bluuebunny/crossref_metadata_2025_split huggingface dataset:
До питання побудови математичної моделі гідравлічного мультиплікатора
Authors: Богуславський О.В. , Костюк Д.В. 
Published: December 2023

Мета дослідження – розкриття особливостей роботи гідравлічного мультиплікатора тиску. Побудова математичної моделі, огляд принципових схем, наявних на ринку зразків. Оскільки основною задачею мультиплікатора є підвищення тиску, то при побудові моделі обов’язково необхідно враховувати стискуваність рідини. Іншим фактором, що впливає на ефективність роботи мультиплікатора є швидкодія клапанів, які в ньому застосовуються, та їх характеристики, зокрема коефіцієнт витрати. Наукова новизна полягає в описі існуючих мультиплікаторів, методика опису яких є уніфікованою. Дослідження роботи мультиплікатора в складі гідравлічної системи відбувається за рахунок комп’ютерного математичного моделювання функціонування пристрою в складі гідравлічної системи. Ці дослідження мають прикладне значення в розробці та проектування майбутніх пристроїв.

The purpose of the study is to reveal the features of the hydraulic pressure multiplier. Construction of a mathematical model, review of schematic diagrams available on the market of samples. Since the main task of the multiplier is to increase the pressure, it is necessary to take into account the compressibility of the liquid when the model is built. Another factor that affects the efficiency of the multiplier is the speed of the valves used in it, and their characteristics, in particular the flow rate. The scientific novelty is in the description of existing multipliers, the method of description of which is unified. The study of the multiplier in the hydraulic system is due to computer mathematical modeling of the operation of the device in the hydraulic system. These studies are of practical importance in the development and design of future devices.
Дослідження міцності захисного покриття елементів обшивки пасажирського літака
Authors: Зворикін О. К. , Пискунов С. О. 
Published: December 2023

Під час експлуатація , на обшивку літака постійно діють зовнішні чинники, як природного походження так і пов’язані із дією зовнішніх агресивних середовищ. Найбільш дешевим варіантом захисту обшивки літака є лакофарбові покриття (ЛФП).
Експериментальна перевірка того чи іншого конструкційного рішення в авіабудівній галузі із використанням натурних моделей має велику собівартість. Використання в розрахунках та проектуванні методу скінчених елементів (МСЕ) значно зменшує витрати на випробування, конструювання та проектування, відчутно покращує продуктивність, якість та комфорт в авіаційній галузі.
Основним завданням роботи, що проводиться, є перевірка міцності захисного покриття елементів обшивки пасажирського літаків експериментальними методами із використанням зразків обшивки та розрахунковими засобами спеціалізованого програмного забезпечення для віртуального моделювання процесів деформування під дією зовнішніх впливів - MSC.PATRAN, MSC.NASTRAN, Femap.
During operation, the aircraft skin is constantly exposed to external factors, both of natural origin and associated with the action of external aggressive environments. The cheapest option to protect the aircraft skin is paint.
Experimental verification of a design solution in the aircraft industry using full-scale models has a high cost. The use of the finite element method in calculations and design significantly reduces the costs of testing, design and engineering, significantly improves performance, quality and comfort in the aviation industry.
The main task of this work is to test the strength of the protective coating of the elements of the skin of passenger aircraft by experimental methods using samples of the skin and calculation tools of specialized software for virtual modeling of deformation processes under external influences - MSC.PATRAN, MSC.NASTRAN, Femap.
The Impact of Climate Change on Groundwater and Crop Yield in Asia: A Comprehensive Review
Authors: Santhosh Anandhi , Prabhakaran Sujatha , Veeraswamy Davamani , Srinivasulu Asadi , Lal Alvin , Naidu Ravi 
Published: December 2023

The effect of climate change plays a significant role on groundwater level variations and crop yield. The change in climate leading to increased temperatures, decreased rainfalls and extreme drought conditions ultimately cause low groundwater level and crop yield. Judicious groundwater management technology viz., water recharge options, need based irrigation, crop selection, must be adapted for further increasing the water table level in soil ecosystem. Additionally, climate change impacts combined with changes in agricultural water use can affect groundwater dynamics. Increased irrigation demand and decreased summer precipitation can lower groundwater levels, impacting crop production. Overall, climate change affects both groundwater resources and crop yield highlighting the need for sustainable water management practices and consideration of soil properties in agricultural modelling. The authors carefully selected relevant research articles addressing the impact of climate change on ground water level in Asian countries. The review highlights the use of machine learning method to ground water level and crop yield modelling. According to the study, machine learning techniques have made significant contributions to predicting groundwater level changes and crop yield with higher accuracies, high performance and less running time.
Importance of STEM and STEAM Education for Improvement of the Land in the RURAL Environment: Examples in Latin America
Authors: STARKIE ELISA ISABEL GAVARI , Gutiérrez Patricia-Teresa Espinosa , Baquero Cristina Lucini , Huguet Josep pastrana 
Published: December 2023

Interdisciplinary STEM and STEAM education give us an opportunity for creativity and educational innovation in a world scenario that needs training in which students can achieve all educational objectives and are prepared to achieve sustainable development. The rural environment with its land is a scenario that provides us with a range of educational resources for the development of STEM and STEAM projects in which students who are better trained and prepared for the needs of today&#039;s world are developed, as well as students who are more linked and sensitized to the environment, with the rural environment and its land, so important in our time. In this article, we will collect examples from Latin America; STEM projects are being developed in which young people establish links with their environment, territory, and the local environment surrounding them. We must look carefully at projects and works in which students&#039; ties with their land and environment are valued through the STEM and STEAM education necessary today. In this scenario, a comparison has been made between Latin American countries and Spain.
A Deep Reinforcement Approach for Computation Offloading in MEC Dynamic Networks
Authors: Fan Yibiao , Cai Xiaowei 
Published: December 2023

Abstract
In this paper, we study the dynamic time-slot scheme server selection problem in mobile edge computing (MEC) system, which takes into account the dynamic access of users at edge servers and introduces the dynamically changing factors affecting the workload of edge servers, such as offloading policies, offloading ratios, user’s transmitting power, and reserved capacity of the servers. However, the above factors make it tricky to achieve
long-term optimization in the edge server selection process. To cope with the above challenges, we model the server selection problem faced as a Markov Decision Process (MDP) and propose a Deep Reinforcement Learning (DRL) based algorithm to solve it. Selection strategy learning is performed based on the observed server selection performance in previous phases. Simulation results show that the DRL-based algorithm proposed in this paper has the lowest average latency compared to benchmark algorithms.
Fatigue life prediction under mean stresses using
critical plane approach
Authors: Santos Simelia Dos , Ferreira Jorge L. de A 
Published: December 2023

Abstract
This paper suggests that multiaxial fatigue criteria can serve as damage parametersin the formulation of critical plane theory. We propose that by incorporatingstrain rate effects, critical plane approximation parameters can be effectivelyused to estimate fatigue life under various test conditions. Unlike the classicalapproach, this improvement offers the advantage of building the parameter versuslife relationship, regardless of the type of test used for calibration. To definethis new relationship, we present a calibration strategy that considers criticalplane models based on the Fatemi-Socie and Smith-Watson-Topper criteria. Theaccuracy of the method is verified using data sets extracted from the literature.A study on the impact of the stress ratio on the parameter versus life curve isincluded, indicating that although the relationships obtained depend on the valueof the stress ratio (R) used in the calibration, the life predictions derived fromthese relationships are statistically similar.
Distributed WSN Vulnerability Remediation System Based on Mobile-N Policy
Authors: Zhou Zihan 
Published: December 2023

Abstract
Wireless sensor networks are widely used in military reconnaissance, environmental monitoring, and other fields. Due to its characteristics such as high node deployment difficulty, limited energy, etc. makes the network coverage area appear vulnerability, etc. leads to serious security problems, the study proposes a distributed wireless sensor network vulnerability repair system based on the Mobile-N strategy, through the vulnerability detection to determine the location of the vulnerability edge node, and at the same time proposes an energy and performance optimization strategy, through the mobile distance, redundancy and the remaining energy of the comprehensive comparison to select the optimal repair node. Experimental results show that the Mobile-N strategy performs well in repairing network vulnerabilities and can effectively repair vulnerabilities while minimizing energy consumption and maximizing network stability. Specifically, the effective repair area ratio and node repair rate of the Mobile-N strategy in each experiment are higher than those of other algorithms, with an average effective repair area ratio of 94.9% and an average failed node repair rate of 94.9%, which indicates that the strategy has obvious advantages in terms of repair energy efficiency and repair node rate. Therefore, the distributed WSN vulnerability repair system based on Mobile-N strategy is of great research significance for improving the security and efficiency of wireless sensor networks and ensuring their stable operation.
Aspect and root trench effect of Eucalyptus globules boundary plantation on barley yield and soil physicochemical properties in the Gummer district, Central highlands of Ethiopia
Authors: Ameha Neway , Asfaw Zebene 
Published: December 2023

Abstract
The expansion of Eucalyptus globules boundary plantation (EGBP) along farm boundaries considered to have effects on yield of underneath crops. Tree root pruning or trench is a potential tool for managing belowground competition. We evaluated aspect and trench distance effect of EGBP on barley yield and soil physicochemical properties in Gummer woreda, central Ethiopia. Two months before sowing, on one side of each aspect of EGBP trenches were prepared at distances of 0.5m, 1m and 1.5m using split-split plot design with three replications. At 1.5m trench distance, the North faced field showed 20.4–31.2% additional yield variation respect to South, East and West faced fields. Also 15.2–43% additional yield was observed as the field distance from EGBP increased from 3m to 12m. Relative to un-trenched field, trenched fields showed 31.9–73.4% additional yield variations. Regarding to soil physicochemical properties, aspect of EGBP had no significant effect. However, except for texture, pH and extractable potassium, trench showed a significant difference on soil organic matter, total nitrogen, available Phosphors and CEC status. Relative to un-trenched fields of 6m and 9m, 1.5 m trenched field of 3m field distance showed 48% and 15% additional yield variations. That means root trench minimized on average 24% of the field distance effect of EGBP on barley yield. Therefore, root pruning at 1.5m distance from EGBP using 0.5m x 0.5 m trench is an applicable and advisable method that will help farmers to maximize barley yield with higher land-use efficiency.
Non-invasive quantification of 18F-florbetaben with total-body EXPLORER PET
Authors: Holy Emily Nicole , Li Elizabeth , Bhattarai Anjan , Fletcher Evan , Alfaro Evelyn R. , Harvey Danielle J. , Spencer Benjamin A. , Cherry Simon R. , DeCarli Charles S. , Fan Audrey P. 
Published: December 2023

Abstract
Purpose
Kinetic modeling of 18F-florbetaben provides important quantification of brain amyloid deposition in research and clinical settings but its use is limited by the requirement of arterial blood data for quantitative PET. The total-body EXPLORER PET scanner supports the dynamic acquisition of a full human body simultaneously and permits noninvasive image-derived input functions (IDIFs) as an alternative to arterial blood sampling. This study quantified brain amyloid burden with kinetic modeling, leveraging dynamic ¹⁸F-florbetaben PET in aorta IDIFs and the brain in an elderly cohort.
Methods
¹⁸F-florbetaben dynamic PET imaging was performed on the EXPLORER system with tracer injection (300 MBq) in 3 individuals with Alzheimer's disease (AD), 3 with mild cognitive impairment, and 9 healthy controls. Image-derived input functions were extracted from the descending aorta with manual regions of interest based on the first 30 seconds after injection. Dynamic time-activity curves (TACs) for 110 minutes were fitted to the two-tissue compartment model (2TCM) using population-based metabolite corrected IDIFs to calculate total and specific distribution volumes (VT, Vs) in key brain regions with early amyloid accumulation. Non-displaceable binding potential (\({BP}_{ND})\) was also calculated from the multi-reference tissue model (MRTM).
Results
Amyloid-positive (AD) patients showed the highest VT and VS in anterior cingulate, posterior cingulate, and precuneus, consistent with \({BP}_{ND}\) analysis. \({BP}_{ND}\)and VT from kinetic models were correlated (r² = 0.46, P < 2\({e}^{-16})\) with a stronger positive correlation observed in amyloid-positive participants, indicating reliable model fits with the IDIFs. VT from 2TCM was highly correlated (\({r}^{2}\)= 0.65, P < 2\({e}^{-16}\)) with Logan graphical VT estimation.
Conclusion
Non-invasive quantification of amyloid binding from total-body ¹⁸F-florbetaben PET data is feasible using aorta IDIFs with high agreement between kinetic distribution volume parameters compared to \({BP}_{ND}\)in amyloid-positive and negative older individuals.
Analytical analysis of the effects of the porosity distribution on liquid-water management in the cathode of a polymer electrolyte membrane fuel cell
Authors: Khemili Faycel , Najjari Mustapha 
Published: December 2023

Abstract

Proton Exchange Membrane Fuel Cell (PEMFC) technology has been receiving more attention recently and can play a more expanded role in space missions with low gravity or microgravity. The liquid water generation in the Gas Diffusion Layer (GDL) of a Proton Exchange Membrane Fuel Cell (PEMFC) increases the resistance to oxygen flow toward the catalyst layer. Water flooding inside the GDL can affect the PEMFC performance especially at higher current densities. Therefore, a good understanding of the effect of liquid water amount in the GDL is crucial to water management and, subsequently, to the performance of the fuel cell. The purpose of the present study is to investigate the effect of the microstructure characteristics of the GDL on the water flooding and liquid water distribution inside the GDL. A one-dimensional theoretical model has been developed. Results indicate that the porosity gradient has a significant effect on the liquid water saturation and the performance of the PEM fuel cell.
Epichloë endophyte enhances intraspecific competition of Achnatherum inebrians under nitrogen stress
Authors: Huan Liu , Wang Meijun , Cui Xuelian , Nan Zhibiao , Xia Chao 
Published: December 2023

Abstract
Background and aims Drunken horse grass (DHG, Achnatherum inebrians) is a perennial grass widely distributed in the grasslands of northwestern China, forming a symbiosis with the Epichloë endophyte, and has a strong growth advantage in the community. However, the mechanism of its competitive success remains unclear.
Methods Endophyte-infected (EI) and endophyte-free (EF) DHG were employed in greenhouse experiments. EI plants served as competitive species, while EF plants were the target species. Aggressivity was employed to quantify the competitiveness between EI and EF plants. The effects of endophyte, plant density, and three different nitrogen levels in pot on the competitiveness of DHG plants were investigated.
Results The presence of Epichloë endophytes significantly improved growth performance, photosynthetic capacity, and nitrogen uptake efficiency of the host grasses, especially under low nitrogen conditions. the competitive abilities of DHG. Importantly, the gain effect of the endophyte on the competitiveness of DHG gradually weakened with the decrease in the number of EI plants.
ConclusionThe Epichloë endophyte enhances DHG competitiveness under nitrogen limitation but diminishes as soil nitrogen content increases. These results provide insights into the strong competitive advantage of EI DHG and the high infection rate of DHG in natural grasslands with harsh habitats.
How can forest management can regulate noise level from wind turbines?
Authors: HEINONEN Tero , SELKIMÄKI Mari , RANA Parvez , TOKOLA Timo 
Published: December 2023

Abstract
Forest can effectively serve as noise barrier, with their noise attenuation capacity varying based on the forest’s characteristics. Specifically, the attenuation level depends on the sound’s travel distance through the forest and the size and density of trees. Our study findings indicate that forest can provide up to 10 dB of additional noise attenuation. This was achieved by integrating a forest structure-based model into forest planning calculations, aimed at mitigating noise pollution from wind turbines. Incorporating this noise model as a management objective significantly reduced noise levels in the pilot study area, outperforming traditional business-as-usual management strategies. Furthermore, adapting a combination of uneven-aged and even-aged forest management approaches resulted in more forested landscape, which was more effective in mitigating higher noise levels. Our results contribute important insights that, along with further research, can guide future forest planning and management towards enhanced sustainability.
A fast and enhanced shallow learning framework for solving free boundary options pricing problems
Authors: Nwankwo Chinonso , Ware Tony , Dai Weizhong 
Published: December 2023

Abstract

We consider various non-standard and non-linear free boundary options pricing problems comprising the non-linear free boundary local volatility model, exotic options, and dividend-paying pricing model and present a fast and enhanced shallow learning framework for solving free boundary options pricing problems with auxiliary neural operators (ANOs). To this end, we first rigorously explore the efficacy of some featured activation functions (FAFs) for solving these models with ANOs. We observe that some existing and ad-hoc activation functions perform well, but are not suitable for generalization. Rather, they should be enhanced to be adaptable to specific model characteristics and conditions based on their positivity, boundedness, convexity, vanishing points, discontinuous points, exploding points, etc. By adapting some of the existing activation functions and accustoming new ones, we then obtain a fast and enhanced shallow learning method which substantially improve the performance of neural network methodologies for non-standard options pricing models.
Traditional Fermented Drinks: Korefe, Borde, and Booka and their Safety, Nutritiousness, and Usefulness in Southern Ethiopia
Authors: Hirbo Hirbo Geremew , Hola Roba Nebi 
Published: December 2023

Abstract
Ethiopia is among the nations where a vast array of traditional fermented drinks are made and long-consumed. Native to a region, traditional fermented drinks are made by the locals employing age-old methods and readily available ingredients. They are also very popular there. In this study, the ingredients were sorghum, barely, and maize, in that order. Borde, Booka, and Korefe are a few examples of the naturally occurring, traditionally fermented beverages produced by Ethiopian indigenous people. These products are made with a combination of microbe cultures. Yeast and lactic acid bacteria, the two most prevalent fermenting microorganisms, are employed as a catalyst to enhance nutritional quality, good organoleptic qualities, and safety. The following ranges were observed: 78.9–83.4, 0.97–4.8, 7.3–9.75, 6.71–2.33, 2.31–5.47, and 78.05–125.95 for moisture, ash, protein, fat, CHO, and energy, respectively. Ethiopian beverage preparation practices involve traditional home processing, which is linked to lower microorganisms in fermented beverages and their potential for improvement. Standardizing the procedures for beverage fermentation processes is crucial now and in the future to raise the quality of the product.
Women's Political Participation in City Council, Debretabor City Administration, Ethiopia: An Exploration of Barriers
Authors: Kebede Agenagn 
Published: December 2023

Abstract
Introduction
Women have traditionally been marginalized within the political sphere, notwithstanding their significant achievements. The study looks at the barriers that stand in the way of women participating actively in politics, with a particular emphasis on the Debretabor City Administration Council.
Method
A case study research design was used in the study. The sample techniques used were maximum variation, deviant case, and intensity sampling. Semi-structured interviews, life histories, and focus group discussions (FGD) were also used to obtain the data.
Results
The findings showed that women's political engagement in city council was in danger due to a variety of factors, including gender bias in decision-making processes, the country's shifting political landscape, and Islamic religion fellows' perspectives.
Conclusion
Women faced certain obstacles when attempting to participate in city council politics. This case was critical in city administration, particularly, in city council.
Policy implication
In light of this, the research findings urged the need for gender-sensitive policy formulation within the city administration council.
A New Approach to Teaching Concepts: A Case of Teaching Derivative Concepts in Calculus for High School Students Based on Realistic Mathematics Education (Rme) Approach With the Support of Geogebra Software
Authors: Nguyen Da 
Published: December 2023

Abstract
This paper aims at the following goals: (1) Providing teachers with confidence in a new approach to teaching Calculus concepts, creating lively, intuitive lessons that can attract participation. students' positivity; (2) Provide teachers with ways to use GeoGebra software to teach concepts in Calculus (Limits, derivatives, integrals); (3) Support students to improve their understanding of the nature of concepts in Calculus through visual images and movements of mathematical objects (points, lines) that are impossible to practice on paper. ; (4) Provide students with opportunities to explore Calculus concepts with the support of technology and teacher guidance; (5) Enhance students' interest, confidence, stimulate curiosity and arouse curiosity in learning mathematics; (6) Help students have the opportunity to practice and develop skills in using technology in studying Mathematics in general and studying Calculus in particular; (7) Raise students' awareness of the role of technology in learning Mathematics.