Pub Date : 2024-07-21DOI: 10.1088/1361-6463/ad61f4
Nilton F Azevedo Neto, Felipe S Miranda, Pedro W P Moreira Junior, Marcelo P Gomes, Clodomiro Alves Junior, Cristiane Y Koga-Ito and Rodrigo S Pessoa
This research explores the synergistic application of Dielectric Barrier Discharge (DBD) and Gliding Arc Plasma Jet (GAPJ) in a Hybrid Plasma Discharge (HPD) setup for enhanced water activation. The HPD system demonstrated balanced and sustained generation of reactive oxygen and nitrogen species (RONS), maintaining efficiency at higher specific input energy (SIE) values. Comparative analyses with DBD and GAPJ systems highlighted the superior performance of the HPD system in generating RONS and modifying water’s molecular structure. Key observations included a decrease in water’s pH and an increase in oxidation-reduction potential, total dissolved solids, and conductivity, stabilizing beyond 5 l min−1 airflow and 10 min of treatment. UV−Vis spectroscopy identified nitrites, nitrates, hydrogen peroxide, and nitrous acid, while Raman spectroscopy captured shifts in vibrational modes, particularly in librational and O–H stretching bands. These changes correlated with alterations in reactive species concentrations and pH levels. Overall, the HPD system emerged as a versatile and efficient approach for generating plasma-activated water, suitable for applications in microbial deactivation, surface sterilization, and electrocatalytic process optimization, offering stable and continuous production of reactive species across a range of SIE values.
{"title":"Physical and chemical characteristics of plasma-activated water generated by hybrid dielectric barrier discharge and gliding arc discharge","authors":"Nilton F Azevedo Neto, Felipe S Miranda, Pedro W P Moreira Junior, Marcelo P Gomes, Clodomiro Alves Junior, Cristiane Y Koga-Ito and Rodrigo S Pessoa","doi":"10.1088/1361-6463/ad61f4","DOIUrl":"https://doi.org/10.1088/1361-6463/ad61f4","url":null,"abstract":"This research explores the synergistic application of Dielectric Barrier Discharge (DBD) and Gliding Arc Plasma Jet (GAPJ) in a Hybrid Plasma Discharge (HPD) setup for enhanced water activation. The HPD system demonstrated balanced and sustained generation of reactive oxygen and nitrogen species (RONS), maintaining efficiency at higher specific input energy (SIE) values. Comparative analyses with DBD and GAPJ systems highlighted the superior performance of the HPD system in generating RONS and modifying water’s molecular structure. Key observations included a decrease in water’s pH and an increase in oxidation-reduction potential, total dissolved solids, and conductivity, stabilizing beyond 5 l min−1 airflow and 10 min of treatment. UV−Vis spectroscopy identified nitrites, nitrates, hydrogen peroxide, and nitrous acid, while Raman spectroscopy captured shifts in vibrational modes, particularly in librational and O–H stretching bands. These changes correlated with alterations in reactive species concentrations and pH levels. Overall, the HPD system emerged as a versatile and efficient approach for generating plasma-activated water, suitable for applications in microbial deactivation, surface sterilization, and electrocatalytic process optimization, offering stable and continuous production of reactive species across a range of SIE values.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"13 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141743169","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 : 2024-07-21DOI: 10.1088/1361-6463/ad6267
Airi Nakayama, Siwei Liu, Ken-ichi Yano, Tomoki Nakajima and Takehiko Sato
Plasma medicine is a novel field of research that has the potential in life sciences, including cancer treatment. It has been believed that all of these potential applications depend on the chemical factor of the plasma. However, the electrical factors that are produced simultaneously with the chemical factors have not been researched thoroughly. To assess the effect of plasma on the response of cells, a system that enables simultaneous comparison of the effects of chemical and electrical factors of plasma with equal electricity was invented. This system separates the polarity of plasma and isolates the chemical species from the electric stimulation. Using this system, HT-1080 cells were exposed to plasma for 10 min, 1 h, and 24 h. The 10 min plasma treatment showed a clear difference in the polarity of plasma, where cells under exposure to positive plasma died while cells in other conditions survived. An hour of plasma treatment affected the cells under the negative plasma, where the cell viability was reduced to half. Meanwhile, the electric stimulation did not affect the cell viability but did alter the cell membrane. Collectively, this study demonstrates the differential effects of three factors (electric factor, positive plasma, negative plasma) under the same condition: both the electrical and chemical effects of plasma-generated stimuli with equal amounts of electricity were successfully observed.
{"title":"Cellular response to plasma-generated electrical and chemical stimulation of equal electricity","authors":"Airi Nakayama, Siwei Liu, Ken-ichi Yano, Tomoki Nakajima and Takehiko Sato","doi":"10.1088/1361-6463/ad6267","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6267","url":null,"abstract":"Plasma medicine is a novel field of research that has the potential in life sciences, including cancer treatment. It has been believed that all of these potential applications depend on the chemical factor of the plasma. However, the electrical factors that are produced simultaneously with the chemical factors have not been researched thoroughly. To assess the effect of plasma on the response of cells, a system that enables simultaneous comparison of the effects of chemical and electrical factors of plasma with equal electricity was invented. This system separates the polarity of plasma and isolates the chemical species from the electric stimulation. Using this system, HT-1080 cells were exposed to plasma for 10 min, 1 h, and 24 h. The 10 min plasma treatment showed a clear difference in the polarity of plasma, where cells under exposure to positive plasma died while cells in other conditions survived. An hour of plasma treatment affected the cells under the negative plasma, where the cell viability was reduced to half. Meanwhile, the electric stimulation did not affect the cell viability but did alter the cell membrane. Collectively, this study demonstrates the differential effects of three factors (electric factor, positive plasma, negative plasma) under the same condition: both the electrical and chemical effects of plasma-generated stimuli with equal amounts of electricity were successfully observed.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"90 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141743170","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 : 2024-07-17DOI: 10.1088/1361-6463/ad5b6f
Vaibhavi Gulavani, Musthafa Ottakam Thotiyl, Bibin John and Ashish Yengantiwar
The present work emphases on the post-mortem study of silica/carbon composite as functional anode in Li-ion batteries (LIBs). Herein, the silica/carbon composite is synthesized by facile in-situ hydrothermal technique. The x-ray diffraction (XRD) pattern indicates the amorphous nature of silica/carbon composite. The stacked sheet-like morphology of silica/carbon composite is seen in the high-resolution transmission electron microscopy (HR-TEM) & scanning electron microscopy (SEM) images. In addition, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, energy dispersive x-ray analysis (EDAX), and x-ray photoelectron spectra (XPS) characterizations of silica/carbon composite has been studied in detail. The rate capability of silica/carbon composite anode in LIB indicates 99% capacity retention after applying current density ranging from 50 mA g−1 to 1000 mA g−1, successively. The composite anode delivers a stable specific capacity ∼300 mAh g−1 at a current density of 100 mA g−1 for 500 cycles. Electrochemical impedance spectroscopy (EIS) study analyzed the faster Li-ion diffusion and increment in the diffusion coefficient by a factor of 1000 after 500 cycles. To the best of our knowledge, this is the first work on the post-mortem study of silica/carbon composite as anode in LIB. Post-cycling characterizations including XRD, FTIR, and SEM reveal the absence of any impurity phases and negligible volumetric expansion after prolonged cycling. It further confirms that the carbon present in the silica/carbon composite helps to accommodate the volumetric expansion of silica and prevents cracking of the anode over 500 cycles.
本研究的重点是对二氧化硅/碳复合材料作为锂离子电池（LIB）功能阳极的后期研究。本文采用简便的原位水热技术合成了二氧化硅/碳复合材料。X 射线衍射（XRD）图表明二氧化硅/碳复合材料具有无定形性质。从高分辨率透射电子显微镜（HR-TEM）和扫描电子显微镜（SEM）图像中可以看到二氧化硅/碳复合材料的叠层片状形态。此外，还详细研究了二氧化硅/碳复合材料的拉曼光谱、傅立叶变换红外光谱、能量色散 X 射线分析和 X 射线光电子能谱特性。二氧化硅/碳复合阳极在 LIB 中的速率能力表明，在电流密度从 50 mA g-1 到 1000 mA g-1 的范围内，其容量保持率为 99%。在 100 mA g-1 的电流密度下，该复合阳极可在 500 个循环中提供稳定的比容量 ∼300 mAh g-1。电化学阻抗谱（EIS）研究分析表明，500 次循环后，锂离子扩散速度加快，扩散系数增加了 1000 倍。据我们所知，这是首次对二氧化硅/碳复合材料作为 LIB 负极进行死后研究。包括 XRD、傅立叶变换红外光谱和 SEM 在内的循环后特性分析表明，在长时间循环后，该材料不存在任何杂质相，体积膨胀也可以忽略不计。这进一步证实了二氧化硅/碳复合材料中存在的碳有助于适应二氧化硅的体积膨胀，防止阳极在 500 次循环后出现裂纹。
{"title":"Post-mortem study and long cycling stability of silica/carbon composite as anode in Li-ion cells","authors":"Vaibhavi Gulavani, Musthafa Ottakam Thotiyl, Bibin John and Ashish Yengantiwar","doi":"10.1088/1361-6463/ad5b6f","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5b6f","url":null,"abstract":"The present work emphases on the post-mortem study of silica/carbon composite as functional anode in Li-ion batteries (LIBs). Herein, the silica/carbon composite is synthesized by facile in-situ hydrothermal technique. The x-ray diffraction (XRD) pattern indicates the amorphous nature of silica/carbon composite. The stacked sheet-like morphology of silica/carbon composite is seen in the high-resolution transmission electron microscopy (HR-TEM) & scanning electron microscopy (SEM) images. In addition, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, energy dispersive x-ray analysis (EDAX), and x-ray photoelectron spectra (XPS) characterizations of silica/carbon composite has been studied in detail. The rate capability of silica/carbon composite anode in LIB indicates 99% capacity retention after applying current density ranging from 50 mA g−1 to 1000 mA g−1, successively. The composite anode delivers a stable specific capacity ∼300 mAh g−1 at a current density of 100 mA g−1 for 500 cycles. Electrochemical impedance spectroscopy (EIS) study analyzed the faster Li-ion diffusion and increment in the diffusion coefficient by a factor of 1000 after 500 cycles. To the best of our knowledge, this is the first work on the post-mortem study of silica/carbon composite as anode in LIB. Post-cycling characterizations including XRD, FTIR, and SEM reveal the absence of any impurity phases and negligible volumetric expansion after prolonged cycling. It further confirms that the carbon present in the silica/carbon composite helps to accommodate the volumetric expansion of silica and prevents cracking of the anode over 500 cycles.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"39 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141743363","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 : 2024-07-17DOI: 10.1088/1361-6463/ad60da
Ning Zhang and Hengyi Xu
Ferromagnetic insulators may exhibit magnon Hall effects when subjected to a temperature gradient due to the Dzyaloshinsky–Moriya interaction. In this study, we investigate the magnon thermal Hall conductivity of kagome ferromagnets in real space using the kernel polynomial method. We first establish the formalism in real space within the framework of linear response theory, which enables efficient numerical calculations of thermal transport properties under various imperfections. The validity and accuracy of the real-space approach are confirmed by comparing the calculations with those obtained in momentum space. This approach is particularly advantageous for computing the thermal transport coefficients of disordered lattices. We consider two types of disorder in kagome ferromagnets and observe that both types significantly influence across the entire temperature range. This is in contrast to the effects of strains, where strains primarily impact the maximum values of .
{"title":"Real-space calculation of thermal Hall effects in strained and disordered kagome ferromagnets","authors":"Ning Zhang and Hengyi Xu","doi":"10.1088/1361-6463/ad60da","DOIUrl":"https://doi.org/10.1088/1361-6463/ad60da","url":null,"abstract":"Ferromagnetic insulators may exhibit magnon Hall effects when subjected to a temperature gradient due to the Dzyaloshinsky–Moriya interaction. In this study, we investigate the magnon thermal Hall conductivity of kagome ferromagnets in real space using the kernel polynomial method. We first establish the formalism in real space within the framework of linear response theory, which enables efficient numerical calculations of thermal transport properties under various imperfections. The validity and accuracy of the real-space approach are confirmed by comparing the calculations with those obtained in momentum space. This approach is particularly advantageous for computing the thermal transport coefficients of disordered lattices. We consider two types of disorder in kagome ferromagnets and observe that both types significantly influence across the entire temperature range. This is in contrast to the effects of strains, where strains primarily impact the maximum values of .","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"90 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141743364","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 : 2024-07-16DOI: 10.1088/1361-6463/ad60d9
Zifeng Wang, Xiangyu Wang, Shenghang Xu, Dingxin Liu, Jingyao Zhang, Qiuyi Yue, Luge Wang, Pengfei Zhang, Yikang Jia, Jishen Zhang, Li Guo, Dandan Pei, Chang Liu and Mingzhe Rong
Plasma-activated water (PAW) has broad prospects in the medical field because it is rich in reactive nitrogen and oxygen species. However, in most production processes of PAW, a large proportion of gaseous reactive species is converted into long-lived aqueous species with minor biochemical activity, and only a small proportion is converted into crucial short-lived aqueous species, which results in inefficient activation of PAW. Given the indispensability and easy availability of long-lived aqueous species, this study proposes to preload HNO3 and H2O2 into water and then generate plasma to induce short-lived aqueous species, thus improving the production rate of PAW. The addition of 1 mM HNO3 and 0.5% H2O2 results in a 100-fold increase in the production rate of the PAW with a bactericidal rate exceeding 99.9999%, and the preloaded HNO3 and H2O2 promote the dissolution of O3 and the generation of short-lived aqueous species, respectively. Moreover, the preloaded species improve the validity period of PAW and the resistance of sterilization to acid-base neutralizers. This study offers a novel approach for upgrading the production of PAW, which holds promise for realizing rapid PAW production with a portable device for clinical medical applications.
{"title":"Upgrading the production of plasma-activated water for sterilization by preloading long-lived reactive species","authors":"Zifeng Wang, Xiangyu Wang, Shenghang Xu, Dingxin Liu, Jingyao Zhang, Qiuyi Yue, Luge Wang, Pengfei Zhang, Yikang Jia, Jishen Zhang, Li Guo, Dandan Pei, Chang Liu and Mingzhe Rong","doi":"10.1088/1361-6463/ad60d9","DOIUrl":"https://doi.org/10.1088/1361-6463/ad60d9","url":null,"abstract":"Plasma-activated water (PAW) has broad prospects in the medical field because it is rich in reactive nitrogen and oxygen species. However, in most production processes of PAW, a large proportion of gaseous reactive species is converted into long-lived aqueous species with minor biochemical activity, and only a small proportion is converted into crucial short-lived aqueous species, which results in inefficient activation of PAW. Given the indispensability and easy availability of long-lived aqueous species, this study proposes to preload HNO3 and H2O2 into water and then generate plasma to induce short-lived aqueous species, thus improving the production rate of PAW. The addition of 1 mM HNO3 and 0.5% H2O2 results in a 100-fold increase in the production rate of the PAW with a bactericidal rate exceeding 99.9999%, and the preloaded HNO3 and H2O2 promote the dissolution of O3 and the generation of short-lived aqueous species, respectively. Moreover, the preloaded species improve the validity period of PAW and the resistance of sterilization to acid-base neutralizers. This study offers a novel approach for upgrading the production of PAW, which holds promise for realizing rapid PAW production with a portable device for clinical medical applications.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"27 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717609","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 : 2024-07-11DOI: 10.1088/1361-6463/ad5e91
J Franke, F Zysk, S Wilski, M O Liedke, M Butterling, A G Attallah, A Wagner, T D Kühne and R Dahlmann
Here we show a novel approach to characterize the gas transfer behavior of silicon-oxide (SiOx) coatings and explain the underlying dynamics. For this, we investigate the coating on a nm-scale both by measurement and simulation. Positron annihilation spectroscopy (PAS) and quantum mechanical electronic structure-based molecular dynamics simulations are combined to characterize the porous landscape of SiOx coatings. This approach analyses the influence of micropores smaller than 2 nm in diameter on gas permeation which are difficult to study with conventional methods. We lay out the main pore diameter ranges and their associated porosity estimates. An influence of layer growth on pore size and porosity was found, with an increased energy input during layer deposition leading to smaller pore sizes and a reduced porosity. The molecular dynamics simulations quantify the self-diffusion of oxygen and water vapor through those PAS deducted micropore ranges for hydrophilic and hydrophobic systems. The theoretical pore size ranges are fitting to our PAS results and complete them by giving diffusion coefficients. This approach enables detailed analysis of pore morphology on mass transport through thin film coatings and characterization of their barrier or membrane performance. This is a crucial prerequisite for the development of an exhaustive model of pore dominated mass transports in PECVD coatings.
在这里，我们展示了一种新方法来描述氧化硅（SiOx）涂层的气体传输行为并解释其基本动态。为此，我们在纳米尺度上对涂层进行了测量和模拟研究。正电子湮灭光谱（PAS）和基于量子力学电子结构的分子动力学模拟相结合，描述了氧化硅涂层的多孔结构。这种方法分析了直径小于 2 纳米的微孔对气体渗透的影响，而传统方法很难研究这些微孔。我们列出了主要的孔隙直径范围及其相关的孔隙率估计值。我们发现，层的生长对孔径和孔隙率有影响，层沉积过程中能量输入的增加会导致孔径变小和孔隙率降低。分子动力学模拟量化了氧气和水蒸气通过亲水和疏水系统的 PAS 扣除微孔范围的自扩散情况。理论孔隙大小范围与我们的 PAS 结果相匹配，并通过给出扩散系数来完善这些结果。通过这种方法，可以详细分析孔隙形态对薄膜涂层质量传输的影响，并鉴定其阻隔或膜性能。这是开发 PECVD 涂层中孔隙主导质量传输详尽模型的重要前提。
{"title":"Consideration of the effect of nanoscale porosity on mass transport phenomena in PECVD coatings","authors":"J Franke, F Zysk, S Wilski, M O Liedke, M Butterling, A G Attallah, A Wagner, T D Kühne and R Dahlmann","doi":"10.1088/1361-6463/ad5e91","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5e91","url":null,"abstract":"Here we show a novel approach to characterize the gas transfer behavior of silicon-oxide (SiOx) coatings and explain the underlying dynamics. For this, we investigate the coating on a nm-scale both by measurement and simulation. Positron annihilation spectroscopy (PAS) and quantum mechanical electronic structure-based molecular dynamics simulations are combined to characterize the porous landscape of SiOx coatings. This approach analyses the influence of micropores smaller than 2 nm in diameter on gas permeation which are difficult to study with conventional methods. We lay out the main pore diameter ranges and their associated porosity estimates. An influence of layer growth on pore size and porosity was found, with an increased energy input during layer deposition leading to smaller pore sizes and a reduced porosity. The molecular dynamics simulations quantify the self-diffusion of oxygen and water vapor through those PAS deducted micropore ranges for hydrophilic and hydrophobic systems. The theoretical pore size ranges are fitting to our PAS results and complete them by giving diffusion coefficients. This approach enables detailed analysis of pore morphology on mass transport through thin film coatings and characterization of their barrier or membrane performance. This is a crucial prerequisite for the development of an exhaustive model of pore dominated mass transports in PECVD coatings.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"32 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141612297","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 : 2024-07-11DOI: 10.1088/1361-6463/ad5c6f
R Mata, A Cros, B Gimeno and D Raboso
The recent high demand of secondary electron emission yield (SEY) measurements in dielectric materials from space industry has driven SEY laboratories to improve their facilities and measurement techniques. SEY determination by the common capacitive method, also known as pulsed method, is well accepted and has given satisfactory results in most cases. Nevertheless, the samples under study must be prepared according to the experimental limitations of the technique, i.e. they should be manufactured separated from the devices representing faithfully the surface state of the own device and be as thin as possible. A method based on the Kelvin probe (KP) is proposed here to obtain the SEY characteristics of electrically floating Platinum, Kapton and Teflon placed over dielectric spacers with thicknesses ranging from 1.6 to 12.1 mm. The results are compared with those of the capacitive method and indicate that KP SEY curves are less sensitive to spacer thickness. An explanation based on the literature is also given. In all, we have established that KP is better suited for the analysis of dielectric samples thicker than 3 mm.
{"title":"Secondary electron emission yield in thick dielectric materials: a comparison between Kelvin probe and capacitive methods","authors":"R Mata, A Cros, B Gimeno and D Raboso","doi":"10.1088/1361-6463/ad5c6f","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5c6f","url":null,"abstract":"The recent high demand of secondary electron emission yield (SEY) measurements in dielectric materials from space industry has driven SEY laboratories to improve their facilities and measurement techniques. SEY determination by the common capacitive method, also known as pulsed method, is well accepted and has given satisfactory results in most cases. Nevertheless, the samples under study must be prepared according to the experimental limitations of the technique, i.e. they should be manufactured separated from the devices representing faithfully the surface state of the own device and be as thin as possible. A method based on the Kelvin probe (KP) is proposed here to obtain the SEY characteristics of electrically floating Platinum, Kapton and Teflon placed over dielectric spacers with thicknesses ranging from 1.6 to 12.1 mm. The results are compared with those of the capacitive method and indicate that KP SEY curves are less sensitive to spacer thickness. An explanation based on the literature is also given. In all, we have established that KP is better suited for the analysis of dielectric samples thicker than 3 mm.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141614875","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 : 2024-07-10DOI: 10.1088/1361-6463/ad5dcb
Asfakujjaman, Mainak Ghosh, Suman Chowdhury and Debnarayan Jana
In this study, we thoroughly explored the thermal transport and thermoelectric properties of BN-co-doped phagraphene structures in the context of first-principles computations combined with machine learning interatomic potential (MLIP) techniques. Our results demonstrate that doping positions can critically tune the thermal properties, offering potential advantages for both thermoelectric and heat transfer applications. Notably, enhanced thermal conductivity has been obtained for phagraphene with 10 co-doping. Additionally, the rectangular structural symmetry of phagraphene plays an important role for targeted thermal transport. Further, we observe negative Grüneisen parameter in these structures, suggesting negative thermal expansion. This will serves as an unique mechanism for controlling the thermal conductivity at different frequencies. Interestingly, n-type behavior of the structures is indicative of its negative Seebeck coefficient within the temperature range of 300–900 K. Moreover, these structures display significantly larger electrical conductivity compared to other two-dimensional (2D) materials. Apart from that, the calculated figure of merit of the structures under a constant relaxation time at 300 K shows considerably better response for some specific doped structures. We believe this study will play an important role in understanding the importance of structural modifications in tailoring the thermal properties of carbon-based 2D systems.
在本研究中，我们通过第一性原理计算结合机器学习原子间势（MLIP）技术，深入探讨了掺杂 BN 的相思结构的热传输和热电性能。我们的研究结果表明，掺杂位置可以对热特性进行关键调整，从而为热电和传热应用提供潜在优势。值得注意的是，掺杂了 10 个共掺物的法拉吩的热导率得到了增强。此外，石墨烯的矩形结构对称性在有针对性的热传输中发挥了重要作用。此外，我们还在这些结构中观察到负的格鲁尼森参数，这表明它们具有负热膨胀性。这将成为控制不同频率下热导率的独特机制。有趣的是，这些结构的 n 型行为表明其在 300-900 K 温度范围内具有负塞贝克系数。此外，在 300 K 的恒定弛豫时间条件下，计算得出的结构优越性数据显示，某些特定掺杂结构的响应要好得多。我们相信，这项研究将对理解结构修饰在定制碳基二维系统热特性方面的重要性起到重要作用。
{"title":"Harnessing BN co-doping for superior thermal transport in phagraphene monolayer","authors":"Asfakujjaman, Mainak Ghosh, Suman Chowdhury and Debnarayan Jana","doi":"10.1088/1361-6463/ad5dcb","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5dcb","url":null,"abstract":"In this study, we thoroughly explored the thermal transport and thermoelectric properties of BN-co-doped phagraphene structures in the context of first-principles computations combined with machine learning interatomic potential (MLIP) techniques. Our results demonstrate that doping positions can critically tune the thermal properties, offering potential advantages for both thermoelectric and heat transfer applications. Notably, enhanced thermal conductivity has been obtained for phagraphene with 10 co-doping. Additionally, the rectangular structural symmetry of phagraphene plays an important role for targeted thermal transport. Further, we observe negative Grüneisen parameter in these structures, suggesting negative thermal expansion. This will serves as an unique mechanism for controlling the thermal conductivity at different frequencies. Interestingly, n-type behavior of the structures is indicative of its negative Seebeck coefficient within the temperature range of 300–900 K. Moreover, these structures display significantly larger electrical conductivity compared to other two-dimensional (2D) materials. Apart from that, the calculated figure of merit of the structures under a constant relaxation time at 300 K shows considerably better response for some specific doped structures. We believe this study will play an important role in understanding the importance of structural modifications in tailoring the thermal properties of carbon-based 2D systems.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"56 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141587230","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 : 2024-07-10DOI: 10.1088/1361-6463/ad5c71
Sonakshi Puri, Sumit Kumar Mandal, Navin Kumar Sharma, Priti Pal, Ram Prakash Lamba, Vandana Miller, Udit Narayan Pal and P R Deepa
Wound healing is a dynamic and intricate biological process crucial for tissue repair and regeneration. This study explores the potential therapeutic impact of non-thermal plasma generated by a hand-held cold atmospheric pressure plasma jet (C-APPJ) source on fibroblast cells (NIH/3T3) in vitro. The sequential phases of wound healing—inflammation, cell proliferation, and tissue remodelling, were assessed in the context of cell migration and oxidative stress dynamics. Typically, plasma generates a mixture of several reactive oxygen/nitrogen (ROS/RNS) species. The present study investigates the safety and efficacy of C-APPJ under distinct operating conditions (argon (GI) and argon + nitrogen (GII)) and exposure times (1 min and 3 min). Cell viability assays confirmed the non-cytotoxic nature of the cold plasma conditioned medium. The levels of ROS/RNS and malondialdehyde (biomarker of oxidative stress) in the plasma-treated samples remained comparable with the control fibroblast cells grown in normal media, suggesting the favourable modulation of ROS by the cellular antioxidant mechanisms. Accelerated wound-closure rates from 6th hour to 24th hour in all the treated groups ranged from 38.76% to 45.66%, when compared to 34.25% in the control cells. Substantial cell migration leading to 51.59% of wound closure was recorded in the argon + nitrogen (GII) group exposed for 3 min. Taken together, the potential of cold plasma to effectively heal wounds without causing prolonged oxidative stress and chronic inflammation is implicated. These outcomes suggest scope for clinical application of C-APPJ as safe and cost-effective treatment of wounds (ulcers, burns, diabetic foot) and wound disinfection.
{"title":"Biochemical evaluation of wound healing efficacy of cold plasma-conditioned media under different operational conditions","authors":"Sonakshi Puri, Sumit Kumar Mandal, Navin Kumar Sharma, Priti Pal, Ram Prakash Lamba, Vandana Miller, Udit Narayan Pal and P R Deepa","doi":"10.1088/1361-6463/ad5c71","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5c71","url":null,"abstract":"Wound healing is a dynamic and intricate biological process crucial for tissue repair and regeneration. This study explores the potential therapeutic impact of non-thermal plasma generated by a hand-held cold atmospheric pressure plasma jet (C-APPJ) source on fibroblast cells (NIH/3T3) in vitro. The sequential phases of wound healing—inflammation, cell proliferation, and tissue remodelling, were assessed in the context of cell migration and oxidative stress dynamics. Typically, plasma generates a mixture of several reactive oxygen/nitrogen (ROS/RNS) species. The present study investigates the safety and efficacy of C-APPJ under distinct operating conditions (argon (GI) and argon + nitrogen (GII)) and exposure times (1 min and 3 min). Cell viability assays confirmed the non-cytotoxic nature of the cold plasma conditioned medium. The levels of ROS/RNS and malondialdehyde (biomarker of oxidative stress) in the plasma-treated samples remained comparable with the control fibroblast cells grown in normal media, suggesting the favourable modulation of ROS by the cellular antioxidant mechanisms. Accelerated wound-closure rates from 6th hour to 24th hour in all the treated groups ranged from 38.76% to 45.66%, when compared to 34.25% in the control cells. Substantial cell migration leading to 51.59% of wound closure was recorded in the argon + nitrogen (GII) group exposed for 3 min. Taken together, the potential of cold plasma to effectively heal wounds without causing prolonged oxidative stress and chronic inflammation is implicated. These outcomes suggest scope for clinical application of C-APPJ as safe and cost-effective treatment of wounds (ulcers, burns, diabetic foot) and wound disinfection.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"23 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141586976","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 : 2024-07-09DOI: 10.1088/1361-6463/ad5cfe
Amina Hadjoudja, Felipe Garcia-Sanchez, Luis Lopez-Diaz
The response of a magnetic domain wall to an external magnetic field in a perpendicularly magnetized synthetic antiferromagnet is studied using both micromagnetic simulations and a reduced model. It is found that the external field induces a sizable displacement between the position of the domain wall in each layer, which can be larger than the domain wall width for a sufficiently strong field. We also study the dynamic evolution of the system when this field is applied or removed. In both cases we find a complex response with two distinct phases that involve both internal domain wall rotation and coupled interlayer domain wall oscillations. As a result of this dynamics spin waves are radiated. The emitted radiation is characterized by a broadband spectrum and can be detected far away from the domain wall.
{"title":"Interlayer coupled domain wall dynamics induced by external magnetic field in synthetic antiferromagnets","authors":"Amina Hadjoudja, Felipe Garcia-Sanchez, Luis Lopez-Diaz","doi":"10.1088/1361-6463/ad5cfe","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5cfe","url":null,"abstract":"The response of a magnetic domain wall to an external magnetic field in a perpendicularly magnetized synthetic antiferromagnet is studied using both micromagnetic simulations and a reduced model. It is found that the external field induces a sizable displacement between the position of the domain wall in each layer, which can be larger than the domain wall width for a sufficiently strong field. We also study the dynamic evolution of the system when this field is applied or removed. In both cases we find a complex response with two distinct phases that involve both internal domain wall rotation and coupled interlayer domain wall oscillations. As a result of this dynamics spin waves are radiated. The emitted radiation is characterized by a broadband spectrum and can be detected far away from the domain wall.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"42 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141576453","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}
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