bluuebunny/crossref_metadata_2025_split huggingface dataset:
Histosol soil respiration rate study: measurement and implications in Humbang Hasundutan Regency
Authors: Manalu Sarah Patumona , Sari Yasmine Anggia , Nadhira Ade Citra 
Published: February 2025

Abstract
Histosol soil is a type of marginal soil that has low plant productivity characteristics and can occur due to low soil fertility levels. The level of soil fertility is affected by the activity of microorganisms, organic matter, and nutrient content in the soil. The soil respiration rate can be seen through the activity of microorganisms which release CO2 content into the atmosphere. This study aims to analyze the soil respiration content of histosol in Lintong Nihuta District, Dolok Sanggul District, Pollung District, Humbang Hasundutan Regency, North Sumatra Province. The soil respiration content was tested in the Laboratory of Soil Chemistry and Biology, Agrotechnology Study Program, Faculty of Agriculture, Universitas Sumatera Utara. The results of this study showed that the soil respiration content in histosol soil samples from Lintong Nihuta1, Lintong Nihuta2, Dolok Sanggul Location 11, Dolok Sanggul Location 12, Dolok Sanggul Location 21, Dolok Sanggul Location 22, Pollung1, and Pollung2 respectively 1.371 mgCO2/day, 2.057 mgCO2/day, 8.571 mgCO2/day, 8.228 mgCO2/day, 7.542 mgCO2/day, 7.200 mgCO2/day, 6.857 mgCO2/day, 8.228 mgCO2/day.
Extraction of tannin from guava leaves (Psidium Guajava L) by soxhletation method and application as iron corrosion inhibitor in sea water medium
Authors: Manurung Renita , Simanungkalit Y , Amelia F 
Published: February 2025

Abstract
Research on inhibitors is currently focused on organic types, as they are environmentally friendly and abundant in nature. One organic compound that plays a role in corrosion prevention is tannin. The ability of tannins to prevent corrosion naturally has been known for a long time, but systematic research has only been carried out in recent decades. Guava leaf (Psidium Guava L.) is one of the sources of tannins that are available in nature. This study aims to determine the ability of guava leaves as a corrosion inhibitor in the form of concentrated extracts, and tannins. The extraction of tannin compounds in guava leaves was carried out using the succulent method and using a sample-to-solvent ratio of 1:25 g/mL, 1:30 g/mL, 1:35 g/mL, and 1:40 g/mL. The powder size used as an inhibitor is 50 mesh. The concentration of inhibitor used was 1% with a variation of soaking time of 1 day, 2 days, 3 days, and 4 days. Tannin content was determined by UV-Vis spectrophotometry. The parameters measured in the corrosion test were corrosion rate and inhibition efficiency. The method of measuring corrosion rate is iron weight reduction. The results showed that the highest tannin content was obtained at 1.253% in the extraction variation of 1:25 g/mL. In the corrosion testing of the three types of inhibitors, the lowest corrosion rate was obtained for the tannin inhibitor with an extraction variation of 1:25 g/mL with a rate of 41.723 mpy, as well as the highest efficiency occurred with the same inhibitor with an efficiency value of 76.328%.
Urban digitalization through clean energy: policies and communication of Medan City government towards “Medan Smart City”
Authors: Purba Arief Marizki , Dirbawanto Nana Dyki , Dalimunthe Maulana Andinata 
Published: February 2025

Abstract
This article examines the process of urban digitalization through clean energy in Medan City as part of the effort to realize Medan Smart City. The urgency of this research lies in the increasing need for smart and sustainable city infrastructure, especially in addressing air pollution and public service efficiency. The main problem identified is the need for more awareness and participation of the community in supporting clean energy and digitalization initiatives. The research methodology used a qualitative approach with in-depth interviews as the main data collection technique. Primary data were obtained from government officials, renewable energy experts, and information technology practitioners, while secondary data were obtained from official reports and related literature. Data analysis was conducted through triangulation techniques to ensure data validity and reliability. Data validity testing involved cross-checking information from various sources and validation by experts in related fields. The results show that the application of Information and Communication Technology (ICT) in public services in Medan has improved operational efficiency and service accessibility. The use of renewable energy, such as solar panels and wind power generation, has contributed to the reduction of carbon emissions and operational costs. However, challenges such as lack of public awareness and technical barriers still exist. The Medan City Government has established regulations to support the implementation of clean energy and digitalization policies, including incentives for renewable energy use and ICT infrastructure development. Cross-sector collaboration and effective public communication are considered essential to increase community participation and the success of this initiative.
Identification of fungi in Avicennia marina leaf litter decomposition in the estuary of the Deli River, Belawan District
Authors: Yunasfi  , Purba Jhon Ganda , Sembiring Sephia , Sihotang Vinacia Mia S. , Sitepu Gloury Arizona , Lubis Sri Rusmayanti 
Published: February 2025

Abstract
Through decomposition, mangrove litter contributes organic material to the ecosystem of mangroves. This decomposition creates a nutrient cycle in the ecosystem. This study’s goal was to ascertain the rate of decomposition of A. marina litter, identify the species fungus discovered in the leaf litter of A. marina that being decomposed, and determine the levels of carbohydrates and proteins detected in the leaf litter of A. marinaduring the process of decomposition. The findings indicated that five different species of fungi were discovered during the decomposition of A. marina leaf litter, including Aspergillus niger, Aspergillus fumigatus, Aspergillus sp.1, Aspergillus sp.2, and Rhizopus sp. The average value of fungal diversity in the decomposition of A. marina leaf litter was included in the medium category, namely 1.52. The decomposition rate value obtained Leaf litter from A. marina is 10.81/year. Measurement of carbohydrate and protein levels in A. marinaleaf litter showed a decrease in carbohydrate and protein along with the increase in litter decomposition time.
Reproductive biology of Silver Whiting fish (Sillago sihama) landed at the Bagan Deli Fish Landed Site (TPI) Belawan North Sumatra Province
Authors: Hasibuan Julia Syahrani , Nasution Aisyah Canda , Manurung Vindy Rilani , Desrita  
Published: February 2025

Abstract
Silver Whiting Fish (Sillago sihama) is one of the demersal fish which is included in the main catch of fishermen in the waters of the Malacca Strait. This research aims to determine the reproductive biology of silver whiting fish (S. sihama) which was landed at TPI Bagan Deli Belawan, North Sumatra. This research was carried out in Oktober–Desember 2023. The number of fish samples during the research was 207 with a total length between 112-196 and a total weight between 13-56 grams. The growth pattern of silver whiting fish is negative allometric with a less flat condition factor value in the range of 0.58–1.45. Silver Whiting Fish reproduction shows an unbalanced sex ratio of 1:2, but the stock in these waters is still considered ideal. The level of fish gonad maturity is at GML I-IV with the GSI value as the GML increases. Egg fecundity ranges from 18,642-45,276 with classified as a partial spawner.
Diversity of waterbird species in the Sicanang Belawan mangrove ecotourism area
Authors: Abdillah Nasution Ahmad Luthfi , Jumilawaty Erni , Wahyuningsih Hesti 
Published: February 2025

Abstract
Waterbirds are a group of birds highly dependent on wetlands, aquaculture ponds, mudflats, mangroves, and coastal areas. The Sicanang Mangrove Ecotourism Area serves as one of the habitats for these waterbirds. However, currently the condition of the mangroves in the Sicanang Mangrove Ecotourism Area has declined, affecting the wildlife inhabiting the area, including waterbirds. Waterbird surveys were conducted at two distinct locations: Bird Island and the industrial area, which differ in landscape characteristics. The Block Method and Point Count techniques were employed to collect data, followed by the calculation of the diversity index (H’) and evenness index (EH
). The waterbird species found at Bird Island consisted of 6 species with a total of 824 individuals, while in the industrial area, 4 species were recorded with a total of 48 individuals, the most commonly found species was the Great Egret (Egretta alba). The diversity index values at Bird Island and the industrial area were 1.48 and 1.25, respectively, indicating moderate species diversity. Evenness index values for the two sites were 0.82 and 0.9, respectively, reflecting high species evenness. The waterbird diversity index in the Sicanang Mangrove Ecotourism area is moderate, indicating the need for habitat conservation to protect the wildlife that live in and depend on this habitat.
Diversity of aquatic insects at the abandoned marble mining site in Leang Leang Village, Maros Regency, South Sulawesi, Indonesia
Authors: Sadapotto Andi , Amada Hardiansyah Yusty , Budiaman  
Published: February 2025

Abstract
The abandoned marble mining site in Leang Leang Village, Maros Regency, has been neglected since 2019. The area has since been filled with rainwater, forming a water body utilized by the surrounding community as a water reserve during the dry season. Marble mining generates waste in the form of marble dust that can pollute water bodies. Aquatic insects are organisms that can be used to determine water pollution levels. This research aims to assess the diversity of aquatic insects and evaluate water quality based on aquatic insect families as bioindicators. Aquatic insect samples collected were identified and analyzed. Diversity, richness, and water quality observations were conducted using the Shannon-Wiener index (H’) and Hilsenhoff Family Biotic Index (HFBI) methods. The aquatic insect diversity index at the abandoned marble mining site in Leang Leang recorded a value of 1.03 (moderate category). The richness index scored 0.52, categorizing it as low. Based on the HFBI classification, water quality at the abandoned marble mining site in Leang Leang falls under the very poor category.
Natural resource management through digital transformation supporting forestry innovation 4.0 in North Sumatra
Authors: Eriza Faisal , Nasution Nabila Fahira , Thamrin Muhammad Husni 
Published: February 2025

Abstract
This research investigates the impact of digital transformation on natural resource management, focusing on forestry innovation 4.0 in North Sumatra Province, Indonesia. Despite challenges such as limited public awareness and technological infrastructure, the Indonesian government has emphasized digitalization through initiatives like Presidential Regulation 82 of 2023, promoting digital transformation across services, including natural resource management. The study employs a literature review approach, analyzing peer-reviewed journals, government reports, and policy documents to explore integrating digital technologies such as Geographic Information Systems (GIS), IoT, and AI in forestry management. Findings highlight how digitalization enhances operational efficiency, transparency, and environmental sustainability by enabling real-time monitoring, data-driven decision-making, and community engagement. Case studies from North Sumatra Province illustrate the implementation of digital applications like SIPUHH, SIMPONI, SIMBA and SILK, which optimize forest management and public service delivery. Key challenges identified include improved data accuracy, workforce training in technology, and enhanced cross-sector coordination. Recommendations include infrastructure development, capacity building, and fostering public awareness to maximize the benefits of digital transformation. Ultimately, this research provides insights for policymakers and stakeholders to strengthen digitalization strategies, supporting forestry innovation 4.0 and sustainable natural resource management in North Sumatra Province and beyond.
Koi varieties identification based zero parameter simple linear iterative clustering and support vector machine
Authors: Setiawan Alexander , Sapphira Amadea , Setyati Endang 
Published: February 2025

Abstract
There’s currently 120 types of koi fish that has been bred around the world. The types of koi fish depend on the colour patterns and shapes they have. There’s alot of patterns that has similarity between one type with another. For example, sanke and showa koi fish will look similar from a non-expert’s point of view, because both type has same colour pattern, which is red, black and white. In actuality, sanke koi is dominantly red and white with slight black accent, while showa’s dominant colour is red and black, with white accent. In this research, Zero Parameter Simple Linear Iterative Clustering (SLICO) method and Simple Linear Iterative Clustering (SLIC) will be tested and used to process the image segmentation process to eliminate the background of the image. Colour Local Binary Pattern method is used to get the textures on images through the RGB, HSV, and grayscale colour space. Support Vector Machine is used to identify types of koi fish. To test the SVM, two kind of kernel is used, which is linear kernel and Radial Basis Function (RBF) kernel. The results of this study are the program able to recognize types of koi from images. The test results show an accuracy of 36% in grayscale colour space, 50% in RGB colour space, and 48% in HSV colour space.
Diffractive elements with multi-ring spectra
Authors: Rasouli Saifollah , Hebri Davud , Narimani Seyed Mohammad Hasan , Ponomarenko Sergey A 
Published: February 2025

Abstract
We introduce pure amplitude almost periodic structures (APSs) with multi-ring spatial spectra, characterized by four degrees of freedom in the spectral domain: the number of rings, the number of impulses on each ring, the radius of each ring, and the angular positions of the impulses within a ring. A comprehensive mathematical framework is developed to describe the diffraction of arbitrary optical beams by such structures. This framework is theoretically validated and experimentally verified through the analysis of diffraction patterns produced under Gaussian beam illumination. The method is systematically tested on various APS configurations, including structures with one, two, three, and four rings, as well as different impulse arrangements within these rings, demonstrating its robustness and adaptability. Notably, each APS achieves a high diffraction efficiency, transferring approximately

1

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(
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2
N
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1
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(
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of the transmitted beam power to each impulse, where 2N represents the total number of impulses excluding the zero-diffraction order. This efficiency is significantly superior to that of conventional spatial light modulators. Additionally, a detailed comparison between theoretical predictions and experimental measurements of power ratios for the diffraction orders confirms the accuracy and reliability of our approach. The versatility of APS makes them highly suitable for a range of applications, including optical communications, optical tweezing, multi-particle trapping, screening, micro-manipulation, and microscopy. For example, APS-enhanced Gaussian lattice beams can improve imaging speed in fluorescence microscopy. Furthermore, their ability to enable three-dimensional optical multiple trapping and beam splitting positions APS as a powerful tool for advancing laser and optical research.
Erosion behaviour of micro and nanostructured Cr3C2NiCrBSi coating on IN718 alloy via HVOF processing
Authors: Shankar R , Balasubramanian K R , Sabanayagam S , Rajadurai R 
Published: February 2025

Abstract
Surface degradation of materials due to solid particles (Erosion) in high-temperature environments is a major contributor to wear in applications such as power plants, petrochemical plants, and aeroplane engines. This degradation can result in decreased efficiency, higher maintenance costs, and potential equipment failure. The erosion rate is influenced by a number of variables, including the characteristics of the target material and particle shape, velocity, and angle of impingement. Surface coating, especially HVOF spraying, improves erosion resistance leading to increase the material durability, reducing wear and extending equipment life. The high-temperature erosion behaviour of microstructured and nanostructured HVOF-sprayed Inconel 718 superalloy materials is investigated in an air jet erosion tester. Following the tests, the eroded samples are examined using scanning electron microscopy (SEM), Energy dispersive x-ray spectroscopy (EDX) and x-ray diffraction (XRD) to analyze the effects of erosion. The results indicate that uncoated samples experience higher erosion rates at all impact angles compared to both coated samples. Erosion rates for both microstructured and nanostructured coated samples are higher at a 30° impact angle compared to a 90° angle, indicating a ductile behaviour in response to impact. The lower porosity of the nanostructured coating is believed to enhance its ability to protect the substrate from erodent particles. The Cr3C2NiCrBSi nanostructured coating provides better erosion resistance and effectively protects the surface of the Inconel 718 superalloy.
The influence of defect thickness on defect characterization using pulsed thermography: a numerical study on stainless steel material
Authors: Sharath D , Menaka M , Venkatraman B 
Published: February 2025

Abstract
The combined effect of defect thickness and lateral size on defect characterization in AISI 316 L Stainless Steel material using Pulsed Thermography method is studied numerically. As the defect volume (thickness and lateral width) decreases for the same depth, the magnitude of change in surface temperature decreases, deteriorating the defect visibility. The change in the surface temperature can be related to the apparent reduction in the Reflection Coefficient, R, of the material and defect interface. The finite difference analysis is used to simulate the Pulsed Thermography experiment on steel material. A least-square-based optimization technique is used to estimate the R as a function of defect depth and lateral size to establish a relationship between them. The contrast derivative and log 2nd derivative methods are used for depth quantification. To carry out the defect visibility study, a noise matrix was generated using noise data obtained from an actual IR camera and superimposed on the numerical results to create a dataset that closely resembles actual experimental data. The study concluded that the defect thickness has the least effect on defect visibility and depth quantification if the thickness of the defect is greater than 500 μm for Stainless Steel. This work provides useful insight into the impact of defect volume on the precise measurement of defect depth and its visibility.
dCG—differentiable connected geometries for AI-compatible multi-domain optimization and inverse design
Authors: Luce Alexander , Grünbaum Daniel , Marquardt Florian 
Published: February 2025

Abstract
In the domain of geometry and topology optimization, discovering geometries that optimally satisfy specific problem criteria is a complex challenge in both engineering and scientific research. In this work, we propose a new approach for the creation of multidomain connected geometries that are designed to work with automatic differentiation. We introduce the concept of differentiable connected geometries, discussing its theoretical aspects and illustrating its application through simple toy examples and a more sophisticated photonic optimization task. Since these geometries are built upon the principles of automatic differentiation, they are compatible with existing deep learning frameworks, a feature we demonstrate via the application examples. This methodology provides a systematic way to approach geometric design and optimization in computational fields involving dependent geometries, potentially improving the efficiency and effectiveness of optimization tasks in scientific and engineering applications.
They Do It with Mirrors?
Authors: Clifford Emily 
Published: February 2025

Abstract
This chapter probes the relationship between objects in a material world and concepts in a mental one by studying some Attic pots. It focuses on drinking cups and oil flasks, and the portal that these offer onto visualizations of death in the symposium and beside the grave. The two parts are bound together by several themes. One is a fixation on revelation and concealment of the dead: what is and is not visible? The second is the way in which engaging with the pot and its images generates reflection on death more generally, as an experience that will, at some point, belong to the viewer. The third theme comprises the epistemological meditations that are provoked by a pot’s form.
Deaths Old and New
Authors: Clifford Emily 
Published: February 2025

Abstract
Conversation Two pulls in some comparative material to avoid an overly stark picture of what may or may not be distinctive about the material focused on in the book. It takes a brief look at two Archaic deaths, one verbal, one visual: the death of Hector in Iliad 22.361–3 and the Mykonos pithos, a seventh-century bce storage pot decorated in relief with scenes drawn from the fall of Troy. After considering the similarities and the differences between the encounters offered by each medium, it argues that the picture offered in this book is a culturally specific one: the particularity of the explorations of death that are proposed lie partly in the medium-specific way in which they generate reflection and partly in the degree of epistemological emphasis.
The Extraordinary Death of Sophocles’ Oedipus at Colonus
Authors: Clifford Emily 
Published: February 2025

Abstract
This chapter examines the ways in which dying and death are made mentally present and visible in Greek tragedy. It focuses on Sophocles’ Oedipus at Colonus, opening with a scene in which there is a gear change in expectation when death becomes imminent and a splitting of perspectives as the dying man diverges from the living in knowledge and trajectory. It then discusses the Messenger’s speech, in which an ecphrastic set-up brings ideas of distance to the fore. Finally, it delves into some attributes of Oedipus’ death that put pressure on its potentially exemplary force. To what extent might an audience derive general ideas about what death is and is like from this play?