuration is the best, according to this study.
A Literature Review of the Kalina Cycle and Trends
Authors: Dela Cruz Graciano Emmanuelito E. , Manuel Mark Christian E. 
Published: July 2022

Abstract
The demand for electricity and power has been increasing with the increase of the population of the world. The Covid-19 Pandemic has affected the way of life of human beings starting last year. The pandemic and economic downturn also affected the electricity demand of the world, but this is only short-term. Once the lockdowns around the world ease and back to normal situation begin, demand for power and electricity shall continue to grow. The century-old Rankine cycle has been the basis for power plants widely used today. However, a modified Rankine cycle known as the Kalina cycle has been proving more efficient than the standard Rankine cycle and might be able to provide the additional power needed in medium and low-temperature sources and waste heat recovery. This paper look into the development of the Kalina cycle and the trends that might be of use for the global electricity requirement.
Optimization and Integration of Renewable Energy Sources with Regional Tourism Potentials to Improve the Welfare of Local Communities
Authors: Asyuri R K , Setiawan E A 
Published: July 2022

Abstract
Indonesia is a country with a tropical climate and has tens of thousands of islands. One of the challenges is that archipelagic countries generally have limited local resources and high energy import costs. Renewable energy technologies in most islands are often not running and are unsustainable due to the many problems involved, one of which is the lack of clarity on management and generating assets. As a result, power plants generally only run for a short time and do not provide electrical energy for the community. In addition to the unavailability of electricity, the COVID-19 virus certainly also affects activities, especially people who rely heavily on the tourism sector as their main livelihood. Therefore, it is necessary to explore how an island could survive in this force majeure situation, both from the sustainability of renewable energy and the tourism sector. This research aims to explain what factors affect the sustainability of renewable energy in supplying electricity to the community in the long term and will present the interrelation between the tourism sector and the presence of renewable energy technology. The method used is an in-depth interview and questionnaire with a Likert scale. The research was conducted on the island of Mecan and the obtained data were simulated in the form of CLD (Causal Loop Diagram). The results indicate that renewable energy sustainability on Mecan Island has made access to electricity available throughout the day and has improved the welfare of residents.
Hosting Capacity of the Power Grid for Electric Vehicles - A Case Study on a Swedish Low Voltage Grid
Authors: Sandström M , Bales C , Dotzauer E 
Published: July 2022

Abstract
Hosting capacity (HC) is described as the maximum amount of new production or consumption that can be added to the grid without causing a violation. In this case study, a deterministic approach is used to investigate the HC of electric vehicle (EV) charging in a low-voltage grid, containing 13 detached single-family houses. It investigates how different parameters affect the HC, and what is causing the violation in the grid. Two different performance indices (PI) are used in the study: power cable overloading and voltage drop. The local grid is simulated for one year for four cases and the HC is derived for these. The cases are distinguished by two different violation thresholds for the voltage drop and two different implementation orders of the location of the charging. The results show that the HC of the grid is 6-11 EVs charging simultaneously. The difference in HC is primarily due to variation in the baseload through the year and location of charging. The cable between the substation and the first cable cabinet was the major contributor to the fault, and the PI causing the violation differed depending on what case was used.
Temperature based Enhanced Desorption of Adsorbed Biomethane Stored on Sustainable Nanoporous Materials
Authors: Adlak Komalkant , Chandra Ram , Vijay Virendra Kumar , Pant Kamal Kishore 
Published: July 2022

AbstractIn recent years, adsorbed natural gas storage has been seen as a better alternative to storing methane-rich gas on porous materials. Especially when these porous materials can be derived from a source like biomass whole process becomes valuable development. However, the problem of lower delivery capacity and the amount of gas released upon releasing the pressure remains unsolved. The micropores developed on the activated carbons retain the gas as they cannot get the activation energy to detach from the surface. The thermodynamics of the desorption process discourages the overall technological development of the system. We have carried out studies under particular temperatures by placing material and gas-filled cylinder in a water bath to overcome this challenge. Coconut based activated carbons were used in the study, which were procured from the market. Adsorption isotherm and other characteristics were performed for activated carbons. The desorption amount of the gas was recorded for different temperatures of 40, 45, 50 and 55 °C. At room temperature, nearly 54% of adsorbed gas is being released. Whereas, at 55 °C, approximately 80% of the gas is being recovered. This work will be useful for the externally cylinder fitted vehicles where the exhaust stream can be channelised to warm the surrounding of the cylinder to facilitate the higher discharge of the adsorbed gas.
Building Assessment and Statistical Characterisation of the Mediterranean Social Housing Stock in Southern Spain
Authors: Calama-González C M , Escandón R , Alonso A , León-Rodríguez Á L , Suárez R 
Published: July 2022

Abstract
Given that the existing residential buildings are expected to become a huge part of the future stock due to their low replacement rate, retrofitting plans are crucial to meet 2030 and 2050 energy efficiency targets. Notwithstanding, an extensive assessment of the current energy and thermal performance of the stock must be conducted prior to the proposal of energy saving measures in order to properly tackle the retrofit process. Thus, the analysis and characterisation of the existing buildings under real variability conditions through statistical techniques is key to provide useful information at the stock level, instead of the most commonly single-building level approach. In the presented study, a statistical analysis on the most predominant variability ranges of the social housing stock of southern Spain (Andalusia) is carried out. Efforts are focused on the building characterisation of the linear block typology. To do so, an extensive database, which contains information on slightly under 39,500 social dwellings, is analysed. The conclusions reported in this study may be implemented into the construction of real case building archetypes through bottom-up building stock modelling techniques with the objective of assessing the real energy and thermal performance of the existing stock, providing useful information for public stakeholders.
Traditional Architecture as a Typological Basis for Ecological and Sustainable Architectural Design from a Climatic Perspective. The Colonial Houses of the Central Valley; Santiago, Chile.
Authors: Flores David , Pareti Stefania , Valdebenito Vicente , Carmona Samuel 
Published: July 2022

Abstract
The present study aims to explore the Colonial House in the central valley of Chile, as a typological basis for an ecological and sustainable architectural design, mainly in relation to passive climate conditioning strategies, thinking about the minimization of external agents that take care of this. The city of Santiago is selected as a case study because it is a highly urbanized area, implying constant challenges about sustainable urban development. Regarding the object, these are traditional constructions with local materials and vernacular techniques, therefore they are related to the material heritage of the area and present proven climatic strategies that can be extrapolated to establish them within a contemporary context. The methodology is carried out through a constructive analysis of a typical house to understand the decisions taken and how they influence the habitability of the building. This will be complemented with the study of secondary sources and the comparison with contemporary examples to explore the application of the referenced strategies. It is concluded that traditional typologies allow the development of new proposals associated with sustainable logics due to the constructive and climatic understandings that vernacular notions imply.
Model of University Development in Thailand 4.0 Era toward “Green Campus Concept”
Authors: Mongkoldhumrongkul Krittaphas , Sukkanta Phatcharapron 
Published: July 2022

Abstract
Beneath the green university concept, actions for university sustainability are the approaches to mitigate environmental impacts. For effective operation, understanding of patterns and key factors contributed to a green university in order to plan and improve the performance for maximum efficiency. The research aim was to develop a university development model in Thailand 4.0 era toward “green campus concept”. The participants of this study were students at King Mongkut’s University of Technology North Bangkok, Rayong campus in the 2019 academic year. The sample size was 364 respondents derived from simple random sampling. The collecting data acquired from the questionnaire which verified the model by Structural Equation Modelling. The results revealed that the model was in accordance with the empirical data and passed the evaluation criteria. All factors: Satisfaction, Attitude, Participation, and Perception had influence on Green University Model. Attitude and Perception have a significant impact on Participation of Green University Model development. Furthermore, Satisfaction affected Participation indirectly and significantly (P=0.01). Its Chi-square probability level, relative Chi-square, goodness of fit index, and root mean square error of approximation were 0.246, 0.132, 0.93, and 0.042 respectively. The statistical significance of this study was set at 0.05. Based on the findings, the implementation for green campus should stress on Perception factor and Satisfaction factor because they have direct and indirect effects on Green University Model. Understanding the causal model would endorse the chief executive to plan and decide on successful green university projects.