bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistic Study of Particulate Matter Air Contamination in the City of Vidin, Bulgaria
Authors: Minkova Irina , Zheleva Ivanka , Filipova Margaritka 
Published: December 2023

Abstract
In the EU there are many regulations for monitoring the air contamination, for different norms of the air pollutants and aims for improving the air quality. Bulgaria as a member of the European Union has to comply with all these regulations.This paper deals with PM air contamination in the city of Vidin, Bulgaria. Vidin is located in northwestern Bulgaria, on the south bank of the river Danube. On the other side of the Danube is the town of Calafat, Romania. In Vidin during the winter periods of the years there are PM, sulfur and carbon dioxides air pollution greater than accepted norms. Due to the lack of central heating, the population uses mainly solid fuels for heating both in the domestic and in the public sectors. In Vidin there are days with PM10 pollution greater than the daily norm of 50μg/m3. This paper aims to study PM10 air pollution in the city of Vidin, Bulgaria for the period 2012 – 2022.
Orthonormal eigenfunction expansions for sixth-order boundary value problems
Authors: Papanicolaou N C , Christov I C 
Published: December 2023

Abstract
Sixth-order boundary value problems (BVPs) arise in thin-film flows with a surface that has elastic bending resistance. To solve such problems, we first derive a complete set of odd and even orthonormal eigenfunctions — resembling trigonometric sines and cosines, as well as the so-called “beam” functions. These functions intrinsically satisfy boundary conditions (BCs) of relevance to thin-film flows, since they are the solutions of a self-adjoint sixth-order Sturm–Liouville BVP with the same BCs. Next, we propose a Galerkin spectral approach for sixth-order problems; namely the sought function as well as all its derivatives and terms appearing in the differential equation are expanded into an infinite series with respect to the derived complete orthonormal (CON) set of eigenfunctions. The unknown coefficients in the series expansion are determined by solving the algebraic system derived by taking successive inner products with each member of the CON set of eigenfunctions. The proposed method and its convergence are demonstrated by solving two model sixth-order BVPs.
Mathematical and computer modelling of age-related changes of basic anthropometric and mass-inertial characteristics of Bulgarian females
Authors: Nikolova G , Dantchev D , Tsveov M , Kotev V 
Published: December 2023

Abstract
We study the age changes of the anthropometric as well as of the mass-inertial characteristics (MIC) of Bulgarian women aged 18-25 versus those aged 30-40. We do that via mathematical modelling of the human body (HB). Nowadays mathematical modelling is one of the modern methods for the determination of the MIC of different segments of the body, as well as of the whole body, and for studying the changes of the inertial characteristics during a specific motion of the considered person. The current work presents a 3D mathematical model (MM) of the HB, that is also generated in a computer environment. Both the model and its computer generation allow for the calculation of the MIC of all segments of the body, as well as for the whole HB in specific body positions. We consider such body postures which are presented in the corresponding classification of astronauts’ standard positions of interest for NASA. The obtained results are compared with those reported in the literature by other authors. The proposed models shall be also helpful in problems appearing in medicine (orthopaedics and traumatology), computer simulations, rehabilitation robotics, and sports, as well as in areas such as ergonomics, simulation of human behaviour in space, forensics (body fall, car crash) and more.
Reconstruction of time-dependent right-hand side in parabolic equations on disjoint domains
Authors: Koleva Miglena N. , Vulkov Lubin G. 
Published: December 2023

Abstract
We study inverse problems of reconstructing the time-dependent right-hand side from point observation in a one dimensional parabolic equation on disjoint intervals. These problems are ill-possed, i.e. very slight errors in the additional input may cause relatively significant errors in the output of the left and right internal right-hand side. In this work, we construct computational algorithms, using the loaded equation method. First, we perform a decomposition with respect to the unknown source of the inverse problem solutions. Then the inverse problems are reduced to a loaded parabolic equation problems. The well-posedness of the inverse problems is studied on the base of loaded equation ones. The numerical performance of the approach is realized by finite difference schemes, solved with decomposition algorithms. Computational experiments show the efficiency of the method.
Air Pollution Modeling of UNI-DEM Model by using Innovative Stochastic Approaches
Authors: Todorov Venelin , Georgiev Slavi , Dimov Ivan 
Published: December 2023

Abstract
In this paper we develop advanced multidimensional sensitivity analysis, based on some innovative stochastic approaches for performing air pollution modelling on a large-scale model of long-range transport of air pollutants. The Unified Danish Eulerian Model (UNI-DEM) is a very important mathematical model, and can be applied in many different studies related to damaging effects caused by high air pollution levels. We shall use it in this paper to get a reliable answer to a some very important questions regrading environmental protection. We develop some advanced Monte Carlo and quasi-Monte Carlo methods, based on special lattice and digital sequences. In this paper we will improve the digital ecosystem modeling by improving the existence stochastic approaches. The computational efficiency (in terms of relative error and computational time) of the advanced Monte Carlo algorithms for multidimensional numerical integration has been studied to analyze the sensitivity of UNI-DEM model output to variation of input emissions of the anthropogenic pollutants and of rates of several chemical reactions. The algorithms will be applied to compute global Sobol sensitivity measures corresponding to the influence of several input parameters on the concentrations of important air pollutants. The study will be done for the areas of several European cities with different geographical locations.
Development of linear power operational amplifier power supply with pre-regulated voltage controller for TPS correction magnets
Authors: Wang Baosheng , Liu Kuobin , Wong Yongseng 
Published: December 2023

Abstract
The Taiwan Photon Source (TPS) is a renowned 3 GeV
synchrotron accelerator light source. Over the past decade of
successful operation, it has demonstrated outstanding performance,
notably in average beam trip downtime, meeting international
standards. A continuous regimen of scheduled equipment upgrades has
been maintained across all subsystems to ensure ongoing improvement
and the preservation of an optimal research facility
environment. The central focus of this study revolves around the
design and realization of a TPS correction magnet power supply
employing Linear Power Operational Amplifiers (LPOA) in conjunction
with a pre-regulated voltage controller. The power source
predominantly features APEX Corporation's PA05 LPOA, characterized
by bipolar output, high internal power dissipation, and wide
bandwidth. Additionally, a DC Current Transducer (DCCT) was employed
as the current feedback element, integrated with the pre-regulator
voltage controller to form a closed-loop current modulation circuit,
providing the variable voltage required by the LPOA. Through these
measures, we have successfully developed an LPOA power supply unit
equipped with a pre-regulated voltage controller for TPS correction
magnets. The prototype device boasts a maximum output current of
±10 A, operating at 24 V. Validation through control loop
design has led to rapid and stable output current performance. The
output current ripple is maintained within 100 μA, with a
rise time of 75 μs during step response. During frequency
response testing utilizing a 0.1 V disturbance signal, the gain
margin resides within -3 dB at an 11.2 kHz bandwidth and the
phase margin within -45∘ at a 5.1 kHz range. Long-term
output current stability is sustained within ten ppm. Finally, a
hardware prototype circuit has been constructed in the power supply
laboratory, featuring a ±24 V input voltage and ±10 A
output current, achieving a maximum rated power of 240 W.
Microplastic Contaminant in Indonesia: A review on Debris, Exposure, Health Risk and Future Perspective
Authors: Pramaningsih V , Isworo S , Purwanto A D , Kurniawan D 
Published: December 2023

Abstract
Microplastics are growing environmental concern, posing risks to both ecosystem and human health, especially in marine environments. Purpose this review is studied debris, exposure, health risk and future perspective of microplastic contaminant in Indonesia. This review method is collects the studied from google scholar, with publisher: ScienceDirect, Elsevier, Springer, Frontiers, MDPI, IOP Conference, Nature, Taylor & Francis. Keyword was used microplastic, debris, environmental exposure, health risk, Indonesia. Result finds the kind of microplastic debris are Fragment, Fiber, Granule, Film, Foam and Filament. Microplastic exposure the water organism including fish, shellfish, seabirds, table salt, snail and crab. It has an impact on human health when people consume seafood that contains microplastics through the food chain. Human exposure to microplastics occurs through various routes, including ingestion of contaminated food and water, inhalation of airborne particles, and dermal contact. Health risk indicate that microplastics can accumulate in the gastrointestinal tract, potentially leading to inflammation, disruption of gut microbiota, and even the release of hazardous chemicals. The future perspective is needed continued research, monitoring, and policy measures are necessary to effectively mitigate microplastic pollution in Indonesia and safeguard its ecosystems and public health. Overalls, it needs solid waste management and use degradable plastics.
Traders’ motivation in business development-based coastal forest ecotourism : a case study of small islands in the City Of Bandar Lampung
Authors: Harianto Sugeng Prayitno , Arioen Refi , Tsani Machya Kartika , Zuhelmi Tomy Pratama , Surnayanti  
Published: December 2023

Abstract
Small island ecotourism is available in three regencies in Lampung Bay, one of them located in Bandar Lampung City, which has two coastal forest ecotourism areas, notably Pasaran Island and Permata Island. These two islands have quite distinct characteristics. Pasaran Island combines the beauty of the sea with marine products attraction. Permata Island attraction lies in the beauty of the sea and local wisdom stories. Traders that conduct business in Pasaran Island and Permata Island have different motivation and efforts. The goal of this research was to investigate traders’ motives and efforts in business development based on coastal forest ecotourism. Data collection techniques were carried out using in-depth interviews and observation and then evaluated using a qualitative descriptive method. The findings revealed that intrinsic and extrinsic motivation influenced the motivation of Pasaran Island and Permata Island traders in running their ecotourism business. Traders’ efforts to improve ecotourism on Pasaran Island are reflected through environmental stewardship, such as processing marine product away from communities and ecotourism objects to avoid air pollution in the coastal forest ecotourism region. In contrast to the Permata Island traders, who lay a greater emphasis on environmental purity and comfort in the ecotourism sector.
Study of diameter and height increment of Nipa (Nypa fruticans) fronds for the sustainability of mangrove forests management in Pagar Batu Island, Mahakam River Estuary, East Kalimantan
Authors: Herlambang H , Siswanto H , Sianturi N , Rastika W 
Published: December 2023

Abstract
Nipa (Nypa fruticans) is a type of plant that lives in many mangrove forests. The potential of nipa palm has been used as a source of income for the community, such as through the production of nipa plants and their fronds. However, harvesting carried out by the community has the potential to cause damage to nipa palm forests. This research aims to determine the increase in height and diameter of nipa palm fronds until they are ready to be harvested and to ensure that nipa palm harvesting is in accordance with the principles of desire. Sampling was carried out randomly on 30 palm clumps, and diameter and height measurements were carried out repeatedly every ten days for 40 days. The results showed that the average increase in front height was 16.71 cm per day, and the average increase in diameter was 0.18 cm per day. After 40 days of age, the front diameter reaches an average of 7.5 cm and a height of 6.7 m, making it suitable for harvesting in accordance with the principles of sustainable forest management.
Management of the Lati Petangis grand forest park (TAHURA): roles and perceptions of forest farmer groups
Authors: Firdaus  , Nursakinah  
Published: December 2023

Abstract
This research aims to identify and descriptively analyze the roles and perceptions of Forest Farmers Groups in the management of Tahura Lati Petangis in Batu Engau District, Paser Regency. This research uses a quantitative descriptive approach. The sample in this study consisted of all members of the three Forest Farmers Groups located around the Tahura Lati Petangis area, totaling 52 people. The results showed that the role of the Forest Farmer Group, which is a partner in the management of Tahura Lati Petangis, is to make efforts to restore the ecosystem and make efforts to manage forests sustainably in the form of Agroforestry, where partnerships with forest farmer groups are carried out in the form of work orders. While the perception of the Forest Farmer Group in the management of Tahura Lati Petangis shows that this partnership is very beneficial for forest farmer groups, they also get insight, skills, and wages from the Tahura Lati Petangis management, because they have planted and maintained the main plant, namely forest plants, and besides that, they also get additional income from planting intercrops and coaching from the Tahura Lati Petangis management.
Water sustainability in the Anthropocene: challenges and solutions for a changing world
Authors: Annisa C N , Purwanti E , Setiawati  , Sardjono M A 
Published: December 2023

Abstract
Water plays a crucial role in the sustainable development, impacting socio-economic development, environmental health, and human survival. As a common property, effective water management through good governance is essential to accommodate various interests and minimise conflict. The study discussed the global water resources in the era of human domination, highlighting the increasing water scarcity and its implications. It explored the multifaceted roles of water in society, encompassing economic, leisure, political and religious aspects through summarising and analysing the literatures. Results showed that the current global context presents challenges to water availability and quality due to population growth, rising living standards, climate change, and mismanagement. It also acknowledged the recognition of water access as a human right and discussed the progress and remaining challenges in achieving universal access to clean water and sanitation. The paper emphasizes the need for improved water governance to address these challenges and ensure equitable access to water resources. Integrated Water Resource Management (IWRM) was proposed as the popular solution for interdisciplinary and multi-interest water management to ensure sustainable water use, equitable access, and environmental conservation.
Micro spatial planning approach for effective peat restoration concept in Kahayan-Sebangau Rivers Peat Hydrological Units
Authors: Ilona Merty , Lautt Bambang Supriyono , Usup Aswin , Wibowo Agung , Yulianto Santosa 
Published: December 2023

Abstract
Peatland ecosystems play a pivotal role in supporting a diverse array of organisms and offer multiple benefits, encompassing functions as habitats, food sources, regulators of water systems, contributors to biodiversity, and carbon storage. Nevertheless, the degradation of peat can yield substantial consequences, including forest fires and floods. Although government regulations predominantly emphasize peat management on a larger scale, there is a noticeable absence of guidance for planning at meso and micro levels. The objective of this research is to bridge this gap by introducing a micro-scale planning approach for peat restoration. The methodology involves employing spatial analysis to create a micro Peat Hydrological Unit model. Official spatial data from various sources is meticulously processed using Geographic Information System (GIS) and categorized based on multiple factors, including elevation, depth, land cover, ecosystem function, hydrological network, and land management authority. The findings reveal the existence of 44 KHG micro-units, encompassing a total of 523 characteristics and covering an area of 451,081.54 hectares. Furthermore, the study identifies areas with varying levels of damage, with 938.33 hectares experiencing heavy damage, 95,657.21 hectares reflecting moderate damage, and 91,901.94 hectares showing light damage. Drawing on extensive experience in peatland management, the research presents strategic approach to enhance the effectiveness of peat restoration efforts.
Floristic composition of the local family forest in Panarung Village, a subdistrict of Bentian Besar, West Kutai Regency, East Kalimantan, Indonesia
Authors: Matius P , Phambudi F , Aryanto  , Harmonis  , Arifin Z , Ruslim Y 
Published: December 2023

Abstract
Ulin (Eusideroxylon zwageri T et B.) is a unique tree species in Kalimantan because its most durable wood and only grows in mixed lowland dipterocarp forest habitat. The purpose of this study is to examine the floristic composition, variety, and structure of the mixed ulin forest in Penarung village, subdistrict of Bentian Besar, West Kutai Regency, East Kalimantan. Each sample plot was rectangular and was 125 m by 20 m in size. For the tree stage, each sample plot was divided into subplots that measured 25 m by 20 m. Each subplot measured 2 m by 2 m for seedlings, thickets, and herbs and 5 m by 5 m for saplings The Result showed the species richness was 196 species, which consisted of 147 tree species, 16 species of lianas, 13 species of herbs, 12 species of shrubs, 5 species of ferns, 2 species of rattan and 1 species of palm. The tree stage consisted of 97 species, 70 genera, and 36 families. Species diversity (H’), showed that tree and sapling stages were high 3.82 for tree and 3.92 for sapling stages, while seedlings in moderate, with H’= 2.49. Evenness (E) in the tree stage was 0.83, while sapling and seedling were 0.87 and 0.55 respectively. This forest contained 28 species of endemic, 2 species of critically endangered (CR), 2 species endangered (EN), and 10 species of vulnerable (Vu).
Cavity-nesting birds in the forest patch around urban areas: A case study in Bogor, Indonesia
Authors: Adi Nugroho Septian Putra , Mardiastuti Ani , Mulyani Yeni Aryati , Rahman Dede Aulia 
Published: December 2023

Abstract
Cavity-nesting birds lay eggs and raise chicks within their nest inside the cavities. The existence of cavity-nesting birds in nature has important ecological roles. This study aimed to identify and analyze cavity-nesting bird species in the tropical lowland forest patches, particularly in Bogor, West Java Province, Indonesia. The study was conducted in the forested area within the Dramaga Experimental Forest and the Dramaga Campus of IPB University. The cavity-nesting bird species were observed during September – December 2020 and September – December 2021. Each cavity-nesters observed was classified based on how to make and utilize the nesting site (i.e., primary excavator, facultative excavator, non-excavator) and their nest locations (i.e., nesting in the trees or other locations). We observed 12 cavity-nesters in the study area, consisting of 4 primary excavators, 2 facultative excavators, 3 non-excavators in the trees, and 3 non-excavators in the riverbanks. Cavity-nesting bird richness in the Dramaga Campus (12 species) was higher than in the Dramaga Experimental Forest (9 species). This study revealed that the two study areas still provide suitable habitats for cavity-nesting birds. Therefore, it is essential to maintain the presence of cavity-nesting birds and their habitat by initiating conservation efforts, such as habitat management, strengthening conservation actions and policies, and increasing public awareness.
Exploring The Secondary Metabolites and Antioxidant Potential of Litsea elliptica Leaf Extract
Authors: Mala M S , Larasati A G , Putri A S , Kuspradini H 
Published: December 2023

Abstract
Litsea is the largest genus in the Lauraceae family that is widely distributed in Kalimantan and contains natural antioxidants that have an essential role in the health of the human body. This study aims to identify the secondary metabolites of Litsea elliptica leaf extract and determine the antioxidant activity of different-size leaf extracts from L. elliptica. This research was conducted with qualitative phytochemical analysis and an antioxidant test, which was carried out using the DPPH method (2,2-diphenyl-1-picrylhydrazyl) at concentrations of 100, 50, 25, 12.5, and 6.25 ppm. The positive control used in this study wa vitamin C (ascorbic acid). The result of qualitative phytochemical analysis of all different-size leaf extracts showed that the extract contained alkaloids, flavonoids, tannins, carbohydrates, and carotenoids. The highest antioxidant activity was found in the largest-sized (17.9 cm) leaf extract of L. elliptica, with a percentage of 57.4%. Meanwhile, the lowest antioxidant activity (19.5%) was found in the smallest-sized (7.1 cm) leaf extract. The results show that L. elliptica leaf extract could be a source of natural antioxidants.
Characteristics of Wood Fossils From Bengkinang Village Kutai Kartanegara Regency
Authors: Husien N , Aryanto A , Erwin  , Budi AS 
Published: December 2023

Abstract
Fossil wood is petrified wood in which all the organic material has been replaced by minerals (silica and a type of quartz), while preserving the structure of the wood. The purpose of this study was to determine the macroscopic characteristics of wood fossils in general, including their specific gravity, hardness, color, and anatomical features. This research encompassed a survey of fossil discovery locations, the creation of macroscopic wood fossil samples, observation of their macroscopic characteristics, and the measurement of wood hardness as well as the calculation of wood fossil density. The results revealed that the characteristics of the surface cross-section of the fossil samples were dominated by light brown, dark brown, and whitish gray colors. The macro characteristics of the samples exhibited a typical hardwood plant cell structure, characterized by vessels (pores). Unlike previously discovered wood fossils in this area, the wood fossil has axial intercellular canals. The recorded hardness value on the Mohs scale was 5, and the density was measured at 2.7.