bluuebunny/crossref_metadata_2025 huggingface dataset:
Education, Immunity and Autoimmunity—A Study of Medicalized Philosophy of Education
Authors: Bostad Inga , Bondevik Hilde
Published: July 2023

Education has been described as and considered as a remedy or a treatment for the insecurity experienced by many young people today. To recognize mental health problems and to seek treatment is the subject of many of today’s research, analyses and academic debates on education. In this article, however, we will analyze, clarify and discuss how medicalized metaphors contribute to both an understanding and a reinforcing of what we call an “autoimmune reaction”. We explore how the meaning and use of the concepts of “immunity” and “autoimmunity” in the field of philosophy of education present a new understanding of medicalized metaphors, as well as a philosophy of autoimmunity, partly based on Derrida and his analysis of “inflammatory” democracies. We will nuance and offer new perspectives and concepts with which to think, in order to understand the existing dichotomy between normality and abnormal/pathology, health and illness in educational philosophy today.
A Model for the Selection of Active Learning While Taking into Account Modern Student Behavior Styles
Authors: Sytnik Inessa , Stopochkin Artem
Published: July 2023

This paper solves the complex scientific and practical problem of developing the critical thinking skills of the modern student. The solution of the indicated problem was accomplished by generalizing contemporary scientific works and conducting an empirical study (survey) of university students. The conducted research made it possible to distinguish students’ behavior styles according to seven criteria: the student’s level of trust in the higher education system; the student’s tendency to cheat the education system; the student’s degree of self-reliance and self-confidence; the student’s degree of disappointment with the education system; the student’s degree of involvement in the education process; the student’s degree of social inclusion; and the student’s degree of dependence on formal learning results. In this research, we determined the effectiveness of different teaching methods and proved that the student’s preference of teaching methods depends on their behavior styles. This means that in order to increase the effectiveness of the educational process, the academic teacher must select teaching methods while taking into account the behavior styles of the students. To this end, the article develops a model for the selection of active learning methods, taking into account the behavior styles of modern students, and conducts an approval of this model.
The Impact of Topic Selection on Lexico-Grammatical Errors and Scores in English Oral Proficiency Interviews of Korean College Students
Authors: Won Yongkook , Kim Sunhee
Published: July 2023

The primary objective of this study is to identify the types of errors made by Korean college students in an oral proficiency interview in relation to specific task topics, and to examine how these errors affect their lexico-grammatical proficiency scores. Ninety-six two-minute-long audio clips of 32 Korean college students on three different topics were transcribed. Lexico-grammatical errors were then coded for statistical analysis and lexico-grammatical scores were estimated using many-facet Rasch measurement analysis with two raters. Friedman tests and Wilcoxon signed-rank tests showed that noun phrase, verb phrase, and prepositional phrase errors were more frequently found with the descriptive tasks than compare-and-contrast or hypothetical prompts. A hierarchical multiple regression analysis showed that noun phrase and verb phrase errors accounted for 22% of the variance in lexico-grammatical scores. Adding utterance length variables to the initial regression model explained an additional 43% of the variance in the lexico-grammatical scores. These findings suggest that noun phrase errors and verb phrase errors should be a priority in English classes, and that it is beneficial to teach English speaking skills in a way that takes into account the task characteristics and contextual factors.
Hyperspectral Image Classification Based on Dual-Scale Dense Network with Efficient Channel Attentional Feature Fusion
Authors: Shi Zhongyang , Chen Ming , Wu Zhigao
Published: July 2023

Hyperspectral images (HSIs) have abundant spectral and spatial information, which shows bright prospects in the application industry of urban–rural. Thus, HSI classification has drawn much attention from researchers. However, the spectral and spatial information-extracting method is one of the research difficulties in HSI classification tasks. To meet this tough challenge, we propose an efficient channel attentional feature fusion dense network (CA-FFDN). Our network has two structures. In the feature extraction structure, we utilized a novel bottleneck based on separable convolution (SC-bottleneck) and efficient channel attention (ECA) to simultaneously fuse spatial–spectral features from different depths, which can make full use of the dual-scale shallow and deep spatial–spectral features of the HSI and also significantly reduce the parameters. In the feature enhancement structure, we used 3D convolution and average pooling to further integrate spatial–spectral features. Many experiments on Indian Pines (IP), University of Pavia (UP), and Kennedy Space Center (KSC) datasets demonstrated that our CA-FFDN outperformed the other five state-of-the-art networks, even with small training samples. Meanwhile, our CA-FFDN achieved classification accuracies of 99.51%, 99.91%, and 99.89%, respectively, in the case where the ratio of the IP, UP, and KSC datasets was 2:1:7, 1:1:8, and 2:1:7. It provided the best classification performance with the highest accuracy, fastest convergence, and slightest training and validation loss fluctuations.
A Survey on the State-of-the-Art and Future Trends of Multilevel Inverters in BEVs
Authors: Hren Alenka , Truntič Mitja , Mihalič Franc
Published: July 2023

All electric vehicles are the only way to decarbonize transport quickly and substantially. Although multilevel inverters have already been used in some transportation modes, they are rarely used in road transportation, especially in light-duty passenger BEVs. With the transition to a high 800-V DC link to extend the driving range and enable extreme fast charging, the possibility of using multilevel inverters in commercial light-duty passenger BEVs becomes feasible. Higher efficiency, higher power density, better waveform quality, lower switching frequency, the possibility of using low-rated switches, and inherent fault tolerance are known advantages of multilevel inverters that make them an efficient option for replacing 2-level inverters in high DC link passenger BEVs. This paper discusses high DC link voltage benefits in light-duty passenger BEVs, presents the state-of-the-art of different conventional multilevel inverter topologies used in BEVs, and compares them with conventional 2-level inverters from different aspects and limitations. Based on commercial upper-class passengers’ BEV data and a review of multilevel inverters on the market, future trends and possible research areas are identified.
NOMA or OMA in Delay-QoS Limited Satellite Communications: Effective Capacity Analysis
Authors: Yan Xiaojuan , An Kang , Zhang Qianfeng , Du Bo
Published: July 2023

In this paper, we theoretically study the achievable capacity of orthogonal and non-orthogonal multiple access (OMA and NOMA) schemes in supporting downlink satellite communication networks. Considering that various satellite applications have different delay quality-of-service (QoS) requirements, the concept of effective capacity is introduced as a delay-guaranteed capacity metric to represent users’ various delay requirements. Specifically, the analytical expressions of effective capacities for each user achieved with the NOMA and OMA schemes are first studied. Then, approximated effective capacities achieved in some special cases, exact closed-form expressions of users’ achievable effective capacity, and the capacity difference between NOMA and OMA schemes are derived. Simulation results are finally provided to validate the theoretical analysis and show the suitable limitations of the NOMA and OMA schemes, such as the NOMA scheme is more suitable for users with better channel quality when transmit signal-to-noise (SNR) is relatively large, while it is suitable for users with worse link gain when transmit SNR is relatively small. Moreover, the influences of delay requirements and key parameters on user selection strategy and system performance are also shown in the simulations.
Use of a Partially Saturating Inductor in a Boost Converter with Model Predictive Control
Authors: Firpo Pietro , Ravera Alessandro , Oliveri Alberto , Lodi Matteo , Storace Marco
Published: July 2023

Increasing the power density in switched mode power supplies is one of the main goals in power electronics. This aim can be achieved by using smaller inductors operating at partial magnetic saturation. In this work, a partially saturating ferrite core inductor is exploited in a switching DC-DC boost converter, regulated through nonlinear model predictive control. A nonlinear behavioral inductor model, identified through experimental measurements, accounts for both magnetic saturation and losses. The simulation results show that the converter output voltage is correctly regulated and the imposed current constraints are fulfilled, even when partial magnetic saturation occurs. Comparisons with traditional control techniques are also presented.
A Three-Phase Phase-Modular Single-Ended Primary-Inductance Converter Rectifier Operating in Discontinuous Conduction Mode for Small-Scale Wind Turbine Applications
Authors: Lima Guilherme Ferreira de , Kremes William de Jesus , Siqueira Hugo Valadares , Aliakbarian Bahar , Converti Attilio , Illa Font Carlos Henrique
Published: July 2023

Small-scale wind turbines play an important role in distributed generation since customers can use their houses, farms, and business to produce electric energy. The development of the power electronics system that processes the electric energy from small-scale wind turbines is a concern due to cost, simplicity, efficiency, and performance trade-offs. This paper presents the results of applying a three-phase phase-modular single-ended primary-inductance converter rectifier to processing the energy of a small-scale wind turbine system. The rectifier was designed according to the specifications of a commercial small-scale wind turbine system and tested in an emulator workbench, providing experimental data on the operation of the rectifier in this application. The rectifier can process the energy of a non-sinusoidal three-phase system since the permanent magnet synchronous generator has trapezoidal waveforms. The results show that the rectifier has the advantages of (i) using the inductance of the generator as the input filter inductor of the rectifier, (ii) providing input currents with the same shape as the voltages and in phase without the use of a current control system, (iii) simplicity of control of the DC output voltage and PWM modulation, and (iv) phase-modular characteristics that allow operating with phase fault without any additional control techniques. Due to the operation in discontinuous conduction mode, low efficiency in high power and/or low input voltage specifications are disadvantages.
Biomass Based N/O Codoped Porous Carbons with Abundant Ultramicropores for Highly Selective CO2 Adsorption
Authors: Guo Congxiu , Sun Ya , Ren Hongyan , Wang Bing , Tong Xili , Wang Xuhui , Niu Yu , Wu Jiao
Published: July 2023

In this work, N/O codoped porous carbons (NOPCs) were derived from corn silk accompanied by Na2CO3 activation. The porous structures and surface chemical features of as-prepared carbon materials were tailored by adjusting the Na2CO3 mass ratio. After activation, the optimized sample (NOPC1) with abundant ultramicropores and pyrrolic N displays an enhanced CO2 adsorption capacity of 3.15 mmol g−1 and 1.95 mmol g−1 at 273 K and 298 K at 1 bar, respectively. Moreover, this sample also exhibited high IAST selectivity (16.9) and Henry’s law selectivity (15.6) for CO2/N2 at 298 K as well as moderate heat adsorption. Significantly, the joint effect between ultramicropore structure and pyrrolic N content was found to govern the CO2 adsorption performance of NOPCs samples.
Global Gas and LNG Markets: Demand, Supply Dynamics, and Implications for the Future
Authors: Botão Rodrigo Pereira , de Medeiros Costa Hirdan Katarina , dos Santos Edmilson Moutinho
Published: July 2023

This article offers a comprehensive analysis of the global gas and liquefied natural gas (LNG) markets, discussing increasing demand, market volatility, supply and demand dynamics, and the implications of the Paris Agreement on natural gas demand. It emphasizes the potential impacts of decarbonization policies on the LNG market, including changes in energy composition, reduced LNG demand, increased costs, and the need for industry adaptation. The article also examines the future outlook, investment needs, and implications for global gas and LNG markets, highlighting the continued uptake of gas in heavy-duty transport and the importance of investment to avoid supply–demand gaps. Overall, the analysis provides insights into the complex dynamics and challenges facing the global gas and LNG markets in the context of energy transition and climate change mitigation efforts.
Modern Optimization Algorithm for Improved Performance of Maximum Power Point Tracker of Partially Shaded PV Systems
Authors: Eltamaly Ali M. , Almutairi Zeyad A. , Abdelhamid Mohamed A.
Published: July 2023

Due to the rapid advancement in the use of photovoltaic (PV) energy systems, it has become critical to look for ways to improve the energy generated by them. The extracted power from the PV modules is proportional to the output voltage. The relationship between output power and array voltage has only one peak under uniform irradiance, whereas it has multiple peaks under partial shade conditions (PSCs). There is only one global peak (GP) and many local peaks (LPs), where the typical maximum power point trackers (MPPTs) may become locked in one of the LPs, significantly reducing the PV system’s generated power and efficiency. The metaheuristic optimization algorithms (MOAs) solved this problem, albeit at the expense of the convergence time, which is one of these algorithms’ key shortcomings. Most MOAs attempt to lower the convergence time at the cost of the failure rate and the accuracy of the findings because these two factors are interdependent. To address these issues, this work introduces the dandelion optimization algorithm (DOA), a novel optimization algorithm. The DOA’s convergence time and failure rate are compared to other modern MOAs in critical scenarios of partial shade PV systems to demonstrate the DOA’s superiority. The results obtained from this study showed substantial performance improvement compared to other MOAs, where the convergence time was reduced to 0.4 s with zero failure rate compared to 0.9 s, 1.25 s, and 0.43 s for other MOAs under study. The optimal number of search agents in the swarm, the best initialization of search agents, and the optimal design of the dc–dc converter are introduced for optimal MPPT performance.
A Fault Diagnosis Algorithm for the Dedicated Equipment Based on the CNN-LSTM Mechanism
Authors: Guo Zhannan , Hao Yinlin , Shi Hanwen , Wu Zhenyu , Wu Yuhu , Sun Ximing
Published: July 2023

Dedicated equipment, which is widely used in many different types of vehicles, is the core system that determines the combat capability of special vehicles. Therefore, assuring the normal operation of dedicated equipment is crucial. With the increase in battlefield complexity, the demand for equipment functions is increasing, and the complexity of dedicated equipment is also increasing. To solve the problem of fault diagnosis of dedicated equipment, a fault diagnosis algorithm based on CNN-LSTM was proposed in this paper. CNN and LSTM are used in the model adopted by the algorithm to extract spatial and temporal features from the data. CBAM is used to enhance the model’s accuracy in identifying faults for dedicated equipment. Data on dedicated equipment faults were obtained from a hardware-in-loop simulation platform to verify the model. It is demonstrated that the proposed fault diagnosis algorithm has high recognition ability for dedicated equipment by comparing it to other neural network models.
Design and Integration of the WCLL Tritium Extraction and Removal System into the European DEMO Tokamak Reactor
Authors: Utili Marco , Alberghi Ciro , Bonifetto Roberto , Candido Luigi , Collaku Aldo , Garcinuño Belit , Kordač Michal , Martelli Daniele , Mozzillo Rocco , Papa Francesca , Rapisarda David , Savoldi Laura , Urgorri Fernando R. , Valerio Domenico , Venturini Alessandro
Published: July 2023

The latest progress in the design of the water-cooled lithium–lead (WCLL) tritium extraction and removal (TER) system for the European DEMO tokamak reactor is presented. The implementation and optimization of the conceptual design of the TER system are performed in order to manage the tritium concentration in the LiPb and ancillary systems, to control the LiPb chemistry, to remove accumulated corrosion and activated products (in particular, the helium generated in the BB), to store the LiPb, to empty the BB segments, to shield the equipment due to LiPb activation, and to accommodate possible overpressure of the LiPb. The LiPb volumes in the inboard (IB) and outboard (OB) modules of the BB are separately managed due to the different pressure drops and required mass flow rates in the different plasma operational phases. Therefore, the tritium extraction is managed by 6 LiPb loops: 4 loops for the OB segments and 2 loops for the IB segments. Each one is a closed loop with forced circulation of the liquid metal through the TER and the other ancillary systems. The design presents the new CAD drawings and the integration of the TEU into the tokamak building, designed on the basis of an experimental characterization carried out for the permeator against vacuum (PAV) and gas–liquid contactor (GLC) technologies, the two most promising technologies for tritium extraction from liquid metal.
Case Study: Optimizing Grading Ring Design for High Voltage Polymeric Insulators in Power Transmission Systems for Enhanced Electric Field and Voltage Distribution by Using a Finite Element Method
Authors: Aziz Esraa , Aouabed Fatiha , Abdellah Hossam , Dineva Adrienn
Published: July 2023

This research paper aims to investigate the optimal design of grading rings for high-voltage polymeric insulators in an actual power transmission system, with a focus on improving the electrical representation of the insulator strings. One such subsidiary accessory commonly used with porcelain and polymer insulator strings is the grading ring, which is employed to improve the electric field and voltage distribution surrounding the insulator string. The efficiency of insulator strings can be enhanced by grading rings, as they facilitate a more linear potential division along the strings. The design parameters of grading rings significantly influence their performance on insulator strings. In this study, we examine the optimal design of the grading rings of high-voltage polymer insulators, since no uniform design methodology has been developed for high-voltage polymer insulators, and their optimization is currently the subject of many research studies. The electric field on an outdoor polymeric insulator is examined using finite element method (FEM) software and COMSOL Multi-Physics program. A 2D model is utilized to simulate a 220 kV polymeric insulator. The effectiveness of high-voltage polymeric insulators greatly depends on the dimensions and locations of the grading rings. Therefore, the impacts of the radius of the grading ring and that of its tube and the tube’s vertical position are thoroughly investigated, under dry and humid conditions. To achieve this objective, a search algorithm is employed to adjust the dimensions and locations of the grading ring. The optimization approach in this study is based on determining the maximum electric field across the insulator surface, while ensuring that it remains below the corona initiation level.
Inrush Current Reduction Strategy for a Three-Phase Dy Transformer Based on Pre-Magnetization of the Columns and Controlled Switching
Authors: Łukaniszyn Marian , Baron Bernard , Kolańska-Płuska Joanna , Majka Łukasz
Published: July 2023

The methodology and test results of a three-phase three-column transformer with a Dy connection group are presented in this paper. This study covers the dynamics of events that took place in the first period of the transient state caused by the energizing of the transformer under no-load conditions. The origin of inrush currents was analyzed. The influence of factors accompanying the switch-on and the impact of the model parameters on the distribution and maximum values of these currents was studied. In particular, the computational methods of taking into account the influence of residual magnetism in different columns of the transformer core, as well as the impact of the time instant determined in the voltage waveform at which the indicated voltage is supplied to a given transformer winding, were examined. The study was carried out using a nonlinear model constructed on the basis of classical modeling, in which hysteresis is not taken into account. Such a formulated model requires simplification, which is discussed in this paper. The model is described using a system of stiff nonlinear ordinary differential equations. In order to solve the stiff differential state equations set for the transient states of a three-phase transformer in a no-load condition, a Runge–Kutta method, namely the Radau IIA method, with ninth-order quadrature formulas was applied. All calculations were carried out using the authors’ own software, written in C#. A ready-made strategy for energizing a three-column three-phase transformer with a suitable pre-magnetization of its columns is given.
Solar Salt above 600 °C: Impact of Experimental Design on Thermodynamic Stability Results
Authors: Steinbrecher Julian , Braun Markus , Bauer Thomas , Kunkel Sebastian , Bonk Alexander
Published: July 2023

Thermal energy storage (TES) based on molten salts has been identified as a key player in the transition from fossil fuels to renewable energy sources. Solar Salt, a mixture of NaNO3 (60 wt%) and KNO3 (40 wt%), is currently the most advanced heat transfer and storage material used in concentrating solar power (CSP) plants. Here, it is utilized to produce electricity via a Rankine cycle, with steam temperatures reaching 550 °C. The goal of this study is to increase the operating temperature of solar salt to over 600 °C, allowing it to be adapted for use in high-temperature Rankine cycles with steam temperatures greater than 600 °C. Yet, this goal is impaired by the lack of available thermodynamic data given the salt’s complex high-temperature decomposition and corrosion chemistry. The study explores the thermodynamics of the decomposition reactions in solar salt, with a focus on suppressing decomposition into corrosive oxide ions up to a temperature of 620 °C. The results provide a new understanding of the stabilization of solar salt at previously unexplored temperatures with effective utilization of gas management techniques.
Optimal Parameter Identification of a PEM Fuel Cell Using Recent Optimization Algorithms
Authors: Rezk Hegazy , Wilberforce Tabbi , Olabi A. G. , Ghoniem Rania M. , Sayed Enas Taha , Ali Abdelkareem Mohammad
Published: July 2023

The parameter identification of a PEMFC is the process of using optimization algorithms to determine the ideal unknown variables suitable for the development of an accurate fuel-cell-performance prediction model. These parameters are not always available from the manufacturer’s datasheet, so they need to be determined to accurately model and predict the fuel cell’s performance. Five optimization methods—bald eagle search (BES) algorithm, equilibrium optimizer (EO), coot (COOT) algorithm, antlion optimizer (ALO), and heap-based optimizer (HBO)—are used to compute seven unknown parameters of a PEMFC. During optimization, these seven parameters are used as decision variables, and the fitness function to be minimized is the sum square error (SSE) between the estimated cell voltage and the actual measured cell voltage. The SSE obtained for the BES algorithm was noted to be 0.035102. The COOT algorithm recorded an SSE of 0.04155, followed by ALO with an SSE of 0.04022 and HBO with an SSE of 0.056021. BES predicted the performance of the fuel cell accurately; hence, it is suitable for the development of a digital twin for fuel-cell applications and control systems for the automotive industry. Furthermore, it was deduced that the convergence speed for BES was faster compared to the other algorithms investigated. This study aims to use metaheuristic algorithms to predict fuel-cell performance for the development and commercialization of digital twins in the automotive industry.
The Impact of Energy Community Composition on Its Technical and Economic Performance
Authors: Povolato Margherita , Prada Alessandro , Verones Sara , Debiasi Silvia , Baggio Paolo
Published: July 2023

European policies are promoting energy communities and energy sharing to decarbonize the energy system through increased penetration of renewables thereby reducing European energy dependency. However, the implementation of energy communities takes place following different patterns, and it is not entirely clear how the composition may affect community performance. This research evaluates and compares different energy-sharing scenarios at technical and economic levels. Several possible energy community solutions are evaluated. Analyses are conducted by combining the monitored electricity consumption of industries, services, and residential buildings with simulated photovoltaic production and heating consumption. The results highlight the conflict between the economic goal and the objective of maximizing the self-sufficiency of the energy community. The Italian incentive scheme currently makes it possible to double the economic value of the energy fed into the grid if physical self-consumption and shared energy reach 90% of the energy produced.
A Comparative Study on the Energy Flow of Electric Vehicle Batteries among Different Environmental Temperatures
Authors: Zhao Zhichao , Li Lu , Ou Yang , Wang Yi , Wang Shaoyang , Yu Jing , Feng Renhua
Published: July 2023

In the present research, the energy flow of electric vehicle batteries under different environmental temperatures was experimentally examined in a climate chamber. The energy flow characteristics, energy loss conditions, and the critical components’ operating conditions and working efficiency under different environmental temperatures were comparatively analyzed. The test results show that the environmental temperature has a profound impact on an electric vehicle’s performance and the critical components’ working conditions. The driving mileage of the tested vehicle at −7 °C, 23 °C, and 35 °C was found to be 162.89 km, 256.09 km, and 198.69 km, respectively. The environmental temperature does not have much effect on the loss of the motor and motor control unit under driving conditions, and the proportion of those at different temperatures is in all cases about 18%. The battery-recycled energy at 23 °C under braking conditions is much higher than that at −7 °C and 35 °C, leading to a longer driving range. The power battery pack thermal transfer loss at −7 °C is much greater than that at 23 °C and 35 °C due to the low charging and discharging efficiency and the high energy consumption required to warm up the battery at a low environmental temperature. The compressor energy consumption accounts for a large proportion in both braking and driving conditions at 35 °C, and the proportions are 15.25% and 12.41%, respectively. The battery state-of-charge drops the fastest at −7 °C, followed by 35 °C, due to the differences in the power demands of air conditioning, warm air positive temperature coefficient (PTC), and battery PTC in high- and low-temperature environments. The working condition of the front motor under driving conditions at 35 °C is the most severe and leads to the lowest working efficiency.
Modelling Aero-Structural Deformation of Flexible Membrane Kites
Authors: Poland Jelle A. W. , Schmehl Roland
Published: July 2023

Airborne wind energy systems using flexible membrane wings have the advantages of a low weight, small packing volume, high mobility and rapid deployability. This paper investigates the aero-structural deformation of a leading edge inflatable kite for airborne wind energy harvesting. In the first step, a triangular two-plate representation of the wing is introduced, leading to an analytical description of the wing geometry depending on the symmetric actuation state. In the second step, this geometric constraint-based model is refined to a multi-segment wing representation using a particle system approach. Each wing segment consists of four point masses kept at a constant distance along the tubular frame by linear spring-damper elements. An empirical correlation is used to model the billowing of the wing’s trailing edge. The linear spring-damper elements also the model line segments of the bridle line system, with each connecting two point masses. Three line segments can also be connected by a pulley model. The aerodynamic force acting on each wing segment is determined individually using the lift equation with a constant lift coefficient. The particle system model can predict the symmetric deformation of the wing in response to a symmetric actuation of the bridle lines used for depowering the kite (i.e., changing the pitch angle). The model also reproduces the typical twist deformation of the wing in response to an asymmetric line actuation used for steering the kite. The simulated wing geometries are compared with photogrammetric information taken by the onboard video camera of the kite control unit, focusing on the wing during flight. The results demonstrate that a particle system model can accurately predict the geometry of a soft wing at a low computational cost, making it an ideal structural building block for the next generation of soft wing kite models.
CH4 and N2O Emissions of Undrained and Drained Nutrient-Rich Organic Forest Soil
Authors: Butlers Aldis , Lazdiņš Andis , Kalēja Santa , Purviņa Dana , Spalva Gints , Saule Guntis , Bārdule Arta
Published: July 2023

The ability to accurately assess the impact of organic soil drainage on greenhouse gas emissions (GHG) is still limited. Methane (CH4) emissions are characterized by significant variations, and GHG emissions from nutrient-rich organic soil in the region have not been extensively studied. The aim of this study was to assess CH4 and nitrous oxide (N2O) emissions from nutrient-rich organic soil in hemiboreal forests to provide insights into their role in regional GHG balance. Over the course of one year, CH4 and N2O emissions, as well as their affecting factors, were monitored in 31 forest compartments in Latvia in both drained and undrained nutrient-rich organic soils. The sites were selected to include forests of different ages, dominated by silver birch (Betula pendula Roth), Norway spruce (Picea abies (L.) Karsten), and black alder (Alnus glutinosai (L.) Gärtner), as well as clearcuts. Soil GHG emissions were estimated by collecting gas samples using the closed manual chamber method and analyzing these samples with a gas chromatograph. In addition, soil temperature and groundwater level (GW) measurements were conducted during gas sample collection. The mean annual CH4 emissions from drained and undrained soil were −4.6 ± 1.3 and 134.1 ± 134.7 kg CH4 ha−1 year−1, respectively. N2O emissions from undrained soil (4.1 ± 1.4 kg N2O ha−1 year−1) were significantly higher compared to those from drained soil (1.7 ± 0.6 kg N2O ha−1 year−1). In most of the study sites, undrained soil acted as a CH4 sink, with the soil estimated as a mean source of CH4, which was determined by one site where an emission hotspot was evident. The undrained soil acted as a CH4 sink due to the characteristics of GW level fluctuations, during which the vegetation season GW level was below 20 cm.
Method of Wildfire Risk Assessment in Consideration of Land-Use Types: A Case Study in Central China
Authors: Yue Weiting , Ren Chao , Liang Yueji , Lin Xiaoqi , Liang Jieyu
Published: July 2023

Research on wildfire risk can quantitatively assess the risk of wildfire damage to the population, economy, and natural ecology. However, existing research has primarily assessed the spatial risk of wildfires across an entire region, neglecting the impact of different land-use types on the assessment outcomes. The purpose of the study is to construct a framework for assessing wildfire risk in different land-use types, aiming to comprehensively assess the risk of wildfire disasters in a region. We conducted a case study in Central China, collecting and classifying historical wildfire samples according to land-use types. The Light Gradient Boosting Machine (LGBM) was employed to construct wildfire susceptibility models for both overall and individual land-use types. Additionally, a subjective and objective combined weighting method using the Analytic Hierarchy Process (AHP) and Entropy Weight Method (EWM) was utilized to build the wildfire vulnerability model. By integrating susceptibility and vulnerability information, we comprehensively assessed the combined risk of wildfire disasters across land-use types. The results demonstrate the following: (1) Assessing wildfire susceptibility based on different land-use types compensated for limitations in analyzing overall wildfire susceptibility, with a higher prediction performance and more detailed susceptibility information. (2) Significant variations in wildfire susceptibility distribution existed among different land-use types, with varying contributions of factors. (3) Using the AHP-EWM combined weighting method effectively addressed limitations of a single method in determining vulnerability. (4) Land-use types exerted a significant impact on wildfire risk assessment in Central China. Assessing wildfire risk for both overall and individual land-use types enhances understanding of spatial risk distribution and specific land use risk. The experimental results validate the feasibility and effectiveness of the proposed evaluation framework, providing guidance for wildfire prevention and control.
Analysis of Cutting Forces in Cross-Sawing of Wood: A Study of Sintered Carbide and High-Speed Steel Blades
Authors: Krilek Jozef , Melicherčík Ján , Kuvik Tomáš , Kováč Ján , Gendek Arkadiusz , Aniszewska Monika , Mareček Jan
Published: July 2023

This research deals with the processing of wood using a circular saw, which is associated with several risks and factors that affect the wood-splitting process. One of them is the wear of the teeth of the saw blade that change the magnitude of the cutting forces. The aim of this study is to compare real measured values and theoretical values when processing Norway spruce wood using two types of saw blades, i.e., sintered carbide (SC) and high-speed steel (HSS), with a diameter of 600 mm and 54 and 56 teeth, respectively. Experimental measurements were carried out on a special test device with the possibility of moving the tested wood into the cutting devices and a simple saw blade replacement system. The results of the contributions show significant differences, based on defined factors which represent the cutting and feed speed, which are supported by FEM analysis of cutting forces in the process of cutting wood—when changing the design of the saw blade. The results of the experiment show that the cutting conditions (cutting speed and feed speed) do not have a significant effect on the size of the cutting forces. The theoretical and real stress values for HSS discs ranged from 14 to 22 MPa. Significantly larger differences were recorded for discs with SC, where the real values of the maximum stresses were around 14 MPa and the theoretical ones around 25 MPa. When cutting spruce with a disc with SC slices, the maximum values of the theoretical cutting forces were in the range of 76 to 94 N and the maximum values of the measured cutting forces were in the range of 40 to 44 N.
Identification of Late Flavonoid Biosynthesis Genes of Moso Bamboo Reveals the Potential Function of PeANR4 Involved in Osmotic and Salt Stress
Authors: Xiao Xiaoyan , Zhu Chenglei , Yang Kebin , Liu Yan , Gao Zhimin
Published: July 2023

Flavonoids are important secondary metabolites in plants, and their biosynthesis includes various enzymes. Although bamboo is a potential resource with abundant flavonoids, its flavonoids biosynthesis is still unclear. Based on the genome and transcriptome data of moso bamboo (Phyllostachys edulis), 24 late flavonoid biosynthesis genes (LFBGs) were identified. Further molecular characteristics analyses suggested they may have different biological functions in flavonoids biosynthesis. Sixteen differentially expressed genes were identified according to transcriptome data from different-height shoots, including five PeANSs, four PeANRs, three PeLARs, and PeDFR1. PeANR4 expressed continuously under drought stress was selected for further analysis. A co-expression network of PeANR4 and 27 differentially expressed transcription factors (DETFs) was constructed, and the regulatory relationship of four DETFs and PeANR4 was validated by Y1H assays. Furthermore, PeANR4 was ectopically expressed in Arabidopsis, and the transgenic lines had darker seed coat color and higher fresh, dry weight and proanthocyanidin (PA) content than the wild type and mutant. Moreover, the transgenic lines had higher germination rate and longer primary root than the wild type and mutant under osmotic and salt stress. These results provide a full understanding and lay a foundation for further functional studies on the LFBGs of bamboo.
Effects of Moso Bamboo Expansion on the Spatial Pattern of Coarse Woody Debris in Secondary Coniferous and Broad-Leaved Mixed Forest in Wuxie National Forest Park, China
Authors: Chen Xi , Bai Shangbin
Published: July 2023

The spatial pattern of coarse woody debris (CWD) within the surrounding forest changes continuously during the expansion of Moso bamboo (Phyllostachys edulis), which partly reflects the death process of trees within the community. In this paper, we sampled an area of 0.72 hm2 within the transition zone of Moso bamboo expansion, which included continuous secondary coniferous and broad-leaved mixed forest (SF), transitional forest (TF), and Moso bamboo forest (MF) in Wuxie National Forest Park, Zhejiang Province. The spatial pattern and spatial correlation of CWD with different diameter classes, different decay classes, and different types in the three forests were analyzed using Ripley’s L function. The results showed that, with the expansion of Moso bamboo, the volume of CWD in TF was higher than those in SF and MF, and the total density of CWD in the three forests varied, with a decreasing order of MF > TF > SF. The spatial pattern of CWD in the three forests was aggregated on a relatively small scale, but the pattern changed from aggregated to random distribution with the increase in scale. Moreover, the CWD of Moso bamboo in TF showed aggregated distribution, and the aggregation intensity increased with the increase in scale. With the expansion of Moso bamboo, the spatial pattern and spatial correlation of CWD with different diameter classes, decay classes, and types have changed significantly in the three forests. Our study suggests that the expansion of Moso bamboo is increasingly strengthening the intraspecific and interspecific competition and accelerating the death of neighboring trees.
Recent Advances in Flower Color and Fragrance of Osmanthus fragrans
Authors: Qian Yuchen , Shan Linmiao , Zhao Rong , Tang Jinwu , Zhang Cheng , Chen Moxian , Duan Yifan , Zhu Fuyuan
Published: July 2023

Osmanthus fragrans is an evergreen shrub or tree of the Oleaceae family with a long history of cultivation in Asian countries and is one of the ten traditionally famous flowers in China, with important cultural and economic value. The unique floral color and fragrance of O. fragrans are formed by a variety of endogenous metabolites that distinguish it from other flowers and exhibit extraordinary ornamental value. However, many studies on the flower color and fragrance of this plant have been mainly based on bioactive extracts and physiological characteristics, leading to a notable lack of molecular machinery and systematic research. In this review, recent advances in bioactive ingredients associated with the underlying regulatory mechanisms, as well as the prospect for industrial utilization, are comprehensively presented and critically evaluated. In particular, the isolated components and essential genes required for flower color and fragrance are also well summarized, which will provide a scientific basis for molecular breeding for ornamental applications and facilitate the discovery of novel natural products for the future industrial development of O. fragrans. In prospect, we plan to use genetic research and high-throughput omics to analyze the genes related to the flower color and fragrance of O. fragrans, and at the same time, we will hybridize and breed excellent O. fragrans varieties that are resistant to low temperature.
Assisting Drivers at Stop Signs in a Connected Vehicle Environment
Authors: Bani Younes Maram
Published: July 2023

Road intersections are shared among several conflicted traffic flows. Stop signs are used to control competing traffic flows at road intersections safely. Then, driving rules are constructed to control the competing traffic flows at these stop sign road intersections. Vehicles must apply a complete stop with no motion in front of stop signs. First to arrive, first to go, straight before turns, and right then left are the main driving rules at stop sign intersections. Drivers must be aware of the stop sign’s existence, the architecture of the road intersection, and traffic distribution in the competing traffic flows. This is to make the best decision to pass the intersection or wait for other conflicted flows to pass according to the current situation. Due to bad weather conditions, obstacles, or existing heavy vehicles, drivers may miss capturing the stop sign. Moreover, the architecture of the road intersection and the characteristics of the competing traffic flows are not always clear to the drivers. In this work, we aim to keep the driver aware ahead of time of the existing stop signs, the architecture of the road intersection, and the traffic characteristics of the competing traffic flow at the targeted destination. Moreover, the best speed and driving behaviors are recommended to each driver. This is based on his/her position and the distribution of the existing traffic there. A driving assistance protocol is presented in this paper based on vehicular network technology. Real-time traffic characteristics are gathered and analyzed of vehicles around the intersections. Then, the best action for each vehicle is recommended accordingly. The experimental results show that the proposed driving assistant protocol successfully enhances the safety conditions around road intersections controlled by stop signs. This is by reducing the percentage of accident occurrences. Fortunately, the traffic efficiency of these road intersections is also enhanced; the accident percentage is decreased by 25% upon using the proposed protocol.
The Effects and Regulatory Mechanism of Casein-Derived Peptide VLPVPQK in Alleviating Insulin Resistance of HepG2 Cells
Authors: Li Dapeng , Cao Jianxin , Zhang Jin , Mu Tong , Wang Rubin , Li Huanhuan , Tang Honggang , Chen Lihong , Lin Xiuyu , Peng Xinyan , Zhao Ke
Published: July 2023

The liver plays a key role in keeping the homeostasis of glucose and lipid metabolism. Insulin resistance of the liver induced by extra glucose and lipid ingestion contributes greatly to chronic metabolic disease, which is greatly threatening to human health. The small peptide, VLPVPQK, originating from casein hydrolysates of milk, shows various health-promoting functions. However, the effects of VLPVPQK on metabolic disorders of the liver are still not fully understood. Therefore, in the present study, the effects and regulatory mechanism of VLPVPQK on insulin-resistant HepG2 cells was further investigated. The results showed that VLPVPQK exerted strong scavenging capacities against various free radicals, including oxygen radicals, hydroxyl radicals, and cellular reactive oxygen species. In addition, supplementation of VLPVPQK (62.5, 125, and 250 μM) significantly reversed the high glucose and fat (30 mM glucose and 0.2 mM palmitic acid) induced decrement of glucose uptake in HepG2 cells without affecting cell viability. Furthermore, VLPVPQK intervention affected the transcriptomic profiling of the cells. The differentially expressed (DE) genes (FDR < 0.05, and absolute fold change (FC) > 1.5) between VLPVPQK and the model group were mostly enriched in the carbohydrate metabolism-related KEGG pathways. Interestingly, the expression of two core genes (HKDC1 and G6PC1) involved in the above pathways was dramatically elevated after VLPVPQK intervention, which played a key role in regulating glucose metabolism. Furthermore, supplementation of VLPVPQK reversed the high glucose and fat-induced depression of AKR1B10. Overall, VLPVPQK could alleviate the metabolic disorder of hepatocytes by elevating the glucose uptake and eliminating the ROS, while the HKDC1 and AKR1B10 genes might be the potential target genes and play important roles in the process.
Comparison between Ultrasound- and Microwave-Assisted Extraction Methods to Determine Phenolic Compounds in Barley (Hordeum vulgare L.)
Authors: Álvarez-Romero María , Ruíz-Rodríguez Ana , Barbero Gerardo F. , Vázquez-Espinosa Mercedes , El-Mansouri Fouad , Brigui Jamal , Palma Miguel
Published: July 2023

Barley (Hordeum vulgare L.) is one of the major cereal crops worldwide. It is grown not only to be used as fodder but also for human consumption. Barley grains are a great source of phenolic compounds, which are particularly interesting for their health-promoting antioxidant properties, among other benefits. Two extraction methods, namely ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE), have been optimized and compared by using Box–Behnken design (BBD) to determine both the antioxidant power and the phenolic compound levels of the extracts. Three variables have been assessed based on these designs: solvent composition (% MeOH in water), temperature (°C), and sample-to-solvent ratio (mg sample mL−1 solvent). The solvent composition used and the interaction between the solvent and the temperature were the most significant variables in terms of recovery of phenolic compounds and antioxidant capacity of the extracts. Short extraction times, a high precision level, and good recoveries have been confirmed for both methods. Moreover, they were successfully applied to several samples. Significant differences regarding the level of phenolic compounds and antioxidant power were revealed when analyzing three different barley varieties. Specifically, the amounts of phenolic compounds ranged from 1.08 to 1.81 mg gallic acid equivalent g−1 barley, while their antioxidant capacity ranged from 1.35 to 2.06 mg Trolox equivalent g−1 barley, depending on the barley variety. Finally, MAE was found to be slightly more efficient than UAE, presenting higher levels of phenolic compounds in the extracts.