Energy Conversion and Management最新文献

{"title":"CMLLM: A novel cross-modal large language model for wind power forecasting","authors":"Guopeng Zhu ,&nbsp;Weiqing Jia ,&nbsp;Zhitai Xing ,&nbsp;Ling Xiang ,&nbsp;Aijun Hu ,&nbsp;Rujiang Hao","doi":"10.1016/j.enconman.2025.119673","DOIUrl":"10.1016/j.enconman.2025.119673","url":null,"abstract":"<div><div>Accurate short-term wind power forecasting is crucial for ensuring grid stability and optimizing the operation of wind farm-energy storage systems. However, the inherent randomness and high variability of wind energy present significant challenges to wind power forecasting. To leverage the powerful reasoning capabilities and high-level knowledge of large language models for accurately extracting features from non-stationary wind power data, a cross-modal large language model (CMLLM) is proposed for wind power forecasting. This model employs data cross-modal and pre-trained large language models, enabling efficient compatibility with various large language models and adaptability to data with different characteristics. In CMLLM, data is comprehensively processed through the adoption of a cross-modal transfer learning method. Data is converted into text modality, thereby eliminating the need for re-training or fine-tuning large language models, while effectively mitigating the decline in forecasting accuracy due to modal mismatches. A prior knowledge prompt prefix module is designed in the forecasting process to enhance feature extraction and activate the reasoning capabilities of the large language model for wind power forecasting tasks. Extensive experiments are carried out on datasets from three wind farms in China to evaluate the performance of CMLLM. The results validate the model's effectiveness, accuracy, and robustness across diverse datasets and a range of large language models.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"330 ","pages":"Article 119673"},"PeriodicalIF":9.9,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of energy conservation measures in Canadian office buildings","authors":"Sara Gilani,&nbsp;Kamel Haddad,&nbsp;Chris Kirney,&nbsp;Phylroy Lopez,&nbsp;Ali Syed,&nbsp;Meli Stylianou","doi":"10.1016/j.enconman.2025.119661","DOIUrl":"10.1016/j.enconman.2025.119661","url":null,"abstract":"<div><div>Buildings account for 30% of the total energy use in Canada. It is well understood that improving energy performance of buildings is an effective way to reduce their energy use and carbon emissions. This paper provides a comprehensive analysis of the performance of various energy conservation measures (ECMs), from cost, energy, and peak demand perspectives for three office archetypes in six Canadian climate zones. For this purpose, this study developed a simulation-based methodology for generating and simulating a wide range of ECMs automatically. The impacts of ECMs compared to the baselines as per the requirements of the National Energy Code of Canada for Buildings (NECB) were then evaluated. The results indicate that switching to electrical equipment is a cost-effective way to improve energy performance. Across office archetypes and climate zones, 71% of the solution sets at tier 4 use electrical equipment, whereas only 24% of the solution sets at tier 1 use electrical equipment. The results also show that reducing internal loads yields more energy and cost savings in larger offices and milder climates. For instance, the load-related ECMs lead to a maximum energy saving of 13% in the small office archetype while this is 18% in the large office archetype. However, HVAC system performance has a larger impact in smaller offices and colder climates. For instance, the small office archetype has a maximum energy saving of 29% using HVAC-related ECMs while this is 25% in the large office archetype. These findings provide important insights for designing new office buildings in heating-dominated climates.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"330 ","pages":"Article 119661"},"PeriodicalIF":9.9,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative study of a new semi-empirical model of the proton exchange membrane fuel cell for online prognostics applications","authors":"L.M. Perez ,&nbsp;Samir Jemei ,&nbsp;Loïc Boulon ,&nbsp;Alexandre Ravey ,&nbsp;Mohsen Kandidayeni ,&nbsp;Javier Solano","doi":"10.1016/j.enconman.2025.119655","DOIUrl":"10.1016/j.enconman.2025.119655","url":null,"abstract":"<div><div>The prognostic of the proton exchange membrane fuel cell is a current topic of research. Consequently, the complexity of its degradation mechanisms has led to the development of semi-empirical models to improve predictive analysis. The accurate estimation of parameters for these models is a challenging task due to their multivariate, nonlinear, and complex characteristics. This work proposes a new semi-empirical model of the proton exchange membrane fuel cell and compares it with a widely used model in the literature. Unlike other similar studies, this comparison not only focuses on minimizing the sum of squared errors in relation to the experimental data but also evaluates the variation in the solution set and the computational effort involved. For both models, the unknown parameters are estimated using the recent Pelican Optimization Algorithm. Four datasets are used to evaluate the development of the proposed model and the selected benchmark model. The first three datasets are open-access and well-recognized in academic literature, whereas the fourth dataset was obtained from a developed experimental test bench. The results show that the proposed model achieves high accuracy, with a mean absolute percentage error lower than 0.89% and the sum of squared errors below 0.9272 for all the studied scenarios. This model reduces parameter variation and decreases the relative standard deviation by over 12.7% compared to the utilized benchmark model for the first three datasets. Hence, the proposed model not only improves the precision of the estimated parameters without a notable increase in error but also reduces the computational load by at least 21.7% across all case studies.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"331 ","pages":"Article 119655"},"PeriodicalIF":9.9,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance evaluation of single stage flash desalination system under different air intermittences and intake valve opening conditions","authors":"Sarvjeet Singh ,&nbsp;Rachit Garg ,&nbsp;Prodyut R. Chakraborty ,&nbsp;Hardik B. Kothadia","doi":"10.1016/j.enconman.2025.119658","DOIUrl":"10.1016/j.enconman.2025.119658","url":null,"abstract":"<div><div>Drinking water is produced inside the evaporator of thermal desalination plants through the critical processes of water vaporization and condensation. Any leakage in this unit can lead to substantial losses in thermal energy, reduced distillation efficiency, and potential contamination of the distillate product. Therefore, this study aims to introduce and investigate the thermal performance of single-stage flash desalination systems under different air intermittence and intake rates. An experimental system is fabricated, and experiments are performed with different operating conditions to simulate similar leakage conditions. The initial pressure inside the vacuum tank is set at 8.4 kPa, the water height is 60 mm, and the initial temperatures are 80 °C and 70 °C. The investigation explores the influence of different cycle lengths of air intake (<span><math><msub><mrow><mi>t</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span>) and air removal periods (<span><math><msub><mrow><mi>t</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>), ranging from 6 s to 160 s for different intermittent periods. The study also explores different intake valve opening levels, including 0%, 25%, 50% and 100%, to understand how these different opening levels affect heat and mass transfer characteristics. The experiments examined and analysed the effect of different valve opening levels, air intake and removal periods, and initial liquid temperatures on measuring parameters such as temperature, pressure, water mass, and non-equilibrium factor (NEF). The results indicate that decreasing the air intake period and increasing the air removal period significantly improves the temperature and pressure drop. When the air removal period increases from 4 s to 6 s, the pool temperature drop increases from 18.6 °<span><math><mi>C</mi></math></span> to 23.2 °<span><math><mi>C</mi></math></span>. With the increase of initial temperature by 10 °<span><math><mi>C</mi></math></span>,the temperature drop and evaporated mass are increased by 22.4% and 21.7%. The outcomes provided a comprehensive understanding of the effects of leakage on the flashing evaporation process.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"330 ","pages":"Article 119658"},"PeriodicalIF":9.9,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal sizing of fuel cell hybrid electric Heavy-Duty tractor with minimum of unit mileage cost","authors":"Xiaoyu Wang,&nbsp;Shouwen Yao,&nbsp;Pengyu Li,&nbsp;Yuyang Chen,&nbsp;Qinghua Hao,&nbsp;Siqi Huang,&nbsp;Yinghua Zhao","doi":"10.1016/j.enconman.2025.119674","DOIUrl":"10.1016/j.enconman.2025.119674","url":null,"abstract":"<div><div>This paper proposes an optimal hybrid energy sources sizing methodology for fuel cell hybrid heavy-duty tractors (FCHHT) comprising fuel cell system (FCS) with battery (B) and supercapacitor (SC) as hybrid energy storage system (HESS). For this purpose, an objective function of unit mileage (10⁴ km) cost (UMC) is put forward to evaluate the system’s initial cost, degradation cost, and hydrogen consumption cost. Furthermore, an average power and state of charge (APS) based Energy Management System (EMS) is proposed, where power-split strategy of FCS and HESS is given, and the output power of FCS is smoothed by the average power of drive cycle power demand, the power of maximum efficiency point and maximum power of FCS, and SOC of HESS. Finally, to solve the hybrid energy source optimization problem, the cancer cell competition and metastasis algorithm (C3MA) is proposed, where an efficient population position updating strategy is used to simulate the competition and metastasis of cancer cells, and the search space can be explored more effectively. C3MA is evaluated using six benchmark functions, demonstrating its robustness and rapid convergence in high-dimensional problems. The size optimization of a 49-ton tractor was conducted. The optimum can always be achieved using APS EMS in conjunction with C3MA, Particle Swarm Optimization (PSO), and Grey Wolf Optimization (GWO). In comparison to discrete wavelet transform (DWT) EMS, APS demonstrated a 16 % reduction in UMC and a 77 % increase in lifespan. Compared to FCS + B configuration, FCS + B + SC reduces UMC by an average of 19 %.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"330 ","pages":"Article 119674"},"PeriodicalIF":9.9,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Refrigerants evaluation and energy performance optimization for a high-temperature carbon dioxide + hydrofluoroolefin / hydrochlorofluoroolefin cascade heat pump dryer with two air heating circuits","authors":"Yingjie Xu ,&nbsp;Liulu Jia ,&nbsp;Yufeng Ye ,&nbsp;Jiameng Liu ,&nbsp;Xi Shen ,&nbsp;Xiaohong Han","doi":"10.1016/j.enconman.2025.119677","DOIUrl":"10.1016/j.enconman.2025.119677","url":null,"abstract":"<div><div>The carbon dioxide heat pump is promising for energy savings and emission reductions in the drying industry due to its good performance. However, the efficiency of carbon dioxide gas cooler is low under drying working condition, due to significant temperature glide of supercritical state. Moreover, for many drying materials, the drying temperature provided by current heat pumps is still lower than the optimal drying temperature. To resolve these issues, a new low-carbon refrigerant + carbon dioxide transcritical cascade heat pump drying system has been proposed. In this new system, the discharged carbon dioxide from the compressor of low-temperature stage is cooled by both fresh air and the low-carbon refrigerant through two distinct heat exchangers. System simulation and multi-objective optimization are conducted based on experimentally validated model. The results show that when R1234ze(Z) is used at high temperature stage, the system performs the best, with a maximum coefficient of performance of 1.78, heating capacity of 20.2 kW, condensing temperature of 110 ℃, and low-temperature heat source of 10 ℃. The best individual in Pareto front is selected, with 3.55 × 10⁴ CNY/year and 3.47 × 10⁴ kg/year. The optimal geometric parameters of components are determined as follows, 3.39 m² gas-cooler heat transfer area, 48 m² condensing heat transfer area and 9.68 MPa parameters of heat rejection pressure. Additionally, the impact of critical factors on system performance was investigated. The new system and the results of this paper are expected to provide new ideas for high-temperature heat pump drying system and system energy saving.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"330 ","pages":"Article 119677"},"PeriodicalIF":9.9,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancements in biodiesel production from castor oil: A comprehensive review","authors":"Ana V. Veličković ,&nbsp;Dragana D. Rajković ,&nbsp;Jelena M. Avramović ,&nbsp;Ana M. Marjanović Jeromela ,&nbsp;Miljana S. Krstić ,&nbsp;Vlada B. Veljković","doi":"10.1016/j.enconman.2025.119622","DOIUrl":"10.1016/j.enconman.2025.119622","url":null,"abstract":"<div><div>Castor (<em>Ricinus communis</em> L.) is a non-food industrial oleaginous crop with the potential for biofuel production. It grows in diverse regions and thrives in marginal soils without competing with food crops. This paper reviews the current state and perspectives of producing biofuels, primarily biodiesel, from castor oil. It begins with a brief introduction to the castor plant, its genetics, and breeding, as well as methods and challenges of castor oil production, extraction, and refinement. Biodiesel production technologies, optimization, kinetics, thermodynamics, and the techno-economic, environmental, and social assessment are discussed. Other castor-based biofuels are highlighted, including bio-jet fuel, biogas, and bioethanol in biorefineries. The future of biofuel production depends on cost-effective and sustainable methods, land availability, and considering various aspects. Challenges remain for large-scale production, but further research can enable castor biomass to become a sustainable and cost-effective feedstock while mitigating environmental and social impacts.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"330 ","pages":"Article 119622"},"PeriodicalIF":9.9,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clustered carbon capture as a technologically and economically viable concept for industrial post-combustion CO2 capture","authors":"Boreum Lee ,&nbsp;Hyunjun Lee ,&nbsp;Juli Ayu Ningtyas ,&nbsp;Manhee Byun ,&nbsp;Atabay Allamyradov ,&nbsp;Boris Brigljević ,&nbsp;Hankwon Lim","doi":"10.1016/j.enconman.2025.119608","DOIUrl":"10.1016/j.enconman.2025.119608","url":null,"abstract":"<div><div>Industrial CO₂ emission is a primary contributor to the global warming and as such an accelerator of the climate crisis. Countries worldwide have adopted the ‘Paris Agreement’ to restrict the global temperature rise below 2 ℃, and ideally below 1.5 ℃ compared to the pre-industrial levels. Reactive absorption which utilizes aqueous alkanolamine solvents in an absorption and stripping column tandem is the current de-facto standard for a realistic, industrial-scale, post-combustion carbon capture. The solvent regeneration and high concentration CO₂ release in the stripping column represents the bulk of the process’s operating cost, due to high energy requirement of the reboiler unit (∼4–10 GJ / ton CO₂). This fact alone makes the process prohibitively expensive in both energy and economic terms for many major CO₂ emitting entities such as fossil fuel power plants, cement producers, refineries, etc. To address this issue in this work we present a new process topology concept entitled Clustered Carbon Capture. A cluster of major CO₂ point sources in a variable radius all with CO₂ absorption columns of appropriate scale share a centralized stripper column appropriately sized to regenerate the solvent for all the points in the cluster. As a proof-of-concept this work has 3 sources (300–2,000 MW coal power plants) and a ∼ 35 km radius. Utilizing the economies of scale on the most expensive and energy intensive unit our expected results should quantify the amount of cost reduction for the CO₂ capture for each individual point of the cluster. Provided that the cost reduction is significant, clustered carbon capture might well represent an indispensable strategy for economic CO₂ reduction on a large-scale, utilizing an already proven technology.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"330 ","pages":"Article 119608"},"PeriodicalIF":9.9,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy, exergy, economic, and environmental analysis of waste heat source heat pump industrial steam generation system","authors":"Hang Yin,&nbsp;Shicheng Ying,&nbsp;Guangbin Liu,&nbsp;Qichao Yang,&nbsp;Yuanyang Zhao,&nbsp;Liansheng Li","doi":"10.1016/j.enconman.2025.119662","DOIUrl":"10.1016/j.enconman.2025.119662","url":null,"abstract":"<div><div>High-temperature steam is a vital energy for heating, washing, drying, and other industrial processes primarily generated by special coal-fired boilers. The heat pump coupled with the steam compressor is a promising steam generation system due to its high efficiency, high heating temperature, and low pollution. In this paper, a mathematical model of a waste heat source heat pump industrial steam generation system (WHPSG) is developed. The system performance is analyzed using energy, exergy, economy, and environment methods when R245fa, R600, and R601 are selected. The results demonstrate better overall system performance at high waste heat temperature and low condensing temperature than at low waste heat or high condensing temperature. Compared to R245fa and R600, the COP_sys using R601 increased by 3.4% and 3.8%, and power consumption per unit mass flow rate of steam decreased by 3.3% and 3.7. The condensing temperature influences system performance obviously, while the heat pump compressor and steam compressor account for a large percentage of exergy destruction. The system with R601 has the largest total exergy efficiency, which is higher than R245fa and R600 by about 3.0% and 3.2% respectively. The good economic and environmental benefits showed it can be used for steam generation.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"330 ","pages":"Article 119662"},"PeriodicalIF":9.9,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geothermal energy-assisted pumped thermal energy storage: Configuration mapping","authors":"Suzhen Yin,&nbsp;Chuangang Bai,&nbsp;Kaiyue Zheng,&nbsp;Yilun Zhang,&nbsp;Xingpeng Yan,&nbsp;Zhan Liu","doi":"10.1016/j.enconman.2025.119660","DOIUrl":"10.1016/j.enconman.2025.119660","url":null,"abstract":"<div><div>Unstable renewable energy sources, including wind and photovoltaic power generation with the inherent characteristics of intermittency and randomness, pose an extremely significant challenges to the safety and stability of electrical grids. Considered a viable solution, energy storage technology increases the flexibility and regulatory capacity of power grids by storing and releasing excess electricity at different times. Pump thermal energy storage technology offers an efficient large-scale electricity storage solution that is completely free from geographical location limitations. Skillfully integrating pumped thermal energy storage technology with low-grade heat can effectively improve its thermodynamic and economic performance. To significantly enhance the utilization rate of geothermal energy and effectively achieve a more optimal performance of pumped thermal energy storage systems, the in-depth and comprehensive study conducted a thermo-economic evaluation of 15 types of geothermal-assisted transcritical pumped thermal energy storage systems. This study provides configuration selection maps for the round trip efficiency and the levelized cost of storage, thereby enabling an extremely effective and swift evaluation of the performance of these various configuration systems. When the geothermal temperature changes within the range from 50 °C to 90 °C, the efficiency of the systems that are considered to be the most suitable under these conditions varies from 66.2 % to 105.6 %. This variation in efficiency occurs when the compressor outlet pressure is optimized within the range from 5 MPa to 8 MPa. The system levelized cost of storage declines as geothermal temperature rises and its minimum value is 0.472 CNY/kWh when the geothermal temperature is 90 °C.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"329 ","pages":"Article 119660"},"PeriodicalIF":9.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}