Circulation Speed Research Articles

Hybrid Digital-Droplet Microfluidic Chip for Applications in Droplet Digital Nucleic Acid Amplification: Design, Fabrication and Characterization

Microfluidic-based platforms have become a hallmark for chemical and biological assays, empowering micro- and nano-reaction vessels. The fusion of microfluidic technologies (digital microfluidics, continuous-flow microfluidics, and droplet microfluidics, just to name a few) presents great potential for overcoming the inherent limitations of each approach, while also elevating their respective strengths. This work exploits the combination of digital microfluidics (DMF) and droplet microfluidics (DrMF) on a single substrate, where DMF enables droplet mixing and further acts as a controlled liquid supplier for a high-throughput nano-liter droplet generator. Droplet generation is performed at a flow-focusing region, operating on dual pressure: negative pressure applied to the aqueous phase and positive pressure applied to the oil phase. We evaluate the droplets produced with our hybrid DMF–DrMF devices in terms of droplet volume, speed, and production frequency and further compare them with standalone DrMF devices. Both types of devices enable customizable droplet production (various volumes and circulation speeds), yet hybrid DMF–DrMF devices yield more controlled droplet production while achieving throughputs that are similar to standalone DrMF devices. These hybrid devices enable the production of up to four droplets per second, which reach a maximum circulation speed close to 1540 µm/s and volumes as low as 0.5 nL.

Simulation of asymmetrical rotational flow in the flow part of a well jet pump

In order to improve the mathematical model of the working process of the above-bit ejection system for the conditions of its asymmetric rotation in the well, a method of modeling the circulating injected flow using a hydrodynamic vortex function, the center of which is shifted relative to the axis of the mixing chamber of the jet pump, has been developed. In the process of modeling the rotating asymmetric movement of the injected flow, the concept of circulation of the vector of the translational velocity of the liquid along a closed circuit is used. With the help of the components of the complex potential of the hydrodynamic circulation function, a graphical interpretation of the equipotential lines and flow lines of the spatial vortex with one-sided and two-sided displacement of the coordinate center was obtained. Using analytical relations for the velocity potential and stream function, the components of the circulation velocity are determined and the analyticity of the function of the complex potential with a shifted vortex center is proven. The fulfillment of the Cauchy-Riemann conditions allowed us to present the resulting velocity of the circulating current with the coordinate center shifted along the vertical axis in the form of a partial derivative of the complex potential. In contrast to the complex potential for a symmetric vortex, the ratio for determining the circulation speed in case of misalignment of the working nozzle and the mixing chamber of the jet pump contains an additional component in the form of the displacement of the vortex center.In the process of analyzing the results of using the proposed mathematical model, it was established that the resulting speed of the circulation current and the relative displacement of the spatial vortex center are directly proportional. The conducted studies proved that the ratio of the velocities of the symmetric and asymmetric circulation flow is a function of the displacement of the center of the vortex flow coordinates and varies from 1 to zero. The magnitude of the relative speed of the circulation flow is inversely proportional to the displacement of the coordinate center and the distance to the mixing chamber of the jet pump. The developed mathematical model can be used to predict the influence of the rotation of the ejection system on its pressure characteristic in the case of radial relative displacement of the working nozzle and the mixing chamber of the jet pump.

A Study on the Efficiency of Disaster Information Communication Based on the Gate Keeper Theory

In recent years, major disasters have occurred frequently, with sudden floods, rampant epidemics, and typhoons... Faced with sudden disasters, the affected population is often caught unprepared. Under the background of “Internet +”, the speed of information circulation has improved, but the news that the material needs of the disaster victims are not effectively met still often appears in the public’s view. In order to improve the efficiency of disaster information dissemination and enable the efficient distribution of related materials, this paper discusses this issue based on the gatekeeper theory of communication science. With a view to tracing the source and clarifying the reasons for the low efficiency and poor effect of disaster mutual aid information dissemination under the background of “Internet +”, this paper proposes solutions to the problems in combination with the gatekeeper theory of communication, to promote the rational distribution and utilization of resources, meet the material needs of disaster victims, and ensure the basic life of the people.

Ультразвукові критерії затримки росту плода при передчасних пологах

Purpose - to increase the effectiveness of forecasting and early diagnosis of fetal growth retardation (FGR) in premature pregnancy on the basis of ultrasound examination. Materials and methods. 165 pregnant women were examined: 30 patients with an uncomplicated pregnancy that ended in physiological timely delivery - the control group (CG); 45 patients with premature birth (PB) (the Group I); 45 women with full-term pregnancy and FGR (the Group II) and 45 patients with PB and FGR (the Group III). Ultrasound examination included serial dynamic fetometry and placentography, dopplerography of vessels of the umbilical cord, ductus venosus, middle cerebral artery and fetal aorta with determination of systolic blood flow velocity and systolic peak velocity of blood flow, systolic-diastolic ratio, index resistance and pulsation index. Statistical processing of research results was carried out using standard programs «Microsoft Excel 5.0» and «Statistica 8.0». Results. А significant decrease in the parameters of the biparietal size of the fetal head in pregnant women of the Group III was detected at 24-25 weeks of pregnancy: in the CG - 66.4±0.65 mm, in the Group III - 65.02±0.31 mm (p<0.05), in the Group II - 66.2±0.46 mm. A more pronounced slowdown in the rate of growth of the biparietal size of the fetal head was found in pregnant women at 28-29 weeks of gestation, when a significant decrease (p<0.05) in its growth rate was observed in pregnant women of the Groups II and III. The peculiarities of the formation and functioning of the fetoplacental complex in this Groups were characterised by impaired fetal haemodynamics: increase in blood circulation velocity in the venous duct - 74.43±2.24 cm/s vs. 46.54±1.62 cm/s, respectively; p<0.05; increase in pulsatile index in the uterine artery - 1.611±0.04 vs. 1.424±0.07; p<0.05, and in the middle cerebral artery - 1.527±0.02 vs. 1.251±0.03; p<0.005, indicating the tension of subcompensatory reactions. Conclusions. Ultrasound feto- and placentametry in pregnant women with premature births against the backdrop of FGR showed that in patients with premature births, statistically significant deviations in the size of the fetus and placenta are observed from 24-25 weeks of gestation. Disruption of fetal hemodynamics is indicated by a significant increase in the speed of blood circulation in the ductus venosus in the Groups II and III (74.43±2.24 cm/s vs. 46.54±1.62 cm/s; p<0.05). The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Control scheme for polarization circulation speed meter using a dual-retardation waveplate

In interferometric gravitational wave detectors, quantum radiation pressure noise, which is a back action of the measurement, will limit their sensitivities at low frequencies. Speed meters are one of the solutions to reduce the back action noise and improve the sensitivities, and furthermore, they can surpass the standard quantum limit over a wide range of frequencies. The Polarization Circulation Speed Meter is the latest incarnation of the speed meter concept in the sense that it requires a slight modification in the conventional interferometer designs; however, its control scheme has not been developed. The main difficulty is the length and alignment control of the cavity formed by the polarization circulation mirror and the input test masses, whose round-trip phase shift should be kept to $\pi$. In this article, we propose a new control scheme using a dual-retardation waveplate, called Dual-Retardance Control (DRC). In addition, we compare the shot noise level of the DRC to another simpler scheme by dithering. Finally, we design the experimental setup for the demonstration of the DRC and show the expected results through the transfer function measurement.

The Impact of Digital Transformation of Circulation Industry on The Circulation Efficiency of Agricultural Products

This paper aims to study the impact of the digital transformation of the circulation industry on the efficiency of agricultural product circulation. Through literature review and empirical analysis, this paper finds that digital transformation can promote the improvement of the circulation efficiency of agricultural products, mainly in the aspects of informatization, logistics and intelligence. Digital transformation can improve the information transparency of agricultural products, reduce circulation costs, increase circulation speed, and shorten the length of the supply chain. Digital transformation can also improve the transportation efficiency of agricultural products through the application of logistics technology, and further improve the circulation efficiency. Digital transformation can also improve the quality and safety of agricultural products and increase consumers' trust in agricultural products through the application of intelligent technologies. This paper proposes the impact mechanism of digital transformation on the circulation efficiency of agricultural products, and puts forward policy recommendations to promote the application of digital transformation in the circulation of agricultural products.

Solar Thermal Treatment: Case Study for Cashew Juice Pasteurization

Energy and food are very intertwined and important in human life. Cashew juice is a very abundant product in southern Senegal. Unfortunately, due to lack of processing and conservation, this product cannot last 24 hours without being fermented. The aim of this study is to study the heat treatment processes of agri-food products, particularly the pasteurization of cashew fruit juices. Pasteurization often uses heat from fossil fuels. In this heat treatment process of cashew juice, we are interested in the energy source. Thus thermal solar energy is used in this heat treatment. A solar thermal collector with an area of 17.9 m² and a hot water storage tank with a capacity of 0.1 m³ are used. With the pasteurization model used, the juice circulates in a copper coil immersed in hot water coming from the solar thermal field or the hot water storage tank. A numerical simulation program has been developed on Ansys Fluent 2020 R1 to study the evolution of the temperature of the juice from the inlet to the outlet of the coil. The results obtained give outlet temperatures varying from 70 to 80°C depending on the speed of circulation of the juice. We can also achieve outlet temperatures of 100°C. This means that our system can operate in sterilizer mode.

Denitrification in Microbial Fuel Cells Using Granular Activated Carbon as an Effective Biocathode

Nitrate (NO3−-N) and nitrites (NO2−-N) are common pollutants in various water bodies causing serious threats not only to aquatic, but also to animals and human beings. In this study, we developed a strategy for efficiently reducing nitrates in microbial fuel cells (MFCs) powered by a granular activated carbon (GAC)-biocathode. GAC was developed by acclimatizing and enriching denitrifying bacteria under a redox potential (0.3 V) generated from MFCs. Thus, using the formed GAC-biocathode we continued to study their effect on denitrification with different cathode materials and circulation speeds in MFCs. The GAC-biocathode with its excellent capacitive property can actively reduce nitrate for over thirty days irrespective of the cathode material used. The stirring speed of GAC in the cathode showed a steady growth in potential generation from 0.25 V to 0.33 V. A rapid lag phase was observed when a new carbon cathode was used with enriched GAC. While a slow lag phase was seen when a stainless-steel cathode was replaced. These observations showed that effective storage and supply of electrons to the GAC plays a crucial role in the reduction process in MFCs. Electrochemical analysis of the GAC properties studied using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and zeta potential showed distinct properties with different abiotic and biocathode conditions. We found that the enrichment of electrotrophic bacteria on GAC facilitates the direct electron transfer in the cathode chamber for reducing NO3−-N in MFCs as observed by scanning electron microscopy.

Open-source tool for real-time and automated analysis of droplet-based microfluidic.

Droplet-based microfluidic technology is a powerful tool for generating large numbers of monodispersed nanoliter-sized droplets for ultra-high throughput screening of molecules or single cells. Yet further progress in the development of methods for the real-time detection and measurement of passing droplets is needed for achieving fully automated systems and ultimately scalability. Existing droplet monitoring technologies are either difficult to implement by non-experts or require complex experimentation setups. Moreover, commercially available monitoring equipment is expensive and therefore limited to a few laboratories worldwide. In this work, we validated for the first time an easy-to-use, open-source Bonsai visual programming language to accurately measure in real-time droplets generated in a microfluidic device. With this method, droplets are found and characterized from bright-field images with high processing speed. We used off-the-shelf components to achieve an optical system that allows sensitive image-based, label-free, and cost-effective monitoring. As a test of its use we present the results, in terms of droplet radius, circulation speed and production frequency, of our method and compared its performance with that of the widely-used ImageJ software. Moreover, we show that similar results are obtained regardless of the degree of expertise. Finally, our goal is to provide a robust, simple to integrate, and user-friendly tool for monitoring droplets, capable of helping researchers to get started in the laboratory immediately, even without programming experience, enabling analysis and reporting of droplet data in real-time and closed-loop experiments.

Risk Contagion between Commodity Markets and the Macro Economy during COVID-19: Evidence from China

As the basic raw materials of economic activities, major commodities prices have a significant impact on the real economy. Due to the impact of the COVID-19 pandemic, major commodities prices have been fluctuating sharply in a “deep V” pattern since 2020. Therefore, accurately grasping the risk linkage between commodity markets and the macroeconomy is the key to preventing systemic risk and maintaining the smooth operation of the economy. Based on the MF-VAR model, this paper analyzed the risk contagion between China’s commodity markets and macroeconomic sectors from the perspective of volatility spillover, focusing on risk spillover and its dynamic evolution during the COVID-19 pandemic, and deeply analyzed the transmission mechanism of risk spillover based on the mixed-frequency causality test method. Our findings show that China’s commodity markets are the net exporter of risk contagion and that all macroeconomic sectors are the net recipient of risk contagion. During the period of COVID-19, the risk contagion effect was significantly intensified. The fluctuation of the commodity markets has a long-lasting negative impact on the investment sector and has caused changes in macroeconomic sectors, such as the reduction of medium- and long-term loans, the reduction of money circulation speed, and the weakening of micro-individual consumption willingness. The results of causality analysis show that wealth, interest rate, and expectation effects are present in the risk contagion between the commodity markets and macroeconomic sectors. While being directly or indirectly impacted by the commodity markets, each macroeconomic sector also generates adverse feedback to the commodity markets. The complete description of the risk contagion between the commodity markets and the macro economy has guiding significance for regulatory authorities to improve risk control policies and reinforce the macro regulatory system.

Experimental studies on the flow pattern regimes of particles-liquid mixtures in an inner circulation vertical mill

A vertical mill platform for inner circulation is constructed to improve the grinding efficiency. A transparent plexiglass grinding chamber is utilized to study the influence of solids density, particle size, solid volume fraction and agitator speed on the variation and transition of flow pattern regimes. The change regulations of rotor speed to just circulation and complete circulation as well as system energy consumption are analyzed, the empirical correlations for predicting the rotor speed to just circulation and complete circulation are proposed based on the experimental data of particles-liquid mixtures. The results indicate that the flow of particles-liquid mixture shows four different flow patterns with the increase of the agitator speed. In addition, the process of transition between flow patterns is different when the volume fraction of particles is lower or higher than 20%. The just circulation speed and the complete circulation speed of particles increase as the volume fraction of particles increases. The total system power consumption increases slowly when the volume fraction of particles is lower than 40%; but it increases sharply if the solid volume fraction exceeds 40%.

Socio-Economic Analysis of the Transformation of the Functions of Money in Information Economy

The paper represents the study of the transformation of the functions of money in the conditions of digitalization of the economy. The authors describe the main functions of money, which were considered basic for a long period of time and consider specific examples reflecting the functions of money from the point of view of socio-economic analysis. The key indicators that allow analyzing the functions of money are both sociological, such as confidence in monetary institutions, and economic – such as the speed of money circulation, which allows a multidimensional analysis to obtain data that are more extensive. An emphasis is laid on is the study of modern conditions. The authors describe the main structural and systemic shifts that contributed to the transformation of the functions of modern money, and reveal that changes in functions of money affect the state of other functions, which confirms the statement that the functions of money are in the same system and affect each other. New functions of money were identified and described, which were formed in the process of transformations of the socio-economic sphere and began to reflect specific aspects that are affected in the process of using such an instrument as money. In the final part of the article, the authors make an assumption on further development of these functions.

Impact of Fuel Type on Toxic Emissions from a Non-premixed Boundary Layer Laminar Flame in Microgravity – A Numerical Study

Examples from non-premixed boundary combustion representative of fire in microgravity environment are presented. A low forced flow of 0.25 m/s is present, which is typical of air circulation speeds in a spacecraft. The numerical simulations have been conducted to evaluate the modes of heat transfer with an emphasis on a discussion about the effects of various fuels on chemical emissions such as soot, CO, CO2 and unburnt hydrocarbons in reduced-gravity conditions. Typically, evaporation temperature is smaller for heptane than dodecane, and thus a lengthening of the heptane flame seems more pronounced as compared to that of dodecane flame with an increase in the visible flame zone by a factor of 2.3 times. A rapid regression rate of heptane due to the enhanced heat feedback contributes to an additional energy by a factor of 80% in heat release rate as compared to dodecane. In all the cases, only about 15% of the heat generated by an exothermic chemical reaction is supplied to the pyrolysis surface, and a large portion of energy is convected with the forward gas flow. The CO molar fraction reaches to a maximum of about 11% for dodecane and 8% for other fuels as ethylene, propane, propylene and heptane. The maximum mean value of CO concentration depends mainly on fuel injection rate, and appears practically insensitive to oxidizer flow velocity. Dodecane and heptane with a longer carbon chain produces more CO and less unburnt hydrocarbons than ethylene, propane and propylene. The existence of large unburnt toxic gas fuels even for a smaller flame size because of the absence of natural convection has important considerations for spacecraft fire safety due to smoke/gas incapacitation.

Atmospheric impacts of chlorinated very short-lived substances over the recent past – Part 1: Stratospheric chlorine budget and the role of transport

Abstract. Impacts of chlorinated very short-lived substances (Cl-VSLS) on stratospheric chlorine budget over the first two decades of the 21st century are assessed using the Met Office’s Unified Model coupled to the United Kingdom Chemistry and Aerosol (UM-UKCA) chemistry–climate model; this constitutes the most up-to-date assessment and the first study to simulate Cl-VSLS impacts using a whole atmosphere chemistry–climate model. We examine the Cl-VSLS responses using a small ensemble of free-running simulations and two pairs of integrations where the meteorology was “nudged” to either ERA5 or ERA-Interim reanalysis. The stratospheric chlorine source gas injection due to Cl-VSLS estimated from the free-running integrations doubled from ∼40 ppt Cl injected into the stratosphere in 2000 to ∼80 ppt Cl injected in 2019. Combined with chlorine product gas injection, the integrations showed a total of ∼130 ppt Cl injected into the stratosphere in 2019 due to Cl-VSLS. The use of the nudged model significantly increased the abundance of Cl-VSLS simulated in the lower stratosphere relative to the free-running model. Averaged over 2010–2018, simulations nudged to ERAI-Interim and ERA5 showed 20 ppt (i.e. a factor of 2) and 10 ppt (i.e. ∼50 %) more Cl, respectively, in the tropical lower stratosphere at 20 km in the form of Cl-VSLS source gases compared to the free-running case. These differences can be explained by the corresponding differences in the speed of the large-scale circulation. The results illustrate the strong dependence of the simulated stratospheric Cl-VSLS levels on the model dynamical fields. In UM-UKCA, this corresponds to the choice between free-running versus nudged set-up, and to the reanalysis dataset used for nudging. Temporal changes in Cl-VSLS are found to have significantly impacted recent HCl and COCl2 trends in the model. In the tropical lower stratosphere, the inclusion of Cl-VSLS reduced the magnitude of the negative HCl and COCl2 trends (e.g. from ∼-8%(HCl)/decade and ∼-4 ppt(COCl2)/decade at ∼20 km to ∼-6%(HCl)/decade and ∼ −2 ppt(COCl2)/decade in the free running simulations) and gave rise to positive tropospheric trends in both tracers. In the tropics, both the free-running and nudged integrations with Cl-VSLS included compared much better to the observed trends from the ACE-FTS satellite record than the analogous simulations without Cl-VSLS. Since observed HCl trends provide information on the evolution of total stratospheric chlorine and, thus, the effectiveness of the Montreal Protocol, our results demonstrate that Cl-VSLS are a confounding factor in the interpretation of such data and should be factored into future analysis. Unlike the nudged model runs, the ensemble mean free-running integrations did not reproduce the hemispheric asymmetry in the observed mid-latitude HCl and COCl2 trends related to short-term dynamical variability. The individual ensemble members also showed a considerable spread of the diagnosed tracer trends, illustrating the role of natural interannual variability in modulating the diagnosed responses and the need for caution when interpreting both model and observed tracer trends derived over a relatively short time period.

Analysis of Spatial and Temporal Variations of the Near-Surface Wind Regime and Their Influencing Factors in the Badain Jaran Desert, China

Wind regime is one of the main natural factors controlling the evolution and distribution of aeolian sand landforms, and sand drift potential (DP) is usually used to study the capacity of aeolian sand transport. The Badain Jaran Desert (BJD) is located where polar cold air frequently enters China. Based on wind data of eight nearby meteorological stations, this research is intended to explore the temporal variation and spatial distribution features of wind speed and DP using linear regression and cumulative anomaly method, and reveal the relationship between atmospheric circulation and wind speed with correlation analysis. We found that the wind speed and frequency of sand-blowing wind in the BJD decreased significantly during 1971–2016, and the wind speed obviously mutated in 1987. The regional wind speed change was affected by the Asian polar vortex, the northern hemisphere polar vortex and the Tibet Plateau circulation. The wind rose of the annual sand-blowing wind in this region was the “acute bimodal” type. Most of the annual wind directions clustered into the W-NW, and the prevailing wind direction was WNW. During 1971–2016, the annual DP, the resultant drift potential (RDP) and the directional variability (PDP/DP) in the desert showed an obvious downtrend, with a “cliff-like” decline in the 1980s and relative stable fluctuation thereafter. The BJD was under a low-energy wind environment with the acute bimodal wind regime. Wind speed, sand-blowing wind frequency and DP were high in the northeast and low in the southwest.

POTENTIAL AND POSSIBLE EFFECT OF THE DEVELOPMENT OF GEORGIAN FINANCIAL MARKETS

POTENTIAL AND POSSIBLE EFFECT OF THE DEVELOPMENT OF GEORGIAN FINANCIAL MARKETS

Understanding citizens’ satisfaction with the government response during the COVID-19 pandemic in China: comprehensive analysis of the government hotline

PurposeThe objective of this study was to analyse the influencing factors of citizens' dissatisfaction with government services during the COVID-19 pandemic to help government departments identify problems in the service process and possible countermeasures.Design/methodology/approachThe authors first used cosine interesting pattern mining (CIPM) to analyse citizens' complaints in different periods of the pandemic. Second, the potential evaluation indices of customer satisfaction were extracted from the hotline business system through a hypothesis analysis and modelled using multiple regression analysis. During the index transformation and standardization process, a machine-learning algorithm of clustering and emotion analysis was adopted. Finally, the authors used the random forest algorithm to evaluate the importance of the indicators and obtain the indicators more important to citizen satisfaction.FindingsThe authors found that the complaint topic, appeal time, urgency of citizens' complaints, citizens' emotions, level of detail in the case record, and processing timeliness and efficiency significantly influenced citizens' satisfaction. When the government addresses complaints in a more standardized and efficient manner, citizens are more satisfied.Originality/valueDuring the pandemic, government departments should be more patient with citizens, increase the speed of the case circulation and shorten the processing period of appeals. Staff should record appeals in a more standardized manner, highlighting themes and prioritizing urgent cases to appease citizens and relieve their anxiety.

Research on Location of Logistics Distribution Center Based on K-Means Clustering Algorithm

The basic task of the logistics distribution center is to achieve the storage and distribution of materials, and to plan, implement, and manage the effective flow of materials from the supplying place to the consumption place. Scientific location of logistics distribution center can effectively reduce logistics cost, improve the speed of circulation, increase the profits of enterprises, and enhance the core competitiveness of enterprises. Combining the advantages of K-means clustering algorithm, this paper applies it to the location problem of logistics distribution center and proposes a logistics distribution center location method combining K-means clustering theory and D-S reasoning, which provides a better solution for the location problem of logistics distribution center. Through case analysis, K-means clustering algorithm can obtain reasonable location of logistics distribution center, which can be applied to the location of multilevel logistics distribution network, and has certain practical application value.

Estimating the Impact of a Seasonal Fishing Moratorium on the East China Sea Ecosystem From 1997 to 2018

Fisheries management policies (FMPs) have been implemented in coastal countries to ensure a sustainable supply of seafood and the recovery of species diversity. Because of the depletion of fishery stocks, China has introduced a series of FMPs since 1995, including a seasonal fishing moratorium (SFM), a zero-growth strategy, and a minimum mesh size for fishing nets. Here, we built two mass balance models for 1997–2000 (M1997) and 2018–2019 (M2018) using Ecopath with Ecosim 6.6 to illustrate the interannual changes over the past two decades in the East China Sea (ECS). We then simulated two dynamic scenarios from 1997 to 2018, SFM (M2018SFM) and no SFM (M2018no-SFM), to test the role of the SFM under fishing pressure in the ECS. Ecopath showed that the ECS ecosystem is becoming more mature, although it is still unstable, featuring lower total primary production/total respiration, longer cycles, faster organic material circulation speed, and a higher omnivorous degree. This suggests a slow recovery for the ECS ecosystem in the past two decades. The biomass of fish in the ECS—especially the planktivores, dominated by small-sized Benthosema pterotum—significantly increased in M2018 versus M1997, but there were fewer medium- and large-sized fish. The keystone species switched from the planktivores/piscivores dominated by Decapterus maruadsi in M1997 to planktivores in M2018. Ecosim illustrated that the SFM has positive effects on fishery resources recovery, especially for commercial fishes (i.e., large yellow croakers and hairtails), as reflected by the significantly higher predicted biomass of fish in M2018SFM compared to M2018no-SFM and M1997, although the bioaccumulation was consumed by the intense fishing pressure after the SFM. However, the M2018SFM prediction for nektons was still lower than the actual value, especially for planktivores, which display a sharp increase in biomass. This should be partly attributable to the policy of the minimum mesh size (<5 cm was banned), which benefits B. pterotum due to its 3.5 cm maximum body size. Therefore, a series of FMPs, rather than only the SFM, functioned together in the ECS ecosystem. However, the mixed trophic impact indicated a negative impact if the fisheries were further developed. Fishery management in the ECS needs to be strengthened by extending the SFM and reducing fishing pressure after the SFM.

Review of failure risk and outage prediction in power system under wind hazards✰

Given that wind hazards pose a considerable damage to power system in various countries, researchers have developed methods for disaster prevention to diminish the vulnerabilities. This paper attempts to review the failure analysis procedure under the impact of wind hazards, considering the following attributes: wind field generation method, wind-induced electrical component failure model in transmission system, and building outage prediction model from data-driven view in distribution system. First, we compare the calculation of circulation and translation wind speed, with geographical, temporal and uncertainty factors of wind speed considered. Then, we introduce the wind-induced component failure models derived by wind load calculation and fragility curves. The application of the series reliability model in multiple cluster failures is briefly described. Finally, we summarize the applications of data analysis in building outage prediction models. The reviewed literature contains the statistical learning methods and machine learning methods. It is concluded that the frameworks for component-level failure model and user-level outage prediction model are well established. However, most of the studies still develop two models, separately. Future researchers may target at the hybrid application of both models to better provide fault analysis, prediction and emergency in power system under wind hazards.