International Journal of Thermofluids最新文献

{"title":"CFD analysis of the main operating parameters for a complete braking friction system under transient working conditions","authors":"F. Orlandi ,&nbsp;C. De Marco ,&nbsp;S. Meleti ,&nbsp;A. Manian ,&nbsp;M. Milani ,&nbsp;L. Montorsi","doi":"10.1016/j.ijft.2025.101100","DOIUrl":"10.1016/j.ijft.2025.101100","url":null,"abstract":"<div><div>A braking system represents a very complex physical system to be properly modelled since it involves the solution of multiphase flow and thermal distribution and multi-body motions under dynamic operating conditions. Most approaches focus on a single braking element coupling, generally between a steel and a friction material element, which demonstrated to be insufficient to predict the effective behaviour of these systems. The present work extends the approach adopted for a single braking couple, to include a full braking system including the disks and braking piston motions and the thermal dissipated energy along the braking event. The comprehensive numerical model allows to deeply analyse the thermal dissipation of the solid elements and the oil of the systems and thus the cooling efficiency of the lubricant oil can be calculated. Furthermore, a sensitivity analysis with respect of the main braking system operating parameters is carried out to investigate the influence of heat dissipation rate of the oil and the cooling efficiency of the full braking system. In particular, the lubricant oil flow rate, the thermal energy to be dissipated and the characteristic braking time are analysed. The most critical operating conditions are highlighted as well as the optimal configuration is defined.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101100"},"PeriodicalIF":0.0,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169680","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":"Experimental investigation of thermal characteristics of a 12S1P Li-ion NMC-21700 battery module under different environments for EV applications","authors":"Jay Patel,&nbsp;Rajesh Patel,&nbsp;Rajat Saxena,&nbsp;Abhishek Nair","doi":"10.1016/j.ijft.2025.101084","DOIUrl":"10.1016/j.ijft.2025.101084","url":null,"abstract":"<div><div>The rapid growth of electric vehicles (EVs) has placed significant emphasis on the performance and safety of lithium-ion (Li-ion) batteries, which serve as the primary energy storage solution. Effective thermal management is crucial to ensure battery safety, longevity, and efficiency, particularly under high discharge rates where excessive heat generation can compromise performance. This study examines the thermal behaviour of a 4 × 3 Li-ion nickel-cobalt-manganese (NCM)-21,700 battery module with a 12S1P configuration. The focus of this study is to mitigate the challenges associated with heat generation at high discharge rates. Experiments are performed on a single NCM-21,700 cell to estimate the heat generation during charge and discharge. Based on this heat generation data, several experiments are performed on the 4 × 3 battery module under different thermal environments. These environments include natural convection, battery case, and phase change material (PCM) inside the battery case. The objectives of this study are to mitigate heat generation and ensure effective thermal management. The findings of these experiments demonstrate that despite being simple and economical, natural convection is insufficient as the temperature of the battery module rises significantly at high discharge rates. Although standard EV applications do not exceed the range of 0.3–0.6 C-rate, our study is focussed on extreme conditions of 1C and 2C rates. The maximum battery cell temperature in the battery module was found to be 48 °C and 53 °C for 1C and 2C discharge rates, respectively. The maximum temperature difference in the battery module was found to be 6 °Cand 13 °C for 1C and 2C discharge rates, respectively. The maximum temperature and maximum temperature difference of the battery module for PCM were reduced to 20 % and 45.45 % compared to conventional natural convection, respectively for a 1C discharge rate. PCM-based cooling provides better thermal uniformity across the battery module, helps to avoid thermal hotspots, and provides even performance across the battery module. The maximum temperature in any battery module is observed at the central cell due to the lesser space for heat dissipation. The results underscore the need for specialized cooling techniques for enhanced battery life, safety, and performance of high-energy Li-ion batteries in EV applications. This study also offers insights into efficient thermal management techniques for EV battery modules.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101084"},"PeriodicalIF":0.0,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169682","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":"Entropy formation in the radiative flow of bioconvective Oldroyd-B nanofluid across an electromagnetic actuator with second-order slip: Active and passive control approach","authors":"K. Loganathan ,&nbsp;N. Thamaraikannan ,&nbsp;S. Eswaramoorthi ,&nbsp;Sanju Jangid ,&nbsp;Reema Jain","doi":"10.1016/j.ijft.2025.101099","DOIUrl":"10.1016/j.ijft.2025.101099","url":null,"abstract":"<div><div>This research communication provides the impact of heat-mass transmission of Oldroyd-B nanofluid flow having gyrotactic microorganisms past a heated Riga plate. A non-Fourier model is thought to be the one that describes heat and mass fluxes. Second-order slip conditions are introduced into the flow velocity. To develop governing models, a partial differential system is initially built. This system is translated into an ordinary differential model by applying the relevant transformations. Solutions based on convergent series are used to solve the ordinary differential system. Detailed illustrations are presented for the effects of numerous physical factors on nanofluid velocity, thermal, nanofluid concentration, motile microbe density, skin friction coefficient, local Nusselt number, local Sherwood number, motile density microorganism, entropy, and Bejan number profiles. The relaxation and retardation time parameters lead to downturns in the fluid velocity profile. The thermal profile intensifies when enlarging the values of Eckert number and radiation parameter. The chemical reaction parameter and Lewis number play an opposite roles in the nanofluid concentration profile. The bioconvection Lewis number downturns the microorganism profile. Modified Hartmann number causes a reduction in both entropy and Bejan number profiles.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101099"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167645","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":"Nonlinear normalized fractional electroosmotic spacelike fluid model","authors":"Talat Körpinar ,&nbsp;Zeliha Körpinar ,&nbsp;Ali Akgül ,&nbsp;Qasem Al-Mdallal","doi":"10.1016/j.ijft.2025.101057","DOIUrl":"10.1016/j.ijft.2025.101057","url":null,"abstract":"<div><div>In this paper, we present optical recursively fractional <span><math><mrow><mi>SK</mi><mi>μ</mi><mo>−</mo></mrow></math></span>electroosmotic fractional recursively<span><math><mrow><mi>SK</mi><mi>μ</mi><mo>−</mo></mrow></math></span>energy. Also, we have spacelike microfluidicsfractional <span><math><mrow><mi>SK</mi><mi>μ</mi><mo>−</mo></mrow></math></span> electroosmotic recursively tension energy. Moreover, we construct main Katugampola recursive-normal hyperbolic fractional <span><math><mrow><mi>KF</mi><mi>α</mi><mo>−</mo></mrow></math></span>tension field in hyperbolic space. Finally, we characterize spacelike radiative recursively fractional <span><math><mrow><mi>SK</mi><mi>μ</mi><mo>−</mo></mrow></math></span> phase in hyperbolic space.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101057"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168164","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":"On Cattaneo-Chrystov heat flux model for nanofluid flow on Darcy–Forchheimer porous medium past unsteady stretching cylinder","authors":"Sreedhar Sobhanapuram ,&nbsp;S.V.V Rama Devi ,&nbsp;Charankumar Ganteda ,&nbsp;Rajyalakshmi Kottapalli ,&nbsp;Vediyappan Govindan ,&nbsp;Haewon Byeon ,&nbsp;Busayamas Pimpunchat","doi":"10.1016/j.ijft.2025.101101","DOIUrl":"10.1016/j.ijft.2025.101101","url":null,"abstract":"<div><div>In a Darcy-Forchheimer porous medium with variable thermal conductivity, this work describes the convective transport mechanisms of Williamson nanofluid and nanofluid flow via an unstable stretched cylindrical sheet. The governing boundary evaluates issue of the flow regime is formulated utilizing the conservation laws of mass, momentum, energy. A couple of nonlinear partial differential constitutions are used to express the flow. A suitable similarity transformation along with certain approaches are applied to convert the pair of partial differential constitutions into an initial value problem system. In this analysis, the Cattaneo-Chrystov model is introduced. After that, the shooting strategy and the Runge-Kutta fourth order are used to numerically solve the system of initial value problems. Analysis is done on the effects of several factors on the nanofluid's temperature, velocity, and concentration contours. such as the thermal conductivity parameter, the concentration and temperature Biot numbers, the unsteady parameter, and others. Conversely, larger values of the unstable parameter result in significant wall friction that hinders the nanofluid'smobility. Furthermore, under widely accepted assumptions, the numerical approach found here shows great agreement with several previous efforts. An uplifting in the unsteady factor causes the nanofluid's temperature and concentration boundary layers to enlarge. When the corresponding Biot numbers (thermal and concentration) grow, the two boundary layers of the nanofluid expand, initiating the convective mass and heat transfers from the wall to the system. The rates of mass and heat transfers increase and decrease in tandem with increases in the thermal conductivity parameter and thermal Biot number, respectively; however, the transfers exhibit the opposite behavior for higher concentration Biot number values.Compared with the existing research, the outcomes demonstrate excellent congruence.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101101"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167634","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":"A multi-faceted review of wind turbine optimization techniques: Metaheuristics and related issues","authors":"Hegazy Rezk ,&nbsp;Abdul Ghani Olabi ,&nbsp;Tabbi Wilberforce ,&nbsp;Enas Taha Sayed","doi":"10.1016/j.ijft.2025.101077","DOIUrl":"10.1016/j.ijft.2025.101077","url":null,"abstract":"<div><div>Wind energy conversion is increasingly attracting attention as a viable renewable energy source due to its ability to satisfy electricity requirements while considering economic and environmental factors. To get the highest possible power harvesting from wind, optimization approaches are used to address a range of issues about wind energy. This article comprehensively reviews the current optimization state for wind energy systems and examines the use of metaheuristic optimization algorithms. Metaheuristic optimization algorithms combine fundamental heuristic concepts with approximation approaches to effectively explore and utilize research space. They seek ideal or almost ideal results and are based on previous experience. Their applications in the context of wind energy will be investigated in this paper. First, the basics of the wind turbine conversion systems, including the models and classifications, are presented. Then, the main problems related to wind energy are reported. These problems include aerodynamic design, structural design, damage detection, optimal onshore and offshore locations, control optimization, and wind energy assessment. Next, an analysis of the use of metaheuristic optimization algorithms will be provided, followed by an exhaustive study and evaluation of the latest papers published in Scopus that solve problems related to wind energy. Finally, recommendations and future trends are discussed. This review will help scholars broaden their perspectives to investigate potential applications within this subject and beyond.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101077"},"PeriodicalIF":0.0,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168161","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":"Computational study of steady flow across a modified semi-circular cylinder in power-law fluids","authors":"Chandan Kumar Bharti,&nbsp;Geeta Verma,&nbsp;Rabindra Nath Barman","doi":"10.1016/j.ijft.2025.101082","DOIUrl":"10.1016/j.ijft.2025.101082","url":null,"abstract":"<div><div>A numerical study was performed to address the viscous flow characteristics of a power-law model fluid across a semi-circular cylinder with a rectangular extension (referred to as Case A), where the curved surface faces upstream. This configuration was compared with a standard semi-circular cylinder (referred to as Case B). The study was focused on the low Reynolds number (Re) spanning from 5 <span><math><mo>≤</mo></math></span> Re <span><math><mo>≤</mo></math></span> 45, with flow simulations performed for three distinct power-law indices (n = 0.6, 0.8, and 1). Understanding the behavior of non-Newtonian fluids under such configurations is critical for optimizing engineering systems involving flow control, drag reduction, and enhanced performance in food processing industries and biological applications. The study provides a comprehensive analysis of surface parameters, including vorticity and pressure coefficients, along with detailed insights of the separation angle and streamline visualization. The investigation also aimed to determine the critical Reynolds number (<span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math></span>) for case A for various n, revealing <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math></span> = 34 at n = 0.6, <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math></span> = 39 at n = 0.8, and <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math></span> = 46 at n = 1. Furthermore, the wake generated behind the cylinder in Case A exhibited a reduction of 15.426% for n = 0.6 and 12.229% for n = 1 compared to the wake generated in Case B. The coefficient of drag (<span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>D</mi></mrow></msub></math></span>) was observed to be lower for Pseudo-plastic fluids and higher for Newtonian fluids. The transition from n = 1 to n = 0.6 caused a decline in <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>D</mi></mrow></msub></math></span> value of 29.059% for Re = 5 and 28.425% for Re = 45.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101082"},"PeriodicalIF":0.0,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167649","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":"New cogeneration concept applied to diesel power generators–Thermal modeling, parametric analysis and first feasibility study","authors":"Jalal Faraj ,&nbsp;Ahmed Mohsin Alsayah ,&nbsp;Mohammed J. Alshukri ,&nbsp;Angham Fadil Abed ,&nbsp;Samer Ali ,&nbsp;Hicham El Hage ,&nbsp;Mahmoud Khaled","doi":"10.1016/j.ijft.2025.101096","DOIUrl":"10.1016/j.ijft.2025.101096","url":null,"abstract":"<div><div>In this manuscript, we present a unique cogeneration system that combines diesel power generators with thermoelectric generators (TEGs), using the comparatively cool water in an integrated tank and hot exhaust gases to produce additional heat and power. By connecting a series of TEGs and a cold water tank to the diesel generator, the design enables the water to gradually warm up and become appropriate for usage in both domestic and commercial settings. We did a parametric study and created detailed thermal models to verify the viability of our idea. The findings indicate that the temperature differential across each TEG module and the total power output increase roughly linearly, based on the ratio of the diesel generator's power to the thickness of TEG to thermal conductivity. Additionally, the total power output increases linearly with the length of the TEG plate and declines exponentially with the height of the exhaust gas duct. The system may produce up to 3,223 W more electricity under certain circumstances, such as an exhaust gas duct height of 0.05 m, a TEG plate length of 1 m, and a generator output of 150 kW. This improvement could result in a 2.58 % reduction in fuel consumption and an equivalent increase in total power production when compared to conventional systems. The heater system recovers up to 22.4 kW/m² and can heat 100 liters of water in 0.2 h. According to these results, diesel generators and eventually diesel power plants might use less fuel and have more energy efficiency thanks to the suggested cogeneration technology.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101096"},"PeriodicalIF":0.0,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168159","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":"Assessment of soot formation and thermal radiation in syngas flame using oxygen-enhanced combustion under lean mixing conditions and acetylene doping","authors":"Alex Álisson Bandeira Santos ,&nbsp;Paulo Roberto Freitas Neves ,&nbsp;Pollyana da Silva Melo ,&nbsp;Willams Teles Barbosa ,&nbsp;Joyce Batista Azevedo ,&nbsp;Lilian Lefol Nani Guarieiro","doi":"10.1016/j.ijft.2025.101094","DOIUrl":"10.1016/j.ijft.2025.101094","url":null,"abstract":"<div><div>Combustion is a predominant global energy source, yet it contributes substantially to environmental degradation through greenhouse gas emissions and particulate matter, including soot. To alleviate these concerns, improving combustion efficiency and mitigating pollutant emissions are essential. Syngas, a hydrogen-carbon monoxide mixture derived from biomass gasification, offers a promising solution. This investigation examines the effects of oxygen-enhanced combustion, acetylene doping, and lean conditions on soot formation and thermal radiation in a confined flame. Soot formation was assessed via laser light scattering, while thermal radiation was analyzed using radiometers. Experiments were conducted at equivalence ratios of 0.7 and 1.0, with volumetric oxygen contents of 21 % and 30 % in the oxidant, and acetylene doping levels of 1 % and 5 % (by volume). The results demonstrate that acetylene doping significantly influences thermal radiation, particularly at 5 %, due to increased flame temperature. The findings reveal that combining oxygen-enhanced combustion with equivalence ratios of 0.7 and acetylene doping increases soot concentration trends compared to equivalence ratios of 1.0. However, soot levels for the 0.7 condition remain lower than those for the 1.0 condition. These results suggest that oxygen-enriched combustion in syngas flames enhances soot formation relative to non-enriched combustion.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101094"},"PeriodicalIF":0.0,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168158","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":"Artificial intelligence based analysis for magnetized casson fluid in partially heated cavity rooted with heated fin","authors":"Khalil Ur Rehman ,&nbsp;Wasfi Shatanawi ,&nbsp;Lok Yian Yian","doi":"10.1016/j.ijft.2025.101095","DOIUrl":"10.1016/j.ijft.2025.101095","url":null,"abstract":"<div><div>The examination of heat transfer aspects in Casson fluid equipped in cavities is considered important for improved coating, molding, extrusion, designing systems with high efficiency, enhancing medical applications, and understanding industrial and natural processes. Therefore, exploring the heat transfer in Casson remains of great interest to researchers. Owning to such interest we offer artificial neural networks study of heat transfer aspects in partially heated hexagonal cavity in the presence of natural convection and magnetic field. The cavity is rooted with a uniformly heated Y-shaped fin. The lower wall is hot while the top wall is considered an adiabatic. Left and right walls are taken cold. The flow equations are solved by finite element method (FEM). The artificial neural network (ANN) model is trained by using the Levenberg-Marquard algorithm and the Nusselt number is estimated along the uniformly heated fin for both cases namely (i) heated tip and (ii) cold tip. This configuration demonstrates how convective currents and temperature distributions get more intricate and noticeable as the Rayleigh number increases. We noticed that uniformly heated fins effectively regulate and enhance convection, which is important for heat management applications.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101095"},"PeriodicalIF":0.0,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168155","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}