bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptive Collision Avoidance for Multiple UAVs in Urban Environments
Authors: Zhang Jinpeng , Zhang Honghai , Zhou Jinlun , Hua Mingzhuang , Zhong Gang , Liu Hao
Published: July 2023

The increasing number of unmanned aerial vehicles (UAVs) in low-altitude airspace is seriously threatening the safety of the urban environment. This paper proposes an adaptive collision avoidance method for multiple UAVs (mUAVs), aiming to provide a safe guidance for UAVs at risk of collision. The proposed method is formulated as a two−layer resolution framework with the considerations of speed adjustment and rerouting strategies. The first layer is established as a deep reinforcement learning (DRL) model with a continuous state space and action space that adaptively selects the most suitable resolution strategy for UAV pairs. The second layer is developed as a collaborative mUAV collision avoidance model, which combines a three-dimensional conflict detection and conflict resolution pool to perform resolution. To train the DRL model, in this paper, a deep deterministic policy gradient (DDPG) algorithm is introduced and improved upon. The results demonstrate that the average time required to calculate a strategy is 0.096 s, the success rate reaches 95.03%, and the extra flight distance is 26.8 m, which meets the real-time requirements and provides a reliable reference for human intervention. The proposed method can adapt to various scenarios, e.g., different numbers and positions of UAVs, with interference from random factors. The improved DDPG algorithm can also significantly improve convergence speed and save training time.
Exploring the Impact of Rapidly Actuated Control Surfaces on Drone Aerodynamics
Authors: Panta Ashim , Marino Matthew , Fisher Alex , Mohamed Abdulghani , Watkins Simon
Published: July 2023

This study investigates the use of rapidly actuated leading-edge and trailing-edge control surfaces to improve the control authority of small fixed-wing drones. Static and dynamic characteristics were investigated and presented in two separate papers. In this paper, the focus is on the dynamic effects observed from rapidly actuated 30% chord leading- or trailing-edge hinged control surfaces affixed to two flat-plate airfoils. Forces were resolved from surface pressure measurements and are augmented by PIV measurements, smoke flow visualization and analyses. The static study revealed that trailing-edge control surfaces exhibited higher effectiveness in producing time-averaged CL compared to leading-edge control surfaces. However, leading-edge control surfaces exhibit significantly less fluctuation in pressure and lift coefficients at fixed angles of attack and control surface deflections, indicating better stability. Unsteady aerodynamic effects of the airfoil at α=0∘ and “ramp” deflections of trailing- and leading-edge control surfaces from 0∘ to 40∘ with variations in actuation rates showed that CL peaks are approximately three to four times greater than static values for the case of the leading-edge control surface. This has significant implications for fixed-wing drone maneuverability and countering the effects of atmospheric turbulence.
Coherences in the Dynamics of Physical Systems from a Multifractal Perspective of Motion
Authors: Vasincu Decebal , Bruma Andreea Bianca , Rusu Oana , Rusu Cristina Marcela , Ghizdovat Vlad , Agop Maricel
Published: July 2023

Using an analogy between the multi-fractal Schrödinger equation and the dumped oscillator equation through a special ansatz, Stoler-type coherences in the dynamics of physical systems are highlighted. Such a result implies a Ricatti-type gauge, a process that can be considered a calibration of the difference between the kinetic and potential energy of a Lagrangian, specified as a perfect square in generic coordinates.
Towards Multifractality through an Ernst-Type Potential in Complex Systems Dynamics
Authors: Ghizdovat Vlad , Rusu Oana , Frasila Mihail , Rusu Cristina Marcela , Agop Maricel , Vasincu Decebal
Published: July 2023

Some possible correspondences between the Scale Relativity Theory and the Space–Time Theory can be established. Since both the multifractal Schrödinger equation from the Scale Relativity Theory and the General Relativity equations for a gravitational field with axial symmetry accept the same SL(2R)-type invariance, an Ernst-type potential (from General Relativity) and also a multi-fractal tensor (from Scale Relativity) are highlighted in the description of complex systems dynamics. In this way, a non-differentiable description of complex systems dynamics can become functional, even in the case of standard theories (General Relativity and Quantum Mechanics).
The Nexus of Banks’ Competition, Ownership Structure, and Economic Growth on Credit Risk and Financial Stability
Authors: Halim Md. Abdul , Moudud-Ul-Huq Syed , Sobhani Farid Ahammad , Karim Ziaul , Nesa Zinnatun
Published: July 2023

The main object of this research is to find out the nexus of banks’ competition, ownership structure, and economic growth on credit risk and financial stability. In addition, it examines the level of financial stability, economic growth, and ownership structure in the Middle East and North African (MENA) economies. The generalized method of moments (GMM) method was used to examine this study. The study used an unbalanced panel dataset from 2011 to 2021 in MENA countries. This research demonstrates a negative relationship between economic growth, credit risk, and financial stability in MENA economies; nevertheless, it proves an insignificant effect among them. It also shows that the lower the level of bank competition, the lower the level of bank risk taking, and the better the level of financial stability. It further found that market competition and bank ownership structure had a homogenous effect on financial stability when looking at the impact of competition and bank ownership structure. In the long-term sense, the square term of competition is highly favorable with financial stability models ((Lerner square × Islamic banks), (Lerner square × commercial banks), (Lerner square × specialized government institutions)). However, financial stability improves with time, as seen by the competition square term bank ownership structure (a square measure of competition) with the Lerner index (LI) and the Herfindahl–Hirschman index total assets (HHIA). This finding of the square measure of competition is supported by competition stability theory. However, this study also proved that Islamic and commercial banks are less vulnerable to credit risk than specialized government institutions (SGI). This study scrutinized how MENA economies can remain stable through banking competition. This study builds a new brand of literature review. As a result, this research gives MENA policymakers better ideas for making policies that help the banking environment.
Collaborative Composition and Urban Popular Music in Digital Music Didactics
Authors: Merchán-Sánchez-Jara Javier F. , González-Gutiérrez Sara
Published: July 2023

Composition is one of the facets of musical activity that allows a more effective way to interrelate theoretical and practical contents in a real context to enhance the development of creativity and collaborative work in the music classroom. Through a qualitative methodology based on participant observation, the results of several projects aimed at implementing collaborative composition in the training of music teachers at the University of Salamanca through audio production tools (DAW) as a pedagogical strategy to address basic knowledge and specific skills of the curriculum of the music subject in secondary education, are synthesized. From this perspective, this work proposes a structured and sequential model for the collaborative composition of musical productions in the field of popular urban music (with special attention to the rock style), addressing and exemplifying in a practical way issues such as the layered structure in the prototypical song of rock bands, the fundamental rhythmic bases, the harmonic function and the development of chord progressions or the creation and development of melodic lines for the voice.
How Does an Inquiry-Based Instructional Approach Predict the STEM Creative Productivity of Specialized Science High School Students?
Authors: Kim Juah , Im Hyunjung , Ahn Doehee , Cho Seokhee
Published: July 2023

Creative productivity has not been studied much as an outcome of specialized science high schools. Rather, STEM career choices, acquisition of a STEM degree, and taking advanced STEM courses were taken as outcomes. This study examined whether the inquiry-based instructional approaches experienced by students predict their creative productivity and whether its effects are mediated through co-cognitive factors, school engagement, and school GPA. This study is part of a national longitudinal study about students from Science Academies, a type of specialized science high school in South Korea. A total of 599 students at Science Academies were surveyed on experiences of inquiry-based instructional approaches, co-cognitive factors, school engagement, and school GPA in math and science in their second year, and on creative productivity in their last year at Science Academies. Creative productivity was measured by the number of awards received from STEM competitions for research, problem solving, or projects. Confirmatory factor analyses confirmed the convergent validity of the measurement model. Structural equation modeling analysis and bootstrapping analysis revealed the direct, indirect, and total effects of inquiry-based instructional approaches on creative productivity. Inquiry-based instructional approaches experienced by students at Science Academies had a sequentially positive impact on co-cognitive factors, school engagement, and school GPA, ultimately contributing to creative productivity.
Capacitance Estimation for Electrical Capacitance Tomography Sensors Using Digital Processing of Time-Domain Voltage Response to Single-Pulse Excitation
Authors: Kalarickel Ramakrishnan Praveen , Westwood Timothy , Magalhães Gouveia Tomé , Taani Mahdi , de Jager Kylie , Murdoch Kenny , Orlov Andrey A. , Ozhgibesov Mikhail S. , Propodalina Tatiana V. , Wojtowicz Natalia
Published: July 2023

In this paper, a new approach for capacitance measurement for electrical capacitance tomography (ECT) sensors is proposed. The method is based on the digital processing of the time-domain voltage measurements at the sensor electrodes. Furthermore, a robust capacitance estimation algorithm is developed to convert the measured voltage time-series to inter-electrode capacitances. The proposed measurement technique simplifies the electronic design of the ECT sensor and is suitable for use in applications requiring a compact device with a fast scan time. The accuracy and sensitivity of the method are investigated numerically and experimentally using a prototype sensor. In particular, the sensitivity of the estimated capacitance to measurement noise levels is analyzed in detail. Additionally, an analysis of the parameters that affect the accuracy of estimated capacitances is carried out from which we are able to demonstrate that the method is immune to effects such as stray capacitances between the electrodes and the ground. A prototype sensor with an open curved geometry on a millimeter scale is used to test the method empirically. Experimental results obtained for measurements with mineral oil and water are shown and compared against capacitances obtained using a physics-based forward model of the sensor. The inter-electrode capacitances in the range of tens of femtofarads to a few picofarads are estimated and a close match with the forward model results is obtained.
Adaptive 3D Reversible Data Hiding Technique Based on the Cumulative Peak Bins in the Histogram of Directional Prediction Error
Authors: Kasasbeh Dima , Anbar Mohammed , Issa Ghassan , Alabsi Basim Ahmad , Rihan Shaza Dawood Ahmed
Published: July 2023

Reversible data hiding (RDH) is crucial in modern data security, ensuring confidentiality and tamper-proofness in various industries like copyright protection, medical imaging, and digital forensics. As technology advances, RDH techniques become essential, but the trade-off between embedding capacity and visual quality must be heeded. In this paper, the relative correlation between the pixel’s local complexity and its directional prediction error is employed to enhance an efficient RDH without using a location map. An embedding process based on multiple cumulative peak region localization (MCPRL) is proposed to hide information in the 3D-directional prediction error histogram with a lower local complexity value and avoid the underflow/overflow problems. The carrier image is divided into three color channels, and then each channel is split into two non-overlapping sets: blank and shadow. Two half-directional prediction errors (the blank set and the shadow set) are constructed to generate a full-directional prediction error for each color channel belonging to the host image. The local complexity value and directional prediction error are critical metrics in the proposed embedding process to improve security and robustness. By utilizing these metrics to construct a 3D stego-Blank Set, the 3D stego-shadow Set will be subsequently constructed using the 3D blank set. The proposed technique outperforms other state-of-the-art techniques in terms of embedding capacity, image quality, and robustness against attacks without an extra location map. The experimental results illustrate the effectiveness of the proposed method for various 3D RDH techniques.
Emergency Power Supply Restoration Strategy for Distribution Network Considering Support of Microgrids with High-Dimensional Dynamic Correlations
Authors: Yang Zhichun , Han Ji , Wang Chenxia , Li Li , Li Muyuan , Yang Fan , Lei Yang , Hu Wei , Min Huaidong , Liu Yu
Published: July 2023

With the rapid development of renewable energy, microgrids are becoming more and more essential in distribution networks. However, uncertainties brought by new energy sources have posed great challenges to the energy safety and stability of distribution networks, especially in the process of fault restoration. To address these issues, this paper investigates an emergency power supply recovery strategy for distribution networks by considering the support capability of microgrids and the high-dimensional dynamic correlations of uncertainty. Firstly, the structure of distribution networks including microgrids is analyzed. Then, the high-dimensional dynamic vine copula model is proposed to model the joint output uncertainty process. Next, island partition and operation models are established, including the objective function and constraint conditions, and the model solving methods are also presented. Finally, an example analysis is conducted to verify the effectiveness of the proposed strategy. The results show that the proposed strategy is able to deal with the uncertainties brought by renewable energy sources in distribution networks with microgrid support, improving energy safety and stability. This research provides valuable insights for the development of emergency power supply strategies in distribution networks.
CMOS Linear Laser Driver for Intermediate Frequency over Fiber (IFoF) Links
Authors: Paredes-Páliz Diego F. , Martinez-Perez Antonio D. , Aznar Francisco , Celma Santiago
Published: July 2023

The main objective of the proposed linear laser driver (LLD) is to reduce signal distortion in an analog direct modulation laser configuration used for intermediate frequency over fiber links. This work draws on an open-loop configuration featuring two differential pair blocks in a cascade arrangement to achieve a bandwidth measurement of 415 MHz at the half-power point, a total harmonic distortion of 4.57% for a fundamental frequency of 100 MHz, and an amplitude of 100 mVpp. The LLD provides a gain of 12.3 dB for a differential output and an output impedance of 46 Ω. The design, layout, and integration correspond to the process design kit for TSMC 65-nm CMOS technology. Experimental results show the advantage over other previously reported laser drivers.
A Q-Learning-Based Load Balancing Method for Real-Time Task Processing in Edge-Cloud Networks
Authors: Du Zhaoyang , Peng Chunrong , Yoshinaga Tsutomu , Wu Celimuge
Published: July 2023

Edge computing has emerged as a promising solution to reduce communication delays and enhance the performance of real-time applications. However, due to the limited processing power of edge servers, it is challenging to achieve efficient task processing. In this paper, we propose a Q-learning-based load-balancing method that optimizes the distribution of real-time tasks between edge servers and cloud servers to reduce processing time. The proposed method is dynamic and adaptive, taking into account the constantly changing network status and server usage. To evaluate the effectiveness of the proposed load-balancing method, extensive simulations are conducted in an Edge-Cloud network environment. The simulation results demonstrate that the proposed method significantly reduces processing time compared to traditional static load-balancing methods. The Q-learning algorithm enables the load-balancing system to dynamically learn the optimal decision-making strategy to allocate tasks to the most appropriate server. Overall, the proposed Q-learning-based load-balancing method provides a dynamic and efficient solution to balance the workload between edge servers and cloud servers. The proposed method effectively achieves real-time task processing in edge computing environments and can contribute to the development of high-performance edge computing systems.
Morphological, Histological, and Transcriptome Analysis of Doubled Haploid Plants in Poplars (Populus simonii × Populus nigra)
Authors: Wang Yiran , Yu Jiajie , Zhang Xiang , He Yaxin , Chen Song , Fan Erqin , Qu Guanzheng , Chen Su , Liu Caixia
Published: July 2023

In this study, the poplar doubled haploid (DH) plants were used as the experimental material to explore the huge phenotypic differences between homozygous DH plants and the paternal plants, and the molecular regulation mechanism of the differential phenotypes. In this experiment, through morphological and histological observation and statistics, we found that the double haploid plants had significantly reduced plant height and ground diameter, increased leaf aspect ratio, premature senescence phenotype of top bud, and significant changes in the shape and cell area of the shoot apical meristem. Significantly differentially expressed genes were obtained using RNA-seq transcriptome sequencing. They were subjected to GO enrichment and KEGG analysis. Transcription factors with key functions were screened out for qRT-PCR to verify gene expression changes to predict gene function. The results showed that after the IAA and ABA treatment, the expression levels of some hormone-responsive genes in wild type plants were significantly changed with different treatment time. In the dihaploid plants, the corresponding genes also changed to different degrees, which reflected the changes in the response of the dihaploid plants to hormones. Compared to in WT, the differential expressed genes in the double haploids were involved in multiple physiological process such as response to oxidative stress, response to salicylic acid, plant pathogen interaction, and plant hormone signal transduction. A TF–centered gene regulatory network for phytohormone synthesis and plant senescence was constructed with the expression patterns of differentially expressed transcription factors (TFs). This study increases researchers’ understanding of the regulation of poplar growth and development and provides new research ideas for the creation of new species of poplar.
Algae: The Reservoir of Bioethanol
Authors: Chandrasekhar Thummala , Varaprasad Duddela , Gnaneswari Poreddy , Swapna Battana , Riazunnisa Khateef , Anu Prasanna Vankara , Korivi Mallikarjuna , Wee Young-Jung , Lebaka Veeranjaneya Reddy
Published: July 2023

Overuse of non-renewable fossil fuels due to the population explosion urges us to focus on renewable fuels such as bioethanol. It is a well-known fact that ethanol is useful as a blending product with common fuels such as petrol and diesel. This reduces the cost besides bringing down environmental pollution. Apart from chemical methods, bioethanol is generated from photosynthetic plants including algae, plant-based products, microbial organisms and their waste. Specifically, the production of ethanol from microalgal sources has been an attractive method in recent days. The reason behind using microalgal species is their simple structure with photosynthetic ability. In contrast, certain algal species often go disused in some regions. Hence, the production of ethanol from algal sources is one of the best waste management practices. Moreover, it is easy to improve the biomass in microalgal species by altering the physicochemical conditions such as light, pH, temperature, external supply of nutrients, vitamins, nano-sized particles, gene alterations etc., which will enhance ethanol production. In this review, the methods used for ethanol production are discussed. In addition, the factors involved in algal growth and ethanol production are emphasized. Overall, this review focuses on ethanol production from various algal species. This information will be useful for industrial-level production of ethanol and future renewable energy research.
Effect of Mixing Peanut Vine on Fermentation Quality, Nitrogen Fraction and Microbial Community of High-Moisture Alfalfa Silage
Authors: Sun Yu , Wu Chunhui , Zu Xiaowei , Wang Xiaolin , Yu Xiaomeng , Chen Huan , Xu Ling , Wang Mingya , Li Qiufeng
Published: July 2023

Fresh alfalfa is difficult to ensile successfully because of its high moisture content and greater susceptibility to spoilage by Clostridia, Bacilli or Enterobacter. In this study, we evaluated the effects of mixing high-moisture alfalfa with peanut vine in different proportions on the bacterial communities and fermentation characteristics of silage. The high-moisture alfalfa and peanut vine were mixed at ratios of 10:0 (CK), 8:2 (TI), 7:3 (T2), 6:4 (T3) and 5:5 (T4), respectively. For each treatment, silos (25 × 35 cm) were anaerobically fermented in darkness at room temperature and analyzed after 45 days. The results showed that the CK silage was weakly fermented, as indicated by a low lactic acid concentration, a high pH value, and high levels of propionic acid (PA), butyric acid (BA) and ammonia nitrogen (NH3-N). As the proportion of peanut vine in the mixture increased, the pH level decreased, and levels of BA, propionic acid, NH3-N, crude protein(CP), nonprotein nitrogen and soluble protein also declined (p < 0.05), while the lactic acid concentration increased and levels of neutral detergent fiber (NDF) and water-soluble carbohydrates (WSC) also rose (p < 0.05). A protein component analysis of silage mixtures using the Cornell Net Carbohydrate and Protein System (CNCPS) showed that the content of the nonprotein nitrogen component (PA) decreased when the proportion of peanut vine increased, whereas the content of rapidly degraded protein (PB1) increased. Mixing with peanut vine also influenced the distribution of the bacterial community. Compared with the CK silage, the relative abundances of Enterococcus, Garciella and Anaerosporobacter in T2, T3 and T4 were significantly lower, while the relative abundance of Lactobacillus was significantly higher. In the T2, T3 and T4 groups, Garciella and Anaerosporobacter were not detected. In summary, in this study, we ensiled high-moisture alfalfa, which was weakly fermented. We found that mixing with peanut vine improved fermentation quality and optimized the structure of the bacterial community. Therefore, to improve the fermentation quality and nutritional value of silage, high-moisture alfalfa should be ensiled with at least 30% peanut vine.
Effects of Administration of Prebiotics Alone or in Combination with Probiotics on In Vitro Fermentation Kinetics, Malodor Compound Emission and Microbial Community Structure in Swine
Authors: Lee Maro , Choi Yeonjae , Bayo Joel , Bugenyi Andrew Wange , Kim Yangseon , Heo Jaeyoung
Published: July 2023

The objective of this study was to evaluate the effect of Lactobacillus amylovorus, L. plantarum, galacto-oligosaccharide (GOS) and their synbiotic formulations on pH, volatile fatty acids (VFA), malodor, and microbial ecological profiles through a 24-h in vitro fermentation model. Inclusion of GOS alone and in synbiotic combination with either probiotic resulted in consistently lower pH and higher total gas volumes at 12 and 24 h of incubation. Notably, concentrations of odorous compounds (hydrogen sulfide, H2S and methyl mercaptan, CH3SH) in the total gas produced were significantly lower in these GOS-containing treatments relative to the controls and probiotic-only-treated groups. However, although ammonia showed an initial relative reduction at 12 h, concentrations did not differ among treatments at 24 h. Further, the GOS-containing treatments had remarkably higher total and individual VFAs, including acetate, propionate, and butyrate, relative to controls and the probiotic-only treatments. Analysis of microbial composition and diversity showed clustering of GOS-containing treatments away from the controls and probiotic-only treatments at 12 and 24 h of incubation. Our study suggests that GOS supplementation (alone or in combination with L. amylovorus or L. plantarum probiotic strains) has the potential to increase VFA production in the swine gut while lowering emissions of malodorous compounds, except ammonia, in their manure.
Application of an Integrated Granular and Suspended Sludge Methane Reactor for a Two-Stage Anaerobic Digestion System to Deal with Biodegradable Municipal Solid Waste
Authors: Dinh Pham Van , Fujiwara Takeshi
Published: July 2023

This study aims to investigate the performance of a two-stage anaerobic digestion system using a hybrid methane reactor to deal with biodegradable municipal solid waste. The reactor allowed both suspended sludge and granular sludge to work together. The feedstock was fermented in one continuous stirred tank at different pH conditions for 5 d. Furthermore, the liquid hydrolysate was diluted and pumped into a methane reactor with different organic loading rates. In the fermentative reactor, raising the pH condition from 4.5 to 6.5 caused a sharp increase in volatile fatty acids concentration, mainly due to the increase in acetate and propionate. The efficiency of the methane reactor was proven by the results of hydrodynamic analysis and biogas production. The relationship between biogas production and operating parameters in this reactor was modeled using a quadratic multivariate regression model. Overall, by maintaining the fermentative reactor at a pH of 6.0–6.5, the methane reactor was able to achieve an organic loading rate of 7.6 g-TS.L−1·d−1 with outstanding biogas quality and yield. In terms of microbiology, the most dominant phyla in the reactor included Firmicutes, Bacteroidetes, Proteobacteria, Euryarchaeota, Synergistetes, and Chloroflexi. Among them, the species with the highest relative abundance in granular sludge was Firmicutes, while that in suspended sludge was Bacteroidetes.
Short-Term Effects of Prescribed Burn Seasonality on the Understory in a Pinus nigra Arnold subsp. salzmannii (Dunal) Franco Mediterranean Forest
Authors: Fajardo-Cantos Álvaro , Moya Daniel , Lucas-Borja Manuel Esteban , Plaza-Álvarez Pedro Antonio , Peña-Molina Esther , González-Romero Javier , de las Heras-Ibañez Jorge
Published: July 2023

Worsening climate change and increasing temperatures generate more sever and extended wildfires, raising concerns about ecosystem services. Prescribed burns (PB) are used to reduce forest fuel loads. Improving knowledge regarding the vegetation response after PB is essential for generating common points for monitoring ecological burning effects and generating a protocol or practice guide. We compared the PB seasonality of low-intensity (spring, summer, and autumn) and unburned areas in a total of 12 plots in Pinus nigra Arnold ssp. salzmannii Mediterranean forest. Our vegetation analysis was short term (one year after each PB). We analyzed vegetation coverage, α-diversity (Pielou, Simpson, and Shannon’s index), life forms, and fire-adapted traits using the Canfield transect method, followed by statistical analyses such as non-metric multidimensional scaling (NMDS) and two-way ANOVA. α-diversity was significantly decreased (>55% of dissimilarity) in the burned plots during each season, with the lowest values after summer PB (69% of dissimilarity) when comparing the burned and unburned plots. There was a significant increase in hemicryptophytes (15−20%) and geophyte coverage (from 6% to 14%, or from 4% to 8% in certain cases) in the burned plots after PB seasonality; however, the phanerophytes were reduced (from 13% to 5%). Resprouters were more dominant after PB (an increase of 15–20%), which indicates that resprouters have a faster recovery and generate a fuel load quickly for highly flammable species such as Bromus after low-intensity burning. This suggests that low-intensity prescribed burning may not be the best methodology for these resprouting species. This study helps to understand how burning in the early season can affect inflammable vegetation and the change in fuel that is available in semi-arid landscapes. This is key to achieving the basis for the development of a standardized system that allows for the efficient management of forest services in order to reduce wildfire risks. One objective of this line of research is to observe the effects of recurrent burning in different seasons on vegetation, as well as plant−soil interaction using the microbial and enzyme soil activity.
Spherical Diffusion Flames of Ethylene in Microgravity: Multidimensional Effects
Authors: Frolov Sergey M. , Ivanov Vladislav S. , Frolov Fedor S. , Semenov Ilya V.
Published: July 2023

The joint American–Russian Space Experiment Flame Design (Adamant) was implemented on the International Space Station (ISS) in the period from 2019 to 2022. The objectives of the experiment were to study the radiative extinction of spherical diffusion flames (SDF) around a porous burner (PB) under microgravity conditions, as well as the mechanisms of control of soot formation in the SDF. The objects of the study were the normal and inverse SDFs of gaseous ethylene in an oxygen atmosphere with nitrogen dilution at room temperature and pressures ranging from 0.5 to 2 atm. The paper presents the results of transient 1D and 2D calculations of 24 normal and 13 inverse SDFs with and without radiative extinction. The 1D calculations revealed some generalities in the evolution of SDFs with different values of the stoichiometric mixture fraction. The unambiguous dependences of the ratio of flame radius to fluid mass flow rate through the PB on the stoichiometric mixture fraction were shown to exist for normal and inverse SDFs. These dependences allowed important conclusions to be made on the comparative flame growth rates, flame lifetime, and flame radius at extinction for normal and inverse SDFs. The 2D calculations were performed for a better understanding of the various observed non-1D effects like flame asymmetry with respect to the center of the PB, flame quenching near the gas supply tube, asymmetrical flame luminosity, etc. The local mass flow rate of fluid through the PB was shown to be nonuniform with the maximum flow rate attained in the PB hemisphere with the attached fluid supply tube, which could be a reason for the flame asymmetry observed in the space experiment. The evolution of 2D ethylene SDFs at zero gravity was shown to be oscillatory with slow alterations in flame shape and temperature caused by the incepience of torroidal vortices in the surrounding gas. Introduction of the directional microgravity, on the level of 0.01g , led to the complete suppression of flame oscillations.
Estuarine-Specific Migration of Glass Eels in the Ems Estuary
Authors: Huisman Jeroen B. J. , Kuipers Henry J. , Nagelkerke Leopold A. J. , Schollema Peter Paul , van der Knaap Inge
Published: July 2023

Understanding recruitment of glass eels in estuaries is crucial for the conservation of the European eel (Anguilla anguilla). However, basic knowledge on estuarine-specific glass eel migration, including in estuarine harbours, is mostly lacking. Therefore, we studied glass eel migration in the Dutch–German Ems estuary and the harbour at Delfzijl (The Netherlands) and tagged glass eels with Visual Implant Elastomer tags (VIE tags). We released 2000 tagged glass eels into the Ems estuary itself and 1000 tagged glass eels into the tidal harbour at Delfzijl. At three estuarine locations, i.e., Delfzijl–Duurswold, Termunterzijl, and Nieuwe Statenzijl, glass eel collectors were strategically placed, each location being progressively situated further upstream in the Ems estuary. Most glass eels (nuntagged = 97,089, ntagged = 74) were caught at Nieuwe Statenzijl, although this location is much further upstream. Lower numbers of glass eels (nuntagged = 1856, n tagged = 31) were caught at Delfzijl–Duurswold and Termunterzijl (nuntagged = 1192, ntagged = 7). Glass eels arrived approximately a week earlier at Nieuwe Statenzijl than at the other two locations, and the migration speed of tagged glass eels was highest at Nieuwe Statenzijl (>2 km/day) and lower (<1 km/day) at Delfzijl–Duurswold. Our study highlights that migration and the resulting potential recruitment of glass eels in estuaries and harbours may vary considerably both spatially and temporally. Further research on estuarine-specific factors that influence glass eel migration, such as the (anthropogenically altered) tidal action and flow, will provide valuable information on what influences glass eel migration in estuaries.
Comparison of Growth Performance and Muscle Nutrition Levels of Juvenile Siniperca scherzeri Fed on an Iced Trash Fish Diet and a Formulated Diet
Authors: Wang Maoyuan , Lai Mingyong , Tian Tian , Wu Meiying , Liu Yinhua , Liang Ping , Huang Liuting , Qin Zhiqing , Ye Xiaojun , Xiao Wei , Huang Honggui
Published: July 2023

To assess the possibility of using a formulated diet instead of an iced trash fish diet for feeding spotted mandarin fish (Siniperca scherzeri), a 20-week feeding trial was conducted. The objective of the study was to examine the effects of the formulated diet (FG) and the iced trash fish diet (XG) on the growth performance and muscle nutrient composition of the fish. The results showed that the spotted mandarin fish fed with an XG had slightly higher survival rates, weight gain rate, fullness, hepatic index, and viscera index compared to those fed with an FG, although the differences were not significant (p > 0.05). Additionally, in terms of muscle composition, the FG group had higher levels of crude protein and ash content in the fish muscle compared to the XG group (p < 0.05). On the other hand, the crude fat content showed the opposite trend. Among the seventeen amino acids analyzed, only lysine and proline levels differed significantly between the FG and XG groups (p < 0.05). In terms of muscle-hydrolyzed fatty acids, fifteen fatty acids were detected in both groups, with arachidonic acid being exclusive to the FG group. Furthermore, significant differences in the levels of thirteen fatty acids were observed between the two groups (p < 0.05). The FG group had lower levels of saturated fatty acids compared to the XG group (p < 0.05), while monounsaturated fatty acids, polyunsaturated fatty acids, and EPA + DHA contents were higher. This study demonstrates the potential of using a formulated diet as a substitute for an iced trash fish diet in the rearing of spotted mandarin fish. However, further optimization of the formulated diet is necessary to improve the growth of spotted mandarin fish in future research.
Antimicrobial Effects of Plasma-Activated Simulated Seawater (PASW) on Total Coliform and Escherichia coli in Live Oysters during Static Depuration
Authors: Campbell Vashti M. , Hall Steven , Salvi Deepti
Published: July 2023

Recently, our in vitro study on the effects of plasma-activated simulated seawater (PASW) demonstrated its potential as a novel, alternative disinfectant in oyster depuration. In this current study, PASW’s physicochemical and antimicrobial properties were identified and its effects on oyster quality were observed. Simulated seawater (SS) activated by plasma for 10 min (PASW10) increased in temperature, oxidation reduction potential, and electrical conductivity with a decrease in those parameters after 1:1 dilution with SS (PASW10 (1:1)). The pH decreased immediately after plasma activation and subsequently increased after dilution. Nitrate and nitrite concentrations were higher in PASW10 (1:1) compared to PASW10 (3:1). No free available chlorine was detected in undiluted PASW10. Processing using SS and PASW10 (1:1) depuration and refrigeration of E. coli-bioaccumulated oysters was observed. Significantly higher reductions in total coliform and E. coli were noted for PASW10 (1:1) treated oyster samples after 24 h compared to refrigerated samples. No significant differences in values for condition index or biting force of oyster meats were observed for the processed samples after 24 h. Overall, the novel and environment-friendly PASW could be used as an alternative antimicrobial disinfectant in oyster depuration systems because it does not negatively affect an oyster’s viability or quality.
The Screening and Isolation of Ethyl-Carbamate-Degrading Strains from Fermented Grains and Their Application in the Degradation of Ethyl Carbamate in Chinese Baijiu
Authors: Xue Siyu , Dong Naihui , Xiong Kexin , Guo Hui , Dai Yiwei , Liang Huipeng , Chen Yingxi , Lin Xinping , Zhu Beiwei , Zhang Sufang
Published: July 2023

Ethyl carbamate (EC), a 2A carcinogen produced during the fermentation of foods and beverages, primarily occurs in distilled spirits. Currently, most studies focus on strategies for EC mitigation. In the present research, we aimed to screen strains that can degrade EC directly. Here, we report two Candida ethanolica strains (J1 and J116), isolated from fermented grains, which can reduce EC concentrations directly. These two yeasts were grown using EC as the sole carbon source, and they grew well on different carbon sources. Notably, after immobilization with chitosan, the two strains degraded EC in Chinese Baijiu by 42.27% and 27.91% in 24 h (from 253.03 ± 9.89 to 146.07 ± 1.67 and 182.42 ± 5.05 μg/L, respectively), which was better than the performance of the non-immobilized strains. Furthermore, the volatile organic compound content, investigated using gas chromatography-mass spectrometry, did not affect the main flavor substances in Chinese Baijiu. Thus, the yeasts J1 and J116 may be potentially used for the treatment and commercialization of Chinese Baijiu.
Comparative Analysis of the Immune Response and the Clinical Allergic Reaction to Papain-like Cysteine Proteases from Fig, Kiwifruit, Papaya, Pineapple and Mites in an Italian Population
Authors: Giangrieco Ivana , Ciardiello Maria Antonietta , Tamburrini Maurizio , Tuppo Lisa , Rafaiani Chiara , Mari Adriano , Alessandri Claudia
Published: July 2023

Several plant papain-like cysteine proteases are exploited by the food, cosmetic, pharmaceutical and textile industries. However, some of these enzymes can cause allergic reactions. In this context, we investigated the frequency of sensitization and allergic reactions to some fruit and/or latex cysteine proteases, which are used as additives by the food industry to improve and modify the quality of their products. The FABER test was used to analyse the patients‘ sensitization towards five plants and, for comparison, two homologous mite cysteine proteases. In an Italian population of 341 allergic patients, 133 (39%) had IgE specific for at least one of the seven cysteine proteases under investigation. Most of the patients were IgE positive for Der p 1 and/or Der f 1 (96.38%) reported a clinical history suggestive of respiratory allergy to mites, whereas none of the subjects sensitized to the homologs from papaya, pineapple and fig reported allergy symptoms following ingestion of these foods. Only one patient referred symptoms from ingesting kiwifruit. Therefore, the obtained results showed that sensitization to the fruit enzymes was only rarely concomitant with allergic reactions. These observations, together with the literature reports, suggest that the allergy to plant papain-like cysteine proteases might mainly be an occupational disease.
Application of ATR-FTIR Incorporated with Multivariate Data Analysis for Discrimination and Quantification of Urea as an Adulterant in UHT Milk
Authors: Tan Emeline , Binti Julmohammad Norliza , Koh Wee Yin , Abdullah Sani Muhamad Shirwan , Rasti Babak
Published: July 2023

Urea is naturally present in milk, yet urea is added intentionally to increase milk’s nitrogen content and shelf life. In this study, a total of 50 Ultra heat treatment (UHT) milk samples were spiked with known urea concentrations (0–5 w/v%). Attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy with principal component analysis (PCA), discriminant analysis (DA), and multiple linear regression (MLR) were used for the discrimination and quantification of urea. The PCA was built using 387 variables with higher FL > 0.75 from the first PCA with cumulative variability (90.036%). Subsequently, the DA model was built using the same variables from PCA and demonstrated the good distinction between unadulterated and adulterated milk, with a correct classification rate of 98% for cross-validation. The MLR model used 48 variables with p-value < 0.05 from the DA model and gave R2 values greater than 0.90, with RMSE and MSE below 1 for cross-validation and prediction. The DA and MLR models were then validated externally using a test dataset, which shows 100% correct classification, and the t-test result (p > 0.05) indicated that the MLR could determine the percentage of urea in UHT milk within the permission limit (70 mg/mL). In short, the wavenumbers 1626.63, 1601.98, and 1585.5534 cm−1 are suitable as fingerprint regions for detecting urea in UHT milk.
Evaluation of Autochthonous Coagulase—Negative Staphylococci as Starter Cultures for the Production of Pastırma
Authors: Fettahoğlu Kübra , Kaya Mükerrem , Kaban Güzin
Published: July 2023

The aim of the study was to investigate the effects of Staphylococcus xylosus 39, S. equorum 53, or S. vitulinus 75, previously isolated from pastırma, on the quality characteristics of pastırma, a Turkish dry-cured meat product, and to evaluate their potential use as starter cultures. The pastırma production was carried out with a traditional method. The control pastırma groups were manufactured without adding any starter culture. At the end of production, the groups were subjected to microbiological and physico-chemical analyses. The pH was above 5.5, and the aw value was below 0.90 in all groups. The strains used exhibited good adaptation to the pastırma. The S. equorum 53 decreased the thiobarbituric acid reactive substances (TBARS) value in pastırma, while the S. xylosus 39 increased the redness (a*) color value. The autochthonous strains caused a decrease in the palmitic acid (C16:0). However, they had no significant effect on the stearic acid (C18:0) and the oleic acid (C18:1n-9c). A total of 41 volatile compounds were identified in the groups. S. vitulinus 75 increased both benzaldehyde and 2-methyl-3-phenylpropanal levels. In addition, the principal component analysis (PCA) of volatile compounds provided a good separation, and PC1 separated S. xylosus 39 from other groups.
Advances in Microfluidics Techniques for Rapid Detection of Pesticide Residues in Food
Authors: Jiang Zhuoao , Zhuang Yu , Guo Shentian , Sohan A. S. M. Muhtasim Fuad , Yin Binfeng
Published: July 2023

Food safety is a significant issue that affects people worldwide and is tied to their lives and health. The issue of pesticide residues in food is just one of many issues related to food safety, which leave residues in crops and are transferred through the food chain to human consumption. Foods contaminated with pesticide residues pose a serious risk to human health, including carcinogenicity, neurotoxicity, and endocrine disruption. Although traditional methods, including gas chromatography, high-performance liquid chromatography, chromatography, and mass spectrometry, can be used to achieve a quantitative analysis of pesticide residues, the disadvantages of these techniques, such as being time-consuming and costly and requiring specialist staff, limit their application. Therefore, there is a need to develop rapid, effective, and sensitive equipment for the quantitative analysis of pesticide residues in food. Microfluidics is rapidly emerging in a number of fields due to its outstanding strengths. This paper summarizes the application of microfluidic techniques to pyrethroid, carbamate, organochlorine, and organophosphate pesticides, as well as to commercial products. Meanwhile, the study also outlines the development of microfluidics in combination with 3D printing technology and nanomaterials for detecting pesticide residues in food.
High-Pressure Processing of Traditional Hardaliye Drink: Effect on Quality and Shelf-Life Extension
Authors: Atmaca Bahar , Demiray Merve , Akdemir Evrendilek Gulsun , Bulut Nurullah , Uzuner Sibel
Published: July 2023

Hardaliye, as one of the oldest and lesser known traditional beverages, is produced using red grape pomace from wine production. This drink production is achieved through lactic acid fermentation, with the addition of sour cherry leaves and mustard seeds—either heat-treated, grinded, or whole—in various concentrations. Hardaliye has a very short shelf life; thus, efforts have recently been made to process hardaliye with novel processing technologies in order to achieve shelf-life extension. Therefore, the high-hydrostatic-pressure (HHP) processing of hardaliye was performed to determine its impact on important properties, including in microbial inactivation and shelf-life extension, with respect to a Box–Behnken experimental design. Maximum log reductions of 5.38 ± 0.6, 5.10 ± 0.0, 5.05 ± 0.2, and 4.21 ± 0.0 with HHP were obtained for Brettanomyces bruxellensis, total mesophilic aerobic bacteria, Lactobacillus brevis, and total mold and yeast, respectively. The processing parameters of 490 MPa and 29 °C for 15 min were found as the optimal conditions, with the response variables of an optical density at 520 nm and the inactivation of L. brevis. The samples processed at the optimal conditions were stored at both 4 and 22 °C for 228 d. While the non-treated control samples at 4 and 22 °C were spoiled at 15 and 3 d, the HHP-treated samples were spoiled after 228 and 108 d at 4 and 22 °C, respectively.
Comparative Study on In Vitro Fermentation Characteristics of the Polysaccharides Extracted from Bergamot and Fermented Bergamot
Authors: Wu Kaizhang , Lu Xingyu , Fang Fang , Liu Juncheng , Gao Jie , Zheng Yang
Published: July 2023

This study aimed to compare the in vitro fermentation characteristics of polysaccharides from Bergamot and Laoxianghuang (fermented 1, 3, and 5 years from bergamot) using the stable in vitro human gut fermentation model. Results showed that bergamot polysaccharide (BP) and Laoxianghuang polysaccharides (LPs) with different surface topographies were characterized as mannorhamnan (comprising Mannose and Rhamnose) and polygalacturonic acid (comprising Galacturonic acid and Galactose), respectively. The distinct effects on the gut microbiota and metabolome of BP and LPs may be due to their different monosaccharide compositions and surface morphologies. BP decreased harmful Fusobacterium and promoted beneficial Bifidobacterium, which was positively correlated with health-enhancing metabolites such as acetic acid, propionic acid, and pyridoxamine. Lactobacillus, increased by LPs, was positively correlated with 4-Hydroxybenzaldehyde, acetic acid, and butyric acid. Overall, this study elucidated gut microbiota and the metabolome regulatory discrepancies of BP and LPs, potentially contributing to their development as prebiotics in healthy foods.