Ceramics International最新文献

{"title":"Oxidation behavior of supersonic air plasma sprayed Yb2SiO5/Si and Yb2Si2O7/Si coating for CVD-SiC coated C/C composites in wet oxygen at 1773 K: Experimental and first-principle calculation","authors":"Wenhan Gai ,&nbsp;Yulei Zhang ,&nbsp;Jian Zhang ,&nbsp;Hui Chen ,&nbsp;Guohui Chen ,&nbsp;Jing'an Kong","doi":"10.1016/j.ceramint.2024.12.527","DOIUrl":"10.1016/j.ceramint.2024.12.527","url":null,"abstract":"<div><div>The protective effect of Yb₂SiO₅/Si and Yb₂Si₂O₇/Si coatings on CVD-SiC coated C/C composites in high temperature wet oxygen environments was investigated by first-principle calculation and experiment, respectively. The calculation results reveal that the Yttrium silicate (Yb₂SiO₅, YbMS) phase exhibits stronger bonding energy compared to the yttrium disilicate (Yb₂Si₂O₇, YbDS) phase. Moreover, the Si-O bond within the YbMS structure is more stable under similar water vapor corrosion conditions. Consequently, the YbMS structure contributes to the formation of a thinner thermally grown oxide (TGO) and diffusion reaction layer (DRL) at the interface between the Si bond coat and YbMS topcoat under wet oxygen conditions at 1773 K. However, the higher coefficient of thermal expansion (CTE) of the YbMS coating resulted in the formation of larger penetration cracks in YbMS-coated C/C samples during cooling. After 20 h of oxidation in a water vapor environment at 1773 K, the weight change of the YbMS-coated sample was −4.374 %, while the YbDS coated sample was −0.610 %.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 11088-11096"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioactive ceramic-coated carbon black particles/Polycaprolactone membranes for guided bone regeneration: Preparation, characterization and in vitro performance","authors":"Hnin Nandar Soe ,&nbsp;Matthana Khangkhamano ,&nbsp;Jirut Meesane ,&nbsp;Rungrote Kokoo ,&nbsp;Sittichat Chukaew ,&nbsp;Si Thu Myint Maung","doi":"10.1016/j.ceramint.2025.01.018","DOIUrl":"10.1016/j.ceramint.2025.01.018","url":null,"abstract":"<div><div>Barrier membranes are normally employed in guided bone regeneration (GBR) procedures to facilitate bone tissue regeneration at the defect site. Despite being a suitable material for this purpose, polycaprolactone (PCL) is limited in clinical use due to its low degradation rate, inadequate wettability and bioactivity, and poor mechanical properties. This study explored TiC/TiO₂/SrCO₃-coated carbon black particles (TSrCB), a newly introduced bioactive nanocomposite agent, incorporated into PCL matrices as alternative barrier membranes for GBR. The research investigated the impact of TSrCB on the structural, physical, mechanical, thermal, and biological properties of PCL matrices. TSrCB particles were synthesized via molten salt synthesis and hydrothermal process before being incorporated into PCL for membrane fabrication using a solvent casting technique. Varying particle contents were tested. Results showed that adding TSrCB particles into PCL improved mechanical properties, degradation rate, and biological performance, including cell proliferation, adhesion, and protein synthesis in the nanoparticles membranes. Significant enhancement in physical, mechanical, and biological functions was noticed with higher TSrCB contents. The membrane with 20 % particle content was identified as a promising candidate for GBR.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 11634-11648"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interinfluence of film structures like ferroelectric membranes","authors":"E.I. Goldman,&nbsp;G.V. Chucheva,&nbsp;M.S. Afanasiev,&nbsp;D.A. Belorusov","doi":"10.1016/j.ceramint.2025.01.022","DOIUrl":"10.1016/j.ceramint.2025.01.022","url":null,"abstract":"<div><div>An interinfluence effect of neighboring metal-ferroelectric-semiconductor (MFS) membrane structures synthesized on the common insulating layer was found. Different voltages applied to the field electrodes of the two adjacent structures produce, in the free-of-substrate ferroelectric film surrounding the elements, common inhomogeneous deformation and polarization fields through which the interinfluence occurs. The interinfluence phenomenon is strong enough: the HF capacity of the MFS object increases by up to 3 times after applying an up to 5 V bias to the adjacent similar element for which the C–V characteristics are measured. The interinfluence phenomenon was observed in thin-substrate structures whose geometry was far from that of perfect membranes: the thickness of the ferroelectric layer was 66 times smaller than that of the semiconductor. Interinfluence shows itself at each hysteresis loop of the MFS structure C–V characteristic in the transition section between the two plateaus. The capacity of the test specimen increases with the absolute bias value and depends but slightly on the bias polarity applied to the adjacent object.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 11684-11689"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation and mechanical properties of jute fiber knit-derived SiC composites prepared by Si slurry infiltration","authors":"Min Yu ,&nbsp;Chenxin Shen ,&nbsp;Zeya Huang ,&nbsp;Renli Fu ,&nbsp;Wei Zhong ,&nbsp;Dou Zhang","doi":"10.1016/j.ceramint.2024.11.206","DOIUrl":"10.1016/j.ceramint.2024.11.206","url":null,"abstract":"<div><div>Bioinspired SiC composites have great potential applications in fields such as electromagnetic shielding, catalytic filtration, aerospace, etc. The jute fiber knit-derived C-SiC composites were successfully prepared by slurry impregnation method combined with two densification routes (route 1: impregnation with carbon powders slurry, route 2: impregnation with PCS (polycarbosilane) slurry) were used to further densify the composites. Effects of impregnation times, sintering temperatures and densification routes on the microstructures and mechanical properties of the composites were investigated in details. The compressive strength of composites increased from 1.6 ± 0.2 MPa to 2.8 ± 0.4 MPa, with the sintering temperatures increasing from 1400 °C to 1600 °C. This might result from the higher crystallinity of SiC formed in composites at 1600 °C. The composites prepared by densification route 1 exhibited the highest compressive strength of 7.1 ± 1.7 MPa, which was ∼253.6 % higher than the non-densified composites (2.8 ± 0.4 MPa). This might result from a small porosity, a thick silicon carbide layer (0.8–1.1 μm) and particles formed in composites, leading to reinforcement. In addition, the composites sintered at 1600 °C exhibited an increased compressive strength by ∼219.2 % (from 2.6 MPa to 8.3 MPa), after high-temperature oxidation at 1400 °C. The flexural strength of composites increased from 2.5 ± 0.2 MPa to 4.2 ± 0.5 MPa, with the sintering temperatures increasing from 1400 °C to 1600 °C. This might result from the high crystallinity of SiC formed, leading to the crack deflection. The composites prepared by densification route 2 showed the highest flexural strength of 10.6 ± 1.3 MPa, which was ∼252.4 % higher than the non-densified composites (4.2 ± 0.5 MPa). Therefore, the combination of slurry impregnation and densification routes provides a viable route to improve the mechanical properties of the composites.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 10984-10997"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermoluminescence characterization of europium doped gadolinium aluminum borate phosphors: Impacts of europium doping under beta irradiation","authors":"O. Madkhali","doi":"10.1016/j.ceramint.2025.01.015","DOIUrl":"10.1016/j.ceramint.2025.01.015","url":null,"abstract":"<div><div>In this study, the thermoluminescence (TL) characteristics and kinetic parameters of Eu³⁺ activated GdAl₃(BO₃)₄ (GAB), synthesized via the sol-gel method, were examined. The impact of Eu³⁺ doping on the crystal structure of undoped GAB was analysed using X-ray diffraction (XRD). The doped GAB retained its rhombohedral crystal structure, consistent with the PDF#72–1985 standard. The glow curves of the Eu³⁺ doped GAB phosphors revealed three distinct peaks at approximately 86 °C, 185 °C, and 300 °C. Among these, the phosphor with the highest TL sensitivity was 1 wt% Eu-doped GAB. The optimal heating regime to erase the TL signal at the 86 °C peak was determined to be heating 135 °C for 16 s. The TL signal exhibited a fading of 14.71 % over three-month period. The minimum detectable dose (MDD) was calculated to be 1.290 ± 0.02 mGy, indicating its suitability for low radiation dosimetry. The dose response of the phosphor showed linearity over a wide range of doses (2–300 Gy), with the phosphor's sensitivity remaining stable across the tested dose range. E_a-T_stop analysis identified six peaks with activation energies ranging between 0.99 eV and 1.18 eV, further confirming material's suitability for dosimetry applications.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 11603-11617"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing thermal stability and structural integrity in polystyrene nanocomposites with rutile TiO₂ nanoparticles","authors":"A. Rahimli ,&nbsp;A. Huseynova ,&nbsp;R. Alekberov ,&nbsp;M. Jafarov","doi":"10.1016/j.ceramint.2025.01.016","DOIUrl":"10.1016/j.ceramint.2025.01.016","url":null,"abstract":"<div><div>The structural, thermal, and optical properties of TiO₂/Polystyrene (PS) nanocomposites were investigated to understand the effects of incorporating rutile-phase TiO₂ nanoparticles. The nanocomposites were synthesized using a solution mixing method followed by hot pressing. Structural analysis, employing both Scherrer's and Williamson-Hall methods, revealed that the crystallite size increased and strain decreased as TiO₂ content increased, indicating a structural evolution. SEM-EDX analysis confirmed uniform distribution of TiO₂ within the PS matrix. Thermal analysis via DSC showed a significant increase in the melting temperature (Tm), rising by up to 41 °C, reflecting enhanced thermal stability due to restricted polymer chain mobility. The glass transition temperature (T_g) also increased, suggesting stronger interfacial interactions between TiO₂ and PS. TGA results demonstrated improved thermal stability, with a significant shift in decomposition temperatures from 450 °C for pure PS to 480 °C for PS/10 % TiO₂, highlighting the positive effect of TiO₂ nanoparticles in enhancing the heat resistance of the nanocomposites. Activation energy calculations using Kissinger and Arrhenius models further revealed that TiO₂ nanoparticles act as thermal barriers, significantly increasing the energy barrier for thermal decomposition. This work highlights the potential of TiO₂/PS nanocomposites for use in protective coatings, packaging, and optoelectronic devices, and provides valuable insights into designing high-performance, sustainable polymer nanocomposites for industrial applications.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 11618-11626"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal diffusivity and conductivity of ceramics based on the GdFeO3– GdCrO3 system","authors":"K.M. Kenges ,&nbsp;M.O. Enikeeva ,&nbsp;M.V. Tomovich ,&nbsp;Е.А. Тugova","doi":"10.1016/j.ceramint.2025.01.171","DOIUrl":"10.1016/j.ceramint.2025.01.171","url":null,"abstract":"<div><div>Gadolinium ferrochromites were successfully synthesized as continuous solid solutions in the GdFeO₃ – GdCrO₃ system via solid-state reaction. Structural and microstructure analyses revealed the formation of an orthorhombic perovskite-type phase with isometric chain-like grains. SEM data demonstrated a systematic decrease in the average grain size, from ∼9.0 μm to ∼2.0 μm, as the Cr content increased. The thermal properties, including thermal diffusivity and thermal conductivity, were investigated using the laser-flash diffusivity method. Thermal diffusivity was observed to decrease with increasing Cr substitution, consistent with enhanced phonon scattering induced by finer grains and increased porosity. Compositions with <em>x</em> = 0.50 and 0.77, sintered at 1400 °C for 24 <em>h</em>, exhibited optimal thermal insulation properties, characterized by porosity levels of 44–48 % and thermal conductivities of 0.6–0.7 W/(m∗K) at room temperature. These findings demonstrate that the microstructure and thermal properties of GdFe_1-xCr_<em>x</em>O₃ oxides can be tuned through Cr doping, making them promising candidates for thermal insulation applications in high-temperature conditions.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 10","pages":"Pages 13271-13276"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Si3N4 powder modified by sebacic acid on slurry properties and oxygen content of ceramics","authors":"Ziyu Liu ,&nbsp;Haolin Dong ,&nbsp;Huangyang Luo ,&nbsp;Xiaole Yang ,&nbsp;Peng Liu ,&nbsp;Yuanbing Li ,&nbsp;Xianfeng Yang","doi":"10.1016/j.ceramint.2025.01.172","DOIUrl":"10.1016/j.ceramint.2025.01.172","url":null,"abstract":"<div><div>The silicon nitride (Si₃N₄) powders were modified using sebacic acid for aqueous tape casting to fabricate Si₃N₄ ceramic substrates. The effects of the powder modification on the chemical composition, slurry properties and the oxygen content of ceramics were investigated systematically. New organic groups from sebacic acid appear on Si₃N₄ powder surfaces by graft or adsorption and the dehydration-condensation reaction is weak. The slurry from the modified Si₃N₄ powder with more sebacic acid possesses a lower ΔpH, higher absolute value of zeta potential, stronger absorbance and lower viscosity, improving the hydrolysis resistance, dispersibility, stability and solid content successfully of aqueous suspensions. Si₃N₄ ceramic substrates fabricated at 1850 °C under nitrogen atmosphere from the corresponding aqueous casting tapes have the lowest oxygen content of 0.13 wt%, demonstrating that the modification of Si₃N₄ powders by sebacic acid shows great potential for the aqueous tape casting to fabricate Si₃N₄ ceramic substrates.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 10","pages":"Pages 13277-13287"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of hydrophobic zirconia ceramic mould inserts through the integration of self-assembled monolayer modification and stereolithography 3D printing technology","authors":"Yan Lou ,&nbsp;Qingke Yu ,&nbsp;Jiangtao Yu ,&nbsp;Piao Qv ,&nbsp;Guijian Huang ,&nbsp;Mingyu Liu","doi":"10.1016/j.ceramint.2024.12.531","DOIUrl":"10.1016/j.ceramint.2024.12.531","url":null,"abstract":"<div><div>Microstructured ceramic mould inserts face significant challenges in practical applications due to their hydrophilicity. Self-assembled monolayers (SAMs), recognized as a promising surface modification technology for micro-nanostructured surfaces, offer a potential solution to this issue. Meanwhile, stereolithography (SLA) 3D printing, with its exceptional flexibility and precise manufacturing capabilities for complex structures, is particularly well-suited for applications in micro-nanostructured moulds. This study proposes a novel method for fabricating hydrophobic zirconia microstructured mould inserts by combining SLA 3D printing with SAM modification. The results show that phosphonic acid SAMs significantly reduce the surface free energy of zirconia ceramics, transforming the surface from hydrophilic to hydrophobic and increasing the water contact angle by 114.8 %. Compared to commercial zirconia ceramics, SAM technology demonstrates superior modification effects on 3D-printed zirconia surfaces, achieving over twofold improvements in hydrophobicity and frictional properties. Among the three SAMs with varying chain lengths, short-chain hexyl phosphonic acid (HPA) SAMs exhibit the highest molecular packing density and order. Additionally, phosphonic acid SAMs significantly reduce the friction coefficient of 3D-printed zirconia, effectively minimizing surface fatigue and wear while enhancing wear resistance. The study identifies molecular packing density and order as critical factors influencing surface wettability, friction performance, and stability, with these properties improving consistently with greater packing density and order. Finally, zirconia microstructured mould inserts modified with HPA SAMs successfully injection-moulded polypropylene (PP) micro-cylinders with a diameter of 650 μm and a height of 1195 μm, achieving automatic demoulding. This study highlights the potential of 3D-printed zirconia moulds in practical applications, offering new directions for innovation in this field.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 11121-11135"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic anti-corrosion of self-healing microcapsule hybridized by MgAl LDHs-NO2: A combined experimental and DFT approach","authors":"Jielu Zhu ,&nbsp;Lina Xiao ,&nbsp;Weiwei Zhang ,&nbsp;Ruifeng Cheng ,&nbsp;Bingzhi Xiang ,&nbsp;Junwei Song ,&nbsp;Haijiao Xie","doi":"10.1016/j.ceramint.2024.12.534","DOIUrl":"10.1016/j.ceramint.2024.12.534","url":null,"abstract":"<div><div>The anti-corrosion of the steel bar is greatly reduced by the coupling effect of matrix microcracks and chlorides. To realize the synergistic anti-corrosion of cement-based materials through self-healing, chlorine binding and corrosion inhibition, the self-healing microcapsule was hybridized by MgAl LDHs-NO₂. The agglomeration of LDHs and the synergistic anti-corrosion of cement-based materials have been effectively solved by this work. The anti-corrosion properties and mechanism of microcapsules were revealed by experiments and DFT calculations. The results demonstrated that the microcapsules were well dispersed. The average particle sizes of SM, HM10 and HM20 were 91.24, 126.52 and 143.94 μm, respectively. The appropriate dosage of microcapsules optimizes the internal pores of mortar and improves the compactness and resistance to chloride ion penetration of cement-based materials. The highest impermeability recovery ratio and healing ratio of cement-based materials doped with microcapsules were 112.46 % and 23.28 %, respectively. The chlorine binding capacity of the cement paste was increased by 22.5 % and 40.2 % for 3 % and 6 % microcapsule dosage, respectively. The highest protection efficiency of electrochemical samples mixed with microcapsules was 97.84 %. The anti-corrosion property was improved by the synergistic effect of hybridized microcapsules with the core-wall structure. The electron charge recombination of LDHs-NO₂@EC hybridized microcapsule was confirmed by XPS characterization and DFT calculation, and Bader charge analysis showed that LDHs-NO₂ migrated out of the electron charge is 2.12 e⁻. The LDHs-NO₂ component of the wall showed persistent and targeted anti-corrosion effect. The microcapsule is triggered by the extended microcrack, and the matrix microcrack is healed by the generated polymer.</div></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":"51 9","pages":"Pages 11159-11173"},"PeriodicalIF":5.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}