bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the Combustion Process for Two Refuse-Derived Fuel (RDF) Streams Using Statistical Methods and Heat Recovery Simulation
Authors: Brożek Piotr , Złoczowska Ewelina , Staude Marek , Baszak Karolina , Sosnowski Mariusz , Bryll Katarzyna
Published: December 2022

This study characterises materials that belong to the group of refuse-derived fuels (RDF). This group of materials regarded as an alternative fuel is derived from industrial, municipal solid and commercial wastes. The aim of this study is to evaluate the quality of waste composition, demonstrate statistically different values and the energy efficiency of the fuel derived from waste. Data on incinerated waste were collected from two different sources. The basic physical and chemical parameters of waste include density and water content. The lower heating value (LHV) of waste, chlorine concentration and ash content of two groups of incinerated waste were also evaluated and compared for a given period of time (one year, with monthly breakdown). Statistical analysis indicated the differences in the combustion of waste groups, visualized by box plots and other diagrams to show the distribution of the results. An analysis of exhaust gas parameters was carried out, both in terms of chemical composition and energy parameters. The RDF combustion process was presented through simulations for the adopted conditions of heat recovery. It was found that for each kilogram of RDF, about 3.85 kWh (13,860 kJ) of heat can be obtained. The combustion process was simulated using Aspen Plus software.
Hilbert-Optic Diagnostics of Hydrogen-Oxygen Inverse Diffusion Flame
Authors: Arbuzov Vitaly , Arbuzov Eduard , Dubnishchev Yuriy , Zolotukhina Olga , Lukashov Vladimir , Tupikin Andrey
Published: December 2022

The aim of this work is to adapt the methods of optical Hilbert diagnostics for the visualization and study of inverse diffusion H2/O2 flame. The diagnostic complex is implemented on the basis of the IAB-451 device with modified optical filtering. Visualization of phase perturbations induced by the studied medium in a probing multiwave light field is performed via polychromatic Hilbert and Foucault-Hilbert transformations in combination with registration and RGB-per-pixel processing of the dynamic structure of the images. From solution to the inverse problem of Hilbert optics using a physically justified initial approximation of the problem under consideration, the temperature field of the flame is reconstructed and the value of the H2, H2O, O2 and N2 concentrations may be restored.
Gasification Kinetics of Organic Solid Waste Pellets: Comparative Study Using Distributed Activation Energy Model and Coats–Redfern Method
Authors: Wang Xiangxi , Hu Zhenzhong , Mian Inamullah , Dacres Omar D. , Li Jian , Wei Bo , Zhong Mei , Li Xian , Rahman Noor , Luo Guangqian , Yao Hong
Published: December 2022

The gasification kinetics of pellets obtained from organic solid wastes (OWS) and raw materials were studied using the Coats–Redfern and DAEM methods. The different methods were comparatively analyzed for mutual verification, and the similar activation energies obtained by each method affirmed the accuracy of the kinetics calculation. Overall, the activation energies of the char gasification stage ranged from 200 to 265 kJ mol−1, higher than those of the devolatilization stage, which ranged from 130 to 200 kJ mol−1 for all pellets and raw materials. During the devolatilization stage, the activation energies of the pellets were invariably higher than those of their corresponding raw materials, which was the opposite for the char gasification stage. A detailed comparison between the calculation results from the Coats–Redfern and DAEM methods confirmed that the devolatilization stage is controlled by one-dimensional diffusion, and the gasification stage is controlled by two-dimensional or three-dimensional diffusion for pellets and raw materials.
A Novel High-Performance Anode Material with an Enlarged Potential Window for a Hybrid Energy Storage System
Authors: Mateen Abdul , Zubair Muhammad , Saleem Muhammad , Golubenkova Alexandra , Voskressensky Leonid , Alothman Asma , Ouladsmane Mohamed , Ahmad Awais , Javed Muhammad
Published: December 2022

Cobalt-iron (CoFe) layered double hydroxides (LDHs) have received much interest for supercapacitors (SCs) because of their ion-insertable layer structure. However, there is still a need for more effort to increase their potential window and overall electrochemical energy storage capability as SC electrodes. In this work, we present a straightforward approach to synthesizing CoFe-LDHs on zinc oxide seeded carbon cloth (ZnO@CC) via a one-step hydrothermal reaction; the obtained electrode is denoted as CoFe-LDH@ZnO@CC. The electrochemical energy storage properties of CoFe-LDH@ZnO@CC are tested as an anode material using a three-electrode setup for SC applications in 1 M Na2SO4 electrolyte. It can operate in a wider potential window reaching up to 1.6 V, exceeding most previously reported anode materials. The CoFe-LDH@ZnO@CC displayed capacitive charge storage accounting for 76% of the total charge stored at 20 mV/s. The CoFe-LDH@ZnO@CC anode delivered a maximum capacitance of 299.8 F/g at 2 A/g, outstanding cycle stability, and retained 97.7% of the initial capacitance value for 5000 cycles at 16 A/g. This study introduces a new strategy for structurally designing electroactive materials for energy storage devices, which might be useful as an anode for SCs.
Day-Ahead Operation Analysis of Wind and Solar Power Generation Coupled with Hydrogen Energy Storage System Based on Adaptive Simulated Annealing Particle Swarm Algorithm
Authors: Chen Kang , Peng Huaiwu , Gao Zhenxin , Zhang Junfeng , Chen Pengfei , Ruan Jingxin , Li Biao , Wang Yueshe
Published: December 2022

As the low-carbon economy continues to evolve, the energy structure adjustment of using renewable energies to replace fossil fuel energies has become an inevitable trend. To increase the ratio of renewable energies in the electric power system and improve the economic efficiency of power generation systems based on renewables with hydrogen production, in this paper, an operation optimization model of a wind–solar hybrid hydrogen energy storage system is established based on electrochemical energy storage and hydrogen energy storage technology. The adaptive simulated annealing particle swarm algorithm is used to obtain the solution, and the results are compared with the standard particle swarm algorithm. The results show that the day-ahead operation scheme solved by the improved algorithm can save about 28% of the system operating cost throughout the day. The analytical results of the calculation example revealed that the established model had fully considered the actual operational features of devices in the system and could reduce the waste of wind and solar energy by adjusting the electricity purchased from the power grid and the charge and discharge powers of the storage batteries under the mechanism of time-of-use electricity price. The optimization of the day-ahead scheduling of the system achieved the minimization of daily system operation costs while ensuring that the hydrogen-producing power could meet the hydrogen demand.
Pool Fire Suppression Using CO2 Hydrate
Authors: Gaidukova Olga , Misyura Sergey , Donskoy Igor , Morozov Vladimir , Volkov Roman
Published: December 2022

This paper presents experimental findings on heat and mass transfer, phase transitions, and chemical reactions during the interaction of CO2 hydrate in powder granules and tablets with burning liquid fuels and oil. The experiments involved CO2 hydrate tablets and spheres made of pressed granules. The fire containment and suppression times were established experimentally. Using the gas analysis data, we studied the effects of the mitigation of anthropogenic emissions from the combustion of liquids and their suppression by gas hydrates. We also compared the performance of water aerosol, foaming agent emulsion, snow, ice, and CO2 hydrate samples as laboratory-scale fire suppressants. The paper further describes the numerical modeling of the CO2 hydrate dissociation during liquid fuel combustion. The rapid carbon dioxide release is shown to prevent the oxidizer from the combustion zone. The suppression of a flame using powder with a granule size of 3 mm requires 20-times less carbon dioxide hydrate than in the case of pressed tablets. Effective conditions are identified for using CO2 hydrates to extinguish fires involving flammable liquids and most common fuels.
Influence of Battery Aging on the Operation of a Charging Infrastructure
Authors: Andrenacci Natascia , Di Monaco Mauro , Tomasso Giuseppe
Published: December 2022

The increasingly widespread use of electric vehicles requires proper planning of the charging infrastructure. In addition to the correct identification of the optimal positions, this concerns the accurate sizing of the charging station with respect to energy needs and the management of power flows. In particular, if we consider the presence of a renewable energy source and a storage system, we can identify strategies to maximize the use of renewable energy, minimizing the purchase costs from the grid. This study uses real charging data for some public stations, which include “normal” chargers (3 kW and 7 kW) and “quick” ones (43 kW and 55 kW), for the optimal sizing of a photovoltaic system with stationary storage. Battery degradation due to use is included in the evaluation of the overall running costs of the station. In this study, two different cost models for battery degradation and their influence on energy flow management are compared, along with their impact on battery life.
Response Surface Methodology Analysis of Pyrolysis Reaction Rate Constants for Predicting Efficient Conversion of Bulk Plastic Waste into Oil and Gaseous Fuels
Authors: Irfan Muhammad , Nabi Rao Adeel Un , Hussain Hammad , Naz Muhammad Yasin , Shukrullah Shazia , Khawaja Hassan Abbas , Rahman Saifur , Ghanim Abdulnoor A. J. , Kruszelnicka Izabela , Ginter-Kramarczyk Dobrochna , Legutko Stanisław
Published: December 2022

The growing production of plastic waste and improper dumping after use has become a worldwide challenge. This waste is a substantial source of petroleum and can be effectively converted into pyrolytic oil and other useful products. A statistical prediction of the rate constants is essential for optimizing pyrolysis process parameters, such as activation energy (Ea), frequency factor (Ao), temperature (T), and kinetic rate constants (k). In this research, we utilized Box–Behnken using RSM with Design Expert software to predict statistical rate constants at 500 °C and 550 °C. The efficiency of the predicted rate constants was investigated and compared to the findings of experimental rate constants extracted from the literature. At 500 °C, the estimated rate constants did not reveal a significant rise in the oil output since these constants promoted high gas yield. Compared to the experimental rate constants, statistically predicted rate constants at 550 °C demonstrated substantially high-oil output with only 1% byproducts. The experimental rate constants yielded 32% oil at 550 °C, whereas the predicted rate constants yielded 85% oil. The statistically predicted rate constants at 550 °C could be used to estimate commercial-scale extraction of liquid fuels from the pyrolysis of high-density plastics. It was also concluded that Ea, Ao, and T must be analyzed and optimized according to the reactor type to increase the efficiency of the expected rate constants.
Techno-Economic Comparison of Brayton Pumped Thermal Electricity Storage (PTES) Systems Based on Solid and Liquid Sensible Heat Storage
Authors: Frate Guido Francesco , Ferrari Lorenzo , Desideri Umberto
Published: December 2022

To integrate large shares of renewable energy sources in electric grids, large-scale and long-duration (4–8+ h) electric energy storage technologies must be used. A promising storage technology of this kind is pumped thermal electricity storage based on Brayton cycles. The paper’s novel contribution is in the techno-economic comparison of two alternative configurations of such storage technology. Liquid-based and solid-based pumped thermal electricity storage were studied and compared from the techno-economic point of view. The cost impacts of the operating fluid (air, nitrogen, and argon), power rating, and nominal capacity was assessed. Air was the most suitable operating fluid for both technologies, simplifying the plant management and achieving cost reductions between 1% and 7% compared to argon, according to the considered configuration. Despite a more complex layout and expensive thermal storage materials, liquid-based systems resulted in being the cheapest, especially for large applications. This was due to the fact of their lower operating pressures, which reduce the cost of turbomachines and containers for thermal energy storage materials. The liquid-based systems achieved a cost per kWh that was 50% to 75% lower than for the solid-based systems. Instead, the cost per kW benefited the solid-based systems up to nominal power ratings of 50 MW, while, for larger power ratings, the power conversion apparatus of liquid-based systems was again cheaper. This was due to the impact of the turbomachines on the total cost. The machines can represent approximately 70% of the total cost for solid-based systems, while, for liquid-based, approximately 31%. Since the cost of turbomachines scales poorly with the size compared to other components, solid-based systems are less suitable for large applications.
Can Industry Keep Gas Distribution Networks Alive? Future Development of the Gas Network in a Decarbonized World: A German Case Study
Authors: Oberle Stella , Neuwirth Marius , Gnann Till , Wietschel Martin
Published: December 2022

With the growing need for decarbonization, the future gas demand will decrease and the necessity of a gas distribution network is at stake. A remaining industrial gas demand on the distribution network level could lead to industry becoming the main gas consumer supplied by the gas distribution network, leading to the question: can industry keep the gas distribution network alive? To answer this research question, a three-stage analysis was conducted, starting from a rough estimate of average gas demand per production site and then increasing the level of detail. This paper shows that about one third of the German industry sites investigated are currently supplied by the gas distribution network. While the steel industry offers new opportunities, the food and tobacco industry alone cannot sustain the gas distribution network by itself.
Influence of Rock Properties on Structural Failure Probability—Caprock Shale Examples from the Horda Platform, Offshore Norway
Authors: Rahman Md Jamilur , Fawad Manzar , Mondol Nazmul Haque
Published: December 2022

In any geological subsurface fluid injection, a viable top seal is required to contain the vertical movement of the injected fluid plume. However, seal integrity assessment is challenging because of the uncertainties possessed by various parameters. A probabilistic solution might be more appropriate when significant uncertainties are present. In this study, we evaluate Drake shale caprock structural reliability using a stochastic method. Drake shale is the primary top seal in the Aurora CO2 storage site, located in the Horda Platform area in the northern North Sea. Based on the lithological variations, Drake caprock shale is divided into two parts designated by upper and lower units. Six model scenarios from the upper and lower Drake units have been tested. The probabilistic structural failures of varying model scenarios are estimated using the First-Order Reliability Method (FORM). Drake Formation shale shows a considerably low probability of failure (~0) with a high reliability index in the initial stress-state condition and after-injection scenarios. Moreover, the parameter sensitivity study indicates that horizontal stress and cohesion are the most influential input parameters during reliability estimation. Comparative analysis between the caprock properties and failure probability reveals that rock strength properties such as cohesion and friction angle strongly dictate the probability of failure estimation. Moreover, comparing two caprock shale formations indicates that the structural failure values are not correlatable; hence, a formation-specific failure assessment is recommended.
The Potential of the Bioenergy Market in the European Union—An Overview of Energy Biomass Resources
Authors: Wieruszewski Marek , Mydlarz Katarzyna
Published: December 2022

One of the bases of the European policy and energy strategy is the biomass and bioenergy obtained from it. It is estimated that by 2023, the annual demand for biomass will have increased from the current level of 7 EJ to 10 EJ. There are significant differences between estimates of the bioenergy potential due to the fact that the authors of publications do not use consistent methodology and assumptions. Forest biomass, agricultural residues, and energy crops are the three main sources of biomass for energy production. Energy crops are likely to become the most important source of biomass. Land use and its changes are a key issue in the sustainable production of bioenergy as the availability of biomass determines its potential for energy security. This article is a review of the latest publications on the bioenergy potential of the member-states of the European Union. The consumption of energy and its potential were presented, with a special focus on renewable sources, especially biomass. The potential of biomass resources was presented and the types of biomass and its sources of origin were indicated. The research was conducted on the member-states of the European Union, whose policy is based on long-term development from the dependence on fossil resources to the dominance of renewable resources. As results from the research, in recent years, there has been a significant increase in the potential of both forest biomass (from 4.8 EJ per annum to the forecasted 15 EJ per annum) and agricultural biomass from (from 2.3 EJ per annum to the forecasted 7 EJ per annum). The increase in the demand for energy biomass in the EU member-states is balanced by partial imports from non-EU countries.
Identifying Improvement Opportunities in Product Design for Reducing Energy Consumption
Authors: Relich Marcin , Gola Arkadiusz , Jasiulewicz-Kaczmarek Małgorzata
Published: December 2022

The paper is concerned with predicting energy consumption in the production and product usage stages and searching for possible changes in product design to reduce energy consumption. The prediction of energy consumption uses parametric models based on regression analysis and artificial neural networks. In turn, simulations related to the identification of improvement opportunities for reducing energy consumption are performed using a constraint programming technique. The results indicate that the use of artificial neural networks improves the quality of an estimation model. Moreover, constraint programming enables the identification of all possible solutions to a constraint satisfaction problem, if there are any. These solutions support R&D specialists in identifying possibilities for reducing energy consumption through changes in product specifications. The proposed approach is dedicated to products related to high-cost energy use, which can be manufactured, for example, by companies belonging to the household appliance industry.
A Comparative Study of NOx Emission Characteristics in a Fuel Staging and Air Staging Combustor Fueled with Partially Cracked Ammonia
Authors: Kim Namsu , Lee Minjung , Park Juwon , Park Jeongje , Lee Taesong
Published: December 2022

Recently, ammonia is emerging as a potential source of energy in power generation and industrial sectors. One of the main concerns with ammonia combustion is the large amount of NO emission. Air staging is a conventional method of reducing NO emission which is similar to the Rich-Burn, Quick-Mix, Lean-Burn (RQL) concept. In air-staged combustion, a major reduction of NO emission is based on the near zero NO emission at fuel-rich combustion of NH3/Air mixture. A secondary air stream is injected for the oxidation of unburned hydrogen and NHx. On the other hand, in fuel-staged combustion, NO emission is reduced by splitting NH3 injection, which promotes the thermal DeNOx process. In this study, NOx emission characteristics of air-staged and fuel-staged combustion of partially cracked ammonia mixture are numerically investigated. First, the combustion system is modeled by a chemical reactor network of a perfectly stirred reactor and plug flow reactor with a detailed chemistry mechanism. Then, the effects of ammonia cracking, residence time, and staging scheme on NOx emission are numerically analyzed. Finally, the limitations and optimal conditions of each staging scheme are discussed.
Why Biomass Fuels Are Principally Not Carbon Neutral
Authors: Ahamer Gilbert
Published: December 2022

In order to realistically fulfil global and national climate protection targets, all potential measures have to be made use of to a maximum extent. Because it is readily available, biomass energy has been playing a key practical role for decades, supported by the traditional assumption of its carbon neutrality: under sustainable conditions, carbon dioxide emitted during combustion is held to be equal to its absorption during plant growth. In order to clarify conditions of carbon (C) neutrality, it is therefore necessary to model the annual natural C cycle on the entire planet and to include changes caused by a variety of growth strategies for biomass fuels. The “Combined Energy and Biosphere Model” CEBM calculates the cycle of plant growth, decay, biomass fuel production and its combustion on 2433 grid elements worldwide. CEBM results suggest that over many decades, the C pools of litter and especially soil organic carbon (i.e., humus layer) deplete considerably as a consequence of the interrupted natural carbon cycle. Overall, based on this finding, the earlier assumption of “carbon-neutral biomass fuels” is disapproved of in a long-term evaluation and—as a coarse rule of thumb—might be reduced to “half as carbon neutral as previously assumed” (when compared to a current fuel mix). On top of this principal effect, it is well known that life-cycle emissions, indirect or secondary emissions such as energy input related to production, transport and conversion into fuels will still add to this already principally highly incomplete carbon neutrality of biomass.
Review of Current State-of-the-Art Research on Photovoltaic Soiling, Anti-Reflective Coating, and Solar Roads Deployment Supported by a Pilot Experiment on a PV Road
Authors: Hassan Sharmarke , Dhimish Mahmoud
Published: December 2022

The objective of this review paper is to provide an overview of the current state-of-the-art in solar road deployment, including the availability of anti-reflection and anti-soiling coating materials for photovoltaic (PV) technology. Solar roads are built using embedded PV panels that convert sunlight into electricity, which can be stored for later use. Prototypes of solar roads have been tested on various continents, but the lack of suitable PV materials has limited their effectiveness compared to conventional PV systems. By analyzing the existing literature on solar roads and PV materials, including anti-reflection and anti-soiling coatings, we aim to identify gaps in knowledge and propose an action plan to improve the resiliency, durability, and reliability of PV panels in solar road applications. This will enable the deployment of solar roads as a clean, renewable energy source.
Energy Transition of the Coal Region and Challenges for Local and Regional Authorities: The Case of the Bełchatów Basin Area in Poland
Authors: Żak-Skwierczyńska Małgorzata
Published: December 2022

The transition to a climate-neutral economy presents a particular challenge for the areas where the economy is based on rich lignite resources. One of them is the Bełchatów Basin Area in Poland. The complexity of the phenomena occurring in the area of transformation requires an interdisciplinary and integrated approach to development planning and managing. It is important to create stable conditions, allowing for the introduction of necessary changes, including the involvement of various stakeholders. The research is aimed at identifying the challenges faced by the region with a lignite-based economy, the inhibitors of the transformation process, and recommendations for public policy. During the research, secondary and primary data were analysed with the use of triangulation, which allowed to combine various techniques and sources, as well as an in-depth description and multi-faceted understanding of the case under study. The study poses a key question as to whether the public authority is capable of implementing the energy transition that would protect the global public interest. The conducted research showed deficiencies negatively affecting its implementation. There are barriers affecting cooperation in the public sphere and with other stakeholders. An analysis of the limitations in cooperation showed the dysfunction of energy policy implementation at the regional level. Vertical and horizontal actions between different stakeholders of the transformation are necessary to identify seed industries representing a transformational opportunity in the Bełchatów Basin. Renewable energy sources may play a key role in this process. Their share in electricity production should be increased. A clear and precise vision of the development of this territory, as well as a stable and diversified system of financing are important elements of change. The article draws attention to the lack of a transformation leader. Identifying an actor responsible for the protection of the global public interest is essential.
Two-Phase Experimentation to Determine the Optimal Composition for the Production of Biogas and Biol Substrate Mixing Waste from the Camal de Guayaquil
Authors: Arla Sandra , Delgado Reinaldo , Goyos Leonardo , Robaina Leandro
Published: December 2022

In this two-phase study, it was shown that a mixture with equal parts of manure and resulting animal blood was the optimal combination for obtaining biogas and biol. A quadratic growth trend in variable gas pressure over time—as well as its behavior—was confirmed for pHs around the neutral value for the substrate used in both the pilot phase and in the microplant, which had a mechanical implementation and mechatronic system for the control of variables that intervene in the anaerobic digestion process; this allowed for the confirmation of the results found in the first phase of research—without concerns that a lack of control over the process variables would cause—in such a way that it constituted a path for the industrialization of the waste treatment process in slaughterhouses that could be optimized by the use of the optimal combination that produces the greatest cm3 amount of gas. Anaerobic digestion in biodigesters is carried out at different constant temperature values within the mesophilic range, with a hydraulic retention time of 25 days. A direct relationship was found between temperature, biogas production and pH behavior in the buffer(s). The pH remained close to neutral and the gas pressure increased from 15 to 20. The findings indicated that the value for the C/N ratio of the blood of four was compensated for by its buffer system, composed of bicarbonate, hemoglobin, proteins and phosphates.
Impact of a HVDC Link on the Reliability of the Bulk Nigerian Transmission Network
Authors: Olasunkanmi Omowumi Grace , Apena Waliu O. , Barron Andrew R. , White Alvin Orbaek , Todeschini Grazia
Published: December 2022

Regular and reliable access to energy is critical to the foundations of a stable and growing economy. The Nigerian transmission network generates more electricity than is consumed but, due to unpredicted outages, customers are often left without electrical power for several hours during the year. This paper aims to assess the present reliability indices of the Nigerian transmission network, and to determine the impact of HVDCs on system reliability. In the first part of this paper, the reliability of the Nigerian transmission system is quantified by building a model in DIgSILENT PowerFactory and carrying out a reliability study based on data provided by the Nigerian transmission-system operator. Both network indices and load-point indices are evaluated, and the weakest points in the network are identified. In the second part of the paper, an HVDC model is built and integrated into the existing network at the locations identified by the reliability study. A comparative study using two different HVDC connections is then carried out, to determine the critical impact of HVDC on system reliability. The reliability results indicate that the weakest points of the transmission system are the radial feeders, and the highest impact could be achieved by spanning an HVDC line between two busbars located at the two extremes of a radial feeder: Azura and Yola.
Research on Vibration Characteristics of an Underground Powerhouse of Large Pumped-Storage Power Station
Authors: Zhang Lijuan , Guo Yaohua , Wang Haijun , Yang Xuliang , Lian Jijian
Published: December 2022

With the rapid development of pumped storage, the vibration problems caused by the operation of power stations have become increasingly prominent. In this paper, a large-scale pumped-storage power station is taken as the research object, and a three-dimensional refined finite element model of the underground powerhouse including the surrounding rock mass is established. Based on the analysis of the vibration source of the powerhouse and the water diversion pipeline, the modal and dynamic response analysis of the underground powerhouse of the hydropower station is carried out, and the distribution law of the larger vibration displacement position is revealed. The calculation results show that under the premise that the vibration source is selected reasonably and the numerical model is accurate, the main frequency of the underground powerhouse structure can be obtained more accurately. After optimizing the design of the underground powerhouse based on the calculation results, the resonance problem of the underground powerhouse of the hydropower station can be avoided. The dynamic elastic modulus of the rock mass around the underground powerhouse has little influence on the mode shape of the powerhouse, but has a great influence on its fundamental frequency. When the dynamic elastic modulus of the rock mass increases by 50%, the fundamental frequency of the plant increases by about 29%. At the same time, the mode shape of each order of the underground powerhouse structure does not change much, mainly manifested as the vibration of the beam system structure, which is mainly caused by the stiffness of the beam system components being much smaller than the structural stiffness of the windshield, machine pier, and mass concrete around the volute. The research results can provide references for the design of underground powerhouses of large-scale pumped-storage power stations and the analysis of vibration problems.
Study of the Technologies for Freeze Protection of Cooling Towers in the Solar System
Authors: Liu Jingnan , Zhang Lixin , Chen Yongbao , Yin Zheng , Shen Yan , Sun Yuedong
Published: December 2022

A cooling tower is an important guarantee for the proper operation of a solar system. To ensure proper operation of the system and to maintain high-efficiency points, the cooling tower must operate year-round. However, freezing is a common problem that degrades the performance of cooling towers in winter. For example, the air inlet forms hanging ice, which clogs the air path, and the coil in closed cooling towers freezes and cracks, leading to water leakage in the internal circulation. This has become an intractable problem that affects the safety and performance of cooling systems in winter. To address this problem, three methods of freeze protection for cooling towers are studied: (a) the dry and wet mixing operation method—the method of selecting heat exchangers under dry operation at different environments and inlet water temperatures is presented. The numerical experiment shows that the dry and wet mixing operation method can effectively avoid ice hanging on the air inlet. (b) The engineering plastic capillary mats method—its freeze protection characteristics, thermal performance, and economics are studied, and the experiment result is that polyethylene (PE) can meet the demands of freeze protection. (c) The antifreeze fluid method—the cooling capacity of the closed cooling towers with different concentrations of glycol antifreeze fluid is numerically studied by analyzing the heat transfer coefficient ratio, the air volume ratio, the heat dissipation ratio, and the flow rate ratio. The addition of glycol will reduce the cooling capacity of the closed cooling tower.
A Study on a Design Considering the Transient State of a Line-Start Permanent Magnet Synchronous Motor Satisfying the Requirements of the IE4 Efficiency Class
Authors: Park Hyun-Jong , Hong Hyeon-Bin , Lee Ki-Doek
Published: December 2022

In this paper, the transient state analysis of a Line-Start Permanent Magnet Synchronous Motor (LSPMSM) and the optimum design for high efficiency were studied. In the case of an LSPMSM, aluminum bars and permanent magnets are inserted in the rotor. Since it has aluminum bars, it can be directly started on-line without closed-loop control at the time of starting, like an induction motor. Furthermore, once driven, it rotates at a synchronous speed due to the permanent magnets in the steady state. Theoretically, since the rotor bars have no induced current, copper loss does not occur in the rotor bars. Further, because of the inserted permanent magnets, an LSPMSM has a higher power density than an induction motor with the same output power. However, since it is driven directly on-line, the transient state is longer than that of a synchronous motor driven by an inverter. Therefore, it is important to analyze the characteristics of the transient state depending on the rotor shape in the LSPMSM design. In this study, an LSPMSM that has the same outer diameter of a 7.5 kW IE3 efficiency class induction motor currently used for the industry was designed. The optimal design of the motor was designed using Finite-Element Analysis (FEA) and Design of Experiment (D.O.E). In the design process, the velocity ripple was minimized in the transient state, and the steady state was quickly reached. Finally, the efficiency of the motor satisfies the requirements of the IE4 efficiency class, an efficiency standard described in IEC 60034-30, which is an international standard.
Relationship among Economic Growth, Energy Consumption, CO2 Emission, and Urbanization: An Econometric Perspective Analysis
Authors: Myszczyszyn Janusz , Suproń Błażej
Published: December 2022

The key goal of this research was to figure out the short and long run relationship between environmental degradation caused by carbon dioxide (CO2) emissions and energy consumption, the level of GDP economic growth, and urbanization in the Visegrad Region countries (V4). The study used data from the years 1996–2020. In the methodological area, ARDL bound test, and ARDL and ECM models were used to determine the directions and strength of interdependence. The results show that in the case of some V4 countries (Poland, Slovakia, and Hungary), changes in the urbanization rate affect CO2 emissions. Moreover, it was confirmed that the phenomenon of urbanization influences the enhanced energy consumption in the studied countries. In the case of individual countries, these relationships were varied, both unidirectional and bidirectional. Their nature was also varied—there were both long and short-term relationships. These findings suggest that the V4 countries should increase renewable and ecological energy sources. It is also recommended to enhancement energy savings in the areas of both individual and industrial consumption by promoting low-emission solutions. This should be done while considering changes in urbanization.
Relay Protection Setting Calculation System for Nuclear Power Plant Based on B/S Architecture and Cloud Computing
Authors: Hong Yuan , Yu You , Tian Jingfu , Ye Han , Wang Bin , Yu Wenxiang
Published: December 2022

Nuclear power plants have a complex structure and changeable operation mode, which induces low setting calculation efficiency. After analyzing the technology, architecture, and functional logic of a variety of relay protection setting calculation systems and combining the characteristics of the setting calculation of nuclear power plants, the relay protection setting calculation system in nuclear power plants based on B/S architecture and cloud computing is studied in this paper. The system adopts three-tier B/S architecture, applies two key technologies, the cloud computing task distribution synchronization mechanism and the cloud component automatic assembly mechanism, and introduces a particle swarm optimization algorithm to provide technical support for nuclear power plant setting calculation; the running example of the nuclear power plant system fully proves the efficiency and reliability of the relay protection setting calculation system of the nuclear power plant, which has high practical value.
The Effects of Suillus luteus Inoculation on the Diversity of Fungal Communities and Their Structures in the Soil under Pinus massoniana Located in a Mining Area
Authors: Yu Peiyi , Ning Chen , Chen Jingzhen , Zhu Fan , Sun Yujing , Shen Airong , Zeng Wenbin , Jiang Lijuan
Published: December 2022

As important decomposers and plant symbionts, soil fungal communities play a major role in remediating heavy-metal-polluted soils. However, the diversity and structures of fungal communities generally remain unclear in mining areas. This study aimed to assess the rhizospheric fungal-community composition of Masson pine (Pinus massoniana) in the lead-zinc mining area of Suxian District, Hunan Province, China. This experiment undertook the following three treatments: Masson pine inoculated with or not inoculated with Suillus luteus, and bulk soil without plants as a control. The results thereof showed that inoculation of ectomycorrhizal fungi could enlarge plants’ capability to absorb heavy metals and secrete soil enzymes. The richness and diversity of fungi in the rhizospheric soil were significantly higher than of those in the bulk soil (p < 0.05), but no significant difference was noted between the rhizospheric soils inoculated with and not inoculated with ectomycorrhizal (ECM) fungi as the community structure changed. The rhizospheric fungi belonged to 6 phyla, 25 classes, 65 orders, 115 families, and 150 genera, and the dominant phyla were Chytridiomycota (50.49%), Ascomycota (38.54%), and Basidiomycota (9.02%). Through use of LEfSe and heatmapping, the relative abundances of Suillus, Paraglomus, Agaricus, and Tulasnella were found to be the highest in the soil with ECM fungus inoculation. RDA showed that the community structure nearly changed with ECM-fungus inoculation; this was significantly related to soil water content, the carbon–nitrogen ratio, bulk density, available potassium, and soil enzymes. Altogether, inoculation with ECM fungi may change the habitation environments of microorganisms and dominant fungi in soil, providing keystone screenings in heavy-metal-contaminated mining areas.
Cold Hardiness of Prunus mume ‘Xiang Ruibai’ and Its Parents Based on Biological Indexes and Physical Parameters
Authors: Ding Anqi , Bao Fei , Ding Aiqin , Zhang Qixiang
Published: December 2022

Low temperature is a primary factor limiting the distribution of Prunus mume. In order to produce a variety that has both cold tolerance and the characteristic fragrance of true mume, previous researchers crossbred a strong-tolerance variety apricot mei, P. mume ‘DF’ (‘Dan Fenghou’) and the weak-tolerance variety of true mume, P. mume ‘BY’ (‘Beijing Yudie’). They gained an offspring variety named P. mume ‘XR’ (‘Xiang Ruibai’), but its cold tolerance is unknown at this point. Here, three varieties (XR, BY, and DF) were selected as the materials, and different low-temperature treatments were used, with temperature as the only variable. Conventional biological methods, such as ion leakage rate, different tissues, and plant viability statistics, were used, as well as an innovative use of infrared engineering and moisture monitoring for dynamic observation of the water-to-ice process in tissues. The results were as follows: DF cold tolerance was the highest, followed by XR and then BY. The LT50 of XR was increased by 6 °C after five days of cold priming at 4 °C, which indicated a stronger cold acclimation ability than the parent varieties. The XR variety enhanced the antioxidant capacity by increasing SOD and POD enzyme activities during low temperature treatment, thus enhancing the cold tolerance. The antioxidant enzyme genes PmSOD3, PmPOD2, PmPOD19, and PmPOD22 had important regulatory roles in XR’s cold acclimation process.
Inter- and Intraxylary Phloem in Vascular Plants: A Review of Subtypes, Occurrences, and Development
Authors: Rajput Kishore S. , Kapadane Kailas K. , Ramoliya Dhara G. , Thacker Khyati D. , Gondaliya Amit D.
Published: December 2022

Phloem is one of the vital tissues of the vascular system that plays a crucial role in the conduction of photosynthates. In vascular plants, it develops external to the vascular cambium but in a small fraction of eudicots (formerly known as dicots), it occurs within (interxylary) and inside (intraxylary) the secondary xylem. Ontogenetically, it is classified as Strychnos, Combretum, Azima, and Calycopteris types. In all four cases, phloem islands remain enclosed within the secondary xylem but each has unique origins. Similarly, the deposition of the phloem at the pith margin is common in several plants. It develops from procambial derivatives or adjacent pith cells or by initiating an intraxylary phloem cambium. Functionally, this cambium can produce only phloem or both secondary xylem and phloem. In some instances, the deposition of the secondary xylem and phloem in the same direction has also been documented. Some experimental evidence is available on the role of phloem but is it applicable to inter- and intraxylary phloem? The presence of inter- and intraxylary phloem is attributed to a defence mechanism against insects or plants that show sudden and enormous flowering or it can correlate with high temperatures or an unconducive climate in a desert region where sieve tube elements have become nonfunctional due to high temperatures. The present review is an attempt to analyse the role of interxylary and intraxylary phloem.
Carbon and Nutrient Transfer via Above- and Below-Ground Litter in Forests
Authors: Wu Fuzhong , Xu Zhenfeng , Yang Wanqin
Published: December 2022

Plants periodically shed more than 90% of their biomass production as above- and below-ground litter, including leaves, twigs, flowers, logs, roots and other tissues [...]
The Rendering of Traditional Fermented Foods in Human Diet: Distribution of Health Benefits and Nutritional Benefits
Authors: Plessas Stavros
Published: December 2022

Most fermented foods are based on the cultural preferences of different geographical areas and the heterogeneity of traditions from where they are produced. For instance, many consumers in Asian countries prefer fermented seafood, while consumers in Europe prefer fermented cereal and dairy food products. Even though the food industry has developed various novel techniques in order to produce novel foods (genetic modification, nanotechnology and other processing techniques), traditional foods still represent a significant proportion of the food industry, which has recently appeared to develop further. In addition, the progress in various developed analytical techniques has revealed new knowledge that documents and corroborates certain benefits of traditional foods, mostly regarding their nutritional and health benefits. In this context, the main target of this Special Issue is to deliver new data on how traditional foods exhibit their health-promoting properties and ameliorate the nutritional value of fermented food systems. In addition, the involvement of wild starter culture in the production of traditional foods is a subject area that must be highlighted.
Analysis of the Microbial Community Structure and Volatile Metabolites of JIUYAO in Fangxian, China
Authors: Zhang Wendi , Ren Qing , Wang Zhongchao , Liu Huijie , Huang Mingquan , Wu Jihong , Sun Baoguo
Published: December 2022

JIUYAO is an important saccharification starter in the production of huangjiu and is also an important source of flavor. In this study, the microbial community structure of JIUYAO from Fangxian was studied by high-throughput sequencing (HTS) technology for the first time. The volatile flavor compounds of the JIUYAO metabolites were also analyzed by headspace solid-phase microextraction combined with full two-dimensional gas chromatography-mass spectrometry (HS-SPME-GC×GC/MS) for the first time. The results showed that there were 15 dominant bacterial genera, including Weissella, Pediococcus, unclasssified_k_norank_d_Bacteria, Lactobacillus, Leuconostoc, etc. Thirteen species of dominant fungi included Wickerhamomyces, Saccharomycopsis, Rhizopus, etc. The different samples of JIUYAO were similar in their microbial species, but the number of species was significantly different. A total of 191 volatile flavor compounds (VFCs) were detected, among which esters, alcohols, acids, and alkenes were the main flavor compounds, and 21 terpenoids were also detected. In addition, the functional prediction of micro-organisms in JIUYAO revealed that global and overview maps, amino acid metabolism, and carbohydrate metabolism were the dominant categories. Through correlation analysis, 538 potential correlations between the dominant micro-organisms and the different flavor compounds were obtained. This study revealed the interactions between the micro-organisms and the volatile metabolites in JIUYAO, which provided reliable data for the analysis of the microbial community structure of Fangxian JIUYAO and provided theoretical support for the quality evaluation of JIUYAO.
Cloning and Expression of Sox2 and Sox9 in Embryonic and Gonadal Development of Lutraria sieboldii
Authors: Lu Min , Xing Zenghou , Zhou Yurui , Xu Youhou , Peng Huijing , Zou Jie , Dan Solomon Felix , She Zhicai , Wang Pengliang , Liu Jinfeng , Qin Shaomin , Yang Jialin , Zhu Peng
Published: December 2022

The Sox family plays essential roles as transcription factors in vertebrates; however, little is known about the Sox family in Lutraria sieboldii. L. sieboldii are pleasant to eat with a short growth cycle and have become one of the best bottom-seeded enrichment species in Guang Xi. In this study, Sox2 (named LsSox2) and Sox9 (named LsSox9) from L. sieboldii were cloned, and their expression patterns were analyzed. The length of the LsSox2 gene coding sequence was 1011 bp, encoding 336 amino acids, and LsSox9 was 1449 bp, encoding 482 amino acids. LsSox2 had its highest expression levels in the ovary, which were 356 times those in testis, whereas LsSox9 presented higher expression in testis, which was 6 times more highly expressed than in the ovary. LsSox2 exhibited the highest expression during the morula stage, which was 20 times that of the D-shaped larvae or zygote. LsSox9 exhibited two expression peaks, one at the four-cell stage and the other at the trochophore stage, while the lowest expression was in the zygote. LsSox9 was 73 times more highly expressed in the four-cell stage than in the zygote stage. During gonadal development, LsSox2 presented the highest expression in the mature ovary, which was 756 times more highly expressed than in mature testis. LsSox9 presented higher expression in testis at the emission stage which was 6 times more highly expressed than in the ovary. These results indicate that LsSox2 and LsSox9 may play important roles in embryonic and gonadal development.