bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Waste Bioconversion Technology Palm Oil Solid Waste in Order to Realizing Circular Economy Economy of Oil Palm Plantations in Subulussalam City Subulussalam: Case Study of PT. Samudera Sawit Nabati Subulussalam City
Authors: Miswardin  , Deli Anwar , Mariana  
Published: December 2024

Abstract
Oil palm (Elaeis guineensis), produces the most widely produced and used vegetable oil in the world. In addition to its many benefits, the volume of solid waste of TKKS per production also continues to increase. The production of solid waste per hour reaches 6.9 tons per day as much as 41.4 tons and continues to increase every time. Solid waste that accumulates has an impact on the environment and health, but when converted it can produce benefits, one of which is a medium for breeding BSF larvae eggs which later produce maggot as high-protein animal feed, this can also realize a circular economy. The purpose of this study was to determine the application of bioconversion technology of TKKS solid waste in realizing a circular economy. This research applies the experimental method, starting with the hatching of larval eggs until they are ready to be used as animal feed. Then analyzed production costs, benefits, and financial analysis in the form of narratives and tables. The results of the research have been obtained, there are two steps as an effort to minimize the solid waste of TKKS which lasts from 2016 to 2024. During this time, TKKS is only used as compost and burned. Financially, the utilization of solid waste through bioconversion technology can produce animal feed with a selling price of Rp. 10,000-Rp. 15,000 per kilogram of maggot and produce kasgot (fertilizer) reaching 90% with a selling price of around Rp. 10,000 per kilogram.
Feasibility study of processing wood twig waste into liquid smoke at the integrated waste management facility Diponegoro University
Authors: Azzahra F , Yusuf A B , Wicaksono P A , Sari D P 
Published: December 2024

Abstract
The pruning of trees along the road which is carried out every day by Diponegoro University causes piles of wood twig waste. There is no processing system for this waste. On the other hand, wood-waste can be processed into liquid smoke. Liquid smoke produced from processed wood-waste will not leave a coconut taste like liquid smoke in general and has a more distinctive and smokier aroma when it is used. This research aims to assess the market, technical and financial feasibility of processing wood twig waste into liquid smoke at the integrated waste management facility of Diponegoro University. Market feasibility was considered through Segmenting, Targeting and Positioning (STP) framework and marketing mix-4P. Technical feasibility was considered through calculating the availability of raw materials, production capacity and facility requirements. Financial feasibility was considered using the Net Present Value (NPV), Internal Rate of Return (IRR), Payback Period (PP), and Profitability Index (PI) methods. The results indicate that, provided at least 80% of the produced output is successfully sold at a price of IDR 35,000 per liter, the investment in processing wood twig waste into liquid smoke is considered feasible from market, technical, and financial perspectives.
Legal protection of coastal areas and surrounding communities affected by shrimp pond waste (case study: Beting Beach, Bintet Village)
Authors: Puspitasari D , Jannah M , Sari L , Manik J D N 
Published: December 2024

Abstract
Waste pollution from shrimp farming activities in the Beting Beach area of Bintet Village has created a situation of serious concern for the marine ecosystem and the surrounding community. This study aims to determine the impact of shrimp farming activities and the form of legal protection. This research uses empirical juridical method with qualitative approach. The results showed that the impact caused in the form of water pollution, namely changes in the color of water accompanied by foul odors and air pollution that disrupts the social activities of the community. Legal protection for coastal areas that have been polluted by waste must be carried out by taking firm action against shrimp farming businesses and restoring affected areas through Law Number 32 of 2009 addressing Protection and Management among the Environment. The community’s legal protection is governed by One of the laws of 2014 involving Amandements to Law Number 27 of 2007 surrounding Administration of Small Islands and Coastal Areas. The statute in question states that administrative sanctions, such as written warnings, temporary site closure, license revocatiobs, and\or administrative fines, are imposed in the event of a violation pertaining regarding the accepting of location and management permits.
Design and modelling of fastener system on sand core making shell machine
Authors: Suganda W , Purwanto H , Syafa’at I , Dzulfikar M 
Published: December 2024

Abstract
Sand core making shell have been considered as a system for metal casting. In the molding of molten casting, the shell machine needs to be fasten using bolts and nuts. The concept of the article discusses bolt’s strength using analytical methods and numerical calculations of materials and dimensional variations. The size and load received by the mold on the automatic sand casting machine normally 1000 kPa. Sand casting mold have dimension around 470 × 415 × 550 mm. Thus, the proposed clamped by 4 hardened hexagonal bolts. Our study provides understanding for the design and numerical modelling of fastener system for the mold clamping of metal casting.
The effect of adding fly ash on the shear strength of clay soil considering the age of fly ash
Authors: Kusniadi W , Apriyanti Y , Sandy B D A 
Published: December 2024

Abstract
The Clay soils present specific challenges in civil engineering due to their inherent weaknesses. Therefore, it is crucial to enhance bearing capacity of clay soil through stabilization methods such as chemical stabilization using fly ash. This research investigates the effect of fly ash at varying ages as stabilizing agent for clay soil on shear strength. In this research fly ash was added in proportions of 8%, 16%, and 24% by weight of dry soil, using both fly ash aged less than 1 year and fly ash aged more than 1 year. The clay soil used in this research was classified using Unified Soil Classification System (USCS). Shear strength tests were conducted in accordance with Indonesian National Standard (SNI) procedures. The results showed that fly ash aged more than 1 year consistently improves shear strength of the clay soil with increasing fly ash content, with the highest shear strength on 53.089 kN/m2 observed in the mixture of clay soil and 24% fly ash aged more than 1 year. While, for fly ash aged less than 1 year the maximum shear strength on 34.962 kN/m2 was achieved with 16% fly ash, then the strength decreased to 32.372 kN/m2 with 24% fly ash.
Isotope method for uncover characteristics and recharge areas of groundwater in Pangkalpinang City, Bangka Belitung Islands Province
Authors: Yulita R , Putra D P E , Baskoro W A 
Published: December 2024

Abstract
Groundwater recharge areas have an important role in water resources management, especially in maintaining the sustainability of groundwater in terms of quantity and quality. However, groundwater recharge areas whose water is utilized as one of the sources of clean water for the people of Pangkalpinang City have never been studied before. Based on these problems, this study was conducted with the aim of knowing the groundwater recharge area and the isotope characteristics of groundwater utilized by the community in Pangkalpinang City. 3 rainwater samples, 1 spring sample, 5 groundwater samples from dug wells, and 8 groundwater samples from drilled wells were taken directly and analyzed for 2H and 18O isotope content. The analysis results showed that rainwater 2H values are -2,40/00—8,0 9 0/00 and 18O -9,7 40/00—52,8 5 0/00. Spring water has values 2H -8,090/00, 18O -42,240/00. Borehole water has 2H values of 5,8 6 0/00—7,3 2 0/00 and 18O -35,9 2 0/00—45,2 80/00. They dug well water that has values of 2H 3,80/00—6,830/00 and 18O-24,8 5 0/00—41,7 80/00. The results of rainwater data plotting show that springwater, dug well, and drilled well water enters the hydrological cycle or meteoric water. For spring water, borehole water and some dug well water interact with each other and are not affected by evaporation. They are in the same aquifer system or may tend to come from the same source. Still, there is 1 dug well (SG-52) that moves away from the meteoric water trendline, so it can be interpreted that the well water evaporated during the journey from the recharge area. The groundwater recharge area in the study site is located at elevation 67,68-204 masl or outside of the study site, and the groundwater recharge area is most likely along the south to northwest side of the study area.
Optimizing the C/N ratio in composting fresh coconut husk and shell waste for organic fertilizer production
Authors: Tran T , Thi Q V C , Duong D V , Trung L D , Trang N T Q , Hong L T A 
Published: December 2024

Abstract
The Mekong Delta region produces significant organic by-products from agriculture, which can cause environmental pollution and infectious diseases. However, these by-products can be recycled into valuable raw materials for organic fertilizers. This study aims to create an organic substrate from fresh coconut husks and waste shells, reducing waste and maximizing the value of these materials. By determining the nutritional properties of shells and coconut husks, the study calculates the optimal mixing ratio with substrates and additional fertilizers to achieve a suitable C/N ratio for composting. The decomposition process is monitored over 45 days, tracking pH, temperature, total aerobic microorganisms, cellulose-decomposing microorganisms, and pathogenic E. coli - Coliform. Post-decomposition, the treatments are evaluated for organic matter content, total nitrogen, and phosphorus, and compared with the organic fertilizer standard QCVN 01 - 189:2019/BNNPTNT. Preliminary results show effective decomposition from day 6, with temperatures exceeding 50°C. Most final compost samples meet quality standards for organic and microbial fertilizers and show promising results in mustard greens trials. Thus, the fresh coconut husk and shell powder mixture has the potential to produce optimal compost, effectively recycling these materials.
Analysis of land use using Landsat 8 OLI in coastal North Sumatra: a study from 2019 to 2024
Authors: Nabiha R I , Zahra R A 
Published: December 2024

Abstract
Medan and Deli Serdang are recognized as the most developed regions in Northern Sumatra. However, there have been limited studies focusing on recent land use changes in their coastal zones. To address this gap, this study aims to analyze land use in Medan and Deli Serdang and examine the changes between 2019 and 2024. Using recent Landsat 8 OLI imagery, a supervised classification was conducted in Google Earth Engine. The CART classifier was used to divide the land use into water bodies, built-up, agricultural land, and mangroves. The Kappa index for 2019 and 2024 were 0.78 and 0.77, respectively, indicating reasonable classification accuracy. Agricultural land was found to be the dominant land use type, covering 52.78 % in 2019 and 51.76 % in 2024. A decrease was observed in agricultural land and water bodies, while mangrove coverage and built-up areas increased. The findings provide current conditions of land use in the coastal area of Medan and Deli Serdang, especially for planning and conservation in the coastal area.
Hydrophobic properties of phytoplankton-enhanced tapioca starch biocomposites
Authors: Setiawan Y , Ariksa J , Asriza R O , Wijianti E S , Taufiq M A 
Published: December 2024

Abstract
Sustainable material production from renewable resources is currently popular. This is due to the increasing awareness of the community towards the environment. Various products have been developed with natural materials to replace conventional plastics. Alternative materials to replace conventional plastics that are environmentally friendly are readily available, such as tapioca starch. Starch is a natural polymer that is very abundant and promising as a food packaging material. Starch is also easily degraded, non-toxic, and inexpensive. However, starch has bad air barrier properties, low hydrophobicity. To reduce these weaknesses, phytoplankton can be added to pure starch films. This study has succeeded in seeing the hydrophobic properties that the transmittance value for O-H stretching increased after phytoplankton was added to tapioca starch. Meanwhile, the transmittance of O-H at a wavelength of 3292 cm−1 for 0 ml of Starch/PP film was 37.28%. While the addition of phytoplankton suspension, the O-H transmittance at a wavelength of 3292 cm−1 for 20 ml of Starch/PP film was 43.67%. In this case, the addition of phytoplankton suspension increased the transmittance value from 37.38% to 43.67%. This finding indicates that well-dispersed phytoplankton in the PVA matrix form stronger hydrogen bonds, increase the hydrophobic properties of the biocomposite, and reduce the free O-H content.
Analysis of milling time effect on nanomaterial particle size using a laboratory-scale horizontal ball mill machine
Authors: Suhdi S , Saputra A , Rodiawan R 
Published: December 2024

Abstract
The advancement of nanotechnology has driven the need for efficient nanomaterial production methods. This research aims to analyze the effect of milling time on nanomaterial particle size using a laboratory-scale horizontal ball mill machine. The research method involved designing and constructing a horizontal ball mill machine, as well as testing using carbon powder with an initial size of 100 mesh (149 μm). Milling time variations tested were 6, 8, and 10 hours. Particle size characterization was performed using a Scanning Electron Microscope (SEM). Results showed that longer milling times produced smaller particle sizes. Milling for 6 hours resulted in an average particle size of 220.719 nm (63.13% of the sample), 8 hours produced 216.385 nm (77.01% of the sample), and 10 hours yielded 82.519 nm (86.99% of the sample). The study concludes that the designed horizontal ball mill machine can produce nanomaterials, with milling time inversely proportional to the resulting particle size. This research contributes to optimizing nanomaterial production processes using the ball mill method.
Biodegradable antibacterial plastics from porang fermented flour
Authors: Helmi H , Kusmiadi R , Karsiningsih E 
Published: December 2024

Abstract
Plastic is a waste that is difficult to handle and decompose. Biodegradable plastic can be solution to overcome this problem. The aim of this study is to investigate the potential of naturally fermented porang flour as a bioplastic based on the degradation process in the soil and its antibacterial properties as food packaging. The biodegradable plastics were made by mixing vinegar, food grade glycerine and porang fermented flour. The degradable test was carried out by calculating the weight of the plastic after it was buried in the ground for 14 days, the antibacterial test was carried out against bacteria, namely Escherichia coli and Staphylococcus aureus using agar diffusion with paper discs. The antibacterial ability test as a food wrapper was carried out by counting the total bacteria and total fungi after incubation of the rice wrapped in plastic for 2 and 5 days. The results showed that porang fermented flour did not have antibacterial activity. The total colony of bacteria and fungi of biodegradable plastics wrapped rice were lower than synthetic plastic. The biodegradable plastics from porang fermented flour (BPPFF) were faster degradation than synthetic plastics and D2 showed the fastest among them.
Predicting water quality in tin mining using the free drainage column leach test
Authors: Andini D E , Irvani  , Henri  , Susilo N B , Widodo P , Lovina R V 
Published: December 2024

Abstract
The potential for acid mine drainage formation can be predicted by an understanding of the geochemical characteristics of the rocks in question, which in turn informs the planning of effective mine water management techniques. This approach represents an effective method for the prevention of acid mine drainage formation or the control of its movement. In order to ascertain the initial characteristics, leachate water quality modelling was conducted using samples obtained from the tin mining front, which represents the area of exploration and exploitation. Leachate water quality testing is conducted using the Free Draining Column Leach (FDCL) method. The samples were subjected to a wet cycle and a dry cycle, comprising daily cycles. The test results indicated an average pH range of 5 to 6, with a relatively moderate TDS content. In some samples, clay minerals (kaolinite) were present, suggesting that acidity can be neutralised indirectly by these minerals, which are derived from pit walls and outcrops at the tin mining site.
Gender inequality and local patriarchy in the mine industry of Bangka Island
Authors: Hidayat N , Fienda T E , Septia R , Anggraeni D 
Published: December 2024

Abstract
Unconventional mining (TI) has exerted a considerable influence on Bangka Island. A group or individual with minimal resources has been engaged in non-traditional tin mining methods. Primarily, it pertains to artisanal and small-scale mining (ASM), which involves little or basic equipment and low technology but relies heavily on manual labor. We examine the gender perspective in relation to tin mining, a topic that has received limited attention in previous studies. Initially, the primary objective is to examine the concept of gender and the issue of gender inequality at the mining site in Bangka. This study specifically examines the challenges and actual conditions faced by female workers in mining sites. Experiencing unjust treatment, individuals often feel uncomfortable but choose to disregard it as an issue, with many accepting inequity as an inherent aspect of the workplace. Furthermore, they are simultaneously engaged in domestic responsibilities such as nourishing their children, maintaining the cleanliness of the household, tending to the needs of their unwell children, and other maternal duties, all while working at the mining site.
Championing change: enhancing the green knowledge and skill capacities of tobacco farm workers for climate change adaptation and eco-management
Authors: Irawan N C , Mahananto  , Suswadi  , Irianto H , Santoso A B 
Published: December 2024

Abstract
Many tobacco farm workers struggle with limited knowledge of sustainable farming practices, making adopting eco-friendly methods difficult. This lack of awareness leaves them relying on outdated techniques, harming their livelihoods and the environment. Research highlights these challenges, stressing the need for better education and training to empower workers to increase the capabilities and skills of tobacco farm workers to manage land more sustainably. By improving their green knowledge and skills, tobacco farmers can become leaders in climate adaptation and ecological stewardship, ensuring a healthier future for themselves and the planet. The study examines these crucial areas to understand the hurdles, opportunities, and routes for enabling tobacco farm workers to become more ecologically responsible and resilient to climate change and other sustainability issues. The goal is to find ways to improve tobacco farm workers’ lives and protect their ecosystems. This study used mixed methodologies, including quantitative, qualitative, and descriptive methods. It occurred in Central Java’s Gatak District, Sukoharjo Regency. A simple random sample with 75 participants was selected as the respondents. Survey data will be analyzed using frequency counts, percentages, and cross-tabulations. According to the study, tobacco farm workers struggle to implement sustainable agricultural methods due to lacking knowledge, information, and motivation. Education and training initiatives have also improved workers’ productivity, income, and efficiency by teaching them about natural resource conservation, integrated pest management, and sustainable farming. The training helped tobacco farm workers choose climate-resilient crop varieties, adopt eco-friendly methods, and manage agricultural waste sustainably.
The role of civic engagement in post-mining environmental revitalization
Authors: Suntara R A , Darwance  , Satrio N , Hijran M 
Published: December 2024

Abstract
The large tin potential in the Bangka Belitung Islands has an impact on the high level of mining activity that has been carried out for a long time. The ecological impact of mining activities leaves behind post-mining pits or known as kulong are not properly reclaimed. Large and spacious kulongs are found in Perlang and Nibung Villages, Central Bangka Regency. This research explains the contribution of local community towards tourism awareness groups “Pokdarwis” and village-owned enterprises “Bumdes” in revitalizing post-mining sites to become tourist destinations known as Lake Pading and Lake Kaolin. Designed as a qualitative-descriptive approach, the data collection was carried out through observation, interviews and document study. Research findings show that the revitalization of post-mining pit areas, specifically at Lake Pading and Lake Kaolin by Pokdarwis and Bumdes has had a significant impact on the escalation of environmental and tourism use values. Efforts to increase tourism are also a means of sustainable environmental preservation and preventing damage from illegal mining activities. Community participation in revitalizing and preserving the environment reflects principles that are in accordance with the concept of Civic Engagement.
Criteria and sub-criteria for selecting solid waste processing technology through literature review
Authors: Sukma N M W , Marleni N N N , Ahmad J S M 
Published: December 2024

Abstract
The increase in population, urbanization, and alterations in lifestyle have led to a significant increment in waste production. Despite the significant increase, waste management in certain regions largely depends on the collect-transport-dispose system, which substantially impacts the land requirements for final disposal sites. One potential solution to this problem is supplanting landfills with technology-based management system at integrated treatment sites. In this context, diverse geographical conditions and perplexing criteria have been reported to affect the identification of the most suitable system. Therefore, this study aims to explore criteria and sub-criteria used for selecting waste processing technology using the Systematic Literature Review (SLR) method. The results showed that there were 5 crucial factors affecting the choice of technology at integrated waste treatment facilities, including economic, environmental, sociocultural, technical, and institutional. Criteria used for establishing sub-criteria for the selection process were derived from a time series covering 2014 to 2024, geographical regions grouped by continent, and economic situations classified as either Global North or Global South.
Laying Out Pages
Authors: Panchekha Pavel , Harrelson Chris 
Published: December 2024

Abstract
So far, layout has been a linear process that handles open tags and close tags independently. But web pages are trees, and look like them: borders and backgrounds visually nest inside one another. To support that, this chapter switches to tree-based layout, where the tree of elements is transformed into a tree of layout objects before drawing. In the process, we’ll make web pages more colorful with backgrounds.