Reduce Loss Rate Research Articles

Optimize the position of distributed generations in distribution grid by using improved loss sensitivity factor

This research proposed a method to determine the optimal position of distributed generations in a distribution grid. The method is improved from the loss sensitivity factor method. An algorithm is developed to determine both the position and size of distributed generations. This algorithm is validated via IEEE 33 bus distribution grid in two cases of distributed generation size including unknown size and constant size. The results were analyzed and compared to other previous algorithms including loss sensitivity factor-based algorithm and other algorithms. Results indicated the optimal position of each distributed generation to minimize the power loss. Results also indicated that with the proposed algorithm, the loss reduction rate (LRR) is the highest in comparison to that with other previous algorithms.

Comparison and analysis of properties of V-type HV-LSPMSM with non-magnetic and magnetic-wedges

In order to improve the magnetic density distribution and torque ripple waveform of the motor and enhance its efficiency, the effect of slot wedge on motor performance is discussed in this paper. Taking 6 kV, 710 kW high-voltage line-start PMSM (HV-LSPMSM) as an example, the mathematical model is established, the influence mechanism of slot wedge on air gap density, loss, efficiency and torque ripple of motor is analyzed. The HV-LSPMSM prototype was manufactured, the deviations of several important motor parameters are less than 5% by comparing the test data and the finite element analysis (FEA) results, thus, the accuracy and reliability of the modified finite element model (FEM) are verified, it provides an experimental basis for further research on the effect of relative permeability variation on motor performance. The effects of nonmagnetic-wedges and magnetic-wedges on the motor’s performance are systematically compared. The research results show that compared with the non-magnetic wedges, the magnetic wedges are used to make the magnetic density more uniform, the eddy current loss with magnetic wedge (μ = 5) is reduced by 7.292 kW, and the motor efficiency is improved. The torque ripple rate with magnetic wedge (μ = 3) is reduced by 3.35%, and the torque waveform is significantly improved. And It is found that magnetic wedge (μ > 3) slowed down the iron loss reduction rate. The research provides an important theoretical and experimental basis for the design of HV-LSPMSM and the application of magnetic-wedge in motor.

Development of a Bionic Picking Device for High Harvest and Low Loss Rate Pod Pepper Harvesting and Related Working Parameter Optimization Details

Addressing the issues of low harvesting efficiency and high losses in current pod pepper harvesters, this study presents the design of a bionic comb finger pod pepper picking device and an inclined double-spiral bell pepper harvester to improve the harvest rate and reduce loss rate. Through the utilization of discrete element simulation software EDEM, a discrete element model for pod peppers is established. Additionally, a simulation platform for ground drop loss during pod pepper picking is developed, enabling exploration of the movement trajectory and velocity changes of the pod pepper elements. The study also conducts an analysis on the impact of the speed of the picking rollers X1, the feeding speed of pod peppers X2, and the spacing between the two picking rollers X3 on ground drop losses. Based on the results of the single-factor test, the Box–Behnken response surface test was used to optimize the working parameters of the picking device, which resulted in the optimal combination of the working parameters of the picking device: the speed of the picking rollers was 680.41 rpm, the feeding speed of the pod peppers was 0.5 m/s, and the spacing between the two picking rollers was 12 mm, which resulted in the loss rate of pod peppers on the floor of the ground being 3.526%.

Resistance reduction characteristics analysis of the tee based on field synergy and viscous dissipation

There has been increasing attention on reducing pipe resistance friction losses, particularly those represented by tees, in heating, ventilation, and air conditioning systems to enhance the sustainability of buildings. This paper analyzes the resistance characteristics, flow patterns, and force conditions of tee, identifies the locations with great resistance losses, and proposes a novel tee with an added the U-shaped deflector. The resistance reduction effect of the U-shaped deflector through field synergy and viscous dissipation is also analyzed. The results indicate that the resistance loss of the tee is mainly from the main-branch pipe section, with the maximum velocity gradient on the outer side of the branch and the inner side of the straight pipe. The fluid resistance friction loss in the section taken by the branch pipe is much greater than that in the main pipe section, the fluid resistance friction loss in the section taken by the main pipe is not affected by the pipe diameter ratio, and the internal friction force accounts for 83 %–92 % of the resistance friction loss in the branch pipe section. Adding the U-shaped deflector can improve the synergy of the velocity and pressure gradient fields downstream of branch pipes and straight pipes, and reduce viscous dissipation. The total local resistance loss reduction rate of the novel tee is 83.15 %, the volume weighted average synergy angle is increased by 2.09°, and the viscous dissipation is reduced by 22.9 %.

Developing Strategies For Mitigating Losses in The Water Supply System of The Jerimum Site in Missão Velha-Ce: A Focus on The Relationship Between Water and Society

Objective: It is intended to analyze the efficiency of the use of water resources in the Water Supply System (SAA) of the Jerimum Site in Missão Velha-CE, through the monitoring of water losses in the distribution system, in order to propose mitigation measures and control of waste. Method: This qualitative and exploratory study used a bibliographic procedure to investigate the effectiveness of the distribution system of the SAA of the Jerimum Site managed by the Integrated Rural Sanitation System (SISAR). Data collection was carried out through meetings with community leaders and the general population served by the system, analysis of the Loss in Distribution index (IPD) in the period from 2018 to 2022, consultation of the SISAR spreadsheet related to loss control and inspection of the SAA. Results of the research and discussions: The results obtained revealed that the distribution system of the SAA of Sítio Jerimum is considered inefficient, as it does not meet the minimum limit established for IPD of up to 25%, as determined by Ordinance No. 490/2021. The practical and theoretical implications of this research are discussed, providing insights into how the results can be applied in the field of SAA management, specifically rural ones. Research Implications: The research contributes to the literature for its practical propositions about the fight against water losses. In addition to implying the awareness of the population of Sítio Jerimum, Missão Velha-CE, to reduce losses in their SSA. Originality/value: The relevance and value of this research are evidenced by identifying that an efficient management to combat losses requires attention in the technical, inspection and socio-environmental pillars. Thus, this research offers environmental managers tools to verify the efficiency of SAA in terms of water loss control, and consequently ways to reduce loss rates.

Research on the Modeling of Automatic Pricing and Replenishment Strategies for Perishable Goods with Time-Varying Deterioration Rates

This paper focuses on the modeling of automatic pricing and replenishment strategies for perishable products with time-varying deterioration rates based on an improved SVR-LSTM-ARIMA hybrid model. This research aims to support supermarkets in planning future strategies, optimizing category structure, reducing loss rates, and improving profit margins and service quality. Specifically, the paper selects perishable vegetables as the research category and calculates the cost-plus ratio for each vegetable category. Correlation analysis is conducted with total sales, and a non-parametric relationship curve is obtained using support vector regression for nonlinear fitting. The long and short memory recurrent neural network is then used to predict sales volume, and a pricing strategy is calculated based on the fitting curve. Additionally, the paper establishes a correlation between loss rate and shelf life, corrects the daily average sales volume index, and solves the problem of quantity and category of replenishment using a backpack problem approach. By considering multiple constraints, a quantitative category replenishment volume and pricing strategy is obtained. The mathematical model proposed in this paper addresses the replenishment and pricing challenges faced by supermarkets, aiming to improve revenue and reduce loss while meeting market requirements.

Effects of nanosilica on the properties of brine-base drilling fluid

In the process of drilling oil and gas wells, the shrinkage and falling of wellbore walls are often caused by the expansion of mud shale water. To date, conventional additives have been unable to plug the pore throats of shale rock with nanoscale pores and thus cannot effectively solve the problem of wellbore instability encountered in shale formation drilling. In view of this situation, the idea of using nanosilica to plug the nanopore throat of mud shale is proposed to reduce its permeability and to slow water intrusion. The influences of nanosilica on the properties of brine-base drilling fluid drilling fluid are evaluated by measuring the viscosity, filtration loss and swelling of the drilling fluid. The results of laboratory experiments show that the improvement in drilling fluid properties can only be achieved on the basis of salt resistance; that is, a salt-resistant soil slurry should be used. A concentration of 1–5% nanosilica can improve the viscosity of the drilling fluid by increasing the internal friction between particles. However, nanosilica materials are sensitive to salt concentration. Nanosilica particles can be deposited on the surface of a filter cake to block the pores of the filter paper, and the filtration loss reduction rate can reach 40.2%. Blocking the pores of the clay plays a role in preventing the clay from absorbing water and expanding. The optimal addition amount of silica is 3%, and its salt resistance can reach 16%. Considering the experimental results of filtration loss, swelling amount and cost performance, 3%NP + 4%NaCl + SWM-B is selected as the optimal formula. The results of this study can be applied to effectively improve the phenomenon of wellbore instability during drilling in shale formations, and it has important application value.

The importance of reconfiguration of the distribution network to achieve minimization of energy losses using the dragonfly algorithm

In this article, a method for reconfiguring the distribution network with the presence of production sources to minimize energy losses is presented. Also, besides the reconfiguration issue, the Super distribution tap transformers and the power factor of resources in the network will have their optimal values based on the amount of energy consumption as factors affecting the number of losses. According to the stated parameters, the optimization problem in this article is a non-linear problem with a large search space, for which the dragonfly optimization algorithm was used. To make the results realistic, all types of loads, including commercial, residential and office, have been considered in 24 h and two seasons of the year, cold and hot. The program was prepared with the help of MATLAB software on a sample network of 16 buses, and its applications and results have been evaluated. The obtained results show that determining the optimal reconfiguration is very effective in reducing network losses because, with this method, the amount of losses and unsupplied energy of network subscribers has been reduced significantly. Also, by coordinating the reconfiguration with tap transformers and the power factor of distributed generation resources, the loss reduction rate can be made more effective. The results obtained are compared with the genetic algorithm and the results show the superiority of the dragonfly optimization method.

Reducing transport resistance in highly concentrated fine-grained slurry pipelines by vibration-induced fluidization

Reducing the resistance in slurry pipeline systems is a major concern in dredging projects because of its high energy consumption, which can reach up to 80% of the total energy consumed. In this study, a resistance reduction method (a vibratory resistance reducer) for highly concentrated fine-grained slurry pipeline transport based on vibration-induced fluidization was introduced. Further, the major factors influencing the resistance reduction were quantitatively explored through slurry pipeline transport tests. The experimental results show that the proposed method significantly reduces resistance in the slurry pipeline. The resistance loss reduction rate increases with the vibration frequency and an optimal vibration frequency exists for the resistance reduction. Moreover, vibration-induced fluidization results in a higher resistance reduction for a smaller transport capacity of the pipeline. For silt and fine sand, coarser slurry particles have smaller optimal vibration frequency, and higher resistance reduction rate of slurry pipeline transport under a certain vibration frequency. Finally, using the experimental data, an empirical formula for estimating the resistance loss reduction rate of slurry pipeline transport using a vibratory resistance reducer was proposed.

Reactive power optimization for distribution network system with wind power based on improved multi-objective particle swarm optimization algorithm

• In the multi-objective particle swarm optimization algorithm, the adaptive mesh is introduced to reflect the density of particles, and according to the density information, the global optimal particles are selected by roulette mechanism and the scale of external repository is maintained, which effectively ensures the uniformity and diversity of Pareto frontier distribution. • The proposed IMOPSOA has faster convergence speed and shorter average computing time than NSGA-II algorithm, can get Pareto frontier with better distribution and better results, which makes the voltage stability of the distribution network system with wind power higher. Aiming at the uncertainty of the grid-connected output of wind turbines, a scenario analysis method based on probability occurrence is used to transform the uncertainty model into multi scenario problems with different occurrence probabilities, a reactive power optimization model is established with the goal of minimizing the active power network loss and voltage deviation. Aiming at the poor diversity of Pareto frontiers obtained by traditional methods, an improved multi-objective particle swarm optimization algorithm is proposed. The algorithm uses adaptive grids to obtain the density of particles in external archives, selects the global optimal particle and maintains the scale of the external repository according to the density information using a roulette mechanism, effectively ensuring the uniformity and diversity of the Pareto frontier distribution. The algorithm is used to calculate reactive power optimization of the IEEE 33-bus system with wind power, and compared with the existing NSGA-Ⅱ algorithm. The results show that the Pareto frontier obtained by the proposed algorithm is better, the voltage stability and active power loss reduction rate of the distribution network system with wind power is higher.

Experimental study on the thermal performances of a non-pump-driven thermo-activated building system based on flat-plate heat pipe array

• A non-pump-driven thermo-activated building system based on FPHPs is proposed. • Effects of tilt angles and heat loads on FPHP are experimentally investigated. • Preliminary performances of the FPHP-embedded wall are experimentally investigated. • The optimal tilt angle of FPHP is not a fixed value for building integration. • The measured U d is 0.19 and −0.08 W/m 2 °C when Ths is 25 and 35 °C, respectively. As a burgeoning active thermal insulation technique, the pipe-embedded building system has attracted particular attention from architects and engineers. A novel pipe-embedded building system based on flat-plate heat pipe (FPHP) is proposed to solve the inherent issues like operation energy consumption and façade integration. The experimental investigation is firstly conducted on an FPHP prototype to explore its thermal response characteristics at different tilt angles and heat loads and then performed on an FPHP-embedded composite wall to explore the preliminary thermal performances. Results showed that the length of the condensation section with uniform temperature distribution accounted for at least 88.9% when the heat load was smaller than 3000 W/m 2 , which verified the feasibility of using FPHP to complete the heat charging process. The tilt angle had a significant influence on the thermal resistances, startup behavior, and effective thermal conductivity of FPHP, and the optimal tilt angle could be reduced for load reduction mode, while this value could be increased for supplementary heating mode. When the heat source temperature is 25 and 35 °C, the equivalent heat transfer coefficient value of the FPHP-embedded wall under test conditions is 0.19 and −0.08 W/m 2 ·°C, respectively. Meanwhile, the corresponding heat loss reduction rate could reach 62.7% and 116.4%, respectively. Overall, the results evidenced the effectiveness of FPHP-embedded building systems, which could also contribute to its system design, operation control, and further investigation.

APPLICATION OF CONCRETE LOZENGES CHANNELS IN SLOPE EROSION PROTECTION

Water erosion is a phenomenon that threatens not only agricultural land but also road and rail infrastructure. This article investigates the slope stability against water erosion for five embankments situated on the north axis and east axes of the Moroccan linear railroad infrastructure and proposes the use of concrete lozenges channels for slope erosion protection. Using RUSLE erosion model, the assessment of the sensitivity of these infrastructures to water erosion has enabled us to deduct the essential role of water, the type of soil and the slope inclination in triggering instabilities. The new concrete lozenges channel technique proposed by this paper makes it possible to improve a percentage decrease of the soil loss rate by more than 35%. Indeed, the soil loss rate reduction depends on the concrete lozenges channel number. An increase in this number decreases the soil loss rate. For a study case, the concrete lozenges channels were sized to define the number of lozenges necessary in the vertical and horizontal directions of the slope. Important parameters must be defined for this new technique design, namely, the inclined channel section and the ditch section. In fact, the concrete lozenges channel numbers decrease if the number of ditches and inclined channel sections increases. However, the stability of these drainage structures and the project budget must be studied to find an optimal design that considers the quality-price ratio.

Estimation of Crop Height Distribution for Mature Rice Based on a Moving Surface and 3D Point Cloud Elevation

Estimation of rice plant height distribution plays a significant role in keeping the feed rate of rice combine harvesters stable. This is an effective way to guarantee the working stability of the whole machine, as a consequence, improving threshing and cleaning efficiency and reducing loss and damage rates. However, dense growth and leafy and bent branches of mature rice make it difficult to detect the lowest point of aggregated growing plants in three dimensional (3D) point cloud data. Therefore, the objective of this study was to put forward a method to estimate plant height distribution on the basis of a moving surface and 3D point cloud elevation. The statistical outlier removal (SOR) algorithm was used to reduce noise points far away from target point cloud body, and then moving surface fitting elevation was applied to achieve accurate classification of ground and crop point cloud data for plant height estimation. Experiments showed that, compared with the actual value, the average square root error (RMSE) of the estimation results was 8.29, the average absolute percentage error (MAPE) was 9.28%, and the average accuracy was 90%. The proposed method could accurately estimate the height of mature rice and is beneficial to calculating the feed rate in advance, which can provide a reference for further investigation in automatic and intelligent harvesting.

自然降雨下黄土丘陵区草灌植物垂直覆盖结构的减流减沙效应

黄土高原是我国水土流失和生态环境问题最为严重的地区之一，植被恢复是防治水土流失的重要措施。植物垂直覆盖结构包括地上冠层、地表枯落物和地下根系，各组分具有不同的水土保持作用，是研究植被与水土流失关系的基本单元。目前，关于植物垂直覆盖结构不同组分对土壤侵蚀影响的研究主要是基于人工模拟降雨，缺少自然降雨条件下不同植物的垂直覆盖结构对产流、产沙和入渗等多过程影响的系统研究。本研究以黄土丘陵区典型的草本（须芒草）、半灌木（铁杆蒿）和灌木（绣线菊）为研究对象，每种植物进行三种处理（自然状态、去除枯落物和仅留根系）以及裸地对照，观测2015-2016年降雨事件的产流产沙量和入渗量，分析植物不同垂直覆盖结构的减流减沙效益及其相对贡献。结果表明：三种植物均具有较好的减流（45.9%-73.2%）、减沙效益（87.5%-94.6%）和增加入渗作用（4.7%-10.8%），灌木的减流效果（73.2%）显著高于草本（45.9%）和半灌木（63.5%），但三种植物间的减沙效益没有显著性差异。冠层的减流作用最大，贡献率接近一半（48%-50%），草本枯落物的减流贡献率与根系基本一致，而半灌木和灌木枯落物的减流贡献率略高于根系。冠层、枯落物和根系的减沙贡献率基本一致（36%、30%和34%），相对而言，草本的根系对控制侵蚀具有更大作用，减沙贡献率达到39%，而半灌木和灌木的冠层减沙贡献率要略高于枯落物和根系。本研究表明，冠层是减流的重要因子，而冠层、枯落物和根系在减沙方面均发挥了重要作用，植物垂直覆盖结构各组分在不同植物间减流减沙能力的差异主要与植物功能性状有关。上述结果将为黄土丘陵区坡面植被恢复和水土流失治理提供科学依据。;The Loess Plateau is one of the areas with the most serious soil erosion and ecological environment problems in China. Vegetation restoration is an important measure to prevent and control soil and water loss. The plant vertical cover structure includes aboveground canopy, surface litter, and underground root system. Each component has a different role in soil and water conservation. It is the basic unit to study the relationship between vegetation and soil erosion. At present, the research on the effects of different components of plant vertical cover structure on soil erosion in loess hilly areas is mainly based on artificial rainfall, and there is a lack of systematic research on the effects of different plants vertical cover structure on runoff, sediment and infiltration under the condition of natural rainfall. The research objects of this study were the typical grass (Andropogon yunnanensis), sub-shrub (Artemisia sacrorum) and shrub (Spiraea pubescens) in loess hilly areas. Each plant was treated with three different vertical cover structure compositions (e.g., intact condition, removing litter and only roots) and bare land control treatment. The runoff, sediment yield and infiltration of rainfall events from 2015 to 2016 were observed. The runoff and soil loss reduction and relative contributions of different vertical cover structures were analyzed. The results showed that the three types of plants had great runoff reduction (45.9%-73.2%), soil loss reduction (87.5%-94.6%), and increased infiltration (4.7%-10.8%). The runoff reduction of shrub (73.2%) was significantly higher than that of grass (45.9%) and sub-shrub (63.5%). However, there was no significant difference in soil loss reduction among the three plants. The canopy had the greatest effect of reducing runoff, with a contribution rate close to half (48%-50%). The contribution of grass litter to runoff reduction was basically the same as that of the roots, while the contribution of sub-shrub and shrub litter was slightly higher than that of the roots. The contribution of canopy, litter and roots to soil loss reduction was basically same (36%, 30% and 34%). In specific, the roots of grass had a greater effect on controlling erosion, and the contribution to soil loss reduction rate reached 39%, while the contribution of sub-shrub and shrub canopy to soil loss reduction rate was slightly higher than that of litter and roots. The study shows that the canopy is an important factor in runoff reduction, while the canopy, litter and roots all play an important role in reducing soil loss. The differences in the ability of the vertical cover structure to reduce runoff and soil loss among different plants mainly related to plant functional traits. The above results will provide a scientific basis for vegetation restoration and soil erosion control on slopes in the loess hilly region.

Enhanced Interference Management for 6G in-X Subnetworks

Short-range low-power 6th generation (6G) in-X subnetworks are proposed as a viable radio concept for supporting extreme communication requirements in emerging applications such as wireless control of robotic arms and control of critical on-body devices, e.g. wireless heart pacemaker. For these applications, ultra-high reliability (e.g., above 6 nines) with sub-ms latency must be guaranteed at all spatio-temporal instants. To meet these requirements, radio systems that are robust against fading and interference are crucial. In this paper, we present a comprehensive investigation on technology enablers and techniques for interference mitigation in 6G in-X subnetworks. We present several techniques including blind-repetition with pseudo-random frequency hopping and environment-aware mechanisms for interference management via dynamic channel allocation. We further propose two novel enhancements viz: (1) repetition order adaptation involving real-time selection of the number of repetitions based on current channel conditions; and (2) anticipatory packet duplication in which each subnetwork duplicates its transmission on a secondary channel group whenever it detects the presence of a potentially harmful neighbouring subnetwork. We perform extensive simulations in an industrial factory environment with mobile in-X subnetworks using models and parameters defined by the 3rd Generation Partnership Project (3GPP). Results show that in-X subnetworks requires large bandwidth (≥ 1 GHz), up to 2 packet repetitions and environment-aware interference coordination in order to support packet loss rate below 10-6 with a latency < 100μs. The number of repetitions can however be reduced for systems with survival time greater than the cycle time. The proposed enhancements also result in up to ×104 packet loss rate reduction for systems with survival time above 2 cycle times.

EXTENDED EXPOSURE TIME TO EMBRYOGLUE™ Results IN IMPROVED MOUSE FETAL DEVELOPMENT

Human data point towards positive effects of extended incubation times in EmbryoGlue. In the mouse, Gardner and collaborators demonstrated a beneficial effect on implantation after 5 minutes incubation in medium with high levels of hyaluronan. Clinical practice using EmbryoGlue has confirmed its beneficial effect (Heymann et al., 2020). The aim of this study was to evaluate the effect of extended incubation times of mouse embryos in EmbryoGlue on implantation and fetal development. Mouse embryos from hybrid B6CBAF1 females were cultured from the one-cell stage up to day-4 in G-TL before incubation in the transfer medium (Control: G-TL or Test: EmbryoGlue). Transfer dishes with 0.5 mL of medium under oil were prepared and equilibrated overnight. Day-4 blastocysts were randomly allocated to the control and test group. Embryos were incubated for 10 minutes, 1 hour or 4 hours prior to transfer. Transfer procedures were performed using synchronized CD1 pseudopregnant females. For each transfer, the uterine horns were randomized and 4-5 embryos from the control and test group were replaced in each recipient. In total, 90 to 95 blastocysts were transferred from each group in 18 to 19 embryo transfer procedures. Outcome was assessed 10 days after embryo transfer. Implantation sites and fetal development were determined and crown-rump length, fetal and placental weight measured. Results of implantation, loss rate and fetal development are summarized in the table. No significant differences in implantation rates between the control and the test were observed at the different incubation times. A significantly lower (p<0.05) rate of implantation loss after 4 h exposure to EmbryoGlue resulted in increased fetal development in this group (p<0.05) compared to the corresponding control. No statistical differences were found in the mean values of crown-rump length, fetal and placental weight between the different groups. Compared to a medium with low levels of hyaluronan, exposure of mouse embryos to a medium containing high levels of hyaluronan for 4 h before transfer reduces loss rates after implantation and increases fetal development with no effect on fetal outcome parameters on day 14 of gestation.

Towards an Efficient Resource Allocation based on Software-Defined Networking approach

Quality of Service (QoS) provisioning in a converged network is a particularly difficult and yet extremely important task. With the coexistence of different types of services, it is challenging to manage and guarantee a good level of performance through manual customization of QoS policies. The Software-Defined Networking (SDN) paradigm can manage the QoS policies and network resources in an automatic and dynamic way through a controller. SDN orchestrates the equipment that supports the OpenFlow protocol. The Hybrid SDN approach provides the ability to manage SDN and legacy equipment. This paper introduces a new intelligent and flexible QoS management model based on the principle of SDN called “Efficient Resource Allocation” (ERA). Experiment comparisons between different QoS mechanisms demonstrate the effectiveness of our proposed model by minimizing delay, latency, jitter, and reducing loss rate.

Future carbon emissions from global mangrove forest loss.

Mangroves have among the highest carbon densities of any tropical forest. These ‘blue carbon’ ecosystems can store large amounts of carbon for long periods, and their protection reduces greenhouse gas emissions and supports climate change mitigation. Incorporating mangroves into Nationally Determined Contributions to the Paris Agreement and their valuation on carbon markets requires predicting how the management of different land‐uses can prevent future greenhouse gas emissions and increase CO2 sequestration. We integrated comprehensive global datasets for carbon stocks, mangrove distribution, deforestation rates, and land‐use change drivers into a predictive model of mangrove carbon emissions. We project emissions and foregone soil carbon sequestration potential under ‘business as usual’ rates of mangrove loss. Emissions from mangrove loss could reach 2391 Tg CO2 eq by the end of the century, or 3392 Tg CO2 eq when considering foregone soil carbon sequestration. The highest emissions were predicted in southeast and south Asia (West Coral Triangle, Sunda Shelf, and the Bay of Bengal) due to conversion to aquaculture or agriculture, followed by the Caribbean (Tropical Northwest Atlantic) due to clearing and erosion, and the Andaman coast (West Myanmar) and north Brazil due to erosion. Together, these six regions accounted for 90% of the total potential CO2 eq future emissions. Mangrove loss has been slowing, and global emissions could be more than halved if reduced loss rates remain in the future. Notably, the location of global emission hotspots was consistent with every dataset used to calculate deforestation rates or with alternative assumptions about carbon storage and emissions. Our results indicate the regions in need of policy actions to address emissions arising from mangrove loss and the drivers that could be managed to prevent them.

Acute bottlenecks to the survival of juvenile Pygoscelis penguins occur immediately after fledging.

Estimating when and where survival bottlenecks occur in free-ranging marine predators is critical for effective demographic monitoring and spatial planning. This is particularly relevant to juvenile stages of long-lived species for which direct observations of death are typically not possible. We used satellite telemetry data from fledgling Adélie, chinstrap and gentoo penguins near the Antarctic Peninsula to estimate the spatio-temporal scale of a bottleneck after fledging. Fledglings were tracked up to 106 days over distances of up to 2140 km. Cumulative losses of tags increased to 73% within 16 days of deployment, followed by an order-of-magnitude reduction in loss rates thereafter. The timing and location of tag losses were consistent with at-sea observations of penguin carcasses and bioenergetics simulations of mass loss to thresholds associated with low recruitment probability. A bootstrapping procedure is used to assess tag loss owing to death versus other factors. Results suggest insensitivity in the timing of the bottleneck and quantify plausible ranges of mortality rates within the bottleneck. The weight of evidence indicates that a survival bottleneck for fledgling penguins is acute, attributable to predation and starvation, and may account for at least 33% of juvenile mortality.

Application of microbially induced calcite precipitation to prevent soil loss by rainfall: effect of particle size and organic matter content

Soil loss by rainfall is a serious problem in civil and environmental engineering. In this study, microbially induced calcite precipitation (MICP) was applied to reduce rainfall-induced soil loss. Furthermore, the effects of particle size and organic matter content were investigated. A mixture of Sporosarcina pasteurii, 450 mM urea, and 450 mM calcium ions was introduced to sand and sandy loam with 2.6% organic matter content to induce MICP. Artificial rainfall and penetrometer tests were conducted to analyze the soil loss and surface strength, respectively, of the MICP-applied soils. As MICP was applied, the concentration of CaCO3 precipitates increased linearly (9.8 mg CaCO3/g-soil/application), but the strength of the soil reached a plateau of 23.9 ± 1.2 N/mm after five repeated applications (54.5 ± 3.6 mg CaCO3/g-soil). Only after two repeated MICP applications, up to 84% of reduction in loss rate was accomplished in sand under the worst conditions (rainfall intensity of 75 mm/h, slope of 15°), while only 58% of reduction was obtained after five repeated applications in sandy loam with 2.6% organic matter. For the same amount of CaCO3 precipitates, the strength was higher in sand with larger particle size. Lower organic matter content led to the higher strength. SEM revealed that larger CaCO3 precipitates were obtained in sand with lower organic matter content. Our results indicate that the effect of MICP on the prevention of rainfall-induced soil loss is promoted when the particle size is larger and organic matter content is lower.