Physica status solidi (A): Applied research最新文献_第2页

Detection of Harmful Chemical Compounds in Plastic Products Using a High‐Sensitivity Photonic Crystal‐Based Sensor 利用高灵敏度光子晶体传感器检测塑料制品中的有害化合物

Physica status solidi (A): Applied research Pub Date : 2023-08-27 DOI: 10.1002/pssa.202300547

S. Taya, Samer M. Srour, A. Almawgani, A. Hindi, I. Colak, S. Patel

{"title":"Detection of Harmful Chemical Compounds in Plastic Products Using a High‐Sensitivity Photonic Crystal‐Based Sensor","authors":"S. Taya, Samer M. Srour, A. Almawgani, A. Hindi, I. Colak, S. Patel","doi":"10.1002/pssa.202300547","DOIUrl":"https://doi.org/10.1002/pssa.202300547","url":null,"abstract":"The use of plastics can be dangerous due to the numerous industrial chemicals they contain. Di(2‐ethylhexyl) phthalate (DEHP), bisphenol A (BPA), and bisphenol S (BPS) are three detrimental organic chemicals that are used in the plastic industry. In this work, a highly sensitive photonic crystal (PCL) sensor is theoretically proposed and numerically simulated as a detector for DEHP, BPA, and BPS organic chemicals. The proposed PCL is a 1D that has the structure (GaAs/Si3N4/TiN)N/cavity layer/(GaAs/Si3N4/TiN)N, where N is the number of unit cells (UCs). The DEHP, BPA, and BPS analytes are assumed to be separately infiltrated into the cavity layer between two equal numbers of the UCs. The transmission spectra of the PCL are studied using the transfer matrix (TrMx) technique. The most important performance parameter is sensitivity so we have focused on it. A considerable sensitivity enhancement is obtained by raising the defect layer thickness and incidence angle. High sensitivities of 2350.51, 2168.45, and 2042.08 nm RIU−1 are obtained for DEHP, BPA, and BPS, respectively. In the results obtained, the way can be paved for a simple technique to detect chemical compounds.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87112101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fabrication of solid‐state dye‐sensitized solar cells by controlled evaporation of solvents for creation of facile charge transport pathway 通过控制溶剂蒸发制备固态染料敏化太阳能电池，以创造易电荷传输途径

Physica status solidi (A): Applied research Pub Date : 2023-08-27 DOI: 10.1002/pssa.202300116

Y. Kurokawa, T. Kato, S. Pandey

{"title":"Fabrication of solid‐state dye‐sensitized solar cells by controlled evaporation of solvents for creation of facile charge transport pathway","authors":"Y. Kurokawa, T. Kato, S. Pandey","doi":"10.1002/pssa.202300116","DOIUrl":"https://doi.org/10.1002/pssa.202300116","url":null,"abstract":"Solid‐state dye‐sensitized solar cells (ss‐DSSCs) based on MK‐2 dye‐sensitized TiO2 photoanode and the most commonly used I‐/I3\u0000‐ redox electrolyte were successfully fabricated by the simple method of solidification of the injected liquid electrolyte under slow solvent evaporation. The use of the ionic liquid, which is solid at room temperature, and slow evaporation of solvent at low temperature was a key step for solidification towards the fabrication of ss‐DSSCs. It has been demonstrated that ss‐DSSCs thus fabricated not only retains about 80 % of photoconversion efficiency (PCE) as compared to their liquid‐state DSSCs counterpart but also maintain the device stability for more than 1000 hours. PCE of the ss‐DSSCs was found to increase as a function of the increasing concentration of the ionic liquid used for electrolyte preparation. The ionic liquid concentration of 1.2 M, there was a good balance between PCE and durability leading to not only retention of about 70% of PCE as compared to its liquid‐state DSSCs counterparts but also maintaining the stability of the solar cell for more than 1000 hours stored at room temperature.This article is protected by copyright. All rights reserved.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90780210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimizing Strategy for Charge Injection in the Single‐Emitting‐Layer Light‐Emitting Transistor 单发射层发光晶体管电荷注入的优化策略

Physica status solidi (A): Applied research Pub Date : 2023-08-26 DOI: 10.1002/pssa.202300361

Haoxin Tian, Jun Sun, Jingzan Jiang, Shichuan Ke, Xinlu Teng, Lin Lin, Luting Yan, Z. Lou, Yanbing Hou, Yufeng Hu, F. Teng

{"title":"Optimizing Strategy for Charge Injection in the Single‐Emitting‐Layer Light‐Emitting Transistor","authors":"Haoxin Tian, Jun Sun, Jingzan Jiang, Shichuan Ke, Xinlu Teng, Lin Lin, Luting Yan, Z. Lou, Yanbing Hou, Yufeng Hu, F. Teng","doi":"10.1002/pssa.202300361","DOIUrl":"https://doi.org/10.1002/pssa.202300361","url":null,"abstract":"Herein, a single‐layer light‐emitting transistor with a good on/off ratio of more than 106 is presented based on the iridium complex as a light‐emitter layer. Comprehensive experiments and simulations demonstrate that the thickness of the emitting layer can significantly improve the majority carrier injection in the source electrode. The electrode work function determines the minority carrier injection in the drain electrode, which is crucial for the light emission of the transistor. Furthermore, the increased source injection allows for a higher channel current, thereby increasing drain injection. Most importantly, although the above methods can improve the device channel current and light‐emitting brightness, the electroluminescence efficiency cannot be optimized since the increased minority carriers are much less than the increased majority carriers, resulting in most increased majority carriers cannot be contributed to the charge recombination. To achieve a higher efficient device, the channel current is supposed to be low when a conductive channel is well formed. This goal is achieved by using an ionic liquid gate to replace SiO2 gate for fabricating the light‐emitting single‐layer transistor. The efficiency is improved from ≈0.1 to 1.5 cd A−1. This work provides a new strategy for constructing high‐performance single‐layer light‐emitting transistors.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83550476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An Inertial Noncontact Piezoelectric Rotary Energy Harvester with Linear Reciprocating Motion 线性往复运动惯性非接触压电旋转能量采集器

Physica status solidi (A): Applied research Pub Date : 2023-08-26 DOI: 10.1002/pssa.202300330

Xiaotian Zheng, Lipeng He, Shuai Jiang, Lei Sun, Zhonghua Zhang, G. Cheng

{"title":"An Inertial Noncontact Piezoelectric Rotary Energy Harvester with Linear Reciprocating Motion","authors":"Xiaotian Zheng, Lipeng He, Shuai Jiang, Lei Sun, Zhonghua Zhang, G. Cheng","doi":"10.1002/pssa.202300330","DOIUrl":"https://doi.org/10.1002/pssa.202300330","url":null,"abstract":"Herein, an inertial noncontact piezoelectric rotary energy harvester with linear reciprocating motion (L‐PREH) is presented. The existing piezoelectric rotary harvester employing gravity excitation has limited performance when the rotation speed is high due to the negative influence of centrifugal force. L‐PREH translates rotational motion into linear motion via the transmission chain and employs inertial force excitation to overcome high‐speed performance limitations. Using the Euler–Bernoulli beam theory, the motion governing equations of piezoelectric transducers have been derived, and an electromechanical coupling model has been constructed. Moreover, the piezoelectric transducer is simulated and analyzed. The control variable approach is used to explore the key parameters impacting output performance. When the mass is positioned in symmetrical method, the guide rod is fixed in noncentral place, the limiter is fixed in longest distance, the distance between the mass's center and the main frame is the maximum, and the rotating speed is 450 RPM, the maximum peak‐to‐peak output voltage of an L‐PREH single transducer is 24 V. The highest power of two piezoelectric transducers linked in parallel with a load resistance of 400 kΩ is 0.27 mW, which can light up more than 70 light‐emitting diodes. The L‐PREH can drive low‐power devices.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74577338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural, Spectroscopic, and Electrical Properties of (Ho, Mn)‐Codoped Bismuth Ferrites Synthesized Through Solid‐State Route 固态法合成(Ho, Mn)共掺杂铋铁氧体的结构、光谱和电学性质

Physica status solidi (A): Applied research Pub Date : 2023-08-25 DOI: 10.1002/pssa.202300344

Soumya G. Nair, J. Satapathy

{"title":"Structural, Spectroscopic, and Electrical Properties of (Ho, Mn)‐Codoped Bismuth Ferrites Synthesized Through Solid‐State Route","authors":"Soumya G. Nair, J. Satapathy","doi":"10.1002/pssa.202300344","DOIUrl":"https://doi.org/10.1002/pssa.202300344","url":null,"abstract":"Bismuth ferrites (BiFeO3) are popularly known as BFOs and have potential application at room temperature in present‐day material science and ceramic industry due to their multiferroic and optical properties. Synthesis methods, temperature treatments, and doping are effective for tuning the structural and multiferroic properties of BFO, among which rare earth metals in Bi‐site and transition metals in Fe‐site have shown interesting results. This work explores the synthesis and characterizations of (holmium, manganese)‐codoped BFOs where solid‐state synthesis route and some electrical analyses are the novel studies attempted herein. X‐ray diffraction results explain the structural transition from rhombohedral to mixed‐phase ordering. Grain formation and the elemental concentrations are studied using scanning electron microscopy (SEM) and energy‐dispersive ray spectra (EDAX). Electrical analysis such as dielectric behavior with respect to frequency and temperature impedance analysis is studied in detail. Polarization versus electric field (P–E) hysteresis loop shows the ferroelectric nature of the codoped sample with lossy nature and reduced remnant polarization with doping. The dielectric anomalies with frequency and temperature are analyzed in detail, and antiferromagnetic transition around Neel temperature is discussed.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83677150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced Dielectric and Mechanical Performances of the (La + Nb) Codoped TiO2/Silicone Rubber Composites (La + Nb)共掺TiO2/硅橡胶复合材料的介电性能和力学性能

Physica status solidi (A): Applied research Pub Date : 2023-08-25 DOI: 10.1002/pssa.202300462

Y. Zeng, Lu Tang, Guijin Li

引用次数: 0

CsSn0.5Ge0.5I3‐Based Lead‐Free Highly Stable Perovskite Solar Cell: Numerical Modeling for Estimating Performance Ceiling CsSn0.5Ge0.5I3基无铅高稳定钙钛矿太阳能电池:估计性能上限的数值模拟

Physica status solidi (A): Applied research Pub Date : 2023-08-25 DOI: 10.1002/pssa.202300449

M. Sujit, R. Prabu, R. Ramachandran, Atul Kumar

{"title":"CsSn0.5Ge0.5I3‐Based Lead‐Free Highly Stable Perovskite Solar Cell: Numerical Modeling for Estimating Performance Ceiling","authors":"M. Sujit, R. Prabu, R. Ramachandran, Atul Kumar","doi":"10.1002/pssa.202300449","DOIUrl":"https://doi.org/10.1002/pssa.202300449","url":null,"abstract":"CsSn0.5Ge0.5I3 perovskite is reportedly highly stable in ambient open air, lead free, and has excellent optoelectrical properties. An inverted p–i–n solar cell device based on this mixed SnGe perovskite utilizing the reported optical and electrical characteristics of the CsSn0.5Ge0.5I3 is simulated. This theoretical device under various recombination regimes to explore the performance ceiling of CsSn0.5Ge0.5I3 is put. An optimized configuration of CsSn0.5Ge0.5I3‐based perovskite solar cell shows an efficiency of 29% under the impact of only intrinsic recombination losses such as radiative (with radiative recombination coefficient of 10−11) and Auger recombination (recombination coefficient of 10−27). When extrinsic factors are considered, such as resistance losses (series resistance as high as 2 Ω cm2 and shunt resistance as low as 1000 Ω cm2), efficiency decreases to 27.5%. The efficiency is 20% when trap‐assisted Shockley–Read–Hall recombination is considered with voltage loss (V Loss) of 0.5 V. Similarly, V Loss = 0.6 V in V OC restricts device efficiency to 15%. Finally, an efficiency waterfall chart summarizes the CsSn0.5Ge0.5I3, efficiency under different extrinsic losses, and the performance loss analysis, providing an optimal design. The results summarized here are expected to be helpful and prompt experimentalists to fabricate this stable lead‐free perovskite solar cell.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80689172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Understanding Crystal Spatial Symmetry of Sm/Mg Heterovalent‐Doped BST–BNT Ceramics: An Effect Mechanism for Electrical Properties Sm/Mg杂价掺杂BST-BNT陶瓷晶体空间对称性的研究:电性能的影响机制

Physica status solidi (A): Applied research Pub Date : 2023-08-24 DOI: 10.1002/pssa.202300411

Lijia Cao, Mengshi Zeng, Xue Chen, Tiankun Liu

{"title":"Understanding Crystal Spatial Symmetry of Sm/Mg Heterovalent‐Doped BST–BNT Ceramics: An Effect Mechanism for Electrical Properties","authors":"Lijia Cao, Mengshi Zeng, Xue Chen, Tiankun Liu","doi":"10.1002/pssa.202300411","DOIUrl":"https://doi.org/10.1002/pssa.202300411","url":null,"abstract":"The effect mechanism of lattice distortion caused by heterovalent rare‐earth and alkaline‐earth ions co‐doping in the electrical properties of piezo‐ceramics is generally concerning. Herein, the Sm2O3/MgO co‐doped 0.65(Ba0.96Sr0.04TiO3)–0.35(Bi0.50Na0.50TiO3) (BST–BNT: x(Sm, Mg)) (0 ≤ x ≤ 0.25 wt%) ceramics are prepared by Pechini sol–gel method. The reversibility transition from the tetragonal P4/mmm relaxation paraelectric phase to the tetragonal P4mm relaxation ferroelectric phase confirms the doping‐modulated piezoelectric constants’ response to the spatial symmetry. Excessive Sm3+ and Mg2+ in the interstitial lattice inhibit the Jahn–Teller effect of distortion in the crystal spatial symmetry. The restored P4/mmm spatial symmetry of BST–BNT: x(Sm, Mg) (x = 0.15 wt%) ceramics contributes to the large electric‐induced strain, increased Curie temperature, and the stabilized frequency dependence of the Curie temperature (TC [1 MHz] = 167 °C, εr [1 MHz] = 2151.92, d33 = 43 pC N−1, Smax/Emax = 535.22 pm V−1). The samples with large electric‐induced strain and good temperature stability of electrical properties can be applied in the heat dissipation actuators.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75313237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gallium Oxide Heterojunction Diodes for 400 °C High‐Temperature Applications 用于400°C高温应用的氧化镓异质结二极管

Physica status solidi (A): Applied research Pub Date : 2023-08-21 DOI: 10.1002/pssa.202300535

S. H. Sohel, Ramchandra M. Kotecha, Imran S. Khan, K. Heinselman, S. Narumanchi, M. Brooks Tellekamp, A. Zakutayev

{"title":"Gallium Oxide Heterojunction Diodes for 400 °C High‐Temperature Applications","authors":"S. H. Sohel, Ramchandra M. Kotecha, Imran S. Khan, K. Heinselman, S. Narumanchi, M. Brooks Tellekamp, A. Zakutayev","doi":"10.1002/pssa.202300535","DOIUrl":"https://doi.org/10.1002/pssa.202300535","url":null,"abstract":"β‐Ga2O3‐based semiconductor devices are expected to have significantly improved high‐power and high‐temperature performance due to its ultrawide bandgap of close to 5 eV. However, the high‐temperature operation of these ultrawide‐bandgap devices is usually limited by the relatively low 1–2 eV built‐in potential at the Schottky barrier with most high‐work‐function metals. Herein, heterojunction p‐NiO/n‐β‐Ga2O3 diodes fabrication and optimization for high‐temperature device applications are reported, demonstrating a current rectification ratio (ION/IOFF) of more than 106 at 410 °C. The NiO heterojunction diode can achieve higher turn‐on (VON) voltage and lower reverse leakage current compared to the Ni‐based Schottky diode fabricated on the same single‐crystal β‐Ga2O3 substrate, despite charge transport dominated by interfacial recombination. Electrical characterization and device modeling show that these advantages are due to a higher built‐in potential and additional band offset. These results suggest that heterojunction p–n diodes based on β‐Ga2O3 can significantly improve high‐temperature electronic device and sensor performance.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84640794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Coating Silver Tree‐like Fractal Structure with Silica Layer for Inhibiting Chemical Reactions of Analytes in Surface‐Enhanced Raman Scattering 用硅层包裹银树状分形结构抑制分析物表面增强拉曼散射中的化学反应

Physica status solidi (A): Applied research Pub Date : 2023-08-19 DOI: 10.1002/pssa.202300085

Hiroya Watanabe, Yurin Hishii, Kanna Kishimoto, Kohei Nogami, Qingyuan Ma, Tomoya Niki, Tomoki Kotani, T. Kiwa, Satoru Shoji, T. Ohkubo, J. Kano, N. Takeyasu

{"title":"Coating Silver Tree‐like Fractal Structure with Silica Layer for Inhibiting Chemical Reactions of Analytes in Surface‐Enhanced Raman Scattering","authors":"Hiroya Watanabe, Yurin Hishii, Kanna Kishimoto, Kohei Nogami, Qingyuan Ma, Tomoya Niki, Tomoki Kotani, T. Kiwa, Satoru Shoji, T. Ohkubo, J. Kano, N. Takeyasu","doi":"10.1002/pssa.202300085","DOIUrl":"https://doi.org/10.1002/pssa.202300085","url":null,"abstract":"Silica coating is performed onto silver tree‐like fractal structures, which are self‐grown in a solution, through a wet process using tetraethyl orthosilicate. Surface‐enhanced Raman scattering (SERS) of para‐aminothiophenol (p‐ATP) is measured on the silver tree‐like fractal structures with/without silica layer at the excitation wavelength of 532 nm. p‐ATP is chemically transformed into dimercaptoazobenzene (DMAB) on the non‐coated silver tree‐like fractal structures, where DMAB peaks are clearly observed, during the SERS measurements. The DMAB peaks decrease/disappear on the silica‐coated ones although the p‐ATP peaks are observed. In the results, it is indicated that the chemical transformation is inhibited on the silica‐coated ones. The sensitivity is decreased by half compared to the non‐coated silver tree‐like fractal structures, where the lower detection limit is estimated to be ≈2 × 10−5 mol L−1 for p‐ATP. The silica coating is advantageous for inhibiting chemical transformations of analytes, enabling identification/estimation of chemicals in unknown sample with SERS similarly to conventional Raman spectroscopy.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79694101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0