bluuebunny/crossref_metadata_2025 huggingface dataset:
The Optimization of Parallel Resonance Circuit for Wear Debris Detection by Adjusting Capacitance
Authors: Liu Zhijian , Wu Sen , Raihan Mahmud Kamal , Zhu Diyu , Yu Kezhen , Wang Feng , Pan Xinxiang
Published: October 2022

Wear debris in lubrication oil provides important information for marine engine condition monitoring and faults diagnosis. Inductive sensors have been widely used to detect wear debris in lubrication oil. To improve the sensitivity, the inductive coil is always connected with a capacitor in parallel to form parallel LC resonance-sensing circuit. A previous study optimized the parallel resonance circuit by adjusting the excitation frequency. However, multiple parameters (namely, excitation signal, signal detection circuits, and signal-processing program, etc.) need to be adjusted accordingly for a series of the testing frequencies. To simplify the optimization, we propose a method based on adjusting the parallel capacitance in this work. The impedance (inductance and internal resistance) of the sensing coil and its variation induced by particles are first measured, which are the necessary parameters for establishing the function relationship between the parallel capacitance and the relative impedance variation. With the function relationship, the relative impedance variation is calculated directly, and the optimal capacitance is located at the highest absolute value of it. The experimental results for the ferrous and nonferrous particles match the calculation results well. Interestingly, the optimal capacitance for the nonferrous particle was larger than that of the ferrous particle. We speculate that the difference is generated due to the increased resistance induced by the eddy current effect.
Triple-Mode Average Current Control with Valley Current Shaping for DCM/CRM/CCM Boost PFC Converter
Authors: Lu Liangliang , Shen Gaoshuai , Xu Haoran , Tong Qiaoling , Min Run , Zhang Qiao , Yuan Jun , Liu Ningyu
Published: October 2022

This paper presents a triple-mode average current control (TACC) strategy to achieve unity power factor and reduce the current stress for a boost PFC converter. The controller switches among different modes in each half-line cycle, and smooth transition is ensured by mapping of the operation region. By adaptive mode shifting, it reduces the current stress and current distortion caused by non-linear effects. With valley current shaping and comparisons, the TACC controller accordingly incorporates three control laws to adapt different modes. In discontinuous conduction mode (DCM), a variable on-time is calculated while the modulation is equivalent to PWM. In critical conduction mode (CRM), a constant on-time is derived, while the switching cycle is modified to regulate the current average value. For both DCM and CRM, the switching cycle is slightly extended to realize valley switching. Furthermore, with valley current shaping, the proposed controller reuses the CRM calculation to form continuous conduction mode (CCM) control law. To make the control laws compatible, normalized mapping and design rules are provided with respect to mode boundaries. This allows the TACC controller to automatically switch among different modes. Finally, experimental results prove the effectiveness of the controller in reducing the current stress and enlarging the preferable power range.
Influence of Fracture Types on Oil Production in Naturally Fractured Reservoirs
Authors: Pejic Milos , Kharrat Riyaz , Kadkhodaie Ali , Azizmohammadi Siroos , Ott Holger
Published: October 2022

Since more than half of the crude oil is deposited in naturally fractured reservoirs, more research has been focused on characterizing and understanding the fracture impact on their production performance. Naturally open fractures are interpreted from Fullbore Formation Micro-Imaging (FMI) logs. According to the fracture aperture, they are classified as major, medium, minor and hairy fractures in decreasing order of their respective aperture size. Different fracture types were set up in this work as a Discrete Fracture Network (DFN) in synthetic models and a sector model from a highly naturally fractured carbonate reservoir. The field sector model includes four wells containing image logs from two wells and production data from two other wells. Numerous simulations were conducted to capture the contribution of fracture type on production performance. Primary recovery was used for synthetic and field sector models, while waterflooding and gas injection scenarios were considered just for the synthetic models. The results showed that the fracture type and its extent play an essential role in production for all studied models. The reservoir production capabilities might be underestimated by ignoring any fracture types present in the reservoir, especially the major ones. In the secondary recovery, fractures had different impacts. Better displacement and higher recovery were promoted for waterflooding, whereas faster breakthrough times were observed for the gas injection. The performance during gas injection was more dependent on fracture permeability changes than waterflooding. This study’s findings can help in better understanding the impact of the different types of fracture networks on oil recovery at the various production stages. Additionally, the history matching process can be improved by including all types of fractures in the dynamic model. Any simplification of the fracture types might end in overestimating or underestimating the oil recovery.
Energy Saving Evaluation with Low Liquid to Gas Ratio Operation in HVAC&R System
Authors: Ha Ju-wan , Kim Yu-jin , Park Kyung-soon , Song Young-hak
Published: October 2022

Previous studies have been conducted by employing various methods to reduce the condenser water temperature, a crucial control variable to consider when attempting to improve the operational efficiency of a chiller. The existing literature dealing with the effects of low-condenser water temperatures is limited, as the cooling water flow rate is often considered the operating variable of the condenser loop. However, to produce additional low condenser water temperatures, the approach temperature of the cooling tower in the system must be reduced. To reduce the approach temperature, it is necessary to review the physical behavior and efficiency of the cooling tower according to the change in the liquid to gas ratio (LGR), which is dependent upon the condenser water flow rate and the cooling tower fan air flow rate within the condenser loop. However, this process has rarely been reviewed in previous studies. Therefore, this study developed a new cooling tower control algorithm from the LGR perspective, and the operational effectiveness was quantitatively reviewed using EnergyPlus. Compared to the conventional conditions, when the cooling tower operation algorithm for low-approach temperatures was applied, the annual energy saving was 27.0%, the average chiller COP was improved by 27.8%, and the average system COP was improved by 47.4%. Furthermore, even when the algorithm was not applied at the same condenser water set temperature, the annual energy saving was 15%. The average COP of the chiller and COP of the system is improved by 2% and 23.2%, respectively. These results indicated that when a cooling tower is operated with a low LGR, even under the same outdoor air and load conditions, the cooling system’s efficiency can be improved with a change in the control algorithm without installing additional high-efficiency equipment.
Analytical Method for Designing Three-Phase Air-Gapped Compensation Choke
Authors: Kindl Vladimir , Sobotka Lukáš , Frivaldsky Michal , Skalicky Martin
Published: October 2022

The compensating choke plays an important role in many high-power industrial applications with reactive power compensation. Due to the high number of devices installed every year and the EU’s efforts to reduce the energy demands of our society, it is advisable to maximize the efficiency of these devices. Due to the non-linearity of the magnetic core, the requirement of a linear operating characteristic, and the presence of a distributed air gap, this is a difficult task, with various technical challenges. This paper presents an analytical method for the electromagnetic design of a three-phase compensating choke with an air-gapped core and a flat load characteristic. The design method considers the fringing magnetic fields and the current-density dimensioning based on an advanced analytical thermal model. The proposed method is based on the use of existing analytical procedures; however, optimization was conducted to achieve a trade-off between the core and the I2R losses to manipulate the efficiency and the weight and identify optimization possibilities. The presented method was verified by the finite element method (FEM) using the engineering-simulation software, ANSYS.
Numerical Simulation and Theoretical Analysis of Flow Resistance Characteristics in the Honeycomb Ceramic Conduit
Authors: Lan Bo , Gao Peng-Fei , Li You-Rong , Yu Jia-Jia , Li Peng-Cheng
Published: October 2022

In this study, three-dimensional numerical simulations were established for a honeycomb ceramic conduit, and the effects of the inlet methane volume fraction, inlet velocity, and the conduit length on the gas temperature and flow resistance in the conduit were investigated. The simulation results indicate that the mean gas temperature first rises rapidly and then slowly, with an increasing inlet methane volume fraction. The mean gas temperature increases slightly with an increasing inlet velocity, and first increases and then decreases with an increasing conduit length. As the inlet methane volume fraction increases, the conduit pressure loss increases, but the increase rate gradually slows down. The conduit pressure loss increases approximately linearly with an increasing inlet velocity and conduit length. A prediction model for the pressure loss in the conduit was obtained by a theoretical analysis. The theoretical results agree well with the simulation results, and the deviations between the theoretical and simulation results were in the range of 3.7% to 12.3%. When the mean gas temperature in the conduit was less than 1000 K, the deviations were less than 6.5%.
Study on Winter Comfort Temperature in Mixed Mode and HVAC Office Buildings in Japan
Authors: Khadka Supriya , Rijal Hom B. , Amano Katsunori , Saito Teruyuki , Imagawa Hikaru , Uno Tomoko , Genjo Kahori , Takata Hiroshi , Tsuzuki Kazuyo , Nakaya Takashi , Nishina Daisaku , Hasegawa Kenichi , Mori Taro
Published: October 2022

Comfort temperature is important to investigate because the chosen office indoor temperatures affect the energy used in a building, and a thermally comfortable environment makes the occupants be more productive. The effects of temperature on comfort are broadly recognized for thermal comfort. Japanese office buildings are well equipped with air-conditioning systems to improve the thermal comfort of the occupants. The main objectives of this research were to compare the winter comfort temperature in mixed mode (MM) and heating, ventilation and air-conditioning (HVAC) office buildings and to investigate the relationship between the comfort temperature and the indoor air temperature. This study measured the thermal environmental conditions of the office buildings and surveyed the thermal comfort of the occupants. The field survey was conducted during winter in seven office buildings located in the Aichi prefecture of Japan. In total, 4466 subjective votes were collected from 46 occupants. The result suggested that the occupants were found to be more satisfied with the thermal environment of MM buildings than that of HVAC office buildings. Overall, 95% of comfort temperatures were in the range 22~28 °C in MM and HVAC buildings, which were higher than the indoor temperature of 20 °C recommended by the Japanese government. The comfort temperature was highly correlated to the indoor air temperature of the MM buildings than to that of HVAC buildings. This indicated that the occupants were more adapted towards the given thermal environment of MM buildings.
Development of MVMD-EO-LSTM Model for a Short-Term Photovoltaic Power Prediction
Authors: Gao Xiaozhi , Gao Lichi , Lin Hsiung-Cheng , Huo Yanming , Ren Yaheng , Guo Wang
Published: October 2022

The accuracy and stability of short-term photovoltaic (PV) power prediction is crucial for power planning and dispatching in a grid system. For this reason, the multi-resolution variational modal decomposition (MVMD) method is proposed to achieve multi-scale input features mining for short-term PV power prediction. Here, the MVMD combined with Spearman extracts correlation features of the weather data. An equilibrium optimizer (EO) is integrated with MVMD to achieve optimal values of the long short-term memory (LSTM) parameters. Firstly, the correlation of input features is determined and selected by Spearman. The MVMD model is used to mine the high correlation features of solar radiation and conduct cross-correlation analysis to extract input feature components. Secondly, the similar weather days of the sample set are classified to ensure a good adaptability in different weather situations. Finally, the high correlation features are introduced into the photovoltaic power prediction model of EO optimized LSTM. Performance analysis using actual output power data from a PV plant shows that the proposed MVMD feature extraction method can effectively mine correlation features to achieve an optimized dataset under different seasons. Compared with the gray wolf and particle swarm optimization algorithms, the proposed model has a better optimization performance in a low discrimination of input feature decomposition components and low correlation with output power.
Evaluation of Greenhouse Gas Emission Levels during the Combustion of Selected Types of Agricultural Biomass
Authors: Wasilewski Jacek , Zając Grzegorz , Szyszlak-Bargłowicz Joanna , Kuranc Andrzej
Published: October 2022

This paper presents the results of an experimental study of the emission levels of selected greenhouse gases (CO2, CH4, NOx) arising from the combustion of different forms of biomass, i.e., solid biomass in the form of pellets and liquid biomass in the example of engine biofuel (biodiesel). Both types of biomass under study are rape-based biofuels. The pellets are made from rape straw, which, as a waste product, can be used for energy purposes. Additionally, biodiesel contains rape oil methyl esters (FAME) designed to power diesel engines. The boiler 25 kW was used to burn the pellets. Engine measurements were performed on a dynamometer bench on an S-4003 tractor engine. An analyzer Testo 350 was used to analyze the exhaust gas. CO2 emission studies do not indicate the environmental benefits of using any alternative fuels tested compared to their conventional counterparts. In both the engine and boiler tests for NOx emissions, no environmental benefits were demonstrated from the use of alternative fuels. The measured average NOx emission levels for biodiesel compared to diesel were about 20% higher, and for rapeseed straw pellets, they were more than 60% higher compared to wood pellets. Only in the case of engine tests was significantly lower CH4 (approx. 30%) emission found when feeding the engine with rape oil methyl esters.
Operation and Maintenance Optimization for Manufacturing Systems with Energy Management
Authors: An Xiangxin , Si Guojin , Xia Tangbin , Liu Qinming , Li Yaping , Miao Rui
Published: October 2022

With the increasing attention paid to sustainable development around the world, improving energy efficiency and applying effective means of energy saving have gradually received worldwide attention. As the largest energy consumers, manufacturing industries are also inevitably facing pressures on energy optimization evolution from both governments and competitors. The rational optimization of energy consumption in industrial operation activities can significantly improve the sustainability level of the company. Among these enterprise activities, operation and maintenance (O&M) of manufacturing systems are considered to have the most prospects for energy optimization. The diversity of O&M activities and system structures also expands the research space for it. However, the energy consumption optimization of manufacturing systems faces several challenges: the dynamics of manufacturing activities, the complexity of system structures, and the diverse interpretation of energy-optimization definitions. To address these issues, we review the existing O&M optimization approaches with energy management and divide them into several operation levels. This paper addresses current research development on O&M optimization with energy-management considerations from single-machine, production-line, factory, and supply-chain levels. Finally, it discusses recent research trends in O&M optimization with energy-management considerations in manufacturing systems.
Sensor Technologies for Transmission and Distribution Systems: A Review of the Latest Developments
Authors: Swain Akhyurna , Abdellatif Elmouatamid , Mousa Ahmed , Pong Philip W. T.
Published: October 2022

The transmission and distribution systems are essential in facilitating power flow from the source multiple loads over large distances with high magnitudes of voltages and currents. Hence, the monitoring and control of various components of these structures are crucial. Traditionally, this was implemented by sensing only the grid current and grid voltage parameters through coils, clamps, or instrument transformers. However, these have bulky structures that restrict them to the substation and have installation and maintenance issues due to their direct contact with high voltage conductors. Currently, the power grid is undergoing various developments e.g., penetration of renewable energy sources, remote control, and automation, bidirectional power flow, etc. These developments call for compact and energy-efficient sensors to sense multiple grid parameters such as the magnetic field data, temperature, humidity, acoustics, etc., to enable real time, wide area monitoring and the predictive maintenance of the power grid. The goal of this paper is to summarize the advancements in sensing technologies on transmission and distribution systems over a decade and to explain their role in the forthcoming expansion of the power grids. This paper aims to outline the current state-of-affairs of sensor technology as well as to fill research gaps by exploring their limitations.
Thermochemical Properties for Valorization of Amazonian Biomass as Fuel
Authors: Moreira João , Carneiro Alan , Oliveira Diego , Santos Fernando , Guerra Danielle , Nogueira Manoel , Rocha Hendrick , Charvet Félix , Tarelho Luís
Published: October 2022

The use of agroforestry residues for energy purposes has long been a reality in Brazil. About 84.8% of the produced electricity comes from renewable resources; vegetable biomass contributes 9.1% to this total. This percentage has the potential to increase if Amazon biomass residues are processed to be used as fuel. The major difficulty for this scenario is the lack of available information on energy properties, mainly the HHVs for Amazon agroforestry biomass types. Considering that there are important deviations in the equations for predicting the HHVs of Amazon biomass types in the literature, the main objective of this work was to propose equations to determine the HHVs of these biomass types using the proximate or ultimate analysis results as input. The methodology adopted to develop such equations was simple and multiple linear regression methods, using experimental results for HHVs and proximate and ultimate analyses for biomass types from the north region of Brazil. Four distinct equations were considered based on ranges from the proximate and ultimate analyses of the biomass types to deliver better results. The obtained equations were validated by application to 28 other biomass types from the same region. The proposed HHV equations presented good agreement between predicted and experimental values, with errors below 5% for equations based on proximate analysis and below 3% for equations based on ultimate analysis.
A Novel Multi-Objective Optimal Design Method for Dry Iron Core Reactor by Incorporating NSGA-II, TOPSIS and Entropy Weight Method
Authors: Li Yan , Liu Yifan , Li Shasha , Qi Leijie , Xie Jun , Xie Qing
Published: October 2022

Dry iron core reactors are widely used in various power quality applications. Manufacturers want to optimize the cost and loss simultaneously, which is normally achieved by the designers’ experience. This approach is highly subjective and can lead to a non-ideal product. Thus, an objective dry iron core reactor design approach to balance the cost and loss with a scientific basis is desired. In this paper, a multi-objective optimal design method is proposed to optimize both the cost and loss of the reactor, which provides an automatic and scientific design method. Specifically, a three-dimensional finite element model of dry iron core reactor is established, based on which the dependency of cost and loss upon the wire size of the reactor’s winding is studied by using joint Matlab-finite element method (FEM) simulation. The Non-dominated Sorting Genetic Algorithm II (NSGA-II) is used to search for the Pareto optimal solution set, out of which the optimal wire size of the reactor is determined by using the fusion of the technique for order preference by similarity to ideal solution (TOPSIS) method and the entropy weight method. TOPSIS helps the designer to balance the concern between cost and loss, while the entropy weight method can determine the weight information through the dispersion degree of cost and loss. This methodology can avoid personal random subjective opinion when selecting the design solution out of the Pareto set. The calculation shows that the cost and loss can be reduced by up to 17.85% and 19.45%, respectively, with the proposed method. Furthermore, the obtained optimal design is approved by experimental tests.
Sustainability and Cost Effectiveness Analysis of Staggered Jet Impingement on Solar Thermal Collector
Authors: Maithani Rajesh , Kumar Anil , Kumar Manoj , Sharma Sachin
Published: October 2022

The sustainability index, waste energy ratio and improvement potential of a staggered air jet impingement on the staggered spherical protrusions of a roughened absorber plate were derived for the present study to evaluate exergy losses and irreversibility in the system. The experimental analysis was carried out for selected parameters: relative streamwise pitch, relative spanwise pitch and relative jet diameter to hydraulic diameter ratio. The flow Reynolds number ranged from 4000–18,000. The augmentation in Nusselt number and friction factor compared to a smooth surface was 4.9 and 12.4 times, respectively. The statistical correlation developed determined the maximum thermohydraulic performance parameter and exergetic efficiency be 3.02 and 3.87%, respectively. The magnitude of the sustainability index, waste energy ratio and improvement potential was found to be 1.0347, 0.962 and 10.84, respectively, for the entire range of tested parameters. A cost analysis was also performed to evaluate the cost-effectiveness of the solar thermal system with and without turbulent promoters.
Multi-Objective Optimization Design of a New Permanent Magnet Synchronous Motor Based on the Taguchi Method
Authors: Qu Chunyu , Guo Ziqi , Hu Yongzhuang , Wang Xiuping , Han Fangxu
Published: October 2022

To improve the performance and stability of the permanent magnet synchronous motor (PMSM), a new type of built-in permanent magnet synchronous motor (IPMSMB) is proposed. Firstly, the performance indexes of IPMSM, IPMSMA, and IPMSMB are compared by finite element analysis. The results show that the effective harmonic of the air-gap magnetic density of the motor increases when the rotor outer diameter is piecewise eccentric. At the same time, torque ripple and cogging torque decrease. Then the permanent magnet structure of the motor is changed on the basis of IPMSMA to form IPMSMB, which improves the output torque of the motor. Secondly, the Taguchi method is used to optimize the structural parameters of IPMSMB. After optimization, the output torque of IPMSMB is increased by 4.6%. The cogging torque and torque ripple are decreased by 45.5% and 25.7%, respectively. The consumption of permanent magnets is reduced by 7.74%. Finally, the rationality of the motor design is verified by the prototype experiment.
Multi-Objective Optimization of a Heat Sink for the Thermal Management of a Peltier-Cell-Based Biomedical Refrigerator
Authors: Gragnaniello Lorenzo , Iasiello Marcello , Mauro Gerardo Maria
Published: October 2022

Both storage and transport of medical products remains a challenging task because of many variables as well as infrastructures, territory, and so on. Among these variables, monitoring the medical products temperature is fundamental to guarantee their safety. On the other hand, for sectors like aerospace delivery, weight has a crucial role too. For such applications and especially for strongly variable external temperatures, Peltier cells might be employed for either cooling or heating medical products to be stored. Accordingly, this study addresses the optimization of a heat sink for the thermal management of a Peltier-cell-based biomedical refrigerator. In detail, a brute-force multi-objective optimization of an impinging-flow finned heat sink for the Peltier cell is carried out here. Thermal resistance, weight, and pressure drop are chosen as the three-objective functions to be minimized, with both geometrical and volumetric flow rate as design variables. The results present a very large bunch of optimal solutions to design such devices. With the utopia optimum criterion, Rth = 0.159 °C/W, msink = 0.550 kg, and Δp = 14.99 Pa are obtained. Finally, both multiple-linear regression and artificial neural networks are employed to relate design variables with the objective functions, in order to provide the final user with a practical tool for the optimal design of such devices.
Migration Rule of Crude Oil in Microscopic Pore Throat of the Low-Permeability Conglomerate Reservoir in Mahu Sag, Junggar Basin
Authors: Tan Feng-Qi , Ma Chun-Miao , Zhang Xu-Yang , Zhang Ji-Gang , Tan Long , Zhao Dan-Dan , Li Xian-Kun , Jing Yu-Qian
Published: October 2022

The low-permeability conglomerate reservoir in the Mahu Sag has great resource potential, but its strong heterogeneity and complex microscopic pore structure lead to a high oil-gas decline ratio and low recovery ratio. Clarifying the migration rule of crude oil in microscopic pore throat of different scales is the premise of efficient reservoir development. The low-permeability conglomerate reservoir of the Baikouquan Formation in the Mahu Sag is selected as the research object, and two NMR experimental methods of centrifugal displacement and imbibition replacement are designed to reveal the differences in the migration rule of crude oil in different pore throats. According to the lithology and physical properties, the reservoirs in the study area can be divided into four categories: sandy grain-supported conglomerates, gravelly coarse sandstones, sandy-gravelly matrix-supported conglomerates and argillaceous-supported conglomerates. From type I to type IV, the shale content of the reservoir increases, and the physical property parameters worsen. Centrifugal displacement mainly produces crude oil in large pore throats, while imbibition replacement mainly produces crude oil in small pores. In the process of centrifugal displacement, for type I reservoirs, the crude oil in the pore throats with radii greater than 0.5 μm is mainly displaced, and for the other three types, it is greater than 0.1 μm. The crude oil in the pore throats with radii of 0.02–0.1 μm, which is the main storage space for the remaining oil, is difficult to effectively displace. The crude oil in the pore throats with radii less than 0.02 μm cannot be displaced. The two experimental methods of centrifugation and imbibition correspond to the two development methods of displacement and soaking in field development, respectively. The combination of displacement and soaking can effectively use crude oil in the full-scale pore throat space to greatly improve the recovery of low-permeability conglomerate reservoirs.
An Analysis of the Use of Energy from Conventional Fossil Fuels and Green Renewable Energy in the Context of the European Union’s Planned Energy Transformation
Authors: Chudy-Laskowska Katarzyna , Pisula Tomasz
Published: October 2022

Over the past few years, considerable emphasis has been put on decarbonization, which, in the context of the recent events in Europe, proves that mixing energy sources is the best strategy. This article discusses ways in which individual EU member states manage their energy source diversification, while comparing their levels of fossil fuels and renewable energy sources (RESs) usage. The research data was acquired from the Eurostat website and comprises of 15 indicators describing the use of energy both from conventional and renewable sources in the European Union, in 2019. The study employs taxonomical methods, such as ranking and cluster analysis. The authors put forward a hypothesis that EU member states approach the use of energy resources in several ways. There are countries which take advantage of both traditional and renewable sources (Netherlands, Germany, Austria, and Italy). However, there is a group of states that relies on a single energy source and exclusively uses either traditional (Poland) or renewable energy resources (Sweden, Finland). The analyses enabled the isolation of country clusters with similar activities and energy strategies.
Modified Levy-based Particle Swarm Optimization (MLPSO) with Boost Converter for Local and Global Point Tracking
Authors: Charin Chanuri , Ishak Dahaman , Mohd Zainuri Muhammad Ammirrul Atiqi , Ismail Baharuddin , Alsuwian Turki , Alhawari Adam R. H.
Published: October 2022

This paper presents a modified Levy particle swarm optimization (MLPSO) to improve the capability of maximum power point tracking (MPPT) under various partial shading conditions. This method is aimed primarily at resolving the tendency to trap at the local optimum particularly during shading conditions. By applying a Levy search to the particle swarm optimization (PSO), the randomness of the step size is not limited to a specific value, allowing for full exploration throughout the power-voltage (P-V) curve. Therefore, the problem such as immature convergence or being trapped at a local maximum power point can be avoided. The proposed method comes with great advantages in terms of consistent solutions over various environmental changes with a small number of particles. To verify the effectiveness of the proposed idea, the algorithm was tested on a boost converter of a photovoltaic (PV) energy system. Both simulation and experimental results showed that the proposed algorithm has a high efficiency and fast-tracking speed compared to the conventional HC and PSO algorithm under various shading conditions. Based on the results, it was found that the proposed algorithm successfully converges most rapidly to the global maximum power point (GMPP) and that the tracking of GMPP under complex partial shading is guaranteed. Furthermore, the average efficiency for all test conditions was 99% with a tracking speed of 1.5 s to 3.0 s and an average output steady-state oscillation of 0.89%.
Use of Reduced Graphene Oxide to Modify Melamine and Polyurethane for the Removal of Organic and Oil Wastes
Authors: Bakhiia Tamuna , Romanchuk Anna Yu. , Maslakov Konstantin I. , Averin Alexey A. , Kalmykov Stepan N.
Published: October 2022

Methods for obtaining efficient sorption materials based on highly porous melamine and polyurethane matrices modified with reduced graphene oxide were developed. These materials are promising for solving environmental problems such as water pollution with organic products by sorption treatment. Reduced graphene oxides (rGOs) were synthesized from graphene oxide suspensions using potassium hydroxide, ascorbic acid or hydrazine hydrate. Composites with obtained rGO and melamine and polyurethane foam were produced for further characterization. The composites demonstrate high sorption of organic pollutants (oil, diesel fuel and gasoline) and low sorption of water. The composites were comprehensively analyzed by physicochemical techniques (SEM, XPS, Raman spectroscopy, UV–Vis) to elucidate the mechanism of sorption.
Fostering Energy Resilience in the Rural Thai Power System—A Case Study in Nakhon Phanom
Authors: Hart Maria Christina Gudrun , Breitner Michael Hans
Published: October 2022

With rising electricity demand, heavy reliance on imports, and recent economic downturns due to the negative impact of the COVID-19 pandemic, supply chain bottlenecks, and the Russian invasion of Ukraine, Thailand is suffering severely from energy resilience risks. The government has therefore set a goal of decentralizing energy production through small-scale distributed renewable energy systems. To support their design and the planning process, we simulate multiple scenarios with wind turbines, photovoltaic systems, and battery storage for a model community in rural Nakhon Phanom, Thailand. Using the software NESSI4D, we evaluate and discuss their impact on energy resilience by considering environmental sustainability, economic attractiveness, and independence from the central power grid. To fill the gap of missing data on energy demand, we synthesize high-resolution load profiles from the Thailand Vietnam Socio-Economic Panel. We conclude that distributed photovoltaic systems with additional battery storage are only suitable to promote energy resilience if the government provides appropriate financial incentives. Considering temporal variations and local conditions, as well as a participatory decision-making process, are crucial for the long-term success of energy projects. Our advice to decision-makers is to design policies and regulatory support that are aligned with the preferences and needs of target communities.
Perceptions of Youth and Parent Decision-Making Roles Regarding Recombinant Human Growth Hormone Treatment
Authors: Fremont Ettya , Friedrich Elizabeth , Feudtner Chris , Grimberg Adda , Miller Victoria
Published: October 2022

Recombinant human growth hormone (rhGH) is prescribed to youth with growth hormone deficiency (GHD) to support normal growth and ensure healthy physical development, and to youth without GHD to address height concerns. Perceptions of youth involvement in rhGH treatment decisions have not been explored. This study aimed to examine perceptions of youth and parent roles in decisions around rhGH treatment. Youth (n = 22, 11.5 ± 2.0 years) who had undergone evaluation for short stature and their parents (n = 22) participated in semi-structured interviews after stimulation test results had been received. Interviews revealed the following themes: (1) parent provided youth with support; (2) parent facilitated youth’s decision-making involvement; (3) youth had no role or did not remember their role; and (4) youth did not remember conversations with their parents or providers. Parents facilitated their children’s involvement by sharing information and seeking their opinions. While some participants described youth as having a substantial decision-making role, not all youth felt they were involved, and some youth could not recall conversations about rhGH. Parents can bolster youth involvement by having conversations using developmentally appropriate language, which is critical to youth feeling empowered and developing efficacy over their own care.
Are the Modern Diets for the Treatment of Obesity Better than the Classical Ones?
Authors: Koliaki Chrysi , Katsilambros Nicholas
Published: October 2022

Conventional hypocaloric diets, providing continuous energy restriction, are considered to be the cornerstone of dietary management of obesity. Although energy-restricted diets are overall safe, healthy, and modestly effective, their long-term adherence is difficult to accomplish. Intermittent fasting and ketogenic diets have emerged as attractive alternative dietary options for weight loss and improvement in cardiometabolic risk. Intermittent fasting is a unique dietary pattern characterized by periods of eating alternated with periods of fasting. Ketogenic diets are very low in carbohydrate, modest in protein, and high in fat. Several systematic reviews and meta-analyses of randomized controlled trials (RCTs) have reported beneficial but short-lived effects of intermittent fasting and ketogenic diets on various obesity-related health outcomes. Although for both diets, the current evidence is promising and steadily evolving, whether they are better than traditional calorie-restricted diets, whether they can safely lead to sustained weight loss and overall health benefits, and their effects on body composition, weight loss maintenance, energy intake and expenditure, diet quality, and cardiometabolic risk factors are still not unequivocally proven. The aim of the present review is to summarize the current state of evidence regarding the effects of these two popular modern diets, namely intermittent fasting and ketogenic diets. We describe the rationale and characteristics of different dietary protocols, we analyze the major mechanisms explaining their weight loss and cardiometabolic effects, and we provide a concise update on their effects on body weight and cardiometabolic risk factors, focusing on meta-analyses of RCTs. We also discuss knowledge gaps in the field of these diets, and we indicate directions for future research.
Modulation of DNA Methylation/Demethylation Reactions Induced by Nutraceuticals and Pollutants of Exposome Can Promote a C > T Mutation in the Breast Cancer Predisposing Gene PALB2
Authors: Courant Florestan , Bougras-Cartron Gwenola , Abadie Caroline , Frenel Jean-Sébastien , Cartron Pierre-François
Published: October 2022

Background: Deregulation of DNA methylation/demethylation reactions may be the source of C > T mutation via active deamination of 5-methylcytosine to thymine. Exposome, that is to say, the totality of exposures to which an individual is subjected during their life, can deregulate these reactions. Thus, one may wonder whether the exposome can induce C > T mutations in the breast cancer-predisposing gene PALB2. Methods: Our work is based on the exposure of MCF10A mammary epithelial cells to seven compounds of our exposome (folate, Diuron, glyphosate, PFOA, iron, zinc, and ascorbic acid) alone or in cocktail. The qMSRE and RMS techniques were used to study the impact of these exposures on the level of methylation and mutation of the PALB2 gene. Results: Here, we have found that exposome compounds (nutriments, ions, pollutants) promoting the cytosine methylation and the 5-methylcytosine deamination have the ability to promote a specific C > T mutation in the PALB2 gene. Interestingly, we also noted that the addition of exposome compounds promoting the TET-mediated conversion of 5-methylcytosine (Ascorbic acid and iron) abrogates the presence of C > T mutation in the PALB2 gene. Conclusions: Our study provides a proof of concept supporting the idea that exposomes can generate genetic mutation by affecting DNA methylation/demethylation.
Arthrinium arundinis, a Novel Causal Agent of Moso Bamboo (Phyllostachys edulis) Culm Rhomboid Rot and Its Sensitivity to Fungicides
Authors: Zheng Shuzhao , Zhang Qinghua , Song Zhang , Zhou Huixia , Liao Yiran , Zhang Feiping
Published: October 2022

Culm rhomboid rot is a new disease of Moso bamboo (Phyllostachys edulis) and mainly occurs on Moso bamboo grown at an altitude above 800 m. The typical symptoms start with black spots and irregular shapes, which expand vertically into an elongated, fusiform, or rhomboid shape up to 15 cm in length. Eleven fungal isolates were isolated from infected tissue, and the isolate BBB1 was confirmed as the pathogen following Koch’s postulates in vitro and in vivo. Regarding morphology, BBB1 was identified as Arthrinium sp.–conidia single-celled, brown to dark, smooth, globose to subglobose, with an equatorial slit, 5.0–9.3 × 3.1–7.3 μm in size. The conidiophores were reduced to conidiogenous cells, pale brown to dark, smooth, and ampulliform. Phylogenetic analysis based on ITS-TEF1-α-TUB2 concatenate sequences identified BBB1 as A. arundinis. Furthermore, the sensitivity of the pathogen against six common fungicides was investigated with mycelial growth assays. Prochloraz exhibited the most potent inhibition with an EC50 value of 0.019 mg/L; another effective fungicide was difenoconazole, with an EC50 value of 0.195 mg/L. This is the first report of A. arundinis causing culm rhomboid rot of Moso bamboo in China; the results provide a basis for managing Moso bamboo culm rhomboid rot.
Psychological Effects of Green Experiences in a Virtual Environment: A Systematic Review
Authors: Lee Mijin , Kim Eunsoo , Choe Jiwon , Choi Seonhye , Ha Siyeon , Kim Geonwoo
Published: October 2022

As mental health issues increase worldwide, nature-based experiences are being recognized as alternative treatments for improving health and well-being. Increasing urbanization precludes many people from accessing green spaces owing to time or physical limitations. Therefore, opportunities to connect with nature through virtual technology is being encouraged. We conducted a systematic review of studies on the psychological effects of experiencing nature using virtual technology. We searched the academic databases PubMed, Web of Science, and Scopus for relevant studies and assessed their quality using Cochrane’s RoB 2 and ROBINS-I tools. Twenty-one studies were included and the psychological outcomes were negatively synthesized by the intervention characteristics (duration, observation position of the landscape, interaction, environment description, and sensory type). Psychological outcomes were classified into emotional recovery, cognitive recovery, stress reduction, and other indicators. Emotional recovery was most consistently presented, and virtual natural contact alleviated negative emotions more than it elicited positive emotions. Additionally, virtual nature interventions lasting more than 10 min showed more consistent effects than those of less than 10 min. Moreover, an open field of view led to significant emotional recovery and an in-forest view led to significant cognitive recovery. Despite some limitations, our findings will contribute to the development of virtual forest experiences to improve human well-being.
Greater Greening Trend in the Loess Plateau of China Inferred from Long-Term Remote Sensing Data: Patterns, Causes and Implications
Authors: Guo Wei , He Hao , Li Xiaoting , Zeng Weigang
Published: October 2022

The Loess Plateau (LP) of China, which is the pilot region of the “Grain to Green Project” (GGP), has received worldwide attention due to its significant changes in the natural and social environment. Investigation of vegetation variations in response to climate change and human activities is vital for providing support for further ecological restoration planning. This paper aimed to monitor vegetation dynamics of the LP with trend comparisons of various vegetation types, disentangle the effects of climate variations and ecological programs on vegetation variations, and detect the consistency of vegetation variations. More specifically, vegetation dynamics during 1982–2015 were analyzed using the Global Inventory Modelling and Mapping System third-generation Normalized Difference Vegetation Index (GIMMS NDVI3g) data with the application of Breaks for Additive Season and Trend (BFAST) and Hurst Exponent. The results showed that: (1) Vegetation manifested a significant greening trend (0.013 decade−1p < 0.01) in the LP during 1982–2015, and a breakpoint (BP) was detected in 1999, which was the beginning of the GGP. Interannual NDVI after the BP (ABP) showed more than 3.5 times greening rates compared to the NDVI before the BP (BBP). (2) Human activities dominated the vegetation variation (accounted for 59.46% of vegetation variation), among which reforestation and land-use change with steep slopes (i.e., ≥15°) lead to the greening after the GGP implementation. (3) Future trends should be noticed in the Forest Zone and Forest-Grass Zone, where the greening trends tend to slow down or even reverse in the southern LP. The long-term GIMMS NDVI3g time series and multiple geospatial analyses of this study might facilitate a better understanding of the mechanisms of vegetation variations for the assessment of the large restoration programs in fragile ecosystems.
Assessing Leaf Morphometric Symmetry of Four Chinese Quercus Species in a Mixed Forest
Authors: Li Xuan , Yu Xiaojing , Huang Jiefan , EI-Kassaby Yousry A. , Fang Yanming
Published: October 2022

(1) Background: Oaks have achieved notoriety for sufficient levels of sympatric species richness allowing hybridization, thus generating substantial phenotypic variation. Leaf fluctuation asymmetry is an important attribute, as it reflects not only genetic variability but also species buffering capacity. (2) Methods: We investigated the phenotypic diversity of four-oak species (Quercus acutissima, Q. variabilis, Q. fabri, and Q. serrata var. brevipetiolata) using leaf geometric morphometric analysis. Eight leaf morphological indicators (length, width, perimeter, area, left and right areas, areal ratio, and normalized symmetry index) were used to determine the hybridization level, whereas bilateral symmetry indicators were used to assess species environmental adaptation; (3) Results: Phenotypic variation ranged from 1.54 to 29.35 folds and significantly diverged among the studied species. Taxonomically species in Section Quercus (Q. fabri and Q. serrata var. brevipetiolata) are lower than those in Section Cerris (Q. acutissima and Q. variabilis) with good bilateral symmetry. The bilateral symmetry index of Q. variabilis had a larger range of variation, indicating better environmental adaptability; (4) Conclusions: We presume that species in Section Quercus with less leaf fluctuation asymmetry have a high level of genetic heterozygosity; however, this assumption requires further verification. The observed phenotypic diversity reflects a combination of environmental and genetic factors.
Analyses of Impregnation Quality and Mechanical Properties of Radiata Pine Wood Treated with Copper Nanoparticle- and Micronized-Copper-Based Wood Preservatives
Authors: Aguayo María Graciela , Erazo Oswaldo , Montero Claudio , Reyes Laura , Gacitúa William , Gómez Liset , Torres Hugo
Published: October 2022

In this work, the impregnation quality and mechanical properties of Pinus radiata D.Don treated with different copper nanoparticles (CuNP) solutions (named K1 and K2) and a commercial preservative (M) were studied. The impregnation quality of radiata pine wood was analyzed by two indicators, penetration and retention. The micro-distribution of preservative in the treated wood was qualitatively evaluated by SEM-EDS, both in the samples containing CuNP and in those treated with the commercial preservative. In addition, some mechanical properties were studied in the preserved wood including MOE, MOR and hardness. The results indicated values by ED XRF retention of 0.96 kg/m3 and 0.86 kg/m3 for K1 and K2, respectively, and 1.01 kg/m3 for M wood impregnated. In the penetration determined by colorimetric test, the wood samples impregnated (with K1, K2 and M) showed 100% penetration. The distribution of CuNP and micronized copper within the wood structure was confirmed by SEM EDS mapping. In mechanical properties, a reduction in MOE was reflected in all wood treated. The control samples were far superior to the K1 and M treated samples and slightly superior to the K2 samples, with no statistically significant differences. On the other hand, samples impregnated with K1 and K2 showed the highest values in hardness parallel and perpendicular to the grain, revealing that these preservative solutions tend to increase hardness. Overall, when it comes to the samples impregnated with micronized copper (M), the mechanical properties were considerably lower compared to the CuNP treated and control wood. Therefore, the CuNP-based preservative did not strongly affect the mechanical properties of the preserved wood.