bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Enhancement of Grid-Connected Renewable Energy Systems Using UPFC
Authors: Osama abed el-Raouf M. , A. Mageed Soad A. , Salama M. M. , Mosaad Mohamed I. , AbdelHadi H. A.
Published: May 2023

No one denies the importance of renewable energy sources in modern power systems in terms of sustainability and environmental conservation. However, due to their reliance on environmental change, they are unreliable systems. This paper uses a Unified Power Flow Controller (UPFC) to enhance the reliability and performance of grid-tied renewable energy systems. This system consists of two renewable sources, namely photovoltaic cells (PV) and wind turbines (WTs). The UPFC was selected for its unique advantage in both active and reactive power control. The UPFC is controlled with an optimized Fractional Order Proportional–Integral–Derivative (FOPID) controller. The parameters of this controller were tuned using an Atomic Search Optimization (ASO) algorithm. Simulation results confirm the efficiency of the suggested controller in supporting the reliability and performance of the hybrid power system during some disturbance events including voltage sag, swell, and unbalanced loading. In addition, power quality can be improved through reducing the total harmonic distortion. It is worth mentioning that two maximum point tracking techniques had been included for the PV and WT systems separately. MATLAB/SIMULINK 2021a software was used to model the system.
Reproducing Transformers’ Frequency Response from Finite Element Method (FEM) Simulation and Parameters Optimization
Authors: Suassuna de Andrade Ferreira Regelii , Picher Patrick , Meghnefi Fethi , Fofana Issouf , Ezzaidi Hassan , Volat Christophe , Behjat Vahid
Published: May 2023

Frequency response analysis (FRA) is being employed worldwide as one of the main methods for the internal condition assessment of transformers due to its capability of detecting mechanical changes. Nonetheless, the objective interpretation of FRA measurements is still a challenge for the industry. This is mainly attributable to the lack of complete data from the same or similar units. A large database of FRA measurements can contribute to improving classification algorithms and lead to a more objective interpretation. Due to their destructive nature, mechanical deformations cannot be performed on real transformers to collect data from different scenarios. The use of simulation and laboratory transformer models is necessary. This research contribution is based on a new method using Finite Element Method simulation and a lumped element circuit to obtain FRA traces from a laboratory model at healthy and faulty states, along with an optimization method to improve capacitive parameters from estimated values. The results show that measured and simulated FRA traces are in good agreement. Furthermore, the faulty FRA traces were analyzed to obtain the characterization of faults based on the variation of the lumped element’s parameters. This supports the use of the proposed method in the generation of faulty frequency response traces and its further use in classifying and localizing faults in the transformer windings. The proposed approach is therefore tailored for generating a larger and unique database of FRA traces with industrial importance and academic significance.
Energy Consumption Prediction of Electric City Buses Using Multiple Linear Regression
Authors: Sennefelder Roman Michael , Martín-Clemente Rubén , González-Carvajal Ramón
Published: May 2023

The widespread electrification of public transportation is increasing and is a powerful way to reduce greenhouse gas (GHG) emissions. Using real-world driving data is crucial for vehicle design and efficient fleet operation. Although electric powertrains are significantly superior to conventional combustion engines in many aspects, such as efficiency, dynamics, noise or pollution and maintenance, there are several factors that still hinder the widespread penetration of e-mobility. One of the most critical points is the high costs—especially of battery electric buses (BEB) due to expensive energy storage systems. Uncertainty about energy demand in the target scenario leads to conservative design, inefficient operation and high costs. This paper is based on a real case study in the city of Seville and presents a methodology to support the transformation of public transportation systems. We investigate large real-world fleet measurement data and introduce and analyze a second-stage feature space to finally predict the vehicles’ energy demand using statistical algorithms. Achieving a prediction accuracy of more than 85%, this simple approach is a proper tool for manufacturers and fleet operators to provide tailored mobility solutions and thus affordable and sustainable public transportation.
Intensive Data-Driven Model for Real-Time Observability in Low-Voltage Radial DSO Grids
Authors: Blomgren Emma M. V. , Banaei Mohsen , Ebrahimy Razgar , Samuelsson Olof , D’Ettorre Francesco , Madsen Henrik
Published: May 2023

Increasing levels of distributed generation (DG), as well as changes in electricity consumption behavior, are reshaping power distribution systems. These changes might place particular stress on the secondary low-voltage (LV) distribution systems not originally designed for bi-directional power flows. Voltage violations, reverse power flow, and congestion are the main arising concerns for distribution system operators (DSOs), while observability in these grids is typically nonexistent or very low. The present paper addresses this issue by developing a method for nodal voltage estimation in unbalanced radial LV grids (at 0.4 kV). The workflow of the proposed method combines a data-driven grey-box modeling approach with generalized additive models (GAMs). Furthermore, the proposed method relies on experimental data from a real-world LV grid in Denmark and uses data input from only one measuring device per feeder. Predictions are evaluated by using a test data set of 31 days, which is more than twice the size of the training data set of 13 days. The prediction results show high accuracy at root mean squared errors (RMSEs) of 0.002–0.0004 p.u. The method also requires a short computation time (14 s for the first stage and 2 s for the second stage) that meets requirements for the practical, real-time monitoring of DSO grids.
Classification of Anomaly Patterns in Integrated Energy Systems Based on Conditional Variational Autoencoder and Attention Mechanism
Authors: Guo Wei , Sun Shengbo , Tang Chenkang , Li Gang , Bai Xinlei , Zhao Zhenbing
Published: May 2023

By studying the classification of anomaly patterns in integrated energy systems, a deeper understanding of their operational status can be gained, leading to improved reliability and efficiency. This can ultimately result in reduced energy consumption and carbon emissions, contributing to sustainability efforts. This paper proposes a classification method that employs a conditional variational autoencoder and attention mechanism for deep clustering to identify anomaly patterns and distinguish between normal and anomaly datasets. The proposed model effectively addresses the issue of detecting anomalous periods in traditional anomaly detection methods. To account for the periodicity and coupling relationships of different loads, the model integrates sliding windows and attention mechanisms to improve the accuracy of detecting anomaly patterns. Firstly, during the encoder stage, a spatial attention mechanism is incorporated to extract features at each time step of the model input. Secondly, during the decoder stage, a temporal attention mechanism is introduced to perform feature extraction among the multiple time-step hidden layer states of the model input. The proposed method is applied to a typical integrated energy system and compared with existing methods. The experimental results demonstrate the effectiveness of the proposed method in accurately classifying the normal and anomaly patterns of integrated energy systems due to the internal clustering evaluation index.
A Self-Supplied Power Optimizer for Piezoelectric Energy Harvesters Operating under Non-Sinusoidal Vibrations
Authors: Costanzo Luigi , Lo Schiavo Alessandro , Vitelli Massimo
Published: May 2023

A self-supplied circuit that is able to significantly increase the power delivered to a bridge rectifier by a Resonant Piezoelectric Vibration Energy Harvester (RPVEH) is presented and discussed. The proposed circuit, called the Energy Harvester Power Optimizer (EHPO), is implemented by means of a switch-mode converter that emulates a negative capacitance. Unlike switch-mode impedance emulators, based on sophisticated tracking algorithms requiring lossy microcontrollers, EHPO exploits a very light control circuit based on a hysteresis comparator. The EHPO is self-supplied since it does not need an external supply, but it draws the energy for its operation directly from the RPVEH. Moreover, it is developed without the assumption of purely sinusoidal vibrations. Experimental results show that the EHPO can significantly increase the power delivered to a rectifier, both in the case of sinusoidal vibrations (percent gain of the net extracted power up to about 190%) and non-sinusoidal vibrations (percent gain of the net extracted power up to about 245%), regardless of the shape of the forcing acceleration and regardless of the RPVEH resonance frequency.
CFD Methodology for an Underhood Analysis towards the Optimum Fan Position in a Compact Off-Road Machine
Authors: Ferrari Cristian , Beccati Nicolò , Pedrielli Francesca
Published: May 2023

A compact off-road machine tends to have a compact engine structure, which may result in small clearances between the main engine, the cooling system, and the radiator. In the design of its cooling system, the heat exchanger, fan, and conveyor are normally chosen based on their fixed operating point. Unfortunately, these machines work in variable conditions and the performance of each component is different when they are working as a whole under the hood. The aim of this work is to optimize the position of these components through a parametric analysis of some variables, using the Computational Fluid Dynamics technique. The air flows are analyzed in order to show the pressure waves created by the air moved by the fan blades, showing how the fluid interacts with the engine. The results show that optimizing this installation can increase the efficiency of the fan by 10% and reduce the noise emitted by 13 dB. These results should sensitize designers to use CFD analyses, not for a single component, but for the entire system. The methodology shown can be applied for the better design of cooling systems, mainly in off-road vehicles that have noise emission problems.
A Review on Solar Energy Policy and Current Status: Top 5 Countries and Kazakhstan
Authors: Minazhova Saulesh , Akhambayev Ruslan , Shalabayev Timur , Bekbayev Amangeldy , Kozhageldi Bolat , Tvaronavičienė Manuela
Published: May 2023

The article describes the world’s experience in developing the solar industry. It discusses the mechanisms of state support for developing renewable energy sources in the cases of five countries that are the most successful in this area—China, the United States, Japan, India, and Germany. Furthermore, it contains a brief review of state policy in producing electricity by renewable energy facilities in Kazakhstan. This paper uses statistical information from the International Renewable Energy Agency (IRENA), the International Energy Agency (IEA), British Petroleum (BP), and the Renewable Energy Network (REN21), and peer-reviewed sources. The research methodology includes analytical research and evaluation methods to examine the current state of solar energy policy, its motivators and incentives, as well as the prospects for its development in Kazakhstan and in the world. Research shows that solar energy has a huge development potential worldwide and is sure to take its place in gross electricity production. This paper focuses on the selected economic policies of the top five countries and Kazakhstan, in what may be considered a specific research limitation. Future research suggestions for the expansion of Renewable Energy (RE) in Kazakhstan could include analysing the impact of introducing dedicated policies and incentives for solar systems and exploring the benefits and challenges of implementing large RE zones with government–business collaboration.
Innovations in Passive Downdraft Cooling Performance Evaluation Methods: Design and Construction of a Novel Environmental Test Chamber
Authors: Al-Hassawi Omar Dhia , Drake David
Published: May 2023

Energy demand for active mechanical space cooling is projected to double by 2050. Wider adoption of passive cooling systems can help reduce demand. However, familiarity with these systems remains low, and innovation in the field is constrained due to a lack of cost-effective, accessible performance evaluation methods. This paper reports the design, construction, and commissioning of an affordable, self-contained environmental test chamber. The novel chamber replicates a range of outdoor conditions common in hot, dry regions, making possible year-round testing of reduced-scale prototypes. Data from calibration testing are reported, showing no significant difference in evaporative efficiency when a reduced-scale prototype tested in the chamber is compared with datasets from prior full-scale testing. Analyzing the results using an independent sample two-tailed t-test with a 95% confidence interval found a p-value of 0.75. While measured outlet air velocities for reduced-scale and full-scale prototypes differed to some extent (root mean square error of 0.45 m/s), results were nevertheless deemed comparable due to errors introduced by the rapid change in wind speeds and directions at full scale. Future chamber modifications will correct misalignments between data collected from the two scales and prevent observed increases in the chamber’s relative humidity levels during testing.
A Study on Energy Management and Cooperative Control Considering LVRT in a Hybrid Microgrid
Authors: An Chang-Gyun , Lee Hoon , Kim Tae-Gyu , Yi Junsin , Won Chung-Yuen
Published: May 2023

Recently, the establishment of technical standards for grid connection has gained interest in academia and industry. These standards have focused on the reactive power control function of the grid-connected inverter and maintenance of grid operation, and include detailed information about the grid support function. However, remote control communication and control devices for grid support functions, and other distributed sources, such as wind power and energy storage systems, other than inverters have not been addressed. In this paper, the control of the interlinking converter (ILC) in a hybrid microgrid considering low voltage ride-through (LVRT) among grid support functions is investigated. The proposed method consists of an energy management system considering LVRT and a cooperative control scheme. In the energy management system, an algorithm capable of mode selection was constructed by applying the LVRT curve. Then, considering the LVRT situation, the allowable reactive power range of the ILC was mathematically analyzed through the cooperative control of the energy storage device and the ILC. The proposed method enables us to perform active and reactive power control of the ILC in a hybrid distribution network, considering the power factor under various conditions. This functionality, such as supplying reactive power, significantly contributes to the enhanced grid resilience with distributed power sources, including renewable energy. The proposed strategies were verified through experiments after configuring an experimental set of distributed power sources.
A Power Evolution Game Model and Its Application Contained in Virtual Power Plants
Authors: Zhou Jinghong , Chen Ke , Wang Weidong
Published: May 2023

Demand response is an effective way to alleviate the pressure on power systems and improve energy utilisation efficiency. This study constructs a tripartite evolutionary game model on government, power companies and virtual power plants (VPPs), and analyses the dynamic behavioural selection mechanism of the three parties under demand-response mode. The results show that: (1) government guidance and management are effective means to promote the stability and equilibrium of the power system; (2) an increase in government subsidy, a reduction in the demand-response cost and an increase in opportunity cost will increase the enthusiasm for changes in demand-response behaviour in power companies; (3) government subsidies will improve the demand-response behaviour of VPPs. This study effectively provides theoretical support for the demand response of power systems, and realises the goal of power energy saving through the optimal choice of behaviour strategies for all parties in the power system.
Cluster Partition-Based Voltage Control Combined Day-Ahead Scheduling and Real-Time Control for Distribution Networks
Authors: Sun Wenwen , He Guoqing
Published: May 2023

Considering the possible overvoltage caused by high-penetration photovoltaics (PVs) connected to the distribution networks (DNs), a cluster partition-based voltage control combined day-ahead scheduling and real-time control for distribution networks is proposed. Firstly, a community detection algorithm utilizing a coupling quality function is introduced to divide the PVs into clusters. Based on the cluster partition, day-ahead scheduling (DAS) is proposed with the objective of minimizing the operating costs of PVs, as well as the on-load tap changer (OLTC). In the real-time control, a second-order cone programming (SOCP) model-based real-time voltage control (RTVC) strategy is drawn up in each cluster to regulate the PV inverters, and this strategy can correct the day-ahead scheduling by modifications. The proposed strategy realizes the combination of day-ahead scheduling and real-time voltage control, and the optimization of voltage control can be greatly simplified. Finally, the proposed method is applied to a practical 10 kV feeder to verify its effectiveness.
Fluorescence in Smart Textiles
Authors: Patti Antonella , Acierno Domenico
Published: May 2023

Fluorescence has been identified as an advantageous feature in smart fabrics, notably for the protection of humans during outdoor athletic activities, as well as for preventing counterfeiting and determining authenticity. Fluorescence in smart fabrics is achieved using dendrimers, rare earth metal compounds, and fluorescent dye. The principal method for producing fluorescent fabrics is to immerse the sample in a solution containing fluorescent agents. However, covalent connections between fluorophores and textile substates should be established to improve the stability and intensity of the fluorescent characteristics. Fabric can be fluorescent throughout, or fluorescent fibers can be woven directly into the textile structures, made of natural (cotton, silk) or synthetic (polyamide- and polyester-based) fibers, into a precise pathway that becomes visible under ultraviolet irradiation.
Genome-Wide Analysis, Identification, and Characterization of the PFK Gene Family Members of Populus deltoides
Authors: Kim Tae-Lim , Denison Michael Immanuel Jesse , Lim Hyemin , Chung Hoyong , Oh Changyoung
Published: May 2023

Plants produce two phosphorylated enzymes: pyrophosphate-dependent fructose-6-phosphate phosphotransferase (PFP) and ATP-dependent phosphofructokinase (PFK). However, the characterization of phosphofructokinase (PFK) family members and their functions remains unexplored in Eastern Cottonwood (Populus deltoides). This study comprehensively analyzed 17 phosphofructokinase genes in the P. deltoides genome, including their gene structure, conserved domains, evolutionary relationships, and expression patterns. Genome-wide analysis of the poplar genome identified 11 genes belonging to PdPFK and 6 genes belonging to PdPFP. Phylogenetic, gene structure, and motif analyses revealed two main categories of PFK genes: PFK with eleven genes and PFP with six genes. Quantitative PCR (qPCR) analysis demonstrated that all 17 phosphofructokinase genes were induced in various tissues and developmental stages of P. deltoides. PFPs were strongly expressed throughout P. deltoides’ growth and development, notably in the roots, according to the transcript analysis. This genome-wide analysis provides insights into PFK and PFP genes and establishes a foundation for future investigations into the role of genes in P. deltoids.
Assessing Wildfire Hazard in the Wildland–Urban Interfaces (WUIs) of Central Portugal
Authors: Nunes Adélia N. , Figueiredo Albano , Pinto Carlos , Lourenço Luciano
Published: May 2023

In Portugal, the rapid growth in housing in and near wildland–urban interfaces (WUIs) increases the wildfire risk to lives and structures. The goal of our study was to assess wildfire hazard in the Central Region of Portugal and in the contact areas of the 60,373 km of WUIs existing in the study area. The degree to which wildfire is a hazard to the landscape and the different urban interfaces areas was assessed using the spatial arrangement of land use/land cover (LULC), topography, and historical incidence of burnt area. The results show that in more than half of the Central Region territory, the wildfire hazard is high or very high; however, most WUIs are in contact with low or very low hazard classes in a total of 87% of the segments. The LULC analysis in the different wildfire hazard classes in WUI contact areas shows that agricultural crops are predominant in the low and very low hazard classes, while in the very high and high hazard classes shrub communities, coniferous and scrub forests dominate, respectively. These results can assist in designing appropriate prevention measures and improving the effectiveness of fire prevention.
Rahnella aquatilis JZ-GX1 Alleviate Salt Stress in Cinnamomum camphora by Regulating Oxidative Metabolism and Ion Homeostasis
Authors: Li Pu-Sheng , Kong Wei-Liang , Wu Xiao-Qin
Published: May 2023

Salt stress is an environmental stress that severely limits plant growth, development and productivity. The use of symbiotic relationships with beneficial microorganisms provides an efficient, cost-effective and environmentally friendly preventative method. The plant growth-promoting rhizobacteria (PGPR) Rahnella aquatilis JZ-GX1 is a moderately salinophilic strain with good probiotic properties, although its ability to improve woody plant salt tolerance has not been reported. In this study, the effect of JZ-GX1 on Cinnamomum camphora under different salt concentrations (0, 50 and 100 mM NaCl) was investigated to reveal the mechanism by which JZ-GX1 improves salt tolerance in C. camphora. The results showed that JZ-GX1 promoted plant growth and root development. The relative electrolyte leakage (REL) and malondialdehyde (MDA) production of inoculated C. camphora plants were reduced by 37.38% and 21.90%, respectively, and the superoxide dismutase (SOD) activity in the leaves was enhanced by 321.57% under a 100 mM NaCl treatment. It was observed by transmission electron microscopy that under 100 mM salt concentration conditions, the inoculated C. camphora leaf cells showed a significant reduction in plasma membrane–cell wall separation and intact chloroplast structures, with tightly packed thylakoids. Importantly, inoculation reduced Na+ accumulation and promoted K+ accumulation in the seedlings, and these changes were consistent with the upregulated expression of the K+ channel SKOR and the vesicular membrane (Na+, K+)/H+ reverse cotransporter NHX1 in the plant roots. This study revealed the mechanism of the Rahnella aquatilis JZ-GX1 enhancing salt tolerance of C. camphora.
Soil Nutrient, Salinity, and Alkalinity Responses of Dendrocalamopsis oldhami in High-Latitude Greenhouses Depending on Planting Year and Nitrogen Application
Authors: Yin Zixu , Zhou Xiao , Fu Dawei , Zhang Xuan , Liu Liyang , Li Zhen , Guan Fengying
Published: May 2023

This study explored the viability of greenhouse cultivation of Dendrocalamopsis oldhami under the “South Bamboo North Transplanting” initiative. In this study, the effects of planting year and nitrogen application on changes in soil nutrient levels, salinity, and alkalinity over the plant growth period were explored. After the introduction and planting of bamboo in 2017, a soil layer with a thickness of 0–40 cm was sampled at the end of the shooting stage in the greenhouse between 2017 and 2019 (late August), and the bamboo shoot yield and standing culm density were measured. Following the application of nitrogen to the bamboo groves in 2019, three nitrogen levels were established: no nitrogen (N1:0 g grove−1), medium nitrogen (N2:540 g grove−1), and high nitrogen (N3:1080 g grove−1). Soil layers at depths of 0–20 and 20–40 cm were sampled during the shoot elongation stage (late May) and at the end of the shooting stage (late August). The yield and nutrient content of bamboo shoots under different nitrogen treatments were also investigated. The results showed that Ca2+ and HCO3− were the main salt ions in greenhouse soil. With later planting years, the total number of cations (Ca2+, Na+, Mg2+, and K+) decreased, whereas the total number of anions (HCO3−, SO42−, NO3−, and Cl−) increased, resulting in a decrease in the percentage of exchangeable sodium (ESP), pH, and electrical conductivity (EC). The diameter at breast height, individual weight, and quantity of bamboo shoots increased annually, and the standing culm density increased by 1.4 times. Each year, the total nitrogen content decreased, whereas the alkali-hydrolyzed nitrogen, available phosphorus, and available potassium contents increased. Nitrogen application resulted in a significant decrease in ESP and pH and an increase in the total anion, cation, and EC values. It also reduced soil organic carbon, total nitrogen, total phosphorus, total potassium, available phosphorus, and available potassium. Nitrogen application increased the number of bamboo shoots, total yield, and accumulation of N and P; however, there was no significant difference between N2 and N3. In conclusion, the salinization of calcareous soil was alleviated, and the available nutrients were activated following the introduction of D. oldhami from south to north. The mineralization rates of organic matter and soil fertility increased. Soil acidification and EC decreased at the end of the shoot stage. Nitrogen application acidified the soil, and the yield and soil salt accumulation increased with increasing nitrogen levels. The nutrient uptake efficiencies of nutrients at high nitrogen levels were lower than those at medium nitrogen levels. Therefore, soil salt concentrations with values 0.26 < EC < 0.42 hindered the nutrient uptake of D. oldhami.
Poplar Sawdust Biochar Altered Community Composition of Dominant Soil Fungi but Not Bacteria Depending on Pyrolysis Temperature
Authors: Jin Yuanyuan , Tian Ye , Yang Rui , Li Wenhao , Liu Chengyu , Li Tong
Published: May 2023

There is a growing focus on the production of biochar from organic wastes and its forestry use. However, it is unclear how applying biochar pyrolyzed at different temperatures influences both soil bacterial and fungal communities. In this study, two kinds of biochar were pyrolyzed at 350 °C and 600 °C, from poplar sawdust, and then applied as an auxiliary substrate material (15% addition by volume) for the container seedling cultivation of Cyclocarya paliurus, a native timber and medically used tree species, to compare the response of the soil’s microbial traits. The results showed that after 5 months of cultivation, the addition of the biochar application improved the soil’s physical and chemical properties to a certain extent by decreasing its bulk density and increasing its field water-holding capacity, pH and organic carbon content. The soil’s pH and content of organic C, available N and available P were significantly higher in the substrate with the addition of the biochar pyrolyzed at 600 °C (Bioc600) than in that of the substrate with added pyrolyzed biochar at 350 °C (Bioc350). The biochar application also enhanced the soil’s microbial N (MBN) but showed no changes in the MBC/MBN ratio. The biochar application had no effect on the diversity and composition of the soil’s bacterial community, but showed a certain effect on its fungal community composition and had different influences between low and high pyrolysis temperatures. The relative abundance of several of the dominant fungal phyla and genera increased with the addition of biochar due to the increase in the soil’s pH when compared to the CK (no biochar or sawdust addition). When compared with Bioc350, the dominant phylum Basidiomycota and genus Vanrija further increased in abundance with Bioc600. These findings reveal the consistent effects of biochar pyrolysis temperature and demonstrate the different regulatory roles of biochar application in soil bacterial and fungal communities, providing valuable information on how biochar can effectively be used as a substrate for seedling cultivation.
Ultrasound-Assisted Extraction of Hydroxytyrosol from Lactiplantibacillus plantarum Fermented Olive Leaves: Process Optimization and Bioactivity Assessment
Authors: Ilgaz Ceren , Kelebek Haşim , Kadiroglu Pınar
Published: May 2023

Olive leaves are important by-products for the recovery of phenolic compounds and extracts with high phenolic content using lactic acid bacteria during fermentation. Lactiplantibacillus plantarum (L. plantarum) strains as glucosidase-positive strains are starter cultures used to control the fermentation process. The main objective of the present work is to determine the most effective strain for the biodegradation of oleuropein to hydroxytyrosol using two L. plantarum strains for the fermentation of olive leaves. Box–Behnken experimental design was applied to determine the optimum ultrasound-assisted extraction (UAE) conditions to obtain hydroxytyrosol-rich extract using the brine of the fermented leaves. L. plantarum ATCC 14917 (hydroxytyrosol; 126.89 ± 1.59 mg/L) strain showed higher oleuropeinolytic activity than L. plantarum ATCC-BAA 793 (85.93 ± 0.70 mg/L) in olive leaf brine. When the UAE method was applied, it was seen that the hydroxytyrosol concentration of samples that were inoculated with L. plantarum ATCC 14917 (362.29 ± 2.31 mg/L) compared to L. plantarum ATCC-BAA 793 (248.79 ± 4.14) increased. The optimum UAE conditions were determined as 30% amplitude-5 min-30% ethanol for ATCC 14917 and 45% amplitude-9 min-10% ethanol for BAA 793 strain. This study showed that the brines of fermented olive leaves with oleuropeinolytic strains can be considered high added value products.
Molecular Hydrogen Treatment of Sake Yeast and kuratsuki Bacteria Affects Sake Taste
Authors: Saito Misaki , Nishida Hiromi
Published: May 2023

To the best of our knowledge, there are no studies on the effects of molecular hydrogen (H2) on microorganisms. In this study, we performed co-culture experiments using two microorganisms involved in sake brewing: sake yeast strain K1401 and the kuratsuki bacterium Kocuria strain TGY1127_2. The cells were suspended in water or water containing H2 and statically incubated at 4 °C for 2 h before co-culture. Sake taste was estimated using a taste sensor. The taste of sake was affected by H2 treatment of kuratsuki Kocuria as well as sake yeast. These results strongly suggest that H2 treatment alters the physiology of kuratsuki bacteria and sake yeast. We showed that sake undergoes H2 treatment of the microorganisms involved in sake brewing to boost its variety and meet the market demand.
Fermented Milk Produced with Goat Milk Enriched with PUFA Omega-3 by Supplementation of Diet with Extruded Linseed
Authors: Mangia Nicoletta P. , Carta Silvia , Murgia Marco A. , Montanari Luigi , Nudda Anna
Published: May 2023

This research aimed to evaluate goat milk rich in Omega-3 PUFA from animals fed extruded flaxseed as a raw material to produce fermented milk using beneficial lactobacilli. Experimental fermented milks were produced using Lacticaseibacillus paracasei Shirota and two potential probiotic lactobacilli, namely Lacticaseibacillus rhamnosus A2 and Lacticaseibacillus paracasei FS109. The fermented milks were produced using milk from goats fed a basal diet without any supplementation (CON) and milk from goats supplemented with 200 g/d of extruded linseed (LIN). All lactobacilli tested grew well both in CON and LIN milk, reaching high numbers during fermentation. The colony count ranged between 8 and 10 Log CFU/mL, despite slow acidification activity, which occurred especially in milk fermented by L. FS109. By contrast, an undesired post-acidification occurred, more pronounced in CON than in LIN milk, which still highlighted the strong acid-tolerance of L. Shirota and L. rhamnosus A2 in particular. This research showed that goat milk enriched in PUFA had no negative effect on the viability of the tested Lactobacilli. Both values of L. Shirota and L. rhamnosus “live cells” throughout the cold storage of the products were higher than those recommended to guarantee the quality of fermented milk products, making them beneficial to consumers’ health.
Study on Location of Fire Stations in Chemical Industry Parks from a Public Safety Perspective: Considering the Domino Effect and the Identification of Major Hazard Installations for Hazardous Chemicals
Authors: Jiang Junhao , Zhang Xiaochun , Wei Ruichao , Huang Shenshi , Zhang Xiaolei
Published: May 2023

In order to select the location of fire stations more scientifically and improve the efficiency of emergency management in chemical industry parks (CIPs), an improved risk calculation model for hazardous chemicals has been proposed by taking the domino effect and the identification of major hazardous installations for hazardous chemicals into account. In the analysis of the domino effect, the Monte Carlo simulation was used. Then, a location model of the fire stations was established with the optimization objectives of minimizing total cost and maximizing total risk coverage. The solving procedure of the location model is based on the augmented ε-constraint method combined with the TOPSIS method. Finally, a green chemical industry park was used as a case study for the validation and analysis of the location model. The results showed that the improved model could protect the high-risk areas, which is beneficial for the location decisions of fire stations.
Different Diets Based on Yellow Mealworm (Tenebrio molitor)—Part B: Modification of the Intestinal Inflammatory Response and the Microbiota Composition of Rainbow Trout (Oncorhynchus mykiss)
Authors: Melenchón Federico , Larrán Ana María , Hernández Marta , Abad David , Morales Amalia E. , Pula Héctor J. , Fabrikov Dmitri , Sánchez-Muros María José , Galafat Alba , Alarcón Francisco Javier , Lourenço Helena M. , Pessoa María-Fernanda , Tomás-Almenar Cristina
Published: May 2023

With the purpose of improving aquaculture sustainability, the search for protein alternatives to fishmeal makes it necessary to test different variables and the possible repercussions of new ingredients. The use of insect meal as a protein source for aquaculture is well described, but the complex composition of insect meals (fat and other components) can affect the physiology of fish. For this reason, as a part of a bigger study, the aim of the current manuscript was to test diets based on three different presentations of insect meal coming from yellow mealworm (Tenebrio molitor): full fat, partially defatted, and supplemented with a long chain omega–3-enriched oil, and to evaluate their effects on protein digestibility, biometric indices, immunological system and gut health (intestinal histomorphology and microbiota) of rainbow trout (Oncorhynchus mykiss). Digestibility of the protein and body indices showed a minor but consistent trend. The non-specific immunological system did not show changes, but the histology of the intestine showed signs that insect meals could be softening a mild inflammatory response. The gut microbiota suffered several changes, which could be associated with the different amino acid and fatty acid compositions of the diets.
Different Diets Based on Yellow Mealworm (Tenebrio molitor)—Part A: Facing the Decrease in Omega−3 Fatty Acids in Fillets of Rainbow Trout (Oncorhynchus mykiss)
Authors: Melenchón Federico , Larrán Ana María , Sanz Miguel-Ángel , Rico Daniel , Fabrikov Dmitri , Barroso Fernando G. , Galafat Alba , Alarcón Francisco Javier , Morales Amalia E. , Hidalgo M. Carmen , Lourenço Helena M. , Pessoa María-Fernanda , Tomás-Almenar Cristina
Published: May 2023

Aquaculture struggles with sustainability due to the use of fishmeal, and insects are one potential alternative. Insects have low long-chain omega−3 polyunsaturated fatty acid content, and insect-fed fish reflect this in their composition. In total, 500 rainbow trout (Oncorhynchus mykiss, ~46 g) were fed until the fish reached a commercial size (~415 g). Five diets were used: one control based on fishmeal as main source of protein; two with a 50% replacement of fishmeal with yellow mealworm meal (Tenebrio molitor), one with full-fat insect, and another partially defatted; two other diets similar to the one with the full-fat insect, but with the addition of an experimental algal oil rich in omega−3 in two different concentrations (one equivalent to control, the other one to the defatted insect diet). Growth was unaffected, as well as texture and organoleptic profile of the fillets. Lightness, brightness and colour of the fillets were slightly modified by the experimental diets. An increase in omega−3 levels over those of the full-fat insect diet is described. An omega−3 sparing effect was highlighted, causing lipid accumulation in fillets and liver, and a mild increase in oxidative damage. More research is encouraged to evaluate the fatty acid profile of the liver.
Morphological Distribution Patterns and Neuroimmune Communication of Ganglia in Molly Fish (Poecilia sphenops, Valenciennes 1846)
Authors: Mokhtar Doaa , Attaai Abdelraheim , Zaccone Giacomo , Alesci Alessio , Alonaizan Rasha , Hussein Manal
Published: May 2023

Twenty-four adult molly fish (Poecilia sphenops, Valenciennes 1846) were collected to study the morphology and distribution of ganglia using histological, immunohistochemical, and electron microscopy and focusing on their relation to the immune cells. The ganglia were classified spatially into cranial and spinal, and functionally into sensory and autonomic. Spinal ganglia (dorsal root ganglia, DRG) contained large close ganglionic cells, enclosed by satellite cells, as well as bundles of both myelinated and non-myelinated nerve fibers. There are glial cells, immune cells and telocytes close to the ganglion. In addition, oligodendrocytes were closely related to myelinated axons. Glial fibrillary acidic protein (GFAP) expression was confined to the glia cells and the nerve fibers in the cervical ganglia next to the gills, and surprisingly, in the large ganglionic cells of the DRG. The vestibular ganglia were large, connected to the hind brain, and contained numerous neurons packed in columns. The cervical ganglia were large and observed around the pseudobranch, head kidney, and thymus. Their neurons are randomly distributed, and nerve fibers are peripherally situated. CD3-positive T-lymphocytes, dendritic cells, and CD68-positive macrophages were in close contact with the ganglia. Furthermore, the ganglia around the head kidney showed positive Iba1-expressing cells. Most ganglion cells and nerve fibers in the DRG, autonomic, and vestibular ganglia showed moderate to strong S-100 immunoreactivity. The enteric glia, CD68-expressing macrophages, and acetylcholine (Ach)-expressing neurons were observed along the muscular layer of the intestinal wall. In conclusion, different ganglia of molly fish displayed direct communication with immune cells which support and maintain healthy ganglionic cells.
Experimental Determination of the Flow Coefficient for a Constrictor Nozzle with a Critical Outflow of Gas
Authors: Bolobov Victor , Martynenko Yana , Yurtaev Sergey
Published: May 2023

Reduction of energy expenditures required for various technological processes is a pressing issue in today’s economy. One of the ways to solve this issue in regard to liquefied natural gas (LNG) storage is the recovery of its vapours from LNG tanks using an ejector system. In that respect, studies on the outflow of the real gas through the nozzle, the main element of the ejector, and identifying differences from the ideal gas outflow, are of high relevance. Particularly, this concerns the determination of the discharge coefficient µ as the ratio of the actual flowrate to the ideal one, taking into account the energy losses at gas outflow through the nozzle. The discharge coefficient values determined to date for various nozzle geometries are, as a rule, evaluated empirically and contradictory in some cases. The authors suggest determining the discharge coefficient by means of an experiment. This paper includes µ values determined using this method for the critical outflow of air to atmosphere through constrictor nozzles with different outlet diameters (0.003 m; 0.004 m; 0.005 m) in the pressure range at the nozzle inlet of 0.5–0.9 MPa. The obtained results may be used for the design of an ejector system for the recovery of the boil-off gas from LNG tanks, as well as in other fields of industry, for the design of technical and experimental devices with nozzles for various applications.
Functional Food Based on Potato
Authors: Xu Jian , Li Yang , Kaur Lovedeep , Singh Jaspreet , Zeng Fankui
Published: May 2023

Potato (Solanum tuberosum L.) has gradually become a stable food worldwide since it can be a practical nutritional supplement and antioxidant as well as an energy provider for human beings. Financially and nutritionally, the cultivation and utility of potatoes is worthy of attention from the world. Exploring the functionality and maximizing the utilization of its component parts as well as developing new products based on the potato is still an ongoing issue. To maximize the benefits of potato and induce new high-value products while avoiding unfavorable properties of the crop has been a growing trend in food and medical areas. This review intends to summarize the factors that influence changes in the key functional components of potatoes and to discuss the focus of referenced literature which may require further research efforts. Next, it summarizes the application of the latest commercial products and potential value of components existing in potato. In particular, there are several main tasks for future potato research: preparing starchy foods for special groups of people and developing fiber-rich products to supply dietary fiber intake, manufacturing bio-friendly and specific design films/coatings in the packaging industry, extracting bioactive proteins and potato protease inhibitors with high biological activity, and continuing to build and examine the health benefits of new commercial products based on potato protein. Notably, preservation methods play a key role in the phytochemical content left in foods, and potato performs superiorly to many common vegetables when meeting the demands of daily mineral intake and alleviating mineral deficiencies.
Prospective Associations between Dietary Patterns and Abdominal Obesity in Middle-Aged and Older Korean Adults
Authors: Lee Kyung Won , Kang Min-Sook , Lee Seung Jae , Kim Haeng-Ran , Jang Kyeong-A , Shin Dayeon
Published: May 2023

This study aimed to identify major dietary patterns associated with abdominal obesity in middle-aged and older Korean adults. Data from the Korean Genome and Epidemiology Study were used. A total of 48,037 Korean adults aged ≥40 years without abdominal obesity at baseline were followed-up. Dietary assessment was conducted using a validated 106-item food-frequency questionnaire, and dietary patterns were identified using factor analysis. Abdominal obesity was defined as a waist circumference of ≥90 cm for men and ≥85 cm for women, according to the Korean Society for the Study of Obesity. Multivariable Cox proportional-hazards models were used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the future risk of abdominal obesity for each dietary pattern after adjusting for potential covariates. After an average follow-up of 4.89 years, we reported 5878 cases (1932 men and 3946 women) of abdominal obesity. Based on factor analysis, three major dietary patterns were identified in both men and women: the “healthy”, “coffee and sweets”, and “multi-grain” patterns. In the fully adjusted model, the “healthy” pattern was inversely associated with the incidence of abdominal obesity (HR for fourth vs. first quartile: 0.86; 95% CI: 0.75–0.98; p for trend = 0.0358 for men; HR for fourth vs. first quartile: 0.90; 95% CI: 0.83–0.99; p for trend = 0.0188 for women), whereas the “coffee and sweets” pattern was positively associated with it (HR for fourth vs. first quartile: 1.23; 95% CI: 1.08–1.40; p for trend = 0.0495 for men; HR for fourth vs. first quartile: 1.14; 95% CI: 1.04–1.25; p for trend = 0.0096 for women). In contrast, the “multi-grain” pattern in men and women showed no significant association with the incidence of abdominal obesity. Diets rich in colorful vegetables, seaweeds, mushrooms, tubers, fruits, soy products, and fish and low in coffee, sweets, and oils/fats might be favorable for reducing the future risk of abdominal obesity, particularly in middle-aged and older Korean adults.
Determination and Risk Assessment of Flavor Components in Flavored Milk
Authors: Chen Baorong , Wang Xiaodan , Zhang Yumeng , Zhang Wenyuan , Pang Xiaoyang , Zhang Shuwen , Lu Jing , Lv Jiaping
Published: May 2023

This study aimed to determine chemical composition and assess exposure in flavored milk among Chinese residents, based on risk assessment methodologies of acceptable daily intake (ADI) and toxicological concern threshold (TTC). Esters (32.17%), alcohols (11.19%), olefins (9.09%), aldehydes (8.39%), and ketones (7.34%) comprised the majority of the flavoring samples. Methyl palmitate (90.91%), ethyl butyrate (81.82%), and dipentene (81.82%) had the highest detection rates in flavor samples. This study screened fifteen flavor components of concern and discovered that 2,3,5-trimethylpyrazine, furfural, benzaldehyde, and benzenemethanol were detected in 100% of flavored milk samples. Benzenemethanol was found in the highest concentration (14,995.44 μg kg−1). The risk assessment results revealed that there was no risk for Chinese residents in consuming flavored milk, and the maximum per capita daily consumption of 2,3,5-trimethylpyrazine, furfural, and benzenemethanol were 226.208 g, 140.610 g, and 120.036 g, respectively. This study could provide guidelines for amounts of flavor additive ingredients in milk.