Pub Date : 2024-07-01DOI: 10.1088/1742-6596/2796/1/012008
A. Baquero Larriva, J.L. Contreras
Gamma-ray astronomy allows for the exploration of the most energetic phenomena in the universe and has seen significant advances in the 21st century, as evidenced by the development of the LST-1 telescope, a part of the Cherenkov Telescope Array (CTA). The LST-1, situated at the Roque de los Muchachos Observatory in La Palma, Spain, commenced its commissioning phase in October 2018 and captured its first light in December of the same year. This research primarily addresses the characterization of the LST-1 telescope, utilizing Monte Carlo simulations and real data from observations of the Crab Nebula to assess its performance, which is already approaching the design requirements. Furthermore, the results obtained from observations of the Active Galactic Nuclei Markarian 421, Markarian 501, and 1ES 1969+560 agree with those obtained by other telescopes, thus validating the efficacy of the LST-1.
{"title":"Exploring the Universe through Gamma-Ray Astronomy: Characterization and Performance of the LST-1 Telescope","authors":"A. Baquero Larriva, J.L. Contreras","doi":"10.1088/1742-6596/2796/1/012008","DOIUrl":"https://doi.org/10.1088/1742-6596/2796/1/012008","url":null,"abstract":"\u0000 Gamma-ray astronomy allows for the exploration of the most energetic phenomena in the universe and has seen significant advances in the 21st century, as evidenced by the development of the LST-1 telescope, a part of the Cherenkov Telescope Array (CTA). The LST-1, situated at the Roque de los Muchachos Observatory in La Palma, Spain, commenced its commissioning phase in October 2018 and captured its first light in December of the same year. This research primarily addresses the characterization of the LST-1 telescope, utilizing Monte Carlo simulations and real data from observations of the Crab Nebula to assess its performance, which is already approaching the design requirements. Furthermore, the results obtained from observations of the Active Galactic Nuclei Markarian 421, Markarian 501, and 1ES 1969+560 agree with those obtained by other telescopes, thus validating the efficacy of the LST-1.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"3 s4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141689165","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}
Pub Date : 2024-07-01DOI: 10.1088/1742-6596/2791/1/012061
Erhui Wang, Xuefei Luan
With the development of new numerical calculation methods and computer software science and technology, people can have a good understanding of the potential mechanisms of cerebrovascular diseases. Here, we combine the stochastic differential equation (SDE) of discrete Markov chains to numerically simulate the dynamic changes of neural signals, and find that the changes of neural signals exhibit regular fluctuations. By analyzing the variation of voltage over time, we know that the voltage change at the next moment is closely related to the previous moment and has continuity. Based on the knowledge of neural ion channel dynamics, it was found that there will be longer peak changes in voltage, exhibiting a power-law distribution, which is consistent with the actual situation and statistical data related to resignation channels. By analyzing the voltage and peak changes of ion channels, we can gain a new understanding of the transmission laws of neural information and greatly improve the biological mechanisms.
{"title":"Numerical simulation of neural activity based on discrete Markov chains with stochastic differential equations","authors":"Erhui Wang, Xuefei Luan","doi":"10.1088/1742-6596/2791/1/012061","DOIUrl":"https://doi.org/10.1088/1742-6596/2791/1/012061","url":null,"abstract":"\u0000 With the development of new numerical calculation methods and computer software science and technology, people can have a good understanding of the potential mechanisms of cerebrovascular diseases. Here, we combine the stochastic differential equation (SDE) of discrete Markov chains to numerically simulate the dynamic changes of neural signals, and find that the changes of neural signals exhibit regular fluctuations. By analyzing the variation of voltage over time, we know that the voltage change at the next moment is closely related to the previous moment and has continuity. Based on the knowledge of neural ion channel dynamics, it was found that there will be longer peak changes in voltage, exhibiting a power-law distribution, which is consistent with the actual situation and statistical data related to resignation channels. By analyzing the voltage and peak changes of ion channels, we can gain a new understanding of the transmission laws of neural information and greatly improve the biological mechanisms.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"10 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141700525","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}
Pub Date : 2024-07-01DOI: 10.1088/1742-6596/2791/1/012028
Yongshuai Lu, Yunfang Cui
The numerical simulation of R141b flow boiling in micro-fin tubes (MFTs) with a 1 mm equivalent diameter is conducted using the VOF and the Lee models. An analysis of the boiling heat transfer (HT) characteristics has been performed, considering impacts of the four factors. The most suitable correlation of boiling HT has also been evaluated. The summarized findings are as follows: the BHT coefficient within the MFTs consistently rises with increased mass velocity, heat flux, and saturation temperature. However, there is a presence of a partially dry-out region inside the MFTs at high heat flux. Additionally, the enhancement of boiling HT by elevating saturation temperature is not prominent in the low vapor quality range. HT coefficients of the MFTs with various fin structures ranked in magnitude are as follows: tapered MFTs > trapezoidal MFTs > circular MFTs. The model proposed by Wu is identified as the best predictor for flow boiling HT performance in horizontal MFTs, although its prediction accuracy is limited in the low vapor quality range.
{"title":"Numerical simulation of the effects of toothed structure on the flow boiling characteristics of micro-fin tubes","authors":"Yongshuai Lu, Yunfang Cui","doi":"10.1088/1742-6596/2791/1/012028","DOIUrl":"https://doi.org/10.1088/1742-6596/2791/1/012028","url":null,"abstract":"\u0000 The numerical simulation of R141b flow boiling in micro-fin tubes (MFTs) with a 1 mm equivalent diameter is conducted using the VOF and the Lee models. An analysis of the boiling heat transfer (HT) characteristics has been performed, considering impacts of the four factors. The most suitable correlation of boiling HT has also been evaluated. The summarized findings are as follows: the BHT coefficient within the MFTs consistently rises with increased mass velocity, heat flux, and saturation temperature. However, there is a presence of a partially dry-out region inside the MFTs at high heat flux. Additionally, the enhancement of boiling HT by elevating saturation temperature is not prominent in the low vapor quality range. HT coefficients of the MFTs with various fin structures ranked in magnitude are as follows: tapered MFTs > trapezoidal MFTs > circular MFTs. The model proposed by Wu is identified as the best predictor for flow boiling HT performance in horizontal MFTs, although its prediction accuracy is limited in the low vapor quality range.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"45 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141709603","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}
Pub Date : 2024-07-01DOI: 10.1088/1742-6596/2797/1/012010
Kangwei Cai, Ping Fu
Ultrasonic motors are widely used in aerospace, smart cameras, and other applications. For ultrasonic motors to have the highest operating efficiency, the operating frequency of the motor needs to be adjusted in real time so that the motor’s operating frequency tracks the optimum frequency. Since the current research is limited to the optimum frequency tracking under constant velocity, the three-level drive parameters need to be adjusted to stabilize the velocity, which lacks precision and does not consider the frequency tracking under variable velocity. This paper explores an optimum frequency tracking scheme for ultrasonic motors under the three-level constant voltage input drive and proposes a variable step-size optimum frequency tracking scheme. The experimental results show that the optimum frequency of ultrasonic motors in variable velocity motion exists, and the proposed tracking scheme with three-level drive parameters can effectively improve the efficiency of the motor and significantly broaden the application scenario of the optimum frequency of ultrasonic motors.
{"title":"Optimum frequency tracking of the ultrasonic motor based on a three-level constant voltage drive","authors":"Kangwei Cai, Ping Fu","doi":"10.1088/1742-6596/2797/1/012010","DOIUrl":"https://doi.org/10.1088/1742-6596/2797/1/012010","url":null,"abstract":"\u0000 Ultrasonic motors are widely used in aerospace, smart cameras, and other applications. For ultrasonic motors to have the highest operating efficiency, the operating frequency of the motor needs to be adjusted in real time so that the motor’s operating frequency tracks the optimum frequency. Since the current research is limited to the optimum frequency tracking under constant velocity, the three-level drive parameters need to be adjusted to stabilize the velocity, which lacks precision and does not consider the frequency tracking under variable velocity. This paper explores an optimum frequency tracking scheme for ultrasonic motors under the three-level constant voltage input drive and proposes a variable step-size optimum frequency tracking scheme. The experimental results show that the optimum frequency of ultrasonic motors in variable velocity motion exists, and the proposed tracking scheme with three-level drive parameters can effectively improve the efficiency of the motor and significantly broaden the application scenario of the optimum frequency of ultrasonic motors.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141851406","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}
Pub Date : 2024-07-01DOI: 10.1088/1742-6596/2795/1/012019
Chunxin Wang, Yang Lu, Guodong Shan, Wenyu Qu, Jun Xu
With the rapid development of the Electric Power Internet of Things (EPIoT), effectively utilizing reinforcement learning algorithms for optimizing energy management and distribution has become crucial. This paper aims to explore and address one of the primary challenges when applying reinforcement learning algorithms in the context of EPIoT: the issue of linear function fitting. Firstly, we analyze the complexity of data processing in the EPIoT and why standard reinforcement learning algorithms perform poorly in this environment. Subsequently, this research proposes an improved reinforcement learning framework that enhances the accuracy and efficiency of the algorithm in handling large-scale, high-dimensional data by optimizing the linear function fitting process. We validate the performance of the proposed algorithm through a series of experiments using real-world power data. The experimental results demonstrate significant improvements in accuracy and computational speed compared to traditional methods. Finally, this paper discusses the limitations of the study and future research directions, providing new perspectives and ideas for further research in the Electric Power Internet of Things.
{"title":"Optimization of Reinforcement Learning Algorithms for Addressing the Linear Function Fitting Challenge in the Electric Power Internet of Things","authors":"Chunxin Wang, Yang Lu, Guodong Shan, Wenyu Qu, Jun Xu","doi":"10.1088/1742-6596/2795/1/012019","DOIUrl":"https://doi.org/10.1088/1742-6596/2795/1/012019","url":null,"abstract":"\u0000 With the rapid development of the Electric Power Internet of Things (EPIoT), effectively utilizing reinforcement learning algorithms for optimizing energy management and distribution has become crucial. This paper aims to explore and address one of the primary challenges when applying reinforcement learning algorithms in the context of EPIoT: the issue of linear function fitting. Firstly, we analyze the complexity of data processing in the EPIoT and why standard reinforcement learning algorithms perform poorly in this environment. Subsequently, this research proposes an improved reinforcement learning framework that enhances the accuracy and efficiency of the algorithm in handling large-scale, high-dimensional data by optimizing the linear function fitting process. We validate the performance of the proposed algorithm through a series of experiments using real-world power data. The experimental results demonstrate significant improvements in accuracy and computational speed compared to traditional methods. Finally, this paper discusses the limitations of the study and future research directions, providing new perspectives and ideas for further research in the Electric Power Internet of Things.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"22 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141853853","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}
Pub Date : 2024-07-01DOI: 10.1088/1742-6596/2806/1/012011
Xiaohu Zhang, Mengyao Zhang, Ling Xu, Ruanming Huang, Canbing Li
Large-scale offshore wind generation has been integrated to power grids in China. The annual increase in electric vehicles, air conditioning systems, and other electrical facilities has intensified the randomness and volatility of power supply and demand, presenting significant challenges to the safe and economical operation of power systems. Energy storage systems serve as regulators in the power grid, yet the electrical performance and costs associated with various storage technologies differ considerably. Consequently, the strategic planning and development of energy storage solutions tailored to specific local conditions have emerged as critical areas of research. This paper presents an in-depth analysis of power characteristics across source loads, explores an optimized configuration approach for energy storage, and validates this method through a numerical example. The findings confirm the effectiveness of the proposed configuration strategy and offer pertinent recommendations for the implementation of energy storage solutions.
{"title":"Optimal allocation of offshore wind power and energy storage considering source-load power stochasticity","authors":"Xiaohu Zhang, Mengyao Zhang, Ling Xu, Ruanming Huang, Canbing Li","doi":"10.1088/1742-6596/2806/1/012011","DOIUrl":"https://doi.org/10.1088/1742-6596/2806/1/012011","url":null,"abstract":"\u0000 Large-scale offshore wind generation has been integrated to power grids in China. The annual increase in electric vehicles, air conditioning systems, and other electrical facilities has intensified the randomness and volatility of power supply and demand, presenting significant challenges to the safe and economical operation of power systems. Energy storage systems serve as regulators in the power grid, yet the electrical performance and costs associated with various storage technologies differ considerably. Consequently, the strategic planning and development of energy storage solutions tailored to specific local conditions have emerged as critical areas of research. This paper presents an in-depth analysis of power characteristics across source loads, explores an optimized configuration approach for energy storage, and validates this method through a numerical example. The findings confirm the effectiveness of the proposed configuration strategy and offer pertinent recommendations for the implementation of energy storage solutions.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"22 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141848155","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}
The greenhouse effect caused by SF6 gas in the power system cannot be ignored, and N2 has enormous industrial potential to replace pure SF6 by mixing with SF6 due to its advantages of low environmental pollution, low price, and stable chemical performance. This article combines density functional theory (DFT) and transition state theory (TST) to calculate the molecular structure and vibrational frequency information of various reactants, products, and transition states involved in SF6/N2 gas mixtures containing water and oxygen. The single point energy of each component is calculated using the CCSD (T)/cc pvtz theory level, and all reaction barrier energies are obtained. The calculated molecular structure and vibration frequency results are in good agreement with the experimental data of NIST, proving the reliability of the calculation method in this paper. The difficulty of the reaction can be determined by obtaining all the reaction barrier energies. It was found that SF5 molecules are unstable and prone to decomposition. SF4 is very important in the SF6/N2 reaction system, and further decomposition will produce a large number of stable by-products. The calculation method in this article helps to deeply understand the decomposition reaction mechanism of SF6/N2 mixed gas, and is of great significance for the research of decomposition experiments.
{"title":"Calculation of the Structure and Reaction Potential Barrier of the Decomposition Products of SF6/N2 Mixed Gases","authors":"Jien Niu, Yongqi Wang, Gang Liu, Honggang Chen, Huanhuan Niu, Xinhong Fan, Zhengyuan Zhang, Rui Zhao","doi":"10.1088/1742-6596/2774/1/012059","DOIUrl":"https://doi.org/10.1088/1742-6596/2774/1/012059","url":null,"abstract":"\u0000 The greenhouse effect caused by SF6 gas in the power system cannot be ignored, and N2 has enormous industrial potential to replace pure SF6 by mixing with SF6 due to its advantages of low environmental pollution, low price, and stable chemical performance. This article combines density functional theory (DFT) and transition state theory (TST) to calculate the molecular structure and vibrational frequency information of various reactants, products, and transition states involved in SF6/N2 gas mixtures containing water and oxygen. The single point energy of each component is calculated using the CCSD (T)/cc pvtz theory level, and all reaction barrier energies are obtained. The calculated molecular structure and vibration frequency results are in good agreement with the experimental data of NIST, proving the reliability of the calculation method in this paper. The difficulty of the reaction can be determined by obtaining all the reaction barrier energies. It was found that SF5 molecules are unstable and prone to decomposition. SF4 is very important in the SF6/N2 reaction system, and further decomposition will produce a large number of stable by-products. The calculation method in this article helps to deeply understand the decomposition reaction mechanism of SF6/N2 mixed gas, and is of great significance for the research of decomposition experiments.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141851056","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}
High power density is an advance in power electronics. Third generation wide-bandgap semiconductor devices (WBG SICs) offer significantly improved performance compared to standard silicon devices. SIC MOSFET is commonly used in power electronic equipment such as converters due to its low resistance, excellent thermal stability, and rapid switching speed. Increasing the switching frequency effectively reduces the circuit size. This article uses SIC MOSFET and STM32 single-chip MCU to design a high power density and higher frequency buck boost converter and establish a simulation model in LTspice. The driving circuit designed for SIC MOSFET is intended to maximize the converter’s reliability. Synchronous rectification applies to enhance the converter efficiency. Compared to other types of converters, the size of the converter is reduced, achieving the goals of lightweight and high power density of DC/DC converters.
高功率密度是电力电子技术的一大进步。与标准硅器件相比，第三代宽带隙半导体器件（WBG SIC）的性能显著提高。SIC MOSFET 电阻低、热稳定性好、开关速度快，因此常用于转换器等电力电子设备中。提高开关频率可有效缩小电路尺寸。本文利用 SIC MOSFET 和 STM32 单芯片 MCU 设计了一种高功率密度、更高频率的降压升压转换器，并在 LTspice 中建立了仿真模型。为 SIC MOSFET 设计的驱动电路旨在最大限度地提高转换器的可靠性。同步整流可提高转换器的效率。与其他类型的转换器相比，转换器的体积减小，实现了 DC/DC 转换器轻量化和高功率密度的目标。
{"title":"High Power Density Buck Boost DC/DC Converter Using SIC MOSFET","authors":"Zuraiz Rana, Runquan Meng, Kashif Ali, Rashid Haseeb","doi":"10.1088/1742-6596/2774/1/012099","DOIUrl":"https://doi.org/10.1088/1742-6596/2774/1/012099","url":null,"abstract":"\u0000 High power density is an advance in power electronics. Third generation wide-bandgap semiconductor devices (WBG SICs) offer significantly improved performance compared to standard silicon devices. SIC MOSFET is commonly used in power electronic equipment such as converters due to its low resistance, excellent thermal stability, and rapid switching speed. Increasing the switching frequency effectively reduces the circuit size. This article uses SIC MOSFET and STM32 single-chip MCU to design a high power density and higher frequency buck boost converter and establish a simulation model in LTspice. The driving circuit designed for SIC MOSFET is intended to maximize the converter’s reliability. Synchronous rectification applies to enhance the converter efficiency. Compared to other types of converters, the size of the converter is reduced, achieving the goals of lightweight and high power density of DC/DC converters.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"2019 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141851445","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}
Through phase analysis and quantitative calculations of the hydration process, the inclusion of polyacrylamide (PAM) in Anti-dispersion Water Paste affects its hydration characteristics is discovered. Specifically, the presence of PAM reduces early reactivity while accelerating progress in the middle to late stages of hydration. By employing K-D hydration kinetic analysis, it is confirmed that the use of PAM results in the formation of a multi-nucleation homogeneous point system within the cement slurry. This system prolongs the NG (nucleation and growth) process time, increases the hydration degree during the transition from NG to I (induction) process, and inhibits the heterogeneous precipitation of hydration products. Consequently, the early hydration of cement is hindered. As the hydration reaction advances, the microstructure of the product under multi-nucleation points increases the specific surface area. This gradual breakthrough of the hydration threshold barrier shortens the duration of the phase boundary reaction process and reduces the hydration degree during the I and D (diffusion) processes. Consequently, the late-stage hydration rate is accelerated.
通过对水合过程进行相分析和定量计算，发现在抗分散水浆中加入聚丙烯酰胺（PAM）会影响其水合特性。具体来说，PAM 的存在降低了早期反应性，同时加快了水合中后期阶段的进展。通过采用 K-D 水化动力学分析，证实了 PAM 的使用会在水泥浆中形成一个多核均质点系统。该系统延长了 NG（成核和生长）过程的时间，增加了从 NG 过渡到 I（诱导）过程的水化程度，并抑制了水化产物的异质析出。因此，水泥的早期水化受到阻碍。随着水化反应的推进，多核点下产物的微观结构增加了比表面积。水化阈值障碍的逐渐突破缩短了相界反应过程的持续时间，降低了 I 和 D（扩散）过程中的水化程度。因此，后期水合速率加快。
{"title":"Hydration characteristics and kinetic analysis of polyacrylamide (PAM) anti-dispersion cement-based materials","authors":"Yang He, Hua Wei, Chunhe Li, Hao Lu, Fei Xu, Jiaming Zhang","doi":"10.1088/1742-6596/2790/1/012001","DOIUrl":"https://doi.org/10.1088/1742-6596/2790/1/012001","url":null,"abstract":"\u0000 Through phase analysis and quantitative calculations of the hydration process, the inclusion of polyacrylamide (PAM) in Anti-dispersion Water Paste affects its hydration characteristics is discovered. Specifically, the presence of PAM reduces early reactivity while accelerating progress in the middle to late stages of hydration. By employing K-D hydration kinetic analysis, it is confirmed that the use of PAM results in the formation of a multi-nucleation homogeneous point system within the cement slurry. This system prolongs the NG (nucleation and growth) process time, increases the hydration degree during the transition from NG to I (induction) process, and inhibits the heterogeneous precipitation of hydration products. Consequently, the early hydration of cement is hindered. As the hydration reaction advances, the microstructure of the product under multi-nucleation points increases the specific surface area. This gradual breakthrough of the hydration threshold barrier shortens the duration of the phase boundary reaction process and reduces the hydration degree during the I and D (diffusion) processes. Consequently, the late-stage hydration rate is accelerated.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"2011 27","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141851697","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}
Pub Date : 2024-07-01DOI: 10.1088/1742-6596/2774/1/012084
Zhenghong Bao, Jiyun Ren, Lili Wang, Shengjie Wang, Yao Chen, Zibin Li, Zile Wang, Yongfu Ma, Liao Li, Huan Chen
Gas insulated switchgear (GIS) is a critical component in power system, and the insulation testing is crucial before putting it into operation. Despite passing AC withstand tests, some GIS equipment exhibit insulation faults during operation. Existing AC withstand tests fall short in detecting all insulation faults in GIS equipment. To address this issue, a proposal is made to conduct a comprehensive simulation of actual GIS equipment operating conditions through a combined voltage and current boost test, aiming to address the limitations of existing tests. This study, based on a 330kV GIS test platform, compares the partial discharge characteristics of suspension defects under traditional voltage-boosting mode and the combined voltage and current boost mode. The research investigates the influence of simultaneously applying voltage and current on discharge characteristics. It is observed that the voltage and current boost combined mode significantly increase the partial discharge inception voltage (PDIV) and the corresponding apparent discharge compared to other modes. The apparent discharge quantity after a certain period of current flow during the discharge development process is greater than that observed in other modes. The current notably enhances the ultrasonic amplitude of partial discharge. These findings establish an experimental foundation for conducting voltage and current combined boost tests in the field.
{"title":"Research on Partial Discharge Characteristics of Suspension Defect in GIS under the Action of Voltage and Current","authors":"Zhenghong Bao, Jiyun Ren, Lili Wang, Shengjie Wang, Yao Chen, Zibin Li, Zile Wang, Yongfu Ma, Liao Li, Huan Chen","doi":"10.1088/1742-6596/2774/1/012084","DOIUrl":"https://doi.org/10.1088/1742-6596/2774/1/012084","url":null,"abstract":"\u0000 Gas insulated switchgear (GIS) is a critical component in power system, and the insulation testing is crucial before putting it into operation. Despite passing AC withstand tests, some GIS equipment exhibit insulation faults during operation. Existing AC withstand tests fall short in detecting all insulation faults in GIS equipment. To address this issue, a proposal is made to conduct a comprehensive simulation of actual GIS equipment operating conditions through a combined voltage and current boost test, aiming to address the limitations of existing tests. This study, based on a 330kV GIS test platform, compares the partial discharge characteristics of suspension defects under traditional voltage-boosting mode and the combined voltage and current boost mode. The research investigates the influence of simultaneously applying voltage and current on discharge characteristics. It is observed that the voltage and current boost combined mode significantly increase the partial discharge inception voltage (PDIV) and the corresponding apparent discharge compared to other modes. The apparent discharge quantity after a certain period of current flow during the discharge development process is greater than that observed in other modes. The current notably enhances the ultrasonic amplitude of partial discharge. These findings establish an experimental foundation for conducting voltage and current combined boost tests in the field.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141838885","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}
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