ACS Applied Electronic Materials最新文献

{"title":"Analysis of Leaky Integrate-and-Fire Neuron Using Al2O3/Si3N4 Gate Insulator Stack for Spiking Neural Network","authors":"Min-Kyu Park,&nbsp;Joon Hwang,&nbsp;Jonghyun Ko,&nbsp;Jeonghyun Kim,&nbsp;Jong-Ho Bae and Jong-Ho Lee*,&nbsp;","doi":"10.1021/acsaelm.4c0140810.1021/acsaelm.4c01408","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01408https://doi.org/10.1021/acsaelm.4c01408","url":null,"abstract":"<p >Leaky integrate-and-fire (LIF)-based spiking neural networks (SNNs) are analyzed using a field-effect transistor (FET)-type neuron device with a charge trap insulator stack (Al₂O₃/Si₃N₄). By using both the memory functionality and the poor retention characteristic of the device, we successfully implemented the LIF function. SPICE modeling of the device and LIF circuit demonstrated that the large membrane capacitor in a neuron circuit could be replaced, which promises a smaller area and lower energy consumption (∼0.3 pJ/spike). Based on the measured properties, spiking neural networks are simulated to find the optimal leaky constant while maintaining a low operational voltage.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":"6 11","pages":"7728–7733 7728–7733"},"PeriodicalIF":4.3,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and Application of Joule Heating Processes for Decarbonized Chemical and Advanced Material Synthesis","authors":"Anthony Griffin,&nbsp;Mark Robertson,&nbsp;Zoe Gunter,&nbsp;Amy Coronado,&nbsp;Yizhi Xiang and Zhe Qiang*,&nbsp;","doi":"10.1021/acs.iecr.4c0246010.1021/acs.iecr.4c02460","DOIUrl":"https://doi.org/10.1021/acs.iecr.4c02460https://doi.org/10.1021/acs.iecr.4c02460","url":null,"abstract":"<p >Atmospheric CO₂ concentrations keep increasing at intensifying rates due to rising energy and material demands. The chemical production industry is a large energy consumer, responsible for up to 935 Mt of CO₂ emissions per year, and decarbonization is its major goal moving forward. One of the primary sources of energy consumption and CO₂ emissions in the chemical sector is associated with the production and use of heat for material synthesis, which conventionally was generated through the combustion of fossil fuels. To address this grand challenge, Joule heating has emerged as an alternative heating method that greatly increases process efficiency, reducing both energy consumption and greenhouse gas emissions. In this Review, we discuss the key concepts that govern these Joule heating processes including material selection and reactor design, as well as the current state-of-the-art in the literature for employing these processes to synthesize commodity chemicals along with advanced materials such as graphene, metal species, and metal carbides. Finally, we provide a perspective on future research avenues within this field, which can facilitate the widespread adoption of Joule heating for decarbonizing industrial processes.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":"63 45","pages":"19398–19417 19398–19417"},"PeriodicalIF":3.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.iecr.4c02460","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142608281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Designing Amine-Based Capture Units Onboard LNG-Run Ships","authors":"Anikesh Kumar,&nbsp;Preethi Sridhar,&nbsp;Shamsuzzaman Farooq* and Iftekhar A. Karimi*,&nbsp;","doi":"10.1021/acs.iecr.4c0194710.1021/acs.iecr.4c01947","DOIUrl":"https://doi.org/10.1021/acs.iecr.4c01947https://doi.org/10.1021/acs.iecr.4c01947","url":null,"abstract":"<p >Efficient CO₂ capture onboard ships is a vital step in mitigating maritime emissions. In our previous work, we showed that amine-based absorption is the best prospect for onboard capture, and ships powered by LNG are better suited than those using HFO. Hence, in this work, an extensive design for amine-based absorption onboard LNG-run ships with different flue gas conditions (flow rate, temperature, and composition) as well as maximum CO₂ storage capacity and number of days at sea is presented. The design comprises discussions on the selection of key variables for separation, e.g., the dimensions of the absorber and regenerator column and solvent flow rate, as well as the selection of optimal CO₂ storage conditions. Additionally, the best configuration for cold energy integration to minimize the extra power demand for the CO₂ compression is also assessed. The design is based on 90% recovery of CO₂ from the total flue gas to be processed, including emissions stemming from extra fuel burned to fulfill the energy deficit for solvent regeneration and the power demand for CO₂ compression. To this end, a novel noniterative approach to calculate total flue gas to be processed as a function of the flue gas conditions under optimized design conditions is also developed. Lastly, cargo losses from the installation of the capture unit are also presented. In summary, the study intends to provide ship owners with a comprehensive design guide for the installation of an amine-based absorption unit. To illustrate the utility of the study, case studies are presented using reference ships available in the literature.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":"63 45","pages":"19600–19612 19600–19612"},"PeriodicalIF":3.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142608058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polyethylenimine-Supported rGO Conformal Coating over AgNWs to Fabricate Strongly Stable and Flexible Transparent Heaters","authors":"Parinita Changkakoty,&nbsp;Esther Dimngaihvungi,&nbsp;Manjeet Singh*,&nbsp;Atul Kumar Singh and Ashish Kumar Singh*,&nbsp;","doi":"10.1021/acsaelm.4c0162510.1021/acsaelm.4c01625","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01625https://doi.org/10.1021/acsaelm.4c01625","url":null,"abstract":"<p >Recently, reduced graphene oxide (rGO)-overcoated AgNW films have emerged as high-quality flexible transparent electrodes (FTEs). Although the rGO overcoating provides stability against AgNW oxidation and adds some conductivity to the FTE, poor adhesion of rGO with AgNWs remains a challenge to fabricate a high-quality and ultrastable AgNW-based FTE. Due to the large flake size of rGO and its hydrophobic nature, it tends to aggregate when suspended in the water to make ink for coating, which inhibits the formation of a strong conformal coating around the surface of AgNWs. In order to achieve a strong conformal coating over the AgNWs and to increase the adhesion of rGO with AgNWs, a high-quality ink solution of rGO is desirable. In this work, an ink solution of probe-sonicated nanoscale rGO in water is prepared with the support of polyethylenimine (PEI). The electrostatic interactions between rGO and PEI resulted in a suspension that remained stable for several months. The rGO–PEI overcoating ensures uniform coverage of AgNWs, thus providing high conductivity and exceptional stability to the AgNW-based FTE. The PEI-supported rGO coating over the AgNW network delivered a FTE with a sheet resistance (<i>R</i>_s) of 18.4 ± 0.92 Ω/sq with 85% transmittance at 550 nm. The flexible transparent heater using FTE prepared on the PET substrate demonstrated excellent transparent heater properties and exhibited a temperature increase up to 160 °C in 60 s at an applied voltage of only 4 V, which is very suitable for antifogging applications on any curved object.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":"6 11","pages":"8424–8436 8424–8436"},"PeriodicalIF":4.3,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fatigue Behavior of Polymer Nanocomposites under Low-Strain Cyclic Loading: Insights from Molecular Dynamics Simulation","authors":"Tongkui Yue,&nbsp;Hengheng Zhao,&nbsp;Jiajun Qu,&nbsp;Liqun Zhang and Jun Liu*,&nbsp;","doi":"10.1021/acs.langmuir.4c0276910.1021/acs.langmuir.4c02769","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c02769https://doi.org/10.1021/acs.langmuir.4c02769","url":null,"abstract":"<p >Understanding the structural evolution and bond-breaking behavior under cyclic loading is crucial for designing polymer nanocomposites (PNCs) with superior fatigue resistance. Coarse-grained models of PNCs filled with spherical carbon black nanoparticles (NPs) at varying filling fractions of φ were successfully constructed using molecular dynamics simulations. Structural and dynamic simulation results reveal that higher φ leads to increased aggregation of NPs and markedly restricts the relaxation behavior of the polymer matrix. Subsequently, fatigue testing of PNCs was conducted under low-strain cyclic tensile deformation, and the real-time bond-breaking behavior was tracked. The decay behavior of the bond number autocorrelation function was found to be accurately described by the KWW equation, enabling precise determination of the characteristic lifetime τ_<i>f</i>. With increasing φ, the dominant factor influencing bond-breaking behavior gradually shifts from the polymer network, including entanglements and cross-linking networks, to the filler network. This suggests the presence of a critical filling fraction φ_<i>c</i> where τ_<i>f</i> is maximized. For low-strain failure mechanisms, temperature field observations at varying cycles reveal that localized temperature rise emerges as the predominant factor. Furthermore, the mobility of both polymers and NPs increases with cycles. Specifically, the diffusion coefficient of polymer monomers shows a clear power-law relationship with the bond-breaking rate, characterized by <i></i><math><mi>D</mi><mo>∼</mo><msup><msub><mi>f</mi><mi>broken</mi></msub><mn>1.5</mn></msup></math>. Finally, the stiffness of polymer chains significantly influences the fatigue behavior, evidenced by an initial increase followed by a decrease in the τ_<i>f</i> with increasing bending energy <i>k</i>. This behavior is attributed to the competitive relationship between high entanglement density at low <i>k</i> and enhanced preorientation at high <i>k</i>. In summary, this study provides a general paradigm for describing failure behavior under cyclic deformation and offers insights into fatigue mechanisms at the molecular level, thereby guiding the development of improved fatigue-resistant PNCs.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":"40 45","pages":"23816–23824 23816–23824"},"PeriodicalIF":3.7,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142608612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermally Bisignate Anion Responsive Supramolecular Gel and In Situ Generation of a Conductive Hybrid-Gel Nanocomposite","authors":"Oiyao Appun Pegu,&nbsp; and ,&nbsp;Gopal Das*,&nbsp;","doi":"10.1021/acs.langmuir.4c0347010.1021/acs.langmuir.4c03470","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03470https://doi.org/10.1021/acs.langmuir.4c03470","url":null,"abstract":"<p >Understanding the structure–function relationship is a significant challenge in designing supramolecular soft materials such as supramolecular gels. To address this challenge, we report on two urea-based dipodal ligands, <b>PY-NAP</b> and <b>PY-CF</b>_<b>3</b>, with different terminal substituents influencing their gelation properties. The terminal substituents play a crucial role in the gelation abilities. The gel formed from <b>PY-NAP</b> exhibited notably high thermal stability and displayed a unique “thermally bisignate” behavior. Both ligands contain urea and amide units, allowing them to encapsulate the SO₄^2– anion in their pincer cavities in the solid state. The solid-state anion recognition principle is used to construct a selective anion-responsive supramolecular gel. Additionally, the gel was used to sequester precious metal salts from aqueous solutions, achieving an uptake efficiency of over 90%, followed by <i>in situ</i> reduction to form nanoparticles. This concept was then applied to create a conductive supramolecular hybrid gel nanocomposite with significantly high conductivity, holding significant implications for industrial and environmental applications.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":"40 45","pages":"24095–24105 24095–24105"},"PeriodicalIF":3.7,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142608010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into Energetic Penalties in Electrochemical CO2 Separation Systems","authors":"Lauren E. Clarke,&nbsp;Katelyn M. Ripley and Fikile R. Brushett*,&nbsp;","doi":"10.1021/acs.iecr.4c0176310.1021/acs.iecr.4c01763","DOIUrl":"https://doi.org/10.1021/acs.iecr.4c01763https://doi.org/10.1021/acs.iecr.4c01763","url":null,"abstract":"<p >While innovative electrochemical approaches continue to emerge for carbon capture, open questions remain regarding the performance characteristics of these nascent concepts. A wide range of energy requirements have been reported; the different sources of performance loss and their relative magnitudes are not yet fully understood, challenging both quantitative comparisons between devices and identification of performance improvement pathways. Herein, we develop a mathematical framework to evaluate the energetics of four-stage electrochemical separation systems in which soluble capture chemistries are activated and deactivated in an electrochemical reactor, and the liquid capture medium absorbs and desorbs carbon dioxide (CO₂) in separate units. Specifically, we construct a dimensionless electrochemical reactor model, derive key groups associated with thermodynamics, kinetics, ohmic resistance, and mass transport, and, subsequently, evaluate their impact on energetic penalties. We also discuss the use of this model for exploring different performance improvement pathways. Ultimately, this work seeks to facilitate understanding of the interplay between material properties, operating conditions, and energy requirements.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":"63 45","pages":"19707–19727 19707–19727"},"PeriodicalIF":3.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142608080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mixed Halide Passivation of AgBiS2 Quantum Dots for High-Performance Photodetectors","authors":"Defei Yuan,&nbsp;Zeyao Han,&nbsp;Fa Cao*,&nbsp;Xiao Liu,&nbsp;Mei Liu,&nbsp;Li Zhang,&nbsp;Shuang Cao,&nbsp;Junyu Li,&nbsp;Tao Zeng,&nbsp;Yunxia Chen,&nbsp;Xiaobao Xu and Bin Sun*,&nbsp;","doi":"10.1021/acsaelm.4c0164410.1021/acsaelm.4c01644","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01644https://doi.org/10.1021/acsaelm.4c01644","url":null,"abstract":"<p >AgBiS₂ quantum dots (QDs) have been undergoing rapid development in recent years because of their environmental friendliness, abundant elemental reserves, and high optical absorption coefficients. However, previously reported ligand exchange methods for AgBiS₂ CQDs have been ineffective in passivating surface defects, thereby limiting their potential for optoelectronic applications. In this study, we propose a facile solution-phase ligand exchange method assisted by mixed halides for the AgBiS₂ CQDs. This approach, involving AgCl and other halides, effectively suppresses surface defects and enhances the photodetector (PD) performance. The PD exhibits significantly improved optoelectronic characteristics, with a responsivity of 0.27 A W^–¹ and a low noise power density of 6.52 × 10^–9 A Hz^–0.5, achieving the highest specific detectivity of 2 × 10¹² Jones compared to previous reports of AgBiS₂ CQD PDs. This mixed halide passivation strategy introduces new insights into enhancing the performance of AgBiS₂ CQDs in PD applications.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":"6 11","pages":"8455–8462 8455–8462"},"PeriodicalIF":4.3,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydroxyl-Poor Al2O3 Avoids the Formation of ZnAl2O4 Spinel for Propane Dehydrogenation","authors":"Zhiyuan Wang,&nbsp;Hongyin Chen,&nbsp;Shaojia Song*,&nbsp;Bowen Liu,&nbsp;Weiyu Song*,&nbsp;Lin Li and Jian Liu,&nbsp;","doi":"10.1021/acs.iecr.4c0238910.1021/acs.iecr.4c02389","DOIUrl":"https://doi.org/10.1021/acs.iecr.4c02389https://doi.org/10.1021/acs.iecr.4c02389","url":null,"abstract":"<p >Zinc-based catalysts offer the advantages of high catalytic activity, low cost, and low toxicity, which are deemed as promising alternatives for Pt- and CrO_<i>x</i>-based catalysts toward propane dehydrogenation (PDH). However, ZnO/Al₂O₃ is prone to form the ZnAl₂O₄ spinel phase at high temperatures, which limits the further utilization of Zn-based propane dehydrogenation catalysts. Here, the reason for the formation of ZnAl₂O₄ is investigated by changing the calcination atmosphere. XRD, Raman, XPS, UV–vis, and H₂-FTIR characterizations and density functional calculations show that hydroxyl-rich Al₂O₃ promotes the formation of the ZnAl₂O₄ spinel phase. In order to avoid the formation of ZnAl₂O₄ spinel, a sol–gel method was employed to synthesize hydroxyl-poor Al₂O₃, which inhibited ZnAl₂O₄ formation and enabled Zn species to mainly exist in the form of ZnO nanoclusters after calcination. As a result, hydroxyl-poor Al₂O₃-supported ZnO exhibited better PDH performance than the case with hydroxyl-rich Al₂O₃ supports. Combined with quantitative XPS calculations, ZnO was shown to be a more efficient active center for ZnO/Al₂O₃ systems in the PDH reaction.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":"63 45","pages":"19457–19465 19457–19465"},"PeriodicalIF":3.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142608158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical Process for Li-Ion Battery Recycling from Electric Vehicles","authors":"Daniela Romero Guillén*,&nbsp;Júlia Guimarães Sanches,&nbsp;Amilton Barbosa Botelho Junior,&nbsp;Luciana Assis Gobo,&nbsp;Maurício Guimarães Bergerman,&nbsp;Denise Crocce Romano Espinosa and Jorge Alberto Soares Tenório,&nbsp;","doi":"10.1021/acs.iecr.4c0327110.1021/acs.iecr.4c03271","DOIUrl":"https://doi.org/10.1021/acs.iecr.4c03271https://doi.org/10.1021/acs.iecr.4c03271","url":null,"abstract":"<p >The increasing demand for Li-ion batteries driven by the demand of electric vehicles has led to a shortage of critical raw materials. Recycling has therefore become an alternative for natural resource conservation and supply of critical materials throughout the circular economy. The aim of this work was to propose an integrated physical processing route for recycling different Li-ion battery cells (pouch, cylindrical, and prismatic) and cathodes (NMC and NMC-LMO) for hydrometallurgical treatment in a single route. Different physical separation techniques, including attrition cell, dense medium separation, sieving, magnetic, and electrostatic separation, were evaluated to identify the advantages of each method in material separation. Resulting products can be highlighted as the Cu-rich fraction, Al + cathode material, plastic fraction, graphite + cathode fraction, external structure/case of battery cells, and Li solution. There is no use of heat treatment in the process. Different purities were obtained according to the battery type: 65–80% of Cu stream and over 96% of cathode material in Al + cathode streams. The process separated all plastic and external structures into different streams without contaminations. The Al and graphite + cathode streams can be further processed with a hydrometallurgical process to obtain high-purity salts.</p>","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":"63 45","pages":"19788–19803 19788–19803"},"PeriodicalIF":3.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.iecr.4c03271","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142608057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}