Pub Date : 2024-09-18DOI: 10.1088/1361-6463/ad6f20
Yan Wang, Zeyu Wu, Wenming Yu and Zhengqi Liu
Chiroptical metamaterials have attracted considerable attention owing to their exciting opportunities for fundamental research and practical applications over the past 20 years. Through practical designs, the chiroptical response of chiral metamaterials can be several orders of magnitude higher than that of natural chiral materials. Chiroptical metamaterials therefore represent a special type of artificial structures for unique chiroptical activities. In this review, we present a comprehensive overview of the progresses in the development of chiroptical metamaterials. Chiroptical metamaterial progress enables applications, including asymmetric transmission, polarization conversion, chiral absorber, chiral imaging, chiral sensor and chiral emission. We also review fabrication techniques and design of chiroptical metamaterials based on deep learning. In the conclusion, we present possible further research directions in this field.
{"title":"Recent progresses and applications on chiroptical metamaterials: a review","authors":"Yan Wang, Zeyu Wu, Wenming Yu and Zhengqi Liu","doi":"10.1088/1361-6463/ad6f20","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6f20","url":null,"abstract":"Chiroptical metamaterials have attracted considerable attention owing to their exciting opportunities for fundamental research and practical applications over the past 20 years. Through practical designs, the chiroptical response of chiral metamaterials can be several orders of magnitude higher than that of natural chiral materials. Chiroptical metamaterials therefore represent a special type of artificial structures for unique chiroptical activities. In this review, we present a comprehensive overview of the progresses in the development of chiroptical metamaterials. Chiroptical metamaterial progress enables applications, including asymmetric transmission, polarization conversion, chiral absorber, chiral imaging, chiral sensor and chiral emission. We also review fabrication techniques and design of chiroptical metamaterials based on deep learning. In the conclusion, we present possible further research directions in this field.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"27 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1088/1361-6463/ad773e
Guobao Zhang, Wei Yang, Lei Zhang, Zhengyang Wu, Mengyi Cai, Taiyun Zhu, Lei Sun, He Gao and Zhen Li
Epoxy microcomposites are basic materials for gas-insulated switchgear (GIS) spacers that are subjected to huge electrical stress. Previous works have indicated that nanoparticles are beneficial to dielectric performance. However, surface electrical breakdown, a typical fault in GIS of co-doped micro- and nanoparticles in epoxy composites, is seldom studied. In this work, numerous concentrations of micro- and nano-Al2O3 are co-doped into an epoxy matrix; the surface traps, surface charging, and surface breakdown voltages (Vsb) of the co-doped composites are studied, and the influence of micro- and nano-Al2O3 on the electrical surface breakdown is clarified. The results show that Vsb first decreases and then increases with the microparticles, and Vsb decreases from 25.34 kV to 19.52 kV. As the number of nanoparticles increases, Vsb increases and then decreases when the microparticle loading is low, but decreases and then increases when the microparticle loading exceeds 40 wt%. Micro-Al2O3 particles introduce surface shallow traps into epoxy composites, while small amounts of nano-Al2O3 introduce deep traps. Two different mechanisms dominate the surface charging and Vsb of epoxy micro-nanocomposites. When the surface conductivity is lower than 7 × 10−14 S, the surface charges are reduced by the suppression of electrode injection as the trap depth increases, and Vsb increases. When the surface conductivity exceeds 7 × 10−14 S, the surface charge dissipation rate increases with the surface conductivity and Vsb increases as the surface conductivity increases. Our work indicates that co-doped micro- and nano-particles should keep the surface conductivity away from the specic value (7 × 10−14 S) to safeguard insulation properties for GIS spacers.
{"title":"Electrical surface breakdown characteristics of micro- and nano-Al2O3 particle co-doped epoxy composites","authors":"Guobao Zhang, Wei Yang, Lei Zhang, Zhengyang Wu, Mengyi Cai, Taiyun Zhu, Lei Sun, He Gao and Zhen Li","doi":"10.1088/1361-6463/ad773e","DOIUrl":"https://doi.org/10.1088/1361-6463/ad773e","url":null,"abstract":"Epoxy microcomposites are basic materials for gas-insulated switchgear (GIS) spacers that are subjected to huge electrical stress. Previous works have indicated that nanoparticles are beneficial to dielectric performance. However, surface electrical breakdown, a typical fault in GIS of co-doped micro- and nanoparticles in epoxy composites, is seldom studied. In this work, numerous concentrations of micro- and nano-Al2O3 are co-doped into an epoxy matrix; the surface traps, surface charging, and surface breakdown voltages (Vsb) of the co-doped composites are studied, and the influence of micro- and nano-Al2O3 on the electrical surface breakdown is clarified. The results show that Vsb first decreases and then increases with the microparticles, and Vsb decreases from 25.34 kV to 19.52 kV. As the number of nanoparticles increases, Vsb increases and then decreases when the microparticle loading is low, but decreases and then increases when the microparticle loading exceeds 40 wt%. Micro-Al2O3 particles introduce surface shallow traps into epoxy composites, while small amounts of nano-Al2O3 introduce deep traps. Two different mechanisms dominate the surface charging and Vsb of epoxy micro-nanocomposites. When the surface conductivity is lower than 7 × 10−14 S, the surface charges are reduced by the suppression of electrode injection as the trap depth increases, and Vsb increases. When the surface conductivity exceeds 7 × 10−14 S, the surface charge dissipation rate increases with the surface conductivity and Vsb increases as the surface conductivity increases. Our work indicates that co-doped micro- and nano-particles should keep the surface conductivity away from the specic value (7 × 10−14 S) to safeguard insulation properties for GIS spacers.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"19 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1088/1361-6463/ad7471
Marek Šťastný, Kryštof Mrózek, Karel Juřík, Lukáš Havlíček, Michal Novotný and Adam Obrusník
Air breathing electric propulsion (ABEP) systems offer a promising solution to extend the lifetime of very low earth orbit (VLEO) missions by using residual atmospheric particles as propellants. Such systems would operate in very low-pressure environments where plasma ignition and confinement prove challenging. In this contribution, we present results of a global plasma model (GPM) of a plasma ignited in a very low-pressure air mixture. The results are validated against experimental measurements acquired using a laboratory electrodeless ion source utilizing a resonator for plasma ignition. The device is specifically designed to operate within low-pressure environments as it holds potential applications in ABEP systems for VLEO missions. Parametric studies are carried out via GPM to investigate the resonant behavior and its implications. The potential of the model serving as a predictive tool is assessed through experimental validation against measured data, mainly investigating the extracted ion current dependency on operational pressure and external magnetic field strength. The verified model is further utilized to extrapolate additional information about the resonant plasma such as ion composition or a degree of ionization.
{"title":"Numerical simulations of a low-pressure electrodeless ion source intended for air-breathing electric propulsion","authors":"Marek Šťastný, Kryštof Mrózek, Karel Juřík, Lukáš Havlíček, Michal Novotný and Adam Obrusník","doi":"10.1088/1361-6463/ad7471","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7471","url":null,"abstract":"Air breathing electric propulsion (ABEP) systems offer a promising solution to extend the lifetime of very low earth orbit (VLEO) missions by using residual atmospheric particles as propellants. Such systems would operate in very low-pressure environments where plasma ignition and confinement prove challenging. In this contribution, we present results of a global plasma model (GPM) of a plasma ignited in a very low-pressure air mixture. The results are validated against experimental measurements acquired using a laboratory electrodeless ion source utilizing a resonator for plasma ignition. The device is specifically designed to operate within low-pressure environments as it holds potential applications in ABEP systems for VLEO missions. Parametric studies are carried out via GPM to investigate the resonant behavior and its implications. The potential of the model serving as a predictive tool is assessed through experimental validation against measured data, mainly investigating the extracted ion current dependency on operational pressure and external magnetic field strength. The verified model is further utilized to extrapolate additional information about the resonant plasma such as ion composition or a degree of ionization.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"66 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1088/1361-6463/ad7155
C Ferreyra, R Leal Martir, D Rubi and M J Sánchez
Oxygen vacancies (OV) are pervasive in metal oxides and play a pivotal role in the switching behaviour of oxide-based memristive devices. In this study we address OV dynamics in Pt/TaO /Ta2O /TaO /Pt devices, through a combination of experiments and theoretical simulations, In particular, we focus on the RESET transition (from low to high resistance) induced by the application of electrical pulse(s), by choosing different initial OV profiles and studying their kinetics during the mentioned process. We demonstrate that by selecting specific OV profiles it is possible to tune the characteristic time-scale of the RESET. Finally, we show that the implementation of gradual RESETs, induced by applying many (small) successive pulses, allows estimating the activation energies involved in the OV electromigration process. Our results help paving the way for OV engineering aiming at optimizing key memristive figures such as switching speed or power consumption, which are highly relevant for neuromorphic or in-memory computing implementations.
氧空位（OV）普遍存在于金属氧化物中，在基于氧化物的忆阻器件的开关行为中起着举足轻重的作用。在这项研究中，我们通过实验和理论模拟相结合的方法，研究了 Pt/TaO /Ta2O /TaO /Pt 器件中的氧空位动力学，特别是通过选择不同的初始氧空位曲线并研究其在上述过程中的动力学，重点研究了电脉冲诱导的 RESET 过渡（从低电阻到高电阻）。我们证明，通过选择特定的 OV 曲线，可以调整 RESET 的特征时间尺度。最后，我们表明，通过应用许多（小）连续脉冲诱导渐进式 RESET，可以估算出 OV 电迁移过程中涉及的活化能。我们的研究成果有助于为 OV 工程铺平道路，从而优化开关速度或功耗等与神经形态或内存计算实现高度相关的关键内存数据。
{"title":"Oxygen vacancies kinetics in TaO 2 − ...","authors":"C Ferreyra, R Leal Martir, D Rubi and M J Sánchez","doi":"10.1088/1361-6463/ad7155","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7155","url":null,"abstract":"Oxygen vacancies (OV) are pervasive in metal oxides and play a pivotal role in the switching behaviour of oxide-based memristive devices. In this study we address OV dynamics in Pt/TaO /Ta2O /TaO /Pt devices, through a combination of experiments and theoretical simulations, In particular, we focus on the RESET transition (from low to high resistance) induced by the application of electrical pulse(s), by choosing different initial OV profiles and studying their kinetics during the mentioned process. We demonstrate that by selecting specific OV profiles it is possible to tune the characteristic time-scale of the RESET. Finally, we show that the implementation of gradual RESETs, induced by applying many (small) successive pulses, allows estimating the activation energies involved in the OV electromigration process. Our results help paving the way for OV engineering aiming at optimizing key memristive figures such as switching speed or power consumption, which are highly relevant for neuromorphic or in-memory computing implementations.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"48 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-16DOI: 10.1088/1361-6463/ad7511
Zhinan Luo, Xiaoxiao Ding, Jie Yang, Yuhan Wu, Bichao Wang, Ling Miao, Shaowei Bie and Jianjun Jiang
A dispersion compensation design absorber realized by high-density stacking resistive frequency selective surface (RFSS) is proposed for wideband applications. Firstly, the quantitative relationship between the equivalent impedance of RFSS and the permittivity of the effective media is constructed with the help of the transmission matrix method. The dispersion regulation of permittivity is achieved by changing the pattern and the square resistance of RFSS. In terms of absorber design, a uniform absorber with dispersion manipulation is developed as a precursor absorber. The uniform absorber has an absorption performance better than −8.5 dB above 2 GHz at normal incidence. The loss mechanism is analyzed in detail by electric field distribution and surface power loss density distribution, indicating that the uniform design cannot achieve thickness saving when extending to low frequency. Therefore, a dispersion compensation design absorber is proposed to extend −10 dB bandwidth to 1.64–28.8 GHz. Experiment results agree well with the simulation results, validating the analytic methods and design principles.
{"title":"Dispersion compensation design of high-density stacking RFSS absorbers for wideband applications","authors":"Zhinan Luo, Xiaoxiao Ding, Jie Yang, Yuhan Wu, Bichao Wang, Ling Miao, Shaowei Bie and Jianjun Jiang","doi":"10.1088/1361-6463/ad7511","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7511","url":null,"abstract":"A dispersion compensation design absorber realized by high-density stacking resistive frequency selective surface (RFSS) is proposed for wideband applications. Firstly, the quantitative relationship between the equivalent impedance of RFSS and the permittivity of the effective media is constructed with the help of the transmission matrix method. The dispersion regulation of permittivity is achieved by changing the pattern and the square resistance of RFSS. In terms of absorber design, a uniform absorber with dispersion manipulation is developed as a precursor absorber. The uniform absorber has an absorption performance better than −8.5 dB above 2 GHz at normal incidence. The loss mechanism is analyzed in detail by electric field distribution and surface power loss density distribution, indicating that the uniform design cannot achieve thickness saving when extending to low frequency. Therefore, a dispersion compensation design absorber is proposed to extend −10 dB bandwidth to 1.64–28.8 GHz. Experiment results agree well with the simulation results, validating the analytic methods and design principles.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"18 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-16DOI: 10.1088/1361-6463/ad76bb
E Serquen, F Bravo, Z Chi, L A Enrique, K Lizárraga, C Sartel, E Chikoidze and J A Guerra
This work presents a comprehensive investigation into the structural and electrical properties of Ga2O3 thin films grown via metal-organic chemical vapor deposition on both c- and m-plane sapphire substrates. Structural characterization revealed the β-Ga2O3 phase formation in both substrate orientations, with strong epitaxial preferential growth on c-plane substrates and polycrystalline films on m-plane substrates. Results show that Ga2O3/m-sapphire exhibits the lower electrical resistivity than its counterpart grown on c-sapphire. Activation energies of acceptor levels were estimated at ~1.4 and ~0.7 , for Ga2O3 films grown on c- and m-plane, respectively. This result shows that growing Ga2O3 on m-plane sapphire is beneficial to reach a weakly compensated sample. Cathodoluminescence analysis suggests that the additional low activation energy of ~0.18 observed in Ga2O3 grown with the highest oxygen flow on m-plane sapphire can be associated to thermally-induced migration of self-trapped hole states.
这项研究全面考察了通过金属有机化学气相沉积法在 c 面和 m 面蓝宝石衬底上生长的 Ga2O3 薄膜的结构和电气特性。结构表征结果表明，在两种衬底方向上都形成了β-Ga2O3相，在c面衬底上有强烈的优先外延生长，而在m面衬底上则形成了多晶薄膜。结果表明，Ga2O3/m-蓝宝石的电阻率低于在 c-蓝宝石上生长的同类薄膜。在 c 平面和 m 平面上生长的 Ga2O3 薄膜的受体水平活化能估计分别为 ~1.4 和 ~0.7。这一结果表明，在 m 面蓝宝石上生长 Ga2O3 有利于获得弱补偿样品。阴极荧光分析表明，在 m 面蓝宝石上以最高氧流生长的 Ga2O3 中观察到的 ~0.18 的额外低活化能可能与自捕获空穴态的热诱导迁移有关。
{"title":"Impact of c- and m- sapphire plane orientations on the structural and electrical properties of β-Ga2O3 thin films grown by metal-organic chemical vapor deposition","authors":"E Serquen, F Bravo, Z Chi, L A Enrique, K Lizárraga, C Sartel, E Chikoidze and J A Guerra","doi":"10.1088/1361-6463/ad76bb","DOIUrl":"https://doi.org/10.1088/1361-6463/ad76bb","url":null,"abstract":"This work presents a comprehensive investigation into the structural and electrical properties of Ga2O3 thin films grown via metal-organic chemical vapor deposition on both c- and m-plane sapphire substrates. Structural characterization revealed the β-Ga2O3 phase formation in both substrate orientations, with strong epitaxial preferential growth on c-plane substrates and polycrystalline films on m-plane substrates. Results show that Ga2O3/m-sapphire exhibits the lower electrical resistivity than its counterpart grown on c-sapphire. Activation energies of acceptor levels were estimated at ~1.4 and ~0.7 , for Ga2O3 films grown on c- and m-plane, respectively. This result shows that growing Ga2O3 on m-plane sapphire is beneficial to reach a weakly compensated sample. Cathodoluminescence analysis suggests that the additional low activation energy of ~0.18 observed in Ga2O3 grown with the highest oxygen flow on m-plane sapphire can be associated to thermally-induced migration of self-trapped hole states.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"214 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-16DOI: 10.1088/1361-6463/ad76bc
Subrata Ghosh, Giacomo Pagani, Massimilano Righi, Chengxi Hou, Valeria Russo and Carlo S Casari
Advanced material composite of nanocarbons and metal-based materials provides a synergistic effect to obtain excellent electrochemical charge-storage performance and other properties. Herein, 3D porous carbon-metal oxynitride nanocomposites with tunable carbon/metal and oxygen/nitrogen ratio are synthesized uniquely by simultaneous ablation from two different targets by single-step pulsed laser deposition at room temperature. Co-ablation of titanium and vanadium nitride targets together with graphite allowed us to synthesize carbon-metal oxynitride porous nanocomposite and exploit them as a binder-free thin film supercapacitor electrode in aqueous electrolyte. We show that the elemental composition ratio and hence the structural properties can be tuned by selecting target configuration and by manipulating the ablation position. We investigate how this tuning capability impacts their charge-storage performances. We anticipate the utilization of as-synthesized various composites in a single PLD production run as next-generation active materials for flexible energy storage and optoelectronic applications.
{"title":"One-step pulsed laser deposition of carbon/metal oxynitride composites for supercapacitor application","authors":"Subrata Ghosh, Giacomo Pagani, Massimilano Righi, Chengxi Hou, Valeria Russo and Carlo S Casari","doi":"10.1088/1361-6463/ad76bc","DOIUrl":"https://doi.org/10.1088/1361-6463/ad76bc","url":null,"abstract":"Advanced material composite of nanocarbons and metal-based materials provides a synergistic effect to obtain excellent electrochemical charge-storage performance and other properties. Herein, 3D porous carbon-metal oxynitride nanocomposites with tunable carbon/metal and oxygen/nitrogen ratio are synthesized uniquely by simultaneous ablation from two different targets by single-step pulsed laser deposition at room temperature. Co-ablation of titanium and vanadium nitride targets together with graphite allowed us to synthesize carbon-metal oxynitride porous nanocomposite and exploit them as a binder-free thin film supercapacitor electrode in aqueous electrolyte. We show that the elemental composition ratio and hence the structural properties can be tuned by selecting target configuration and by manipulating the ablation position. We investigate how this tuning capability impacts their charge-storage performances. We anticipate the utilization of as-synthesized various composites in a single PLD production run as next-generation active materials for flexible energy storage and optoelectronic applications.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"92 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-16DOI: 10.1088/1361-6463/ad77de
N N Misra, Tejas Naladala and Khalid J Alzahrani
This review explores the engineering and design aspects of plasma activated water (PAW) systems, focusing on their application in food safety and agriculture. This review aims to bridge the gap between research and practical application, paving the way for the development of robust and efficient PAW systems for enhancing food safety and agricultural productivity. By examining a variety of activation methods, including direct gas ionization, underwater discharges, and dynamic interactions of ionized gases with liquids, this work discusses the mechanical designs that facilitate these processes, highlighting their scalability and efficiency. The discussion is grounded in a comprehensive relevant scientific and patent literature, offering a critical overview of the systems’ design parameters that influence the generation of reactive oxygen and nitrogen species (RONS). The designs reported in literature have employed three major approaches, viz. direct underwater discharges, gas ionization followed by introduction of plasma into the liquid, creation of gas liquid mixtures and subsequent ionization. The laboratory systems have relied on natural convective diffusion of the RONS into water, while most of the patents advocate use of forced convective diffusion of RONS to increase transfer rates. Despite widespread laboratory-scale research in PAW, the transition to industrial-scale systems remains underexplored.
{"title":"Design of systems for plasma activated water (PAW) for agri-food applications","authors":"N N Misra, Tejas Naladala and Khalid J Alzahrani","doi":"10.1088/1361-6463/ad77de","DOIUrl":"https://doi.org/10.1088/1361-6463/ad77de","url":null,"abstract":"This review explores the engineering and design aspects of plasma activated water (PAW) systems, focusing on their application in food safety and agriculture. This review aims to bridge the gap between research and practical application, paving the way for the development of robust and efficient PAW systems for enhancing food safety and agricultural productivity. By examining a variety of activation methods, including direct gas ionization, underwater discharges, and dynamic interactions of ionized gases with liquids, this work discusses the mechanical designs that facilitate these processes, highlighting their scalability and efficiency. The discussion is grounded in a comprehensive relevant scientific and patent literature, offering a critical overview of the systems’ design parameters that influence the generation of reactive oxygen and nitrogen species (RONS). The designs reported in literature have employed three major approaches, viz. direct underwater discharges, gas ionization followed by introduction of plasma into the liquid, creation of gas liquid mixtures and subsequent ionization. The laboratory systems have relied on natural convective diffusion of the RONS into water, while most of the patents advocate use of forced convective diffusion of RONS to increase transfer rates. Despite widespread laboratory-scale research in PAW, the transition to industrial-scale systems remains underexplored.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"30 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-16DOI: 10.1088/1361-6463/ad7510
Zhihao Mao, Da Li and Er-Ping Li
Metasurfaces have attracted widespread attention in recent years due to their powerful electromagnetic wave manipulation capabilities. This paper proposes and validates a single-polarized, angle-adjustable reflective digital coding metasurface. Each unit cell achieves independent reflection phase control by loading a PIN diode for on-off switching. The unit’s design and coding scheme are carefully optimized to ensure the performance of the proposed reconfigurable metasurface. As a validation, a prototype consisting of 16×16 elements is fabricated and measured, with a control signal provided by a field-programmable gate array controller. Experimental results demonstrate angle control of up to ±60° in the frequency range of 3.4 GHz–3.6 GHz, a peak gain of 24.9 dBi in a single channel, and gain exceeding 10 dBi across a 200 MHz operational bandwidth. Furthermore, the performance is validated in a communication system, yielding positive results. The proposed reflective digital coding metasurface contributes to the advancement of reconfigurable intelligent surfaces and holds promise for widespread adoption in various communication scenarios.
{"title":"Wide-angle reflection control with a reflective digital coding metasurface for 5G communication systems","authors":"Zhihao Mao, Da Li and Er-Ping Li","doi":"10.1088/1361-6463/ad7510","DOIUrl":"https://doi.org/10.1088/1361-6463/ad7510","url":null,"abstract":"Metasurfaces have attracted widespread attention in recent years due to their powerful electromagnetic wave manipulation capabilities. This paper proposes and validates a single-polarized, angle-adjustable reflective digital coding metasurface. Each unit cell achieves independent reflection phase control by loading a PIN diode for on-off switching. The unit’s design and coding scheme are carefully optimized to ensure the performance of the proposed reconfigurable metasurface. As a validation, a prototype consisting of 16×16 elements is fabricated and measured, with a control signal provided by a field-programmable gate array controller. Experimental results demonstrate angle control of up to ±60° in the frequency range of 3.4 GHz–3.6 GHz, a peak gain of 24.9 dBi in a single channel, and gain exceeding 10 dBi across a 200 MHz operational bandwidth. Furthermore, the performance is validated in a communication system, yielding positive results. The proposed reflective digital coding metasurface contributes to the advancement of reconfigurable intelligent surfaces and holds promise for widespread adoption in various communication scenarios.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"118 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1088/1361-6463/ad76ba
Mingyun Yuan, Duc V Dinh, Soumen Mandal, Oliver A Williams, Zhuohui Chen, Oliver Brandt and Paulo V Santos
Telecommunication of the next generation demands filters that can operate in the 10 GHz range with sufficient bandwidths. For surface-acoustic-wave (SAW) devices this prerequisite translates into high sound velocities and high piezoelectric couplings. Wurtzite AlN on diamond, which exploits the strong piezoelectricity of AlN with the very high SAW velocity of diamond, has been considered a promising platform. A significant boost (up to a factor of 4) of the piezoelectric response can be obtained by alloying AlN with Sc. Here, the main challenge lies in the synthesis of highly-oriented thin (Sc,Al)N films on diamond. In this work, we aim at establishing a platform for SAW devices using plasma-assisted molecular beam epitaxy for the deposition of Sc0.2Al0.8N on diamond. We investigate the structural properties related to SAW generation gearing towards applications at high frequencies. To this end, we prepare (Sc,Al)N thin films on polished polycrystalline diamond wafers and demonstrate the efficient generation of SAW modes with frequencies up to 8 GHz. Systematic studies of the dependence of the SAW velocity and electromechanical coupling coefficient on the Sc0.2Al0.8N film thickness is presented for various SAW modes. Our result demonstrates the potential of this material combination for future application that requires large bandwidth in the ultra-high frequency range.
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