bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved Underwater Single-Vector Acoustic DOA Estimation via Vector Convolution Preprocessing
Authors: Dong Haitao , Suo Jian , Zhu Zhigang , Li Siyuan
Published: May 2024

Remote passive sonar detection with underwater acoustic vector sensor (UAVS) has attracted increasing attention due to its merit in measuring the full sound field information. However, the accurate estimation of the direction-of-arrival (DOA) remains a challenging problem, especially under low signal-to-noise ratio (SNR) conditions. In this paper, a novel convolution (COV)-based single-vector acoustic preprocessing method is proposed on the basis of the single-vector acoustic preprocessing model. In view of the theoretical analysis of the classical single-vector acoustic DOA estimation method, the principle of preprocessing can be described as “to achieve an improved denoising performance in the constraint of equivalent amplitude gain and phase response.” This can be naturally guaranteed by our proposed COV method. In addition, the upper bound with matched filtering (MF) preprocessing is provided in the consideration of the optimal linear signal processing for weak signal detection under Gaussian noise. Numerical analyses demonstrate the effectiveness of our proposed preprocessing method with both vector array signal processing-based and intensity-based methods. Experimental verification conducted in South China Sea further verifies the effectiveness of our approach for practical applications. This work can lay a solid foundation in improving underwater remote vector acoustic DOA estimation under low SNR, and can provide important guidance for future research work.
Novel Self-Organizing Probability Maps Applied to Classification of Concurrent Partial Discharges from Online Hydro-Generators
Authors: de Oliveira Rodrigo M. S. , Fernandes Filipe C. , Barros Fabrício J. B.
Published: May 2024

In this paper, we present an unprecedented method based on Kohonen networks that is able to automatically recognize partial discharge (PD) classes from phase-resolved partial discharge (PRPD) diagrams with features of various simultaneous PD patterns. The PRPD diagrams were obtained from the stator windings of a real-world hydro-generator rotating machine. The proposed approach integrates classification probabilities into the Kohonen method, producing self-organizing probability maps (SOPMs). For building SOPMs, a group of PRPD diagrams, each containing a single PD pattern for training the Kohonen networks and single- and multiple-class-featured samples for obtaining final SOPMs, is used to calculate the probabilities of each Kohonen neuron to be associated with the various PD classes considered. At the end of this process, a self-organizing probability map is produced. Probabilities are calculated using distances, obtained in the space of features, between neurons and samples. The so-produced SOPM enables the effective classification of PRPD samples and provides the probability that a given PD sample is associated with a PD class. In this work, amplitude histograms are the features extracted from PRPDs maps. Our results demonstrate an average classification accuracy rate of approximately 90% for test samples.
Multi Criteria Frameworks Using New Meta-Heuristic Optimization Techniques for Solving Multi-Objective Optimal Power Flow Problems
Authors: Al-Kaabi Murtadha , Dumbrava Virgil , Eremia Mircea
Published: May 2024

This article develops two metaheuristics optimization techniques, Grey Wolf Optimizer (GWO) and Harris Hawks Optimization (HHO), to handle multi-objective optimal power flow (MOOPF) issues. Multi Objective GWO (MOGWO) and Multi Objective HHO (MOHHO) are the names of the developed techniques. By combining these optimization techniques with Pareto techniques, the non-dominated solution set can be obtained. These developed approaches are characterized by simplicity and have few control parameters. Fuel cost, emissions, real power losses, and voltage deviation were the four objective functions considered. The theories used to determine the best compromise solution and organize the Pareto front options are the fuzzy membership equation and the crowding distance approach, respectively. To validate and evaluate the performance of the presented techniques, two standard IEEE bus systems—30-bus and 57-bus power systems—were proposed. Bi, Tri, and Quad objective functions with 21 case studies are the types of objective functions and the scenarios that were applied in this paper. As compared to the results of the most recent optimization techniques documented in the literature, the comparative analysis results for the proposed methodologies demonstrated the superiority and robustness of MOGWO and MOHHO.
The Comparison of Physical and Chemical Properties of Pellets and Briquettes from Hemp (Cannabis sativa L.)
Authors: Roman Kamil , Grzegorzewska Emilia
Published: May 2024

The adaptation of lignocellulosic materials such as Cannabis sativa L. as a new renewable energy source is linked to the fact that the technology must be developed to be able to adapt to local market conditions. Bioenergy consumers are faced with this problem because, when it comes to the selection of briquettes and pellets for energy production, there are only individual standards in place. This research is intended to provide a better understanding of hemp product potential as a new material that can be used in the production of pellets and briquettes for biofuel purpose. Nevertheless, the anisotropic raw material interferes with the compaction process and may expose a poor durability of the pellets and briquettes. The research that was conducted evaluated the conditions of the biofuels by measuring the physical and chemical parameters. The ash content, compressive strength, and durability of the samples were examined. The statistical data analysis was performed after the strength tests on the prepared samples.
Approach for Calculating and Analyzing Carbon Emissions and Sinks of Villages: A Case Study in Northern China
Authors: Du Tiantian , Jiao Yan , Zhang Yue , Jia Ziyu , Wang Jueqi , Zhang Jinhao , Cheng Zheng
Published: May 2024

Despite a gradual decline in rural population due to urbanization, as of 2022, approximately 35% of China’s total population still resides in villages. Over a span of 40 years, carbon emissions from villages have significantly surged, with a sevenfold increase from energy consumption and a 46% rise from agriculture. Consequentially, the development of low-carbon villages is imperative. A comprehensive understanding of the primary sources of carbon emissions in villages is crucial for implementing practical and effective strategies towards low-carbon development. However, limited research has been conducted on quantifying carbon emissions and sinks for Chinese villages. This study aims to address this gap by proposing a methodology for assessing carbon emissions in villages, including the emissions of CO2, CH4 and N2O. Inspired by the IPCC standard methodology for greenhouse gas emissions at national levels and provincial greenhouse gas inventory guidelines customized for China’s context incorporating localized characteristics, this approach has been applied to seven villages in Northern China based on field investigations. Employing a range of methods including field surveys, questionnaires, statistical records and big-data platforms, we collected the carbon emission activity levels of the seven villages using the most up-to-date carbon emission factors. Subsequently, the collected data and facts are quantitatively processed to generate results that are compared among the seven villages. These findings are also compared with those from other studies. The analysis indicates that the primary industries in these villages significantly influence the total carbon emissions. Moreover, the study reveals that energy consumption in buildings, agriculture, transportation and waste disposal are the most influential emission sources. These findings provide valuable insights into the carbon emission landscape of villages and can serve as a guide for implementing strategies and policies aimed at promoting low-carbon development in the rural areas of Northern China.
New Uses for Coal Mines as Potential Power Generators and Storage Sites
Authors: Pous de la Flor Juan , Pous Cabello Juan , Castañeda María de la Cruz , Ortega Marcelo Fabián , Mora Pedro
Published: May 2024

In the context of sustainable development, revitalising the coal sector is a key challenge. This article examines how five innovative technologies can transform abandoned or in-use coal mines into sustainable energy centres. From solar thermal to compressed air energy storage, these solutions offer a path to a more sustainable future while addressing the decline in coal production. This approach not only promotes energy efficiency but also contributes to the mitigation of environmental impacts, thus consolidating the transition to a more responsible energy model. Thus, in this document, the reader can find the explanation of why we have opted for these technologies and not other existing ones. In addition, the economic, environmental and technical feasibility of the different technologies is analysed. Finally, real cases of the successful application of these technologies will be presented once they have gone beyond the project idea phase, and the reasons why we are calling for their transposition to the coal industry in the search for its revitalisation will be explained.
Research on Fault Identification of Hybrid Multi-Feed High-Voltage Direct Current System Based on Line Commutated Converter and Voltage Source Converter
Authors: Wang Ting , Chen Kun , Zhang Long’en , Hu Xingyang , Li Hengxuan , Ye Pangqi
Published: May 2024

With the rapid development of voltage source converter (VSC) and line commutated converter (LCC) technology and the relative concentration of power and load, the inverter station of the flexible DC system is fed into the same AC bus with the conventional DC rectifier station, and the high-voltage direct current (HVDC) parallel hybrid feed system is formed in structure. As the electrical distance between the converter stations is very close, when a fault occurs in the near area, the current on the AC wiring on the VSC side will fluctuate greatly, resulting in the misoperation of the AC wiring protection. For this reason, this paper proposes a fault identification method based on VSC/LCC hybrid multi-fed HVDC system, which discriminates the fault and outputs the protection signal according to the protection criterion, and logically judges the combination of the output protection signal to identify the fault type. The simulation results show that the method can identify all kinds of faults of hybrid multi-feed DC system and solve the problem of protection misoperation of the hybrid multi-feed DC system.
Permeability: The Driving Force That Influences the Mechanical Behavior of Polymers Used for Hydrogen Storage and Delivery
Authors: Sgambitterra Emanuele , Pagnotta Leonardo
Published: May 2024

This article explores the main mechanisms that can generate damage in polymers and polymer-based materials used for hydrogen storage and distribution infrastructures. All of these mechanisms are driven by the permeability process that is enhanced by the operating temperature and pressure conditions. Hydrogen storage and delivery systems typically work under high pressure and a relatively wide range of temperatures, especially during the filling and emptying processes. Therefore, it is of great interest to better understand how this phenomenon can influence the integrity of polymer-based hydrogen infrastructures in order to avoid catastrophic events and to better design/investigate new optimized solutions. The first part of this paper discusses the main storage and delivery solutions for gas and liquid hydrogen. Then, the physics of the permeability is investigated with a focus on the effect of pressure and temperature on the integrity of polymers working in a hydrogen environment. Finally, the main mechanisms that mostly induce damage in polymers operating in a hydrogen environment and that influence their mechanical properties are explored and discussed. Particular focus was placed on the rapid gas decompression and aging phenomena. In addition, some of the limits that still exist for a reliable design of polymer-based storage and delivery systems for hydrogen are pointed out.
Small-Scale Battery Energy Storage System for Testing Algorithms Aimed at Peak Power Reduction
Authors: Sozański Krzysztof , Wermiński Szymon , Kaniewski Jacek
Published: May 2024

This study describes a laboratory model of a battery energy storage system (BESS) designed for testing algorithms aimed at reducing peak power consumption in railway traction substations. The system comprises a DC/DC converter and battery energy storage. This article details a laboratory model of a bidirectional buck-boost DC/DC converter, which is used to transfer energy between the battery energy storage and a DC line. It presents an analysis of DC/DC converter systems along with simulation studies. Furthermore, the results of laboratory tests on the DC/DC converter model are also provided. The control algorithm of the system in the traction substation is focused on reducing peak power, offering benefits such as lower charges for the railway operator due to the possibility of reducing contracted power requirements. From the perspective of the power grid, the reduction in power fluctuations and, consequently, voltage sags, is advantageous. This paper includes a description of a hardware simulator for verifying the system’s control algorithms. The verification of the control algorithms was performed through experimental tests conducted on a laboratory model (a hardware simulator) of the system for dynamic load reduction in traction substations, on a power scale of 1:1000 (5.5 kW). The experimental tests on the laboratory model (hardware simulator) demonstrated the effectiveness of the algorithm in reducing the peak power drawn from the power source.
A High-Resolution Defect Location Method for Medium-Voltage Cables Based on Gaussian Narrow-Band Envelope Signals and the S-Transform
Authors: Chen Wei , Yang Zhenbao , Song Jinyang , Zhou Lifu , Xiang Lingchen , Wang Xing , Hao Changjin , Fan Xianhao
Published: May 2024

The time–frequency-domain reflection method (TFDR) based on the Wigner–Ville distribution (WVD) is confronted with the problem of cross-term interference in existing methods to locate power cable defects. Therefore, a new method of locating cable defects based on Gaussian narrow-band envelope signals and the S-transform is proposed in this paper. In this method, the wide-band cable transfer function is obtained by adjusting the parameters of the Gaussian narrow-band envelope signal because the Gaussian narrow-band envelope signal has a good frequency-adjusting ability and time–frequency characteristics. Then, the time–frequency of the cable signal is transformed by the generalized S-transform, and the time delay of the modular matrix of the transformation matrix is estimated by the generalized cross-correlation algorithm to complete the accurate detection of the cable defect’s location. Compared with traditional methods, the proposed method can adaptively adjust the analysis time width according to the frequency change and provide intuitive time–frequency characteristics without cross-term interference. Finally, the effectiveness and practicability of the proposed method are verified in MATLAB 2017_a by simulating a 40 m/10 kV medium-voltage power cable and submarine cable with a length of 32 km.
Internet of Things Application in an Automated Irrigation Prototype Powered by Photovoltaic Energy
Authors: Borges Rafael C. , Beuter Carlos H. , Dourado Vitória C. , Bento Murilo E. C.
Published: May 2024

Small-scale agriculture is important. However, there are still limitations regarding the implementation of technologies in small-scale agriculture due to the high costs accompanying them. Therefore, it is essential to seek viable and low-cost solutions since the insertion of technologies in agriculture, especially irrigated agriculture, guarantees the sustainable expansion of production capacity. The present work applied the Internet of Things concept to an automated irrigation system powered by photovoltaic panels. The materials used in the prototype consisted of Arduino Uno R3, the ESP8266 development board, a soil moisture sensor, a current sensor, a voltage sensor, a flow sensor, and a humidity and temperature sensor. The prototype was designed to take system readings and send them to the Adafruit platform IO. Furthermore, it was programmed to perform remote irrigation control, enabling this to be activated from distant points through the platform. The medium proved efficient for the monitoring and remote control of the system. This indicates that it is possible to use this medium in small automated irrigation systems.
Investigating the CO2 Geological Sequestration Potential of Extralow-Permeability Reservoirs: Insights from the Es1 Member of the Shahejie Formation in the Dawa Oilfield
Authors: Li Chao , Wang Ende , Wang Dawei , Zhang Ting
Published: May 2024

Extralow-permeability reservoirs have emerged as a significant area of focus for CO2 geological sequestration due to their stable subterranean structure and expansive storage capacity, offering substantial potential in addressing global climate change. However, the full extent of CO2 geological sequestration potential within these extralow-permeability reservoirs remains largely unexplored. To address this gap, this paper utilizes the Shahejie Formation (Es1 member) of the Shuang 229 block in the Liaohe oilfield, Bohai Bay Basin, as a case study. This section is characterized by its abundant oil-gas reserves and serves as an exemplar for conducting experimental research on CO2 storage within extralow-permeability reservoirs. The results demonstrate that the reservoir lithology of the Es1 member is fine sandstone and siltstone, with high compositional and structural maturity. Moreover, the average porosity is 14.8%, the average permeability is 1.48 mD, and the coefficient of variation of the reservoir is approximately 0.5, which indicates a low- to extralow-permeability homogeneous reservoir. In addition, the overburden pressure is >2.0 MPa, the fault can withstand a maximum gas column height of >200 m, and the reservoir exhibits favorable overburden and fault sealing characteristics. Notably, stepwise increasing gas injection in the Shuang 229-36-62 well reveals that the injected liquid CO2 near the wellhead exhibits a relatively high density, close to 1.0 g/cm3, which gradually decreases to approximately 0.78 g/cm3 near a depth of 2000 m underground. The injected fluid changes into a supercritical state upon entering the formation, and the CO2 injection speed is optimal, at 0.08 HCPV/a. According to these findings, it is predicted that the highest burial CO2 volume via the injection of 1.5 HCPVs in the Wa 128 block area is 1.11 × 105 t/year, and the cumulative burial volume reaches approximately 2.16 × 106 t. This shows that the CO2 sequestration potential of extralow-permeability reservoirs is considerable, providing confidence for similar instances worldwide.
Towards an ITU Standard for DLT Energy Consumption
Authors: Nikolaou Ioannis , Anthopoulos Leonidas
Published: May 2024

The emergence of Distributed Ledger Technologies (DLT) in the past decade has challenged our imagination to discover new, innovative and disruptive solutions to problems in domains ranging from finance and healthcare to supply chain and Smart Cities. However, the enormous energy consumption that has been observed in some of the most successful DLT applications raises the question of their long term sustainability. This article reviews the standardization efforts of the International Telecommunications Union (ITU) to provide guidelines to regulators and policy makers for making informed decisions on the applicability and sustainability of DLT architectures from the point of view of energy consumption.
DEM-CFD Simulation Analysis of Heat Transfer Characteristics for Hydrogen Flow in Randomly Packed Beds
Authors: Zhang Quanchen , Xia Yongfang , Cheng Zude , Quan Xin
Published: May 2024

In this study, three randomly packed beds with varying tube-to-particle diameter ratios (D/d) are constructed using the discrete element method (DEM) and simulated via CFD under low pore Reynolds numbers (Rep < 100). An innovation of this research lies in the application of hydrogen in randomly packed beds, coupled with the consideration of its temperature-dependent thermal properties. The axial analysis of the heat transfer characteristics shows that PB−5 and PB−6 achieve thermal equilibrium 44% and 58% faster than PB−4, respectively, demonstrating enhanced heat transfer efficiency. However, at higher flow rates (0.8 m/s), the large-sized fluid channels in PB−6 severely impact the heat transfer efficiency, slightly reducing it compared to PB−5. Additionally, this study introduces a localized segmentation method for calculating the axial local Nusselt number, showing that the axial local Nusselt number (Nu) not only exhibits an inverse relationship with the axial porosity distribution, but also matches its amplitude fluctuations. The wall effect significantly impacts the flow and temperature distribution in the packed bed, causing notable velocity and temperature oscillations in the near-wall region. In the near-wall region, the average temperature is lower than in the core region, and the axial temperature profile exhibits more intense oscillations. These findings may provide insights into the use of hydrogen in randomly packed beds, which are vital for enhancing industrial applications such as hydrogen storage and utilization.
Pre-Treatment of Spent Coffee Grounds Using Hydrodynamic Cavitation
Authors: Szaja Aleksandra , Montusiewicz Agnieszka , Pasieczna-Patkowska Sylwia , Grządka Elżbieta , Montusiewicz Jerzy , Lebiocka Magdalena
Published: May 2024

Spent coffee grounds (SCGs) constitute the main solid residue of the coffee brewing process. SCGs are generated in significant amounts daily, worldwide. The effective management of this waste through biological processes is still an unresolved problem. In this study, the application of hydrodynamic cavitation (HC) as a pre-treatment method for improving the biodegradability of SCGs suspended in municipal wastewater was proposed. An orifice plate with a conical concentric hole having inlet/outlet diameter of 3/10 mm was applied as the cavitation inducer. Three inlet pressures were chosen: 3, 5 and 7 bar. The effects in time intervals of 0, 5, 10, 20, 30 and 45 min were evaluated. The application of HC led to enhanced biodegradability for each case. The results of multi-criteria decision indicated that the most efficient combination in terms of biodegradability and energy usage was obtained at the pressure of 5 bar and duration of 20 or 30 min, depending on the adopted weights. The improvements of DOC/TOC (dissolved organic carbon/total organic carbon) ratio were 57% and 71%, as compared to the untreated samples. The release of caffeine was found at pressures of 5 and 7 bar. However, at 5 bar, this effect was noticed for the longest times, 30 and 45 min, respectively.
Comprehensive Dynamic Interaction Studies in Inverter-Penetrated Power Systems
Authors: Li Fujian , Ma Jin
Published: May 2024

In a renewable-energy-penetrated power system (RPPS), inverter-based resources (IBRs) pose serious challenges to power system stability due to their completely different dynamic characteristics compared with conventional generators; thus, it is necessary to study the dynamic interactions between IBRs and power systems. Although many research efforts have been dedicated to this topic from both power electronics and power system researchers, some research from the power electronics field treats the external power system as a voltage source with an impedance, therefore ignoring the dynamic characteristics of a power system, while most of the research from the power system field applies simulation-based methods, for which it is difficult to directly interpret the interaction mechanism of IBRs and external system dynamics. Thus, none of these studies can explore the accurate dynamic interaction mechanism between IBRs and power systems, leading to performance degradation of IBR-integrated power systems. Our study takes into account the dynamic characteristics of both IBRs and the external power system, resulting in the development of a new open-loop transfer function for RPPSs. Based on this formulation, it is observed that under certain operating conditions, the dynamic interactions between the inverter and the power system help enhance IBR-penetrated power system stability compared with the case for which the external power system is controlled as a voltage source. The study also reveals how the inverter (phase-locked loop, control parameters, etc.), external power system (network strength) and penetration ratio in an IBR-penetrated power system affect the dynamic interactions between IBRs and the external power system using the proposed quantified interaction indices.
Numerical Investigation of a Two-Phase Ejector Operation Taking into Account Steam Condensation with the Presence of CO2
Authors: Kuś Tomasz , Madejski Paweł
Published: May 2024

The application of a two-phase ejector allows for the mixing of liquid and gas and provides effective heat transfer between phases. The aim of the study is a numerical investigation of the performance of a water-driven, condensing two-phase ejector. The research was performed using CFD methods, which can provide an opportunity to analyze this complex phenomenon in 2D or 3D. The 2D axisymmetric model was developed using CFD software Siemens StarCCM+ 2022.1.1. The Reynolds-Averaged Navier–Stokes (RANS) approach with the Realisable k-ε turbulence model was applied. The multiphase flow was calculated using the mixture model. The boiling/condensation model, where the condensation rate is limited by thermal diffusion, was applied to take into account direct contact condensation. Based on the mass balance calculations and developed pressure and steam volume fraction distributions, the ejector performance was analyzed for various boundary conditions. The influence of the suction pressure (range between 0.812 and 0.90) and the steam mass flow rate (range between 10 g/s and 25 g/s) is presented to investigate the steam condensation phenomenon inside the ejector condenser. The provided mixture of inert gas (CO2) with steam (H2O) in the ejector condenser was investigated also. The weakening of the steam condensation process by adding CO2 gas was observed, but it is still possible to achieve effective condensation despite the presence of inert gas.
Drought Monitoring Using Moderate Resolution Imaging Spectroradiometer-Derived NDVI Anomalies in Northern Algeria from 2011 to 2022
Authors: Benhizia Ramzi , Phinzi Kwanele , Hateffard Fatemeh , Aib Haithem , Szabó György
Published: May 2024

Drought has emerged as a major challenge to global food and water security, and is particularly pronounced for Algeria, which frequently grapples with water shortages. This paper sought to monitor and assess the temporal and spatial distribution of drought severity across northern Algeria (excluding the Sahara) during the growing season from 2011 to 2022, while exploring the relationship between the normalized difference vegetation index (NDVI) anomaly and climate variables (rainfall and temperature). Temporal NDVI data from the Terra moderate resolution imaging spectroradiometer (MODIS) satellite covering the period 2000–2022 and climate data from the European Reanalysis 5th Generation (ERA5) datasets collected during the period 1990–2022 were used. The results showed that a considerable portion of northern Algeria has suffered from droughts of varying degrees of severity during the study period. The years 2022, 2021, 2016, and 2018 were the hardest hit, with 76%, 71%, 66%, and 60% of the area, respectively, experiencing drought conditions. While the relationship between the NDVI anomaly and the climatic factors showed variability across the different years, the steady decrease in vegetation health indicated by the NDVI anomaly corroborates the observed increase in drought intensity during the study period. We conclude that the MODIS-NDVI product offers a cost-efficient approach to monitor drought in data-scarce regions like Algeria, presenting a viable alternative to conventional climate-based drought indices, while serving as an initial step towards formulating drought mitigation plans.
A Droplet-Based Microfluidic Impedance Flow Cytometer for Detection of Micropollutants in Water
Authors: Aghel Mohammadreza , Fardindoost Somayeh , Tasnim Nishat , Hoorfar Mina
Published: May 2024

Microplastics as micropollutants are widely spread in aquatic areas that can have a toxic effect on aquatic life. To reduce the potential risk they pose, it is essential to detect the microplastics and the source of the contamination of the environment. Here, we designed and developed a droplet-based microfluidic impedance flow cytometer for in situ detection of microplastics in water. Impedance spectroscopy enables the direct measurement of the electrical features of microplastics as they move in water, allowing for sizing and identification of concentration. To show the feasibility of the developed method, pure and functionalized polystyrene beads ranging from 500 nm to 6 μm in four size groups and different concentrations were used. Focusing on three different frequencies (4.4 MHz, 11 MHz, and 22.5 MHz), the changes in the signal phase at frequencies of 4.4 MHz and 11 MHz are a strong indicator of microplastic presence. In addition, the functionalized microplastics showed different magnitudes of the measured signal phase than the pure ones. A k-nearest neighbors classification model demonstrated our developed system’s impressive 97.4% sensitivity in accurately identifying microplastics based on concentration. The equivalent circuit model revealed that the double-layer capacity of water droplets is significantly impacted by the presence of the microplastics. Our findings show the potential of droplet-based microfluidic impedance flow cytometry as a practical method for detecting microplastics in water.
Impact of Thinning on the Yield and Quality of Eucalyptus grandis Wood at Harvest Time in Uruguay
Authors: Resquin Fernando , Baez Karen , de Freitas Sofia , Passarella Diego , Coelho-Duarte Ana Paula , Rachid-Casnati Cecilia
Published: May 2024

Understanding how thinning strategies impact wood quality and quantity for different purposes is of interest, given that plantation management is often based on parameters that require validation under varying growth conditions. Planted forests for solid purposes in the northern region of Urugay, western Argentina and South of Brazil are usually managed in initial stockings ranging from 800 to 1200 trees·ha−1 depending on the use of clones or seeds. Subsequent thinnings are applied (at plantation ages varying from 3 to 11 years) up to final stockings of around 200 trees·ha−1. This study evaluated contrasting thinning regimes applied early in the crop cycle, with an initial tree density of 840 trees·ha−1. Two thinning treatments were applied at 1.5 and 7.3 years, reducing tree densities to 700–400 and 400–100 trees·ha−1, respectively. Growth analyses were conducted from 1.5 to 20.8 years, considering total height, diameter at breast height, individual volume, total and commercial volume per hectare, mean annual increase, and current annual increase. At the final harvest, contrasting tree densities of 100, 250, and 400 trees·ha−1 were sampled to assess wood density and mechanical properties (bending and compression on small-scale clear samples). Individual growth and wood properties were related to a Stand Density Index to understand the effect of competition on these values. The results identified thinning regimes that resulted in the most significant individual and per-hectare growth (both in thinning and clear felling) and the optimal harvest time under specific growth conditions. We assessed the proportions of commercial logs for sawmill and pulp uses, providing valuable inputs for subsequent economic analyses of thinning regimes aiming for the most convenient combination of wood products. Wood’s physical and mechanical properties were relatively little affected by contrasting levels of competition between trees; therefore, the choice of silvicultural system will depend on production and economic criteria.
Climate Change Responses of High-Elevation Polylepis Forests
Authors: Bedoya-Canas Larry E. , López-Hernández Felipe , Cortés Andrés J.
Published: May 2024

The high mountain forests on Earth are characterized by sharp environmental heterogeneity, high species endemism, and unique phenotypic adaptations. Yet, global warming is jeopardizing this ecosystem as no other as some forests may have nowhere to go beyond the mountain’s summits. One of the most human-endangered high-elevation ecosystems is the Polylepis forest. Despite its vulnerability, forecasting climate reactions in this distinctive high mountain forest type remains a formidable challenge. Therefore, in this study, we modeled climate change responses of high-elevation allopatric Polylepis sericea and P. quadrijuga (Rosaceae) in the northern Andes. The analysis took into account VIF-prioritized bioclimatic variables for near-to-present and future (2081–2100 MPI-ESM1-2-HR) conditions. Model selection was carried out following the AUC scores of 12 MaxEnt and six machine learning algorithms. Predictive power reached 0.97 for MaxEnt’s model fc.H_rm.1 (H-1). Results indicate a moderate vulnerability of P. sericea, with a 29% loss of area in the trailing edge, due to climate change for the period 2081–2100. On the other hand, P. quadrijuga is likely to experience even larger distribution losses, up to 99%, for the same period. The findings of this study suggest that P. quadrijuga, as compared to P. sericea, exhibits a restricted ability to maintain the corresponding habitat requirements in the face of climatic change. Higher niche specialization of P. quadrijuga in the environmentally heterogeneous Eastern Cordillera contrasts with the more generalist nature of P. sericea in the topographically less complex Central Cordillera. In addition to climate change, this trend may be exacerbated by the detrimental effects of agriculture, mining, and an expanding rural population, which represent significant human-driven pressures yet to be modeled in the northern Andean highlands. Yet, based on previous studies, the historical population dynamics during the past glacial cycles suggests that range shifts could play a more significant role at deeper time scales than previously forecasted in the species’ reaction to climate change. Additionally, Polylepis forests may be able to endure at the current locations via local adaptation and plasticity, major drivers of the phenotypic variation in long-lived trees, counteracting the vulnerability scenario under a niche conservatism hypothesis. Ultimately, the modeling procedure employed in this study provides insights into the potential effects of climate change on Polylepis forests 70 years from now. Oncoming studies may consider alternative responses inherent to the gene pool of the species and the interaction with edaphic and biotic agents. We advocate for the application of comparable estimations in other high-elevation tree communities found at the tree line.
Study on the Influence of Host–Guest Interaction on Tourists’ Pro-Environment Behavior: Evidence from Taishan National Forest Park in China
Authors: Lu Feifei , Wang Bingnan , Bi Juan , Guo Weiya
Published: May 2024

This study explores the influence of host–guest interaction on tourists’ pro-environment behavior. On the one hand, the experience attribute of host–guest interaction’s influence on tourists’ experiential value is sorted out. On the other hand, the relationship attribute of host–guest interaction’s activation effect on tourists’ personal norms is identified. Based on social exchange theory and normative activation theory, a structural equation model was established to depict the transmission mechanism from host–guest interaction to tourists’ pro-environment behavior. The data were collected from tourists in Taishan National Forest Park (n = 499). The results indicated that host–guest interaction quality activated tourists’ personal norms through consequence awareness, thus promoting tourists’ pro-environment behavior. Meanwhile, the quality of host–guest interaction positively influenced tourists’ pro-environment behavior through emotional experience value. Host–guest interaction quantity promoted tourists’ pro-environment behavior by activating personal norms through responsibility ascription. In addition, although frequent host–guest interactions can enhance the social experience and functional experience value of tourists, the latter two cannot stimulate tourists’ pro-environmental behavior. This study provides practical implications for promoting the sustainable development of national forest parks.
Study of Physicochemical Quality and Organic Contamination in Algerian Honey
Authors: Derrar Sofiane , Lo Turco Vincenzo , Albergamo Ambrogina , Sgrò Benedetta , Ayad Mohamed Amine , Litrenta Federica , Saim Mohamed Said , Potortì Angela Giorgia , Aggad Hebib , Rando Rossana , Di Bella Giuseppa
Published: May 2024

Honey is a natural product extensively consumed in the world for its nutritional and healthy properties. However, residues of pesticides and environmental contaminants can compromise its quality. For this reason, the physicochemical parameters, and the organic contamination of monofloral and multifloral honey from three regions of Algeria (Tiaret, Laghouat, and Tindouf) were monitored to evaluate the quality of the honey and its safety for consumers. In general, the results obtained from the physicochemical analyses were in line with the EU standards. In terms of contamination, pesticides authorised and used in Algerian agriculture (metalaxyl-M and cyromazine), as well as a banned pesticide (carbaryl), were found in almost all the samples. However, only the concentration of cyromazine was higher than the relative EU maximum residue levels. PCB 180, PCB 189, anthracene, fluorene, and phenanthrene were mainly detected. All the honey shows traces of DiBP, DBP, DEHP, and DEHT, but no traces of bisphenols were found. Moreover, according to the dietary exposure assessment, a small amount of Algerian honey can be safely consumed. Overall, the data from this study should motivate the Algerian government to enhance their monitoring activities in beekeeping and to find solutions for implementing more sustainable agricultural practices harmonising with international legislation.
From Field to Waste Valorization: A Preliminary Study Exploring the Impact of the Wine Supply Chain on the Phenolic Profile of Three Sardinian Pomace Extracts
Authors: Castangia Ines , Aroffu Matteo , Fulgheri Federica , Abi Rached Rita , Corrias Francesco , Sarais Giorgia , Bacchetta Gianluigi , Argiolas Francesca , Pinna Maria Barbara , Murru Mariano , Manca Maria Letizia , Manconi Maria , Nácher Amparo
Published: May 2024

The winemaking process generates an annual global production of about 10 million tons of waste consisting of stalks, skin, and seeds. The possible reutilization of wine pomace is strictly linked to its chemical composition. In this preliminary study, three different Sardinian white grapes (Malvasia, Vermentino and Nasco) grown in the same area were evaluated through a whole wine production chain. To reduce environmental impact, all the grapes were treated following the integrated production practice (IPP) strategies. The adopted agronomic methods and the main physico-chemical parameters of the fresh fruits and musts were evaluated. A fully qualitative and quantitative characterization of the phenolic fraction of the pomace extracts was performed by HPLC-DAD after a post-winemaking process. Water and ethanol were utilized as green solvents in the extraction process. Additionally, the entire pomace post-winemaking process was carried out within the winery facilities to reduce energy loss and road transportation. The findings demonstrated that large amounts of beneficial polyphenols are present in pomace extracts, and that the type of grape used, agronomic practices, and winemaking method all influence the quantity and quality of the extracts. The polyphenol concentrations in the Vermentino (28,391.5 ± 7.0 mg/kg) and Malvasia pomace (11,316.3 ± 6.5 mg/kg) were found to be the highest and lowest, respectively.
Ultrasensitive Ti3C2Tx@Pt-Based Immunochromatography with Catalytic Amplification and a Dual Signal for the Detection of Chloramphenicol in Animal-Derived Foods
Authors: Lin Mengfang , Gao Zhimin , Qian Zhenjie , Deng Youwen , Chen Yanhong , Wang Yu , Li Xiangmei
Published: May 2024

Herein, a catalytic amplification enhanced dual-signal immunochromatographic assay (ICA) based on Pt nanoparticles (Pt NPs) modified with Ti3C2Tx MXene (Ti3C2Tx@Pt) was first developed for chloramphenicol (CAP) in animal-derived foods. Due to the large specific surface area and abundant active sites of Ti3C2Tx@Pt, they can be loaded with hundreds of Pt NPs to enhance their catalytic activity, resulting in a significant increase in the detection sensitivity; the sensitivity was up to 50-fold more sensitive than the reported ICA for CAP. The LODs of the developed method for milk/chicken/fish were 0.01 μg/kg, the LOQs were 0.03 μg/kg and the recovery rates were 80.5–117.0%, 87.2–118.1% and 92.7–117.9%, with corresponding variations ranging from 3.1 to 9.6%, 6.0 to 12.7% and 6.0 to 13.6%, respectively. The linear range was 0.0125–1.0 μg/kg. The results of the LC-MS/MS confirmation test on 30 real samples had a good correlation with that of our established method (R2 > 0.98), indicating the practical reliability of the established method. The above results indicated that an ICA based on the Ti3C2Tx@Pt nanozyme has excellent potential as a food safety detection tool.
Plant Bioactive Compounds in Foods and Food Packages
Authors: Martínez-Hernández Ginés Benito , Taboada-Rodríguez Amaury , Marin-Iniesta Fulgencio
Published: May 2024

There has been growing interest in the use of numerous plant bioactive compounds (PBCs) in food and nutrition technology due to their properties that promote human health by reducing the risk of various serious diseases [...]
Characterizing Edible Oils by Oblique-Incidence Reflectivity Difference Combined with Machine Learning Algorithms
Authors: Sun Xiaorong , Hu Yiran , Liu Cuiling , Zhang Shanzhe , Yan Sining , Liu Xuecong , Zhao Kun
Published: May 2024

Due to the significant price differences among different types of edible oils, expensive oils like olive oil are often blended with cheaper edible oils. This practice of adulteration in edible oils, aimed at increasing profits for producers, poses a major concern for consumers. Furthermore, adulteration in edible oils can lead to various health issues impacting consumer well-being. In order to meet the requirements of fast, non-destructive, universal, accurate, and reliable quality testing for edible oil, the oblique-incidence reflectivity difference (OIRD) method combined with machine learning algorithms was introduced to detect a variety of edible oils. The prediction accuracy of Gradient Boosting, K-Nearest Neighbor, and Random Forest models all exceeded 95%. Moreover, the contribution rates of the OIRD signal, DC signal, and fundamental frequency signal to the classification results were 45.7%, 34.1%, and 20.2%, respectively. In a quality evaluation experiment on olive oil, the feature importance scores of three signals reached 63.4%, 18.9%, and 17.6%. The results suggested that the feature importance score of the OIRD signal was significantly higher than that of the DC and fundamental frequency signals. The experimental results indicate that the OIRD method can serve as a powerful tool for detecting edible oils.
A Sustainable Material for Sheep’s Cheese Wedges Stored under Different Atmosphere Conditions
Authors: Nájera Ana Isabel , Murua Maider , Martínez Olaia , Albisu Marta , Barron Luis Javier R.
Published: May 2024

This study is based on the need to improve packaging sustainability in the food industry. Its aim was to assess the performance of a recyclable plastic material for semi-hard sheep’s cheese wedges packaging as an alternative to conventional non-sustainable plastic materials. Four different packaging treatments (air, vacuum, and CO2/N2 gas mixtures 50/50 and 80/20% (v/v)) were studied. Changes in gas headspace composition, sensory properties, cheese gross composition, weight loss, pH, colour, and texture profile were investigated at 5 ± 1 °C storage for 56 days. The sensory analysis indicated that vacuum packaging scored the worst in paste appearance and holes, and air atmosphere the worst in flavour; it was concluded that cheeses were unfit from day 14–21 onwards. Air and vacuum packaging were responsible for most of the significant changes identified in the texture profile analysis, and most of these happened in the early stages of storage. The colour parameters a* and b* differentiated the air packaging from the rest of the conditions. As in previous studies using conventional plastic materials, modified atmosphere packaging, either CO2/N2 50/50 or 80/20% (v/v), was the most effective preserving technique to ensure the quality of this type of cheese when comparing air and vacuum packaging treatments.
Active Media Perfusion in Bioprinted Highly Concentrated Collagen Bioink Enhances the Viability of Cell Culture and Substrate Remodeling
Authors: Kanokova Denisa , Matejka Roman , Zaloudkova Margit , Zigmond Jan , Supova Monika , Matejkova Jana
Published: May 2024

The bioprinting of high-concentrated collagen bioinks is a promising technology for tissue engineering and regenerative medicine. Collagen is a widely used biomaterial for bioprinting because of its natural abundance in the extracellular matrix of many tissues and its biocompatibility. High-concentrated collagen hydrogels have shown great potential in tissue engineering due to their favorable mechanical and structural properties. However, achieving high cell proliferation rates within these hydrogels remains a challenge. In static cultivation, the volume of the culture medium is changed once every few days. Thus, perfect perfusion is not achieved due to the relative increase in metabolic concentration and no medium flow. Therefore, in our work, we developed a culture system in which printed collagen bioinks (collagen concentration in hydrogels of 20 and 30 mg/mL with a final concentration of 10 and 15 mg/mL in bioink) where samples flow freely in the culture medium, thus enhancing the elimination of nutrients and metabolites of cells. Cell viability, morphology, and metabolic activity (MTT tests) were analyzed on collagen hydrogels with a collagen concentration of 20 and 30 mg/mL in static culture groups without medium exchange and with active medium perfusion; the influence of pure growth culture medium and smooth muscle cells differentiation medium was next investigated. Collagen isolated from porcine skins was used; every batch was titrated to optimize the pH of the resulting collagen to minimize the difference in production batches and, therefore, the results. Active medium perfusion significantly improved cell viability and activity in the high-concentrated gel, which, to date, is the most limiting factor for using these hydrogels. In addition, based on SEM images and geometry analysis, the cells remodel collagen material to their extracellular matrix.