bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing China’s Investment Risk of the Maritime Silk Road: A Model Based on Multiple Machine Learning Methods
Authors: Xu Jing , Zhang Ren , Wang Yangjun , Yan Hengqian , Liu Quanhong , Guo Yutong , Ren Yongcun
Published: August 2022

The maritime silk road policy of China brings opportunities to companies relating to overseas investment. Despite the investment potentials, the risks cannot be ignored and have still not been well assessed. Considering the fact that ICRG comprehensive risk has certain subjectivity, it is not completely applicable to China’s overseas investment. Therefore, based on the data of the China Statistical Yearbook and International Statistical Yearbook, a new indictor is adopted to better capture the Chinese investment risk and to make our prediction more objective. In order to acquire the ability to predict the investment risk in the future which is essential to stakeholders, machine learning techniques are applied by training the ICRG data of the previous year and Outward Foreign Direct Investment (OFDI) data of the next year together. Finally, a relative reliable link has been built between the OFDI indicator in the next year and the left ICRG indicators in the last year with both the best precision score of 86% and recall score of 86% (KNN method). Additionally, the KNN method has a better performance than the other algorithms even for high-level risk, which is more concerning for stakeholders. The selected model cannot only be used to predict an objective and reasonable investment risk level, but can also be used to provide investment risk predictions and suggestions for stakeholders.
Speed Control of Switched Reluctance Motor Based on Regulation Region of Switching Angle
Authors: Zhang Yun , Chen Liang , Wang Zhixue , Hou Enguang
Published: August 2022

This paper studies the speed control strategy of a switched reluctance motor based on angle-position control (APC). The switched reluctance motor has three control parameters: turn-on angle, turn-off angle and voltage PWM duty cycle. This paper studies the function of the three parameters and designs the control algorithms of the parameters, respectively, which can reduce the coupling degree, simplify the control process, and realize the optimal control of the switched reluctance motor. By studying the nonlinear characteristics of the switched reluctance motor, the optimal current waveform in the effective working range of the inductor is obtained, and then a control strategy of the turn-on angle is designed to realize the ideal winding current waveform. According to the torque characteristics of the motor, taking the coincidence of the freewheeling zero point and the position angle at the end of the maximum inductance interval as the control target, a control strategy for the turn-off angle that makes full use of the effective inductance working interval is proposed, which improves the efficiency of the system. For the nonlinear and time-variant switched reluctance motor running process, a data-driven model-free adaptive control algorithm is introduced, and a switched reluctance motor speed control algorithm based on voltage PWM duty cycle is designed. The main contribution of this paper is to propose a control strategy that is generally applicable to switched reluctance motors, which does not depend on the precise mathematical model of the motor. The control algorithms are designed separately for the three control parameters according to the characteristics of the motor, which reduces the degree of coupling among them. A switched reluctance motor drive system based on angle-position control is designed. This strategy is especially suitable for driving the load with sudden large torque pulsation.
Side Fins Performance in Biomimetic Unmanned Underwater Vehicle
Authors: Piskur Paweł
Published: August 2022

This paper presents the experimental research conducted for the Biomimetic Unmanned Underwater Vehicle (BUUV). The study’s major goal is to create a single, flexible side fin with adequate proportions and stiffness for an energy-efficient propulsion system. The experiments were carried out in a laboratory water tunnel equipped with a sensor for direct thrust measurement for various fin dimensions. Further, the particle image velocimetry (PIV) approach was used for a more in-depth examination of fluid–structure interaction (FSI) phenomena. The given experiments indicate the region of superior propulsion system performance and explain the main aspects that have influenced thrust generation using image processing and the PIV approach.
Techno-Economic Analysis and Life Cycle Assessment of Pineapple Leaves Utilization in Costa Rica
Authors: Liao Clara Yuqi , Guan Ysabel Jingyi , Bustamante-Román Mauricio
Published: August 2022

Pineapple production around the world creates large amounts of wasted organic residue, mainly in the form of pineapple leaves. Current management practices consist of in situ decomposition or in situ burning, both of which cause the proliferation of flies and air pollution, respectively. The research conducted aims to develop a utilization process for this residue. Considering that pineapple leaves are rich in carbohydrates and other nutrients, a simple biological process involving a two-step procedure for juice production and ethanol fermentation has been developed to convert the leaves into renewable fuel and spent yeasts for animal feed. The liquid fraction extracted from the leaves is used as the nutrients to culture yeast, Kluyveromyces marxianus, for ethanol and yeast protein production. In Costa Rica, one of the major pineapple-producing countries in the world, the studied process can produce 92,708 and 64,859 tons of bioethanol and spent yeast per year, respectively, from its 44,500 hectares of pineapple plantation. This techno-economic analysis indicates that a regional biorefinery with the capacity to produce 50,000 metric tons per year of ethanol could have a short payback period of 4.72 years. The life cycle analysis further demonstrates the advantages of the studied biorefining concept over the current practice of open burning.
Experimental Study on Static Pressure Sedimentation for a Thick-Walled Bucket Foundation in Sand
Authors: Zhao Hao , Zheng Hongjie , Lian Jijian
Published: August 2022

As an emerging foundation structure for offshore wind turbines, bucket foundations with superior bearing capacities and efficient construction procedures have attracted significant attention in China. Thick-walled bucket foundations with concrete skirts can effectively reduce the cost and prevent the buckling problem of steel skirts during construction, transportation, and installation. However, great challenges are encountered during the sinking process, and the accurate calculation of sinking resistance is a critical process. Static-pressure tests of thin-walled and thick-walled models in sand were performed to measure the penetration resistance and soil pressure at the sidewalls and ends. The horizontal-soil-pressure coefficients of different models were calculated, and the end and skin-friction coefficients in the cone-penetration test method are recommended. The drag-reduction effects of the anti-drag ring and pressure-pull-out loading method were examined, and the drag-reduction effect was evident for the bucket foundation. The drag-reduction effect of the pressure-pull-out loading method is mainly reflected in the end zone.
Numerical Simulation of Oil Shale Retorting Optimization under In Situ Microwave Heating Considering Electromagnetics, Heat Transfer, and Chemical Reactions Coupling
Authors: Wang Hao , Su Jianzheng , Zhu Jingyi , Yang Zhaozhong , Meng Xianglong , Li Xiaogang , Zhou Jie , Yi Liangping
Published: August 2022

Oil shale constitutes an important proportion of unconventional resources, and its efficient exploitation helps alleviate the Chinese oil shortage situation. Nowadays, microwave heating is a promising method for in situ development of oil shale. However, the corresponding numerical simulation lacks in guiding the retorting optimization under microwave heating. A novel pseudo three-dimensional model, considering electromagnetics, temperature field, and chemical reactions coupling was developed and implemented to investigate oil shale reservoirs’ retorting performance under microwave heating based on the finite element method (FEM). The effects of microwave power, antenna number, and antenna position were analyzed creatively to optimize the microwave heating parameters. Numerical results showed high microwave power increased the maximum reservoir temperature quickly near the heating well, but the thermal conductivity of oil shale dominated the temperature of distal formation. For a typical case of two antennas at 0.9 m spacing and 500 W, the maximum temperature can reach 443 °C at 100 days, and the kerogen near the wellbore quickly converts to hydrocarbon products. Moreover, increasing antennas can improve the heating rate, and the specific distance between two antennas should be designed based on the microwave power and oil shale properties.
The Fault Effects on the Oil Migration in the Ultra-Deep Fuman Oilfield of the Tarim Basin, NW China
Authors: Zhu Yongfeng , Zhang Yintao , Zhao Xingxing , Xie Zhou , Wu Guanghui , Li Ting , Yang Shuai , Kang Pengfei
Published: August 2022

A giant, ultra-deep (>7000 m) strike-slip fault-related oilfield has been found in the central depression of the Tarim Basin. However, little research has addressed this discovery to understand the fault effects on the oil migration, which constrains the oil exploitation deployment and well optimization. Based on fault modeling and fluid analysis, we present the effects of fault segment on the oil segmentation and migration in the ultra-deep Fuman Oilfield. The results show a distinct fault segmentation and also subsequent variable fault architecture and non-connected fracture network other than a through-going fault zone. There are fault segment-related isolated fractured reservoirs and fluid variation along the fault strike, which indicates that a large oilfield comprises a series of unconnected small oil reservoirs along the fault segments. The fluid segmentation and molecular indicator of dibenzothiophenes reveal that there is a variable petroleum lateral migration along the strike-slip fault segment. The fault segmentation is a major contribution in the varied oil accumulation along the strike-slip fault zone in Fuman Oilfield. This case study suggests that fault segmentation has variable effects on petroleum migration and accumulation along the strike-slip zone.
Accident Modeling and Analysis of Nuclear Reactors
Authors: Wu Jianhui , Chen Jingen , Zou Chunyan , Li Xiaoxiao
Published: August 2022

Nuclear energy has played and will continue playing a key role in the fight against climate change due to its extremely low green-house gas emissions, and high energy density and reliability [...]
Numerical Investigations of a Non-Uniform Stator Dihedral Design Strategy for a Boundary Layer Ingestion (BLI) Fan
Authors: Pan Tianyu , Shi Kaikai , Lu Hanan , Li Zhiping , Zhang Jian
Published: August 2022

A distributed propulsion system has the advantage of saving 5–15% fuel burn through ingesting the fuselage boundary layer of an aircraft by fan or compressor. However, due to boundary layer ingestion (BLI), the fan stage will continuously operate under serious inlet distortion. This will lead to a circumferentially non-uniform flow separation distribution on the stator blade suction surface along the annulus, which significantly decreases the fan’s adiabatic efficiency. To solve this problem, a non-uniform stator dihedral design strategy has been developed to explore its potential of improving BLI fan performance. First, the stator full-annulus blade passages were divided into blade dihedral design regions and baseline design regions on the basis of the additional aerodynamic loss distributions caused by BLI inlet distortion. Then, to find the appropriate dihedral design parameters, the full-annulus BLI fan was discretized into several portions according to the rotor blade number and the dihedral design parameter investigations for dihedral depth and dihedral angle were conducted at the portion with the largest inflow distortion through a single-blade-passage computational model. The optimal combinational dihedral design parameter (dihedral depth 0.3, dihedral angle 6 deg) was applied to the blade passages with notable flow loss which were mainly located in the annulus positions from −120 to 60 degrees suffering from inlet distortion, while the blades in the low-loss annulus locations were unchanged. In this way, a non-uniform stator dihedral design scheme was achieved. In the end, the effectiveness of the non-uniform stator dihedral design was validated by analyzing the internal flow fields of the BLI fan. The results show that the stator dihedral design in distorted regions can increase the inlet axial velocity and reduce the aerodynamic load near the blade trailing edge, which are beneficial for suppressing the flow separations and reducing aerodynamic loss. Specifically, compared with the baseline design, the non-uniform stator dihedral design has achieved a reduction of aerodynamic loss of about 7.7%. The fan stage has presented an improvement of adiabatic efficiency of about 0.48% at the redesigned point without sacrificing the total pressure ratio. In the entire operating range, the redesigned fan has also shown a higher adiabatic efficiency than the baseline design with no reduction of the total pressure ratio, which provides a probable guideline for future BLI distortion-tolerant fan design.
Improved Active Disturbance Rejection Control (ADRC) with Extended State Filters
Authors: Shi Shangyao , Zeng Zhiqiang , Zhao Chenbo , Guo Luji , Chen Pengyun
Published: August 2022

To address time delay and noise problems in control systems, in this study, we integrated an extended state filter for signal filtering into an active disturbance rejection control (ADRC) system and derived an improved ADRC approach. In addition to the active anti-disturbance and active tracking estimation functions of the existing ADRC, the proposed approach also includes active filtering and active advance prediction functions, which can filter out the effect of measurement noise on system state observation while reducing the delay between the system control output and the detection of the sensor input. We verified through an evaluation in a simulation environment that the proposed approach may be expected to achieve improved control accuracy and increase the stability of closed-loop control systems.
Practical Evaluation of Loss Reduction in Isolated Series Resonant Converter with Fixed Frequency Modulation
Authors: Khan Danish , Hu Pengfei , Waseem Muhammad , Yasir Ali Khan Muhammad , Tahir Mustafa , Annuk Andres
Published: August 2022

Nowadays, power converters with reduced cost, compact size and high efficiency are evolving to overcome the emergent challenges of renewable energy integrations. In this context, there is an increased demand for well-designed power converters in renewable energy applications to reduce energy utilization and handle a variety of loads. This paper proposes a center-tapped bridge cascaded series-resonant LC dual active bridge (DAB) converter for DC-DC conversion. The low part count of the proposed converter enables a high-power density design with reduced cost. The proposed converter offers reduced conduction losses as the reverse current is eliminated by adopting current blocking characteristics. Reverse current blocking also enables zero voltage switching (ZVS) and zero current switching (ZCS) over a wide operating range. Therefore, using a simple fixed frequency modulation (FFM) scheme offers a wide operating range compared to a conventional DAB converter. A thorough comparison of the proposed converter and a conventional DAB converter is provided based on conduction losses and switching losses to illustrate the performance improvement. Lastly, the effectiveness of the proposed converter is validated through simulation and experimental results.
Impact of Solar Thermal Energy on the Energy Matrix under Equatorial Andean Context
Authors: Barragán-Escandón Edgar , Zalamea-León Esteban , Calle-Sigüencia John , Terrados-Cepeda Julio
Published: August 2022

Low-temperature solar thermal energy is a viable and mature alternative to reduce the use of fossil fuels for domestic hot water heating. The impact of the inclusion of this technology in the energy matrix in the Andean city of Cuenca, Ecuador, is analyzed. In Ecuador, liquefied petroleum gas (LPG) is currently used to heat water due to the high state subsidy, with a cost of 0, 11 USD for an LPG kg compared to the international price of 1.18 USD a Kg of LPG in 2021. Sustainability indicators show that the urban energy matrix would be minimally affected by a high penetration of solar thermal systems. The indicators that are positively affected are related to energy self-sufficiency, emissions, and employment at the expense of an increase in the cost of energy. Moreover, the analysis of the impact on consumption exclusively in the residential sector shows that liquefied petroleum gas consumption would drop from 73 to 64%, mainly because the liquefied gas is used in cooking. However, the change in technology is limited by the subsidized cost of liquefied petroleum gas, which makes the adoption of this technology difficult in the current state
Identification of Transient Steam Temperature at the Inlet of the Pipeline Based on the Measured Steam Temperature at the Pipeline Outlet
Authors: Kaczmarski Karol
Published: August 2022

A solution to the inverse heat transfer problem (IHP) occurring in steam pipelines is presented in the paper. The transient steam temperature at the pipeline inlet was determined from the steam temperature measured at the pipeline outlet. Temporary changes of steam temperature at the turbine inlet are set by the turbine manufacturer and result from the conditions of safe starting of the turbine and maintaining high durability of its components. The boiler start-up should be carried out so that the time-temperature changes at the boiler outlet equal the time-temperature changes determined using the inverse problem. In this paper, the inverse problem of heat transfer in the pipeline was solved by the finite volume method using data smoothing, future times steps, and Tikhonov regularization that stabilized the solution of the inverse problem. The determined transient steam temperature at the pipeline inlet was compared with the measured temperatures. The steam temperature at the inlet to the pipeline, which is the solution to the inverse problem, agrees very well with the measured temperature, as the absolute value of the relative difference εT between measured and calculated temperature is between 0.045% and 0.3%, and the root mean square error RMSE is within the range of 0.038 K to 0.322 K.
Research Progress on Triboelectric Nanogenerator for Sports Applications
Authors: Li Caixia , Zhu Yongsheng , Sun Fengxin , Jia Changjun , Zhao Tianming , Mao Yupeng , Yang Haidong
Published: August 2022

Progress in science and technology drives the continuous innovation of energy collection and utilization. In the field of sports, the information collection and analysis based on Internet of things have attracted particular attention. Moreover, triboelectric nanogenerator (TENG) has promising applications in the field of sports. Here, we introduce the working principle of the TENG then the progress of the TENG as a wearable energy sensor is examined in the two fields of basic human activities and sports, especially competitive sports. On this basis, it is considered that the stability of devices, the universality of materials, and the scientificity of application of the TENG in the future need to be improved. We provide a direction for further upgrading energy collection technology to promote the high-quality development of human mechanical energy sensing in the field of sports.
Microalgae Cultures: Environmental Tool and Bioenergy
Authors: Pires José C. M. , Gonçalves Ana L.
Published: August 2022

Microalgae have been intensively studied for CO2 capture, nutrient removal from wastewater, and biofuel production applications [...]
Corporate COVID-19-Related Risk Disclosure in the Electricity Sector: Evidence of Public Companies from Central and Eastern Europe
Authors: Zyznarska-Dworczak Beata , Rudžionienė Kristina
Published: August 2022

Risk disclosures contribute to financial stability by providing stakeholders with a better understanding of companies’ risk exposures and risk management practices. Presently, corporate risk has been accelerated by the COVID-19 pandemic, and the level of disclosure varies across industries, companies, and organizations. Due to the strategic importance of the energy industry, the paper aims to assess COVID-19-related risk disclosure in the biggest electricity companies in Central and Eastern European countries, and to identify the main determinants of the disclosure. For this purpose, risk disclosure was assessed based on publicly available data disclosed by the 10 biggest public electricity companies operating in this region. Our findings indicate that factors such as the company’s size, leverage, and profitability do not significantly affect COVID-19-related risk disclosure in financial reports; nevertheless, COVID-19 risk disclosure in non-financial reports is significantly correlated with the company’s assets and revenues. Moreover, there is a significantly strong positive relationship between the scope of COVID-19-related risk disclosure in the management reports and the number of women on the company’s management board. COVID-19-related risk disclosure in management board’s reports is significantly higher than disclosure in non-financial reports and explanatory notes of financial statements. Our results suggest that risk disclosure is needed to mitigate information asymmetry, especially in pandemic situations.
Residents’ Attitudes and Social Innovation Management in the Example of a Municipal Property Manager
Authors: Kabus Judyta , Dziadkiewicz Michał
Published: August 2022

Corporate responsibility is an effective management strategy which, through conducting social dialogue at the local level, contributes to increasing the competitiveness of enterprises at a global level and simultaneously shaping favourable conditions for social and economic development. A review of the literature on the subject provided the theoretical motivation to undertake an emirical study of the implemented social innovations by the property manager and their reception by resource residents. The main aim of this study was to diagnose the attitudes of residents towards the implementation of social innovations by the municipal property manager. The research presented in the above article has been conducted in the first and second quarter of 2021 among residents of the Department of Housing “TBS” (ZGM TBS) in Częstochowa, Silesian voivoideship, Poland. The research was conducted using the survey method. The measurement instrument was a prepared questionnaire. The survey was completed by 362 respondents (n = 362). To confirm the hypotheses, an analysis using the Mann–Whitney U test and the Anov Kruskal–Wallis test were performed. In order to demonstrate the statistical significance of the assumptions made, the conducted tests were also supported by the p-value test. The research results undertaken made it possible to identify social innovations implemented by the municipal manager, both those which are expected by residents and those which tenants consider superfluous.
A Study on the Integrity Evaluation of Cement Sheaths for Deep Wells in Deep Water
Authors: Wu Yi , Zhou Jianliang , Yang Jin , Qin Wei , Zhang Tianwei , Wu Zhiqiang
Published: August 2022

The complex temperature and pressure conditions of deepwater wells have a serious impact on cementing quality. Therefore, the integrity of the cement seal becomes a critical factor that can restrict the safety of the wellbore, especially for wells ranging from the conventional deep water to deep water with more prominent deep stratum problems. The operating conditions of deep wells in deep water (referred as the dual-deep well) are complex and harsh. For the conventional evaluation device, it is difficult to accurately simulate the alternating HTHP conditions and to clarify the location and situation of the cement sheath leakage, which directly leads to the deviation of the evaluation results from the engineering reality. To solve this defect, based on the condition and structure characteristics of dual-deep wells, a device and method for casing/cement sheath/formation seal integrity evaluation for dual-deep wells at HTHP has been developed and established. Combined with the analysis of microstructure and micromorphology, the sealing ability and integrity of different cement slurry systems were evaluated. Through this study, a set of cement slurry systems suitable for dual-deep wells is selected that can satisfy the requirements of dual-deep wells with excellent isolation ability and seal integrity under temperature and stress changes. The research results provide a reference for deepwater wells’ wellbore integrity evaluation and research.
Hydrophobicity/Oleophilicity of Autoclaved Aerated Concrete (AAC) Grains Coated with Oleic and Stearic Acids for Application as Oil/Water Separating Filtration and Adsorbent Materials in Vietnam
Authors: Matsuno Akihiro , Kawamoto Ken
Published: August 2022

Separation of oil and water is an effective technique to treat oily wastewater. For examining the applicability of porous grains coated with hydrophobic agents (HA) as low-cost and easily available filtration and adsorbent materials in the separation of oil and water, this study assessed the hydrophobicity/oleophilicity of porous grains made from autoclaved aerated concrete scrap coated with low-cost and harmless hydrophobic agents such as oleic and stearic acids. Tests using a sessile droplet method showed unique relationships between the contact angles (CA) of water droplets in air (CAwa), oil droplets in water (CAow) and coated HA concentrations. The CAwa increased linearly with increasing HA concentration and then became almost constant and/or gently increased after a specific point, indicating that a minimum coating amount gives the maximum hydrophobicity to HA-coated porous grains exists. The CAow gradually decreased exponentially with increasing HA concentration. In particular, the CAow of porous grains coated with stearic acid decreased with increasing of HA concentration in a two-step process. Furthermore, analyses of the Pearson correlation showed that both CAwa and CAow correlated well with the specific surface area (SSA), implying that the SSA is a good indicator as a quick assessment of hydrophobicity/oleophilicity of HA-coated porous grains.
How Did the Mild and Humid Areas of China Turn Green? A Case Study on Chongqing
Authors: Zuo Yiting , Cheng Jie , Zhang Hongjie , Tang Feng , Fu Meichen
Published: August 2022

Since the implementation of the Natural Forest Resources Protection Project (NFRP) and the Grain for Green Program (GFGP), two key ecological projects related to forestry, the vegetation cover in Chongqing, has improved significantly. Existing studies have revealed the effects of climate change and human activity on vegetation cover in arid regions. However, more studies are needed to reveal the influence of drivers on vegetation cover in mild and humid areas, to quantify the relative contribution of drivers and to analyze the overall land use characteristics in different regions. In this study, we used Theil–Sen slope analysis and the Mann–Kendall test to investigate the spatial and temporal changes in vegetation cover in Chongqing. Further, we used Pearson correlation analysis to analyze the correlations between vegetation cover and drivers, quantitatively analyzing the relative contributions of these drivers. Complex network model analysis was used for different regions to obtain their land-use system characteristics, and the Hurst index was adopted to predict future vegetation-cover changes. The results of this study showed that the average vegetation cover in Chongqing increased significantly from 2000 to 2020, and the overall greening trend was most obvious in winter. Precipitation and temperature influenced the vegetation cover of Chongqing city to a certain extent, and the positive correlation between vegetation cover and precipitation was more significant than that with temperature. In terms of the precipitation factor, the areas with significant positive correlations were mainly concentrated in the central and southern parts of Chongqing, which could be related to the higher precipitation in the southern part of the city. Under the combined influence of climate change and human activity, vegetation cover increased in 71.95% of the total area. Human activity had a relative contribution of 70.39% and 69.14% in the areas where vegetation cover decreased and increased, respectively. The analysis results of the complex network model showed that woodlands and grasslands contributed more to areas where the vegetation cover exhibited an increasing trend. In the future, it is estimated that 72.92% of the vegetation cover in Chongqing will exhibit a degradation trend. This study helps us further understand vegetation-cover changes in mild and humid areas, providing new research directions for informing forestry-related policies.
The Application of Sonic Tomography (PiCUS 3 Sonic Tomograph) to Detect and Quantify Hidden Wood Decay in Managed Norway Spruce Stands
Authors: Tarmu Toomas , Kiviste Andres , Näkk Ain , Sims Allan , Laarmann Diana
Published: August 2022

Tree mortality plays a vital role in the accuracy of growth and yield calculations. Economic loss caused by Heterobasidion sp. and Armillaria sp. is a common issue in forestry. Estonian forests, which are mostly managed, are susceptible to fungal infection due to freshly exposed wood surfaces, such as stumps and mechanical wounds. External signs of infection are often scarce and may lead to incorrect stand vitality valuation. Modern devices, such as the PiCUS 3 Sonic Tomograph, can be used for non-destructive decay assessment. We assessed decay in two intensively managed Norway spruce (Picea abies L. Karst.) stands in order to identify the reliability of sonic tomography in tree vitality assessment. We hypothesize that the tomograph assessment is more accurate than the visual assessment for detecting the extent of decay damage in Norway spruce stems. The sample trees were first visually assessed without additional equipment. In the second phase, the same sample trees were measured with the PiCUS 3 Sonic Tomograph. In the last part of the study, the sample trees were assessed from the tree stumps following the clear-cut. We identified a relationship (p-value < 0.001) between the tomograph assessment and the stump assessment when major decay was present. We did not discover a relationship between the visual assessment and stump assessment, indicating that evaluating the decay from external signs is inaccurate according to our results. Our data also indicate that the tomograph is not able to detect the early stages of decay damage, since it has no substantial effect on the wood structure.
Improving Soundscape Comfort in Urban Green Spaces Based on Aural-Visual Interaction Attributes of Landscape Experience
Authors: Shao Yuhan , Hao Yiying , Yin Yuting , Meng Yu , Xue Zhenying
Published: August 2022

The importance of multi-sensory perception in constructing human landscape experiences has been increasingly emphasized in contemporary urban life. The aim of this study is to explore aural-visual interaction attributes that may influence people’s perceived overall soundscape comfort in urban green spaces (UGSs). To achieve this, a total of 12 perceptive indicators were identified from the existing literature to evaluate people’s perceived visual and acoustic attributes and types of sound sources, and their relations to the perceived soundscape comfort. 268 responses were obtained in a questionnaire-based survey conducted in five UGSs in Chengdu Outer Ring Ecological Zone. This was done whilst a typical objective acoustic indicator, sound level, was used as a mediator for potential changes on these relations within different sound level ranges. Results suggested that a low level of environmental sound does not correspond to higher ratings on the overall soundscape comfort. It was also found that the environmental sound level of 77 dBA was a turning point in the relation between people’s soundscape comfort and its influential indicators in UGSs. A set of six models was then provided to describe the overall soundscape comfort and its contributing indicators in aural-visual interactions, respectively, in sound level ranges below and above 77dBA.
Carbon Addition Modified the Response of Heterotrophic Respiration to Soil Sieving in Ectomycorrhizal-Dominated Forests
Authors: Zheng Sijia , Zhao Xuechao , Sun Zhaolin , Li Jing , Jing Yanli , Wang Qingkui
Published: August 2022

Soil heterotrophic respiration (Rh) is an important pathway of carbon (C) dioxide release from terrestrial soils to the atmosphere. It is often measured using sieved soil in a laboratory, but the uncertainty of how it is influenced by soil sieving persists, which limits the accuracy of predicting soil organic C dynamics in C models. To address how soil sieving during laboratory incubation affects Rh and its response to increased carbon availability, we investigated Rh in sieved and intact soil cores and its response to 13C-glucose addition. This was conducted through a 27-day laboratory incubation in four forests, including two ectomycorrhizal-dominated (ECM) forests and two arbuscular mycorrhizal-dominated forests. The significant influence of soil sieving on Rh in all forests was not observed during incubation when glucose was not added. After adding glucose, the Rh in the sieved soils on the 5th day of incubation was averaged 27.2% lower than that in intact soils in ECM forests. On the 27th day it was 22.1% lower in the Pinus massoniana forest, but 78.0% higher in the Castanea mollissima forest. Strong relationships were detected between Rh in sieved and intact soils (r2 = 0.888), and in soils both with and without the addition of glucose (r2 = 0.827). The measured soil variables explained 74.7% and 49.7% of the variation in Rh on the 5th and 27th day of incubation, and the role of soil nutrients and microbial PLFA groups in regulating Rh varied temporally. Our findings suggest that plant mycorrhizal types influenced the role of increased C availability to microbes in regulating the response of Rh to sieving in forest ecosystems.
Flammability and Combustibility of Two Mediterranean Species in Relation to Forest Fires in Croatia
Authors: Rosavec Roman , Barčić Damir , Španjol Željko , Oršanić Milan , Dubravac Tomislav , Antonović Alan
Published: August 2022

Climatic conditions are extremely important for the start and spread of forest fires. Flammability and the spread of fire are sensitive to the interactions of variables within ecosystems, such as weather, fuel, and topography. Certain variables are highly significant for forest fires and are applied in various models, particularly the moisture content of potential fuel, and its flammability or combustibility. However, such these models cannot determine the true values of the required variables, unlike actual empirical research. Areas with the highest number of fires show significant variability and differences in air temperature, humidity, and precipitation. These factors have a strong influence on flammability, combustibility, and moisture content of Mediterranean species. This study analyses the flammability and combustibility of two Mediterranean species important for the Adriatic area in Croatia: climazonal holm oak (Quercus ilex L.) and Aleppo pine (Pinus halepensis Mill.) as an important conifer for afforestation and reforestation. The results of linear correlation coefficients of flammability of these species at the studied localities show a statistically significant and very strong correlation between flammability and the moisture content of the tested sample, with the exception of Aleppo pine on the island of Rab. The analysis of variance of combustibility showed that there were no statistically significant differences between nearly all variables tested. The results indicate the significant effect of live fuel moisture content on the flammability and combustibility of natural fuels.
Fibres as Replacement of Horizontal Ties in Compressed Reinforced Concrete Elements: Experimental Study
Authors: Skadiņš Ulvis
Published: August 2022

Steel fibres provide ductility to concrete structures. This, in turn, gives possibility to replace or reduce conventional reinforcement in structural elements. In this study, the focus is on structural walls and the fibres as potential replacements for horizontal reinforcement in areas where vertical rebars are needed. An experimental study was conducted, in which prismatic specimens with longitudinal rebars were subjected to centric loading. Ten samples with 12 specimens in each were tested. The parameters considered were: fibre content, concrete cover for the longitudinal bars, and presence of stirrups. Self-compacting concrete with 30 and 60 kg/m3 steel fibres was used. Relative and normalised values of the test results were calculated; correlation and analysis of variance was used to estimate the effect of fibres. The results show that the fibres eliminated brittle collapse and spalling of concrete at failure. A strong negative correlation (−0.72 to −0.92) between amount of fibres and load-bearing capacity was found. On average, the reduction of the capacity was 8% to 16% if compared to the specimens with no fibres. However, a positive effect of the fibres on the ductility was observed. Specimens with 30 kg/m3 fibres showed the same post-peak behaviour as specimens with minimum horizontal reinforcement required by Eurocode 2. The study suggests that combination of steel fibres and conventional rebars can lead to less qualitative compactness of the self-compacting concrete, which in turn may reduce load-bearing capacity and stiffness of the structure. Special attention on concrete cover and distance between rebars should be paid if self-compacting concrete structures with steel fibres are designed.
An Updated Greek National Checklist of Chondrichthyans
Authors: Giovos Ioannis , Aga-Spyridopoulou Roxani Naasan , Serena Fabrizio , Soldo Alen , Barash Adi , Doumpas Nikolaos , Gkafas Georgios A. , Katsada Dimitra , Katselis George , Kleitou Periklis , Minasidis Vasileios , Papastamatiou Yannis P. , Touloupaki Eleana , Moutopoulos Dimitrios K.
Published: August 2022

Accurate checklists of species are essential for evaluating their conservation status and for understanding more about their distribution, biology and ecology and, therefore, the first step in order to effectively protect them. According to the existing literature, the Greek seas are rich in chondrichthyan biodiversity and herein, we update the most recent chondrichthyan checklist for the country regarding the species that are present in the Greek waters, correct unvalidated miscellaneous sightings and observations and provide guidelines about future research to improve their conservation. In total, 330 sources were collected from which 276 were used for further analysis, resulting in 1485 records of 67 species, among which 61 are confirmed by experts, including 34 sharks, 26 batoids and one chimaera. We are further listing six species as “Questionable/Not Confirmed”.
The Path from Traditional Fisheries to Ecotourism in Cimei Island
Authors: Sung Wei-Ying , Lee Hsiao-Chien , Liu Wen-Hong
Published: August 2022

Cimei Island is a second-class outlying island. In recent years, due to the lack of coastal fishery resources and restrictions on traffic and climate, the traditional fishery and tourism industries that residents rely on for a living have faced challenges. This research is based on the Barbados Programme of Action, from the perspective of environmental conservation, industrial economy, and social development in sustainable development, and from the perspective of local stakeholders, to construct a sustainable tourism action approach and development mechanism in Cimei Island. A qualitative research method was adopted. Various sources of data, including focus discussions and in-depth interviews with local stakeholders, textual materials, and field observations, were collected and analyzed. The results are as follows: (1) Cimei faces great threats in social, economic, and environmental aspects, which has led to Cimei Islands’ promotion of permanent development. (2) The current development of Cimei cannot effectively drive industrial development or the transformation of fishing villages. However, residents are worried that overdevelopment will impact the ecological environment and lifestyle on the Islands. (3) Cimei’s sustainable tourism development approach should be to first take inventory of the ecological environment and cultural resources, plan related environmental laws and regulations, and finally, use sustainable tourism to drive industrial development to carry out island development.
Dietary Bioactive Compounds and Health
Authors: Lee Bonggi , Kim Choon Young
Published: August 2022

Foods primarily obtained from plant materials, such as fruits, vegetable, grains, legumes and other plant foods, provide not only nutrients but also non-nutrients [...]
Protein Ingredients in Bread: Technological, Textural and Health Implications
Authors: Prieto-Vázquez del Mercado Pavel , Mojica Luis , Morales-Hernández Norma
Published: August 2022

The current lifestyle and trend for healthier foods has generated a growing consumer interest in acquiring bread products with a better nutritional composition, primarily products with high protein and fiber and low fat. Incorporating different protein sources as functional ingredients has improved the nutritional profile but may also affect the dough properties and final characteristics of bread. This review focuses on the incorporation of different animal, vegetable, and mixed protein sources, and the percentage of protein addition, analyzing nutritional changes and their impact on dough properties and different texture parameters, appearances, and their impact on bread flavor and health-related effects. Alternative processing technologies such as germination and sourdough-based technologies are discussed. Using fermented doughs can improve the nutritional composition and properties of the dough, impacting positively the texture, appearance, flavor, and aroma of bread. It is essential to innovate alternative protein sources in combination with technological strategies that allow better incorporation of these ingredients, not only to improve the nutritional profile but also to maintain the texture and enhance the sensory properties of the bread and consequently, increase the effects on consumer health.
Future of Structured Lipids: Enzymatic Synthesis and Their New Applications in Food Systems
Authors: Zhou Jun , Lee Yee-Ying , Mao Yilin , Wang Yong , Zhang Zhen
Published: August 2022

Structured lipids (SLs) refer to a new type of functional lipid obtained by modifying natural triacylglycerol (TAG) through the restructuring of fatty acids, thereby altering the composition, structure, and distribution of fatty acids attached to the glycerol backbones. Due to the unique functional characteristics of SLs (easy to absorb, low in calories, reduced serum TAG, etc.), there is increasing interest in the research and application of SLs. SLs were initially prepared using chemical methods. With the wide application of enzymes in industries and the advantages of enzymatic synthesis (mild reaction conditions, high catalytic efficiency, environmental friendliness, etc.), synthesis of SLs using lipase has aroused great interest. This review summarizes the reaction system of SL production and introduces the enzymatic synthesis and application of some of the latest SLs discussed/developed in recent years, including medium- to long-chain triacylglycerol (MLCT), diacylglycerol (DAG), EPA- and DHA-enriched TAG, human milk fat substitutes, and esterified propoxylated glycerol (EPG). Lastly, several new ways of applying SLs (powdered oil, DAG plastic fat, inert gas spray oil, and emulsion) in the future food industry are also highlighted.
A Label-Free Electrochemical Aptasensor Based on Zn/Fe Bimetallic MOF Derived Nanoporous Carbon for Ultra-Sensitive and Selective Determination of Paraquat in Vegetables
Authors: Wu Qiaoling , Tao Han , Wu Yuangen , Wang Xiao , Shi Qili , Xiang Donglin
Published: August 2022

Paraquat (PQ) has high acute toxicity, even at low concentrations. For most people, the main pathway of exposure to PQ is through the diet. Therefore, the development of simple and efficient methods for PQ testing is critical for ensuring food safety. In this study, a new electrochemical detection strategy for paraquat is proposed based on the specific binding of PQ to its nucleic acid aptamer. Firstly, the Zn/Fe bimetallic ZIF derived nanoporous carbon (Zn/Fe-ZIF-NPC) and nickel hexacyanoferrate nanoparticles (NiHCF-NPs) were sequentially modified onto the glassy carbon electrode (GCE). NiHCF-NPs served as the signal probes, while Zn/Fe-ZIF-NPC facilitated electron transfer and effectively enhanced the sensing signal of NiHCF-NPs. Au nanoparticles (AuNPs) were then electrodeposited on the NiHCF-NPs/Zn/Fe-ZIF-NPC/GCE and then the thiolated aptamer was assembled on the AuNPs/NiHCF-NPs/Zn/Fe-ZIF-NPC/GCE via Au-S bonding. When incubated with PQ, the formation of PQ–aptamer complexes delayed the interfacial electron transport reaction of NiHCF-NPs, which caused a decrease in the current signals. As a result, simple and highly sensitive detection of PQ can be readily achieved by detecting the signal changes. A linear range was obtained from 0.001 to 100 mg/L with a detection limit as low as 0.34 μg/L. Due to the recognition specificity of the aptamer to its target molecule, the proposed method has excellent anti-interference ability. The prepared electrochemical aptasensor was successfully used for PQ assay in lettuce, cabbage and agriculture irrigation water samples with recoveries ranging from 96.20% to 104.02%, demonstrating the validity and practicality of the proposed method for PQ detection in real samples.
Linking Processing Parameters and Rheology to Optimize Additive Manufacturing of k-Carrageenan Gel Systems
Authors: Russo Spena Simona , Grizzuti Nino , Tammaro Daniele
Published: August 2022

Additive manufacturing—in particular, three-dimensional (3D) printing—has been introduced since the late 1980s, offering a novel paradigm for engineering design and manufacturing, as it allows the fabrication of very complex structures. Additive manufacturing of hydrogels is a very popular method to produce scaffolds to be used in tissue engineering and other biomedical applications, as well as in other advanced technological areas. When printing a thermoreversible physical hydrogel, a subtle balance between thermal and rheological parameters exists. The characteristic times of the sol–gel transition, regulated by a well-defined thermal history, must be optimized with respect to the characteristic processing times. In this work, we use this thermo-rheological approach to the additive manufacturing of a physical hydrogel. A low-cost desktop 3D printer for thermoplastic polymers was suitably modified to print a 1.5 wt% solution of k-carrageenan. The thermal behavior of the printer was determined by performing experimental measurements of the temperature–time evolution during the different processing steps, from solution loading, to the extrusion of the incoming gel, to the final solidification stage. In parallel, linear viscoelastic oscillatory shear measurements were performed in a rotational rheometer under thermal histories as close as possible to those previously measured in the printing process. The comparison between the rheological results and the quality of printing under different thermal histories is presented and discussed, highlighting the main relations between rheological and processing behavior, which are helpful in the assessment and optimization of the printing conditions.