Energy nexus最新文献

{"title":"Storage solutions for renewable energy: A review","authors":"Eduard Enasel,&nbsp;Gheorghe Dumitrascu","doi":"10.1016/j.nexus.2025.100391","DOIUrl":"10.1016/j.nexus.2025.100391","url":null,"abstract":"<div><div>This review investigates the integration of renewable energy systems with diverse energy storage technologies to enhance reliability and sustainability. Key findings include the high energy density and scalability of lithium-ion and flow batteries, which are crucial for grid-scale applications, despite challenges in cost and raw material availability. Electrical storage methods, such as supercapacitors, provide rapid response capabilities but are limited by low energy density. Mechanical systems, including pumped hydro and compressed air storage, excel in large-scale scenarios but face geographical constraints. Emerging chemical storage technologies, including hydrogen and synthetic natural gas, offer long-term solutions but require advancements in efficiency. Thermal storage systems, such as molten salt and latent heat storage, show significant potential for renewable integration in heating and cooling, although material costs remain a barrier. The integration of hybrid systems demonstrates improved reliability and efficiency, highlighting the necessity of combining technologies to address the intermittent nature of renewable energy. Overall, the findings underscore advancements, challenges, and future research directions required for scalable and sustainable energy storage solutions.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"17 ","pages":"Article 100391"},"PeriodicalIF":8.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling current and future run-off and soil erosion dynamics in Eastern Mediterranean ecosystems using the WEPP model","authors":"Safwan Mohammed","doi":"10.1016/j.nexus.2025.100375","DOIUrl":"10.1016/j.nexus.2025.100375","url":null,"abstract":"<div><div>Run-off (RF) and soil erosion (SE) have a negative impact on the environmental system, with both on-site and off-site effects. This research aimed to evaluate the performance of the Water Erosion Prediction Project (WEPP) model in predicting SE and RF across four locations representing three ecosystems: agricultural land (location-KS at 8 % slope, location-MN at 20 % slope), forest (location-AINF at 35 % slope), and burned forest (location-AINBF at 35 % slope). It also predicts the future responses of the studied ecosystems to SE and RF for the upcoming 20 years. The study was conducted in the eastern Mediterranean from 2019 to 2038, 2019 served as the reference year to compare WEPP model output with measured values at the studied locations. Model performance indicators showed the applicability of WEPP model in predicting SE (model efficiency (NSE) =0.67, coefficient of determination (R²) =0.97), RF (NSE=0.66, R²=0.78). Future projections revealed that the agricultural ecosystem exceeded others in terms of SE and RF. However, annual RF can be ranked as follows: KS (234.7mm±75.6)&gt; MN (141.1mm±50.2)&gt; AINF (145.4mm±47.4) &gt; AINBF (100.3mm±49.2). Similarly, SE can be classified as: KS (2.38 kg/m² ±1.36)&gt; AINF (0.45 kg/m² ±0.17) &gt; MN (0.31 kg/m² ±0.11)&gt; AINBF (0.24 kg/m² ±0.15). However, monthly results of SE and RF were more intense in the KS location and less pronounced in the rest of the ecosystems. An analysis of associated factors, namely, soil water content (θ, %), and soil water hydraulic conductivity (K_sw, mm/hr), revealed the lowest θ values occurred during the summer season (June to August), reaching 46.3 %, 50.3 %, 46.2 %, and 49.2 %, for KS, MN, AINF, and AINBF, respectively. Conversely, the highest K_sw was forecasted in summer, ranging from 3.3 to 6.3 mm/hr. This research promotes utilizing the WEEP model as a sustainable tool for ecosystem management in the eastern Mediterranean, aiding decision-makers in rehabilitation planning.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"17 ","pages":"Article 100375"},"PeriodicalIF":8.0,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving traceability and sustainability in the agri-food industry through blockchain technology: A bibliometric approach, benefits and challenges","authors":"Oliver O. Apeh,&nbsp;Nnamdi I. Nwulu","doi":"10.1016/j.nexus.2025.100388","DOIUrl":"10.1016/j.nexus.2025.100388","url":null,"abstract":"<div><div>The globalization of the agri-food industry in recent years has increased the difficulty and complexity of improving productivity and addressing challenges in food security. Thus, advanced techniques are promptly required to tackle the present obstacles and improve the agri-food sustainability challenges. Hence, blockchain is a prospective distributed information technology that could support food supply chains by decreasing transaction time and cost, improving traceability efficiency, and developing stakeholder trust. The main aim of this paper is to examine the functionalities and characteristics of blockchain technology in the agri-food industry, explore blockchain-based solutions for addressing food traceability and sustainability challenges, and highlight the benefits and challenges related to applying blockchain-based traceability systems. This work examines 114 research papers from 2017 to 2024, demonstrating a review of bibliometric literature to propose a wide and organized body of research regarding blockchain application in the agri-food supply chain. The analysis recognizes essential ideas, fundamental themes, research gaps, and potentials in blockchain application in agri-food. Results show an exponential rise in the number of publications, ranging from 9 % in 2017 to 23 % in 2024, directed mainly at farmers’ advantage, traceability, supply chain efficiency, and food security. For accurate farming possibilities, integrating blockchain and agro-food will encourage smart farms and enhance the regulation of supply-chain systems. Similarly, the bibliometric analysis across the discipline shows that computer science accounts for 18.8 %, engineering records 59.9 %, energy shares 6.9 %, and social sciences contribute 6.5 %. The review describes substantial issues, including the absence of standardization, technical intricacy, and regulatory issues that may deter blockchain's wider application. This analysis presents a guideline for researchers and industry experts, enlightening them on the field's present state, contributing ideas to its route, and offering a basis for future study in improving the sustainability of blockchain technology within the agri-food industry.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"17 ","pages":"Article 100388"},"PeriodicalIF":8.0,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal management of high concentrator photovoltaic module using an optimized microchannel heat sink","authors":"Salah Haridy ,&nbsp;Ali Radwan ,&nbsp;Ahmed Saad Soliman ,&nbsp;Essam Abo-Zahhad ,&nbsp;Osama Abdelrehim","doi":"10.1016/j.nexus.2025.100376","DOIUrl":"10.1016/j.nexus.2025.100376","url":null,"abstract":"<div><div>Microchannel heat sinks (MCHSs) are compact and powerful thermal management devices for concentrator photovoltaic (CPV) modules. This study optimizes the thermal-hydraulic performance of a new MCHS, which is then integrated with a CPV module to ensure efficient thermal management and safe operation. An integrated framework combining computational fluid dynamics simulation and response surface methodology is proposed to analyze and optimize the thermal-hydraulic performance of the MCHS fitted with a twisted tape insert. The effects of fluid inlet velocity, insert initial distance, insert pitch, and insert length on various responses, including the MCHS thermal resistance (<em>R</em>_<em>th</em>), rate of the entropy generation ratio (<em>S</em>_<em>gen</em><em>/S</em>_{<em>gen,o</em>}), heated wall temperature non-uniformity ratio (<em>ΔT/ΔT</em>_<em>o</em>), Nusselt number (<em>Nu</em>), and figure of merits (FOM) are comprehensively evaluated. The results reveal that to minimize the <em>ΔT/ΔT</em>_<em>o</em>, <em>R</em>_<em>th</em>, and <em>S</em>_<em>gen</em><em>/S</em>_{<em>gen,o</em>} while maximizing <em>Nu</em> and FOM, a fluid velocity of 2.11 m/s, an initial distance of 7.47 mm, a pitch of 2 mm, and a twisted tape length of approximately 30 mm should be used. Under these conditions, the predicted responses are <em>R</em>_<em>th</em> = 0.775, <em>Nu</em> = 19.232, FOM = 1.271, S_gen/S_gen,<em>_o</em> = 0.596 and <em>ΔT/ΔT</em>_<em>o</em> = 0.274. Integrating these optimized MCHS dimensions with a CPV module operating at a solar concentration of 1000 suns results in a 22.5% reduction in the average CPV module temperature, compared to a smooth MCHS.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"17 ","pages":"Article 100376"},"PeriodicalIF":8.0,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Greening enhanced oil recovery: A solar tower and PV-assisted approach to post-combustion carbon capture with machine learning insights","authors":"Farzin Hosseinifard ,&nbsp;Milad Hosseinpour ,&nbsp;Mohsen Salimi ,&nbsp;Majid Amidpour","doi":"10.1016/j.nexus.2025.100381","DOIUrl":"10.1016/j.nexus.2025.100381","url":null,"abstract":"<div><div>Carbon Capture Utilization and Storage (CCUS) has become a cornerstone in reducing industrial emissions, mainly through Enhanced Oil Recovery (EOR) in underground reservoirs. Conventional post-combustion carbon capture (PCC) systems, however, face significant energy penalty challenges. This study introduces an innovative solar-assisted approach to optimize the EOR factor while reducing the energy penalty. The proposed system uniquely integrates solar tower heliostats and photovoltaic (PV) systems with up to 7 h of energy storage, marking a dual solar energy integration as the core innovation. This hybrid configuration reduces the energy penalty factor from 21.2 % to 7.4 %. To further enhance operational efficiency, the study incorporates a novel compression stream configuration with process integration into the PCC system. Machine learning models, including linear regression, random forest, decision tree, and XGBoost, were employed to model and predict EOR factors using CO₂ streams from a large-scale carbon capture unit at the Abadan power plant in Iran. The decision tree model achieved superior performance with an R² of 0.98 and accurately forecasted an increase in EOR factor from 19 % to 43.16 %. By combining solar-driven energy systems with advanced CO₂ capture and predictive modeling, this study establishes a sustainable and energy-efficient framework for EOR enhancement. The dual integration of solar towers and PV systems represents a significant leap in reducing fossil fuel dependence and carbon emissions while demonstrating practical applicability in high-emission regions like Abadan.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"17 ","pages":"Article 100381"},"PeriodicalIF":8.0,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimisation of flow configuration for PVT system assisted by MgO nanoparticles PCM cooling","authors":"W. Phukaokaew ,&nbsp;A. Suksri ,&nbsp;K. Punyawudho ,&nbsp;T. Wongwuttanasatian","doi":"10.1016/j.nexus.2025.100389","DOIUrl":"10.1016/j.nexus.2025.100389","url":null,"abstract":"<div><div>To improve the global environment, it is essential to address the significant concerns raised by the rising energy demand. Thermal photovoltaic (PVT) systems enjoy widespread popularity. These systems convert solar energy into electrical/thermal energy; however, elevated temperatures cause problems. Magnesium oxide (MgO) nanoparticles and lauric acid (LA) phase change material (PCM) were utilized. The two were combined and filled into a container. The container's distinctive design incorporates a fully organized micro-channel structure as well as eight integrated water tubes. The system works by first absorbing waste heat from the PV module and then directing it into the water tubes for further utilization. The study also examined the effects of water tube configurations, using three different types: a U-tube, a half-serpentine flow, and a serpentine flow. These configurations affected the absorption of heat from the PV panel, which improved both the power generation and the overall efficiency of the PVT system. Furthermore, the investigation tested the PVT system's water inlet using dimensionless water flow (Reynolds numbers, <em>Re</em>) levels ranging from 1100 to 7700. The findings indicate that every level of <em>Re</em> increases electrical efficiency, with the U-tube configuration approach producing the maximum value. In addition, when it comes to thermal efficiency, serpentine flow configurations yield the highest improvement. The most optimal tube arrangement is a serpentine configuration at <em>Re</em> = 5500, which reduces the PV surface temperature by 3.14 °C while achieving the highest overall efficiency of 80.63 %.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"17 ","pages":"Article 100389"},"PeriodicalIF":8.0,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Techno-economic assessment of PV-diesel-battery hybrid systems for poultry farms: A case study in North Carolina","authors":"Weimin Wang,&nbsp;David Simonson","doi":"10.1016/j.nexus.2025.100372","DOIUrl":"10.1016/j.nexus.2025.100372","url":null,"abstract":"<div><div>This paper presents the techno-economic assessment of PV-diesel-battery hybrid systems for poultry farms via the use of HOMER simulation software. A generic configuration is defined separately for grid-tied and off-grid systems. Major component sizes are then optimized for eight cases with varying utility rates and solar power compensation mechanisms. The case study is based on a farm with three mega-size broiler houses in North Carolina. The results show that after leveraging federal incentives, grid-tied PV investment is profitable only for one case, which has a 20-kW PV as the optimal size and leads to the net present cost $3,200 less than the base case of not using PV. Battery is not yet cost effective at current market conditions. The off-grid hybrid system has $370,000 to $560,000 higher net present cost than the grid-tied systems. The battery price, the PV price, and the diesel price have an ascending order of significance with respect to their impact on the net present cost for the off-grid hybrid system.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"17 ","pages":"Article 100372"},"PeriodicalIF":8.0,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical analysis of Savonius hydrokinetic turbine performance in straight and curved channel configurations","authors":"Shanegowda T G ,&nbsp;Shashikumar C M ,&nbsp;Veershetty Gumtapure ,&nbsp;Vasudeva Madav","doi":"10.1016/j.nexus.2025.100382","DOIUrl":"10.1016/j.nexus.2025.100382","url":null,"abstract":"<div><div>The global shift towards renewable energy has driven research into efficient hydrokinetic energy harvesting, particularly using Savonius turbines for their simplicity and adaptability to low-flow environments. While previous studies have focused primarily on straight channels, the impact of channel bends, commonly found in agricultural canals, rivers, and irrigation channels, remains underexplored. The present 3D transient numerical study addresses this gap by investigating the performance of Savonius hydrokinetic turbines in channels with 30°, 60°, and 90° bends, evaluating their efficiency under varying flow conditions. The research aims to evaluate the impact of these channel bends on key performance parameters such as the tip speed ratio (TSR), torque coefficient (C_T) and power coefficient (C_P), supported by detailed pressure and velocity contour analyses. The turbine positioned in the 30° bend emerged as the most efficient configuration, achieving a C_Tmax of 0.29 at 0.7 TSR and C_Pmax of 0.24 at 1.0 TSR. The 60° and 90° bends exhibited efficiency reductions of 15 % and 30 %, respectively, due to adverse pressure gradients and increased turbulence. Velocity contour plots demonstrated reduced wake regions and optimized flow reattachment for the 30° bend, while pressure contour analysis indicated lower drag forces on the advancing blades. This study highlights the potential of using Savonius turbines in agricultural channels, recommending the 30° bend as the optimal channel configuration to maximize turbine efficiency, providing a sustainable solution for energy generation in rural and low-flow environments.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"17 ","pages":"Article 100382"},"PeriodicalIF":8.0,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Techno-economic and life cycle greenhouse gas assessment of green ammonia produced by low-pressure Haber-Bosch process","authors":"Guohui Song ,&nbsp;Yumeng Chen ,&nbsp;Yingfeng He ,&nbsp;Qize Jia ,&nbsp;Qingjiao Wu ,&nbsp;Xiaobo Cui ,&nbsp;Hao Zhao","doi":"10.1016/j.nexus.2025.100379","DOIUrl":"10.1016/j.nexus.2025.100379","url":null,"abstract":"<div><div>Green ammonia can be used as an energy storage carrier and a sustainable chemical. To improve the competitiveness of green ammonia, two power-to-ammonia (PtA) processes integrated with low-pressure (LP) and ultra-low-pressure (ULP) Haber-Bosch (HB) techniques were designed and optimized based on technical, economic, and environmental performances. The effects of multiple variables were studied. The LP technique is preferred over the ULP technique because the latter has a more complex configuration and a slightly higher levelized cost. The systematic energy efficiency excluding or including the cold energy of liquid ammonia reaches 68.71 % or 73.75 %, respectively. The unit power consumption of green ammonia is as low as 7.64 kWh/kg. The plant scale should not be &lt;10 t/h. Based on the electricity price for energy storage (0.041 €/kWh), the equivalent operating hours should exceed 5000 h to achieve profitability. The life cycle greenhouse gas emission of green ammonia derived from wind power under the Chinese scenario is 257–316 kgCO₂e/t. The life cycle ammonia emissions with NH₃ recovery from the purge gas is &lt;0.06 kgNH₃/t. This study indicates that the PtA technology can efficiently store intermittent electricity with cold energy utilization and effectively decarbonize the ammonia industry.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"17 ","pages":"Article 100379"},"PeriodicalIF":8.0,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetic and thermodynamic insights into sewage sludge torrefaction: Energetic optimization and safety considerations","authors":"Blanca Castells ,&nbsp;Roberto Paredes ,&nbsp;David León ,&nbsp;Isabel Amez","doi":"10.1016/j.nexus.2025.100377","DOIUrl":"10.1016/j.nexus.2025.100377","url":null,"abstract":"<div><div>In the current energetic scenario, biofuels play a crucial role, with torrefaction being one of the most popular pretreatments as it significantly reduces the main disadvantages of these fuels. This study provides novel insights into torrefied sewage sludge as a solid biofuel by examining both the energetic conversion process and associated safety issues. To do so, torrefaction was carried out at three different temperatures (220 °C, 250 °C, and 300 °C) and two residence times (30 and 60 min), resulting in seven distinct samples. These samples underwent proximate analysis, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) in air, nitrogen, and oxygen atmospheres to simulate combustion, pyrolysis, and determine heating values respectively. The analysis reveals that torrefaction at 300 °C for 60 min produces the best results, enhancing the higher heating value (HHV) by 6% and increasing reaction heat by 16%. Additionally, we observed lower pyrolysis activation energies in samples torrefied for 30 min compared to 60 min. The kinetic parameters were meticulously evaluated, showing a clear relationship between torrefaction parameters and pyrolysis activation energy. For instance, the activation energy (<em>Ea</em>) for raw sewage sludge was found to be between 338.02 kJ/mol and 375.43 kJ/mol. In contrast, torrefied samples showed reduced <em>Ea</em> values mostly under 300 kJ/mol. For the first time, we assessed self-ignition risk through TGA, finding that while most samples exhibit low risk, the increased heating value from torrefaction does elevate this risk. This comprehensive evaluation not only advances the understanding of sewage sludge torrefaction but also offers a practical framework for integrating biofuels into sustainable energy systems, supporting global efforts toward cleaner energy transitions.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"17 ","pages":"Article 100377"},"PeriodicalIF":8.0,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}