bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impacts of Energy Efficiency Modelling in Policy Making
Authors: Calvillo Christian
Published: February 2023

Bottom-up energy system models have been used extensively to analyse future energy scenarios, addressing a wide variety of policy questions. This paper focuses on energy efficiency, a key energy, climate, and economic policy area where several examples of energy system model applications can be found in the literature. This paper analyses how different studies implement energy efficiency scenarios in energy system models and explains how the approach taken can affect the results significantly, potentially affecting policy decisions. This analysis contributes to understanding how this type of modelling framework considers energy efficiency policy issues and the extent of insight provided, or not, on different dimensions. With the aim of identifying ‘best practice’ in using energy system models to inform effective analysis of energy efficiency policy, the UK TIMES energy system model is used to implement five different energy efficiency scenarios for residential heating following different modelling approaches and replicating scenarios available in the literature. The study concludes that energy efficiency scenarios, implementing the same target, produce significantly different results in terms of technology mix, energy use, emissions and costs. Additionally, the outcomes show that there is no overall best energy efficiency scenario, as each impacts on different policy targets, which could come into conflict with each other.
Probabilistic Security-Constrained Preventive Control under Forecast Uncertainties Including Volt/Var Constraints
Authors: Ciapessoni Emanuele , Cirio Diego , Conte Francesco , Pitto Andrea , Massucco Stefano , Saviozzi Matteo
Published: February 2023

The continuous increase in generation from renewable energy sources, marked by correlated forecast uncertainties, requires specific methodologies to support power system operators in security management. This paper proposes a probabilistic preventive control to ensure N-1 security in presence of correlated uncertainties of renewable sources and loads. By adopting a decoupled linear formulation of the AC load flow equations, the preventive control is decomposed into two subsequent linear programming problems, the former concerning the active power and the latter the voltage/reactive power-related issues. In particular, in the active control problem, the algorithm combines Third Order Polynomial Normal Transformation, Point Estimate Method, and Cornish–Fisher expansion to model the forecast uncertainties and characterize the chance constraints in the problem. The goal is to find the optimal phase shifting transformer tap setting, conventional generation redispatching, and renewable curtailment at the minimum cost to assure the probabilistic fulfillment of N and N-1 security constraints on branch active power flows. The second stage solves another linear programming problem, which aims to minimize the adjustments to generators’ set-point voltages to avoid violations at node voltages and branch-rated limits due to reactive power flows while meeting generator reactive power constraints. Simulations performed on an IEEE test system demonstrate the effectiveness of the proposed security control method in limiting the probability of violating security limits in N and N-1 state, including voltage/reactive power constraints, in presence of correlated uncertainties.
Detailed Analysis of the Causes of the Energy Performance Gap Using the Example of Apartments in Historical Buildings in Wroclaw (Poland)
Authors: Szulgowska-Zgrzywa Małgorzata , Stefanowicz Ewelina , Chmielewska Agnieszka , Piechurski Krzysztof
Published: February 2023

This paper presents the results of measuring and calculating the final energy consumption for heating and domestic hot water preparation in six apartments located in pre-war tenement houses in Wroclaw (Poland). The calculations were carried out based on energy models of dwellings calibrated with measurement data. Calculation variants were characterized by seven internal parameters (indoor air temperature, heat transfer coefficient by transmission through the internal partition, internal heat gains, air exchange multiplicity in the dwelling, domestic hot water consumption, and domestic hot water temperature and cold water temperature) and two external parameters (outdoor air temperature and insolation). By comparing calculations with measurements, the energy performance gap (EPG) values associated with each parameter were determined. The presented results indicate how much of the differences could be attributed to weather conditions and how much to other factors. It is quite common for the influence of some factors to cancel out the influence of others. Identifying and understanding the real causes of the energy gap may allow for the proposal of better retrofitting solutions or appropriate financial support to households at risk of energy poverty. It is important to note that only in-depth interviews with residents and measurements, such as those carried out in this case, allow such situations to be identified in detail.
Simulation and Exergoeconomic Analysis of a Trigeneration System Based on Biofuels from Spent Coffee Grounds
Authors: Tinoco Caicedo Diana L. , Santos Torres Myrian , Mero-Benavides Medelyne , Patiño Lopez Oscar , Lozano Medina Alexis , Blanco Marigorta Ana M.
Published: February 2023

Biofuels have become a source of renewable energy to offset the use of fossil fuels and meet the demand for electricity, heat, and cooling in the industrial sector. This study aims to (a) develop a simulation of a trigeneration system based on a gas turbine cycle and an absorption chiller unit, using biomass and syngas from spent coffee grounds (SCGs) to replace the conventional system currently supplying the energy requirements of an instant coffee plant located in Guayaquil, Ecuador, and (b) carry out an exergoeconomic analysis of the simulated system to compare the effects of different fuels. The results showed an increase in the exergetic efficiency from 51.9% to 84.5% when using a trigeneration system based on biomass instead of the conventional non-integrated system. Furthermore, the biomass-based system was found to have the lowest operating costs ($154.7/h) and the lowest heating, cooling, and power costs ($10.3/GJ, $20.2/GJ, and $23.4/GJ, respectively). Therefore, the results of this analysis reveal that using SCGs as biofuel in this instant coffee plant is feasible for producing steam, chilled water, and power.
Development of a Dual-Chamber Pyrolizer for Biochar Production from Agricultural Waste in Sri Lanka
Authors: Illankoon W. A. M. A. N. , Milanese Chiara , Karunarathna Anurudda Karunarathna , Alahakoon A. M. Y. W. , Rathnasiri Puhulwella G. , Medina-Llamas Maria , Collivignarelli Maria Cristina , Sorlini Sabrina
Published: February 2023

This study investigates the design and development of a pyrolysis reactor for batch-type biochar production from rice husks. The main objective is to develop an appropriate technology to regulate pyrolysis temperature and biomass residence time that can be easily operated under field and household conditions with minimal operational and technical requirements. The designed novel dual-chamber reactor comprises two concentrical metal cylinders and a syngas circulation system. The outer cylinder is for energy generation and the inner one is for pyrolysis. Temperature profiles, energy exchanges, syngas production, and the physicochemical characteristics of biochar were obtained to determine the performance of the reactor. Different trials were carried out to obtain different pyrolysis temperatures under constant amounts of feedstock and fuel. The temperature was monitored continuously at three predetermined reactor heights, the temperature profile varied from 380 °C to 1000 °C. The biochar yield was 49% with an average production rate of 1.8 ± 0.2 kg h−1. The reactor consumed 11 ± 0.1 kg of rice husk as feedstock and 6 ± 1 kg h−1 of wood as fuel. The gaseous products from the pyrolysis were CH4, CO2, H2, CO, and CnHm, which contributed 23.3 ± 2.3 MJ m−3 of energy as fuel for the pyrolysis process. The specific surface area of the biochar was 182 m2 g−1. The achieved operational capacity and thermal efficiency of the reactor show biochar production is a suitable option to convert discarded biomass into a value-added product that can potentially be used in several environmental applications.
Macroalgae and Microalgae Biomass as Feedstock for Products Applied to Bioenergy and Food Industry: A Brief Review
Authors: da Rosa Michelle Dias Hornes , Alves Cristina Jansen , dos Santos Felipe Nardo , de Souza Alexander Ossanes , Zavareze Elessandra da Rosa , Pinto Ernani , Noseda Miguel Daniel , Ramos Daniela , de Pereira Cláudio Martin Pereira
Published: February 2023

This article is a brief and critical review of the state of the art in algae production in the food and energy industries. Review and experimental articles from the last five years were selected to recapitulate the reasons for interest in algae cultivation, for which we highlight the most valuable phytochemicals passing through their niches in the food market, their bioenergetic potential and the possible uses of algal waste biomass. In addition, we punctuate the advent of algae biorefineries. The objectives of this study were to list the main points related to interest in cultivation, drawing a parallel between the establishment of algae in the food market and its potential to establish itself in the energy market. It was concluded that the use of algae biorefineries has been used as a solution for the food, chemical and energy markets, despite the need for the development of broader research on industrial scale.
Dry Reforming of Methane Using a Swirl-Induced Plasma Discharge Reactor
Authors: Raja R. Bharathi , Halageri Anusha C. , Sankar R. , Sarathi Ramanujam , Vinu Ravikrishnan
Published: February 2023

This study reports the dry reforming of methane (DRM) using non-thermal plasma in a swirl-induced point-plane electrode discharge reactor to produce syngas. This reactor geometry facilitates better mixing of the reactant gases in the plasma region, thus increasing the residence time and conversion of the reactants. The effect of varying flow rates and compositions of CO2/CH4 (v%/v%) on conversion was studied. A high-voltage AC power input of 50 W and 70 W at a frequency of 19 kHz was provided. The voltage–current characteristics with respect to time were studied. The results show that with an increase in the flow rate of the gas mixture from 0.5 to 2 LPM the conversion of both CO2 and CH4 decreases, while an increase in the concentration of CO2 or CH4 (from 25 to 75%) increases the conversion of the respective reactant. The products, viz. syngas (CO and H2), C2 hydrocarbons, and solid carbon, were characterized and quantified. The maximum total conversion of 44% was obtained for a CO2:CH4 ratio of 25:75 (v%/v%) at a flow rate of 0.5 LPM. The solid carbon collected from the reactor walls was analyzed, and it was found to be 89.9% pure with traces of oxygen functionality. The increase in flow rate decreased the specific energy input, which eventually resulted in lowering the energy cost.
An Overview of the Molten Salt Nanofluids as Thermal Energy Storage Media
Authors: Pereira José , Moita Ana , Moreira António
Published: February 2023

The research in the field of the nanofluids has experienced noticeable advances since its discovery two decades ago. These thermal fluids having minimal quantities of nano-scaled solid particles in suspension have great potential for thermal management purposes because of their superior thermophysical properties. The conventional water-based nanofluids have been extensively investigated so far with emphasis in their improved thermal conductivity. A novel class of nanofluids based on inorganic salts has been developed in the last few years with the goal of storing and transferring thermal energy under high temperatures. These molten salt-based nanofluids can in general be recognized by an enhanced specific heat due to the inclusion of the nanoparticles. However, it should be emphasized that this does not always happen since this thermophysical property depends on so many factors, including the nature of the molten salts, different preparation methods, and formation of the compressed layer and secondary nanostructures, among others, which will be thoroughly discussed in this work. This peculiar performance has caused a widespread open debate within the research community, which is currently trying to deal with the inconsistent and controversial findings, as well as attempting to overcome the lack of accurate theories and prediction models for the nanofluids in general. This review intends to present an extensive survey of the published scientific articles on the molten salt nanofluids. Other important realities concerning the development and thermal behavior of the molten salt nanofluids, such as the stability over time of the nanoparticles dispersed in the molten salts, latent heat, viscosity, and thermal conductivity, will be reviewed in the current work. Additionally, special focus will be given to concentrated solar power technology applications. Finally, the limitations and prospects of the molten salts nanofluids will be addressed and the main concluding remarks will be listed.
Pyrolysis of Waste Biomass: Technical and Process Achievements, and Future Development—A Review
Authors: Igliński Bartłomiej , Kujawski Wojciech , Kiełkowska Urszula
Published: February 2023

Pyrolysis has been applied in the human economy for many years, and it has become a significant alternative to the production of chemical compounds, including biofuels. The article focuses mostly on recent achievements in the technical and processing aspects of pyrolysis. The aim of the review is to present the latest research on the process of waste biomass pyrolysis to fuel production. The paper describes the mechanisms of the pyrolysis process, composition, and properties of the obtained fractions, namely pyrolysis gas, bio-oil, and biochar. Additionally, the technical aspects of the pyrolysis process are mentioned, with particular attention to the construction of the reactors. The process of waste biomass pyrolysis allows for obtaining many chemical compounds (second-generation biofuels). Optimization of the pyrolysis process allows obtaining the desired products that are applied in the chemical industry, energy, and transport. The application of pyrolysis gas, oil, and biochar as valuable chemical compounds are related to the intensifying effects of climate change, biofuel production, and waste management in accordance with the principles of sustainable development. In recent years, there has been large-scale research into the use of renewable energy sources through pyrolysis. This will make it possible to significantly reduce the carbon footprint and produce second-generation biofuels in a sustainable manner. Current research into the mechanisms of pyrolysis processes is promising, and will therefore provide access to clean and low-cost compounds that will have broad applications in the energy, chemical, agricultural, and transportation industries.
An Isolated Three-Port Power Converter with 2C3L and 2C2L Resonant Circuits
Authors: Chang Yong-Nong , Yan Yih-Her , Huang Sheng-Min
Published: February 2023

This study proposed an isolated three-port bidirectional resonant converter that combines 2C3L and 2C2L resonant circuits for application in power dispatching. The proposed converter improves the bidirectional power dispatch capabilities of conventional three-port converters and utilizes different resonant converters to complete the energy charge–discharge through ports of different voltage levels. By modulating the frequency alone, bidirectional power regulation and electrical isolation were achieved among the three ports with different voltage levels. The converter involves the use of resonance techniques to enable the power switch to perform soft switching during bidirectional power transmissions, reducing switching loss and electromagnetic interference. The system control of the circuit was a Texas Instruments TMS320F28335 microcontroller. By simulating a DC grid port with a fixed voltage of 400 V, a vehicle battery port with a variable voltage of 280–403 V, and a battery charging port with a variable voltage of 180–213 V, an experimental platform with a rated output of 3 kW was built to determine the accuracy of the proposed theoretical analysis and design method.
Use of Magnetostrictive Actuators for Wave Energy Conversion with Improvised Structures
Authors: Korde Umesh
Published: February 2023

This paper presents work on a wave energy device with an on-board power take-off based on a magnetostrictively actuated deformable structure. Such devices potentially could be used in low-cost, short-term expeditionary operations. The paper discusses an analytical model that describes the heave oscillations of a buoy with two inclined, overhanging beams with magnetostrictive strips affixed to them. This work comprises the first steps toward an analytical model that would enable potential users to obtain quick power estimates at the planning stage. Here, the fully nonlinear magneto-mechanical-electrical constitutive relations are linearized about a desirable operating point, and a coupled dynamic model is derived using a variational formulation that includes buoy heave, flexural oscillations of the two beams, and the voltage response of the magnetostrictive strips. Energy conversion performance in wind-sea-dominated Pierson–Moskowitz spectra is found to be modest. However, present results also indicate that performance could be improved with suitable mechanical modifications.
Numerical Investigation of a Novel Controlled-Temperature Double-Skin Façade (DSF) Building Element
Authors: Georgiou Loucas , Afxentiou Nicholas , Fokaides Paris A.
Published: February 2023

This paper investigates a novel controlled-temperature double-skin façade (DSF) building element. A three-dimensional time-dependent numerical model was developed for six different geometries for the investigation of thermal performance under different orientations (azimuth 0°, 90°, 180° and 270°). The boundary conditions of the numerical model were determined with the PVGIS tool and adjusted with the sol-air temperature equation. The results of the numerical simulation were validated with the use of measurements from an experimental test cell. The numerical results indicated an improved thermal performance when temperature-controlled air and flow were supplied through the building envelope with annual total energy savings in kWh/m2 of 1.99, 1.38, 2.13 and 2.06 for azimuth 0°, 90°, 180° and 270°, respectively. In regard to the total energy savings in %, the maximum benefit was considered to be in the winter season, with values of 65, 29, 80 and 28 for azimuth 0°, 90°, 180° and 270°, respectively. The experimental measurements revealed the test cell’s ability to maintain a relatively constant internal surface temperature and to not be significantly affected by the orientation and diverse ambient conditions.
A Review on the Internalization of Externalities in Electricity Generation Expansion Planning
Authors: Costa Carlos Roberto de Sousa , Ferreira Paula
Published: February 2023

This work addresses the internalization of externalities in energy decision making and in generation expansion planning (GEP). Although the linkage between externalities and energy is well recognized, the issue of the internalization in GEP models and from a sustainability perspective is still far from being fully explored. A critical literature review is presented, including scientific articles published in the period from 2011 to 2021 and selected from scientific databases according to a set of pre-defined keywords. The literature is vast and quite heterogeneous in the models and methods used to deal with these externalities, and therefore a categorization of these studies was attempted. This categorization was based on the methods used, the geographical scope, the externalities included in the planning model and the strategies for their inclusion. As a result, it was possible to perceive that most studies tend to focus on the internalization of externalities related to CO2 and equivalent emissions from a national perspective. Departing from the critical analysis, pathways for future research were presented, highlighting the need to improve the internalization of social externalities to overcome environmental and economic bias, and also highlighting the importance of recognizing regional specificities and development priorities.
The Definition of Power Grid Strength and Its Calculation Methods for Power Systems with High Proportion Nonsynchronous-Machine Sources
Authors: Xu Zheng , Zhang Nan , Zhang Zheren , Huang Ying
Published: February 2023

This paper studies the definition and calculation method of power grid strength in the environment of high-proportion nonsynchronous-machine sources, focusing on the effect of nonsynchronous-machine sources on voltage support strength and frequency support strength. By dividing the nonsynchronous-machine sources into four types, the equivalent circuits of each type under normal state and fault state are derived, respectively. Based on the Thevenin equivalent impedance of the power grid and the equivalent impedance of the connected device, the definition and calculation method of voltage support strength is given, and the new meaning of single-infeed short-circuit ratio and multi-infeed short-circuit ratio in the context of high proportion nonsynchronous-machine sources is presented. Based on the initial frequency change rate and the steady-state frequency deviation of any node in the power grid under the maximum expected active power disturbance, the equivalent inertia lifting factor and steady-state frequency deviation decreasing factor are defined, respectively, to describe the contribution of nonsynchronous-machine sources to the power grid frequency support strength, and the calculation methods of the equivalent inertia lifting factor and the steady-state frequency deviation decreasing factor are given.
Improving the Energetic Efficiency of Biogas Plants Using Enzymatic Additives to Anaerobic Digestion
Authors: Fugol Małgorzata , Prask Hubert , Szlachta Józef , Dyjakon Arkadiusz , Pasławska Marta , Szufa Szymon
Published: February 2023

This study was carried out to estimate the relevance of biological supplementation in improving the economic efficiency of anaerobic digestion (AD). Three kinds of silages—maize, grass, and igniscum—were initially inoculated with digestate and then supplemented with one of four vaccines containing different bacteria species (APD®, PPT®, JENOR®) or a yeast and mold mixture (HAP®). In addition, each plant silage was fermented without any additives (control A—maize silage, B—grass silage, and C—igniscum silage). The biodegradability process was performed in batch tests at a mesophilic temperature (38 °C). To compare the energetic efficiency of AD, the process kinetics, biogas, and methane production were analyzed. We found that the applied supplementation measures improved biogas production in the case of maize and igniscum (7–62% higher than controls), but decreased the yield of AD when grass silage was fermented (2–34% lower than controls). The greatest increase in methane production (by 79%) was observed when maize silage was digested with the PPT® pretreatment, with 427 Nm3∙Mg−1 VS (volatile solids).
Chemical Looping Gasification of Wood Waste Using NiO-Modified Hematite as an Oxygen Carrier
Authors: Xie Jinlong , Zhu Kang , Zhang Zhen , Chen Xinfei , Lin Yan , Hu Jianjun , Xiong Ya , Zhang Yongqi , Huang Zhen , Huang Hongyu
Published: February 2023

Chemical looping gasification (CLG) technology is an effective approach to converting wood waste into high-quality syngas. In the present work, the reactivity of natural hematite is enhanced by doping with nickel oxide (NiO), and the effects of various operating parameters upon the CLG of wood waste are investigated using the NiO-modified hematite as an oxygen carrier. The NiO-modified hematite gives a significantly increased carbon conversion of 79.74%, and a valid gas yield of 0.69 m3/kg, compared to 68.13% and 0.59 m3/kg, respectively, for the pristine (natural) hematite, and 54.62% and 0.55 m3/kg, respectively, for the Al2O3, thereby indicating that the modification with NiO improves reactivity of natural hematite towards the CLG of wood waste. In addition, a suitable mass ratio of oxygen carrier to wood waste (O/W) is shown to be beneficial for the production of high-quality syngas, with a maximum valid gas yield of 0.69 m3/kg at an O/W ratio of 1. Further, an increase in reaction temperature is shown to promote the conversion of wood waste, giving a maximum conversion of 86.14% at reaction temperature of 900 °C. In addition, the introduction of an appropriate amount of steam improves both the conversion of wood waste and the quality of the syngas, although excessive steam leads to decreases in the reaction temperature and gas residence time. Therefore, the optimum S/B (mass ratio of steam to biomass) is determined to be 0.4, giving a carbon conversion and valid gas yield of 86.63% and 0.94 m3/kg, respectively. Moreover, the reactivity of the NiO-modified hematite is well-maintained during 20 cycles, with a carbon conversion and valid gas yield of around 79% and 0.69 m3/kg, respectively. Additionally, the XRD and SEM-EDS analyses indicate no measurable change in the crystal phase of the re-oxidized oxygen carrier.
Design of Electric Bus Transit Routes with Charging Stations under Demand Uncertainty
Authors: Su Xiaoqing , Jiang Lanqing , Huang Yucheng
Published: February 2023

This paper investigates the design problem of an electric bus (E-bus) route with charging stations to smooth the operations between E-bus service and charging. The design variables include the locations of E-bus stops, number of charging piles at charging stations, fare, and headway. A mathematical programming model is proposed to maximize social welfare in consideration of the uncertain charging demand at charging stations. The model solution algorithm is also designed. The model and algorithm are demonstrated on the E-bus route 931 in the city of Suzhou, China. The results of the case studies show that (i) the right number of stops on a bus route can contribute to the highest social welfare; (ii) the pile–bus ratio decreases with the increase of E-bus fleet size, thereby improving the E-bus charging efficiency at charging stations; and (iii) deploying charging stations at one end of a bus route can achieve a shorter waiting time for E-bus compared with deployment at two ends.
Hydrological Characteristics of the Bakony Region (Hungary)
Authors: Veress Márton
Published: February 2023

In this study, the karst systems (karst types) of the Bakony Region are classified and described. The karst features and the groundwater (karstwater) flow, their horst (block) types and the hydrological cycle of horst types were taken into consideration. In the mountains, regional flow with a hypogene branch (hypogene karst system) and epigene karsts systems of local flow were distinguished. Among local epigene systems, epigene karst system, mixed epigene karst system, complex mixed epigene karst system, incomplete epigene karst system and semi-closed epigene karst system were distinguished. Local epigene systems are only temporarily (but not all of them) separated from the regional system that developed below and around them. During their development, separated local systems are more and more becoming the descending branches of regional systems.
Potential Symbiotic Effects of β-1,3 Glucan, and Fructooligosaccharides on the Growth Performance, Immune Response, Redox Status, and Resistance of Pacific White Shrimp, Litopenaeus vannamei to Fusarium solani Infection
Authors: Eissa El-Sayed Hemdan , Ahmed Ragaa A. , Abd Elghany Nadia A. , Elfeky Amal , Saadony Saadea , Ahmed Norhan H. , Sakr Salah El-Sayed , Dayrit Geraldine B. , Tolenada Charlene Princess S. , Atienza Adlene Anne C. , Mabrok Mahmoud , Ayoub Hala F.
Published: February 2023

The potential effects of dietary supplementation with β-1,3 glucan and fructooligosaccharides (β-1,3 GF) on antioxidant activities, immunological response, and growth performance of Pacific white shrimp (Litopenaeus vannamei) was investigated. Four diets (iso-energetic and iso-nitrogenous) with different levels of β-1,3 GF (0, 0.5, 1.0, and 1.5 g kg−1) were fed to healthy shrimp juveniles weighing 3 ± 0.5 g for 75 days. Shrimps were randomly distributed into 12 net enclosures at a density of 30 shrimp/net, and the experiment was performed in triplicate. The results revealed that long-term supplementation with 1.5 g kg−1 β-1,3 GF significantly improved shrimp weight gain, feed conversion ratio, and digestive enzyme profiles compared to the control diet group. However, there were no substantial variations in the contents of moisture, crude protein, total lipids, and ash in the muscles of shrimp fed on different diets. Surprisingly, all antioxidants (superoxide dismutase, catalase, glutathione peroxidase) and immune biomarkers (lysozyme, total hemocyte count, phenol oxidase, and respiratory burst) activities were significantly elevated with increasing levels of β-1,3 GF in the shrimp diet, and the highest values were recorded in the 1.5 g kg−1 diet groups. Challenge test results revealed that F. solani could cause a high mortality rate (86.7%) in a group fed a normal basal diet within 14 days at a dose of 5 × 104 conidia mL−1. Surprisingly, all dietary treated groups with different doses of β-1,3 GF showed high resistance against F. solani, represented by lower cumulative mortality rates (20–43.3%) compared to the control group. Moreover, most of the infected shrimp showed a typical black to brown gill lesion similar to that observed in the natural infection, where an identical fungus was successfully re-isolated from infected gills and muscles. Overall, this study recommends an appropriate incorporation level of β-1,3 GF that could enhance growth performance and improve the antioxidant activities, non-specific immunity, and disease resistance of L. vannamei, with an optimal level of 1.5 g kg−1.
Stability and Resolution Analysis of the Wavelet Collocation Upwind Schemes for Hyperbolic Conservation Laws
Authors: Yang Bing , Wang Jizeng , Liu Xiaojing , Zhou Youhe
Published: February 2023

The numerical solution of hyperbolic conservation laws requires algorithms with upwind characteristics. Conventional methods such as the numerical difference method can realize this characteristic by constructing special distributions of nodes. However, there are still no reports on how to construct algorithms with upwind characteristics through wavelet theory. To solve this problem, a system of high-order and stable wavelet collocation upwind schemes was successfully proposed by constructing interpolation wavelets with specific symmetry and smoothness. The effects of the characteristics of the scaling functions on the schemes were explored based on numerical tests and Fourier analysis. The numerical results revealed that the stability of the constructed scheme is affected by the smoothness order, N, and the asymmetry of the scaling function. The dissipation analysis suggested that schemes with N ∈ even have negative dissipation coefficients, leading to unstable behaviors. Only scaling functions with N ∈ odd and a bias magnitude of 1 can be used to construct stable upwind schemes due to the non-negative dissipation coefficients. Typical numerical examples verified the effectiveness of the proposed method, which is proved to have high accuracy and efficiency in solving high-speed flow problems with multi-scale smooth structures and discontinuities.