Middle-frequency oscillation instability is one of the important issues that threats the safe integration of offshore wind farms. However, analytical explanations to key affecting factors and laws for the middle-frequency oscillation are not clear yet, which makes it difficult to avoid this kind of oscillation effectively. Therefore, in this paper, mechanism for the middle-frequency oscillation induced by the dynamics of converter current inner loops is studied in-depth. First, small-signal transfer function model for a general offshore wind farm integrated via AC submarine cable is established. Then impact of the AC submarine cable and control parameters of the converter current inner loops on oscillation stability of the wind farm is analysed via eigenvalue analysis. It is found that with the length of AC submarine cable increases, frequency for the open-loop pole of the AC grid decreases. When open-loop pole of the AC grid gets close that of the PMSGs on complex plane, the near strong mode resonance can cause middle-frequency oscillation of the system. Finally, effectiveness of the conclusions drawn is evaluated through nonlinear simulations.
{"title":"Mechanisms of middle-frequency oscillations in an offshore wind farm induced by the converter current inner loops","authors":"Yong Chen, Hui Huang, Ruixiong Yang, Xingwang Ren, Yawei Sang, Haobin Wu","doi":"10.1088/1742-6596/2806/1/012012","DOIUrl":"https://doi.org/10.1088/1742-6596/2806/1/012012","url":null,"abstract":"\u0000 Middle-frequency oscillation instability is one of the important issues that threats the safe integration of offshore wind farms. However, analytical explanations to key affecting factors and laws for the middle-frequency oscillation are not clear yet, which makes it difficult to avoid this kind of oscillation effectively. Therefore, in this paper, mechanism for the middle-frequency oscillation induced by the dynamics of converter current inner loops is studied in-depth. First, small-signal transfer function model for a general offshore wind farm integrated via AC submarine cable is established. Then impact of the AC submarine cable and control parameters of the converter current inner loops on oscillation stability of the wind farm is analysed via eigenvalue analysis. It is found that with the length of AC submarine cable increases, frequency for the open-loop pole of the AC grid decreases. When open-loop pole of the AC grid gets close that of the PMSGs on complex plane, the near strong mode resonance can cause middle-frequency oscillation of the system. Finally, effectiveness of the conclusions drawn is evaluated through nonlinear simulations.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"8 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141844541","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}
Microgrids typically consist of various energy resources such as thermal power, solar energy, wind energy, energy storage, and so on. These energy resources have different characteristics and fluctuations. By utilizing the characteristics of different energy resources in a complementary and synergistic manner, their energy utilization efficiency can be promoted and the system stability can be improved. This paper considers the energy storage device in the completion of a single charge and discharge loss, that is, the single-use cost. Special attention to the impact of start-stop costs of unit combinations on microgrid operations. It proposes that in the daily dispatch and operation of microgrids, sinking costs can be reasonably reduced within a reasonable range, and power supply reliability can be appropriately lowered to improve the economic performance of power systems. Using the single-use cost of energy storage devices and the start-stop costs of unit combinations as variables, their impact on the economic operation of isolated microgrids is analyzed. For grid-connected microgrids with the objectives of minimizing operating costs and achieving optimal environmental protection, an optimal balance between economic and environmental performance is achieved through solving by Anti-Entropy weight method and Particle Swarm Optimization combination.
{"title":"Multi-Objective Optimization Scheduling of Microgrids Considering Single Use Cost of Energy Storage and Unit Combination Startup and Shutdown Cost","authors":"Baojie Zhang, Yiqian Sun, Hongfeng Zhao, Hongyan Hao, Pengpeng Kang, Guixing Yang, Defu Liu, Guowei Fan, Guowei Liu","doi":"10.1088/1742-6596/2774/1/012051","DOIUrl":"https://doi.org/10.1088/1742-6596/2774/1/012051","url":null,"abstract":"\u0000 Microgrids typically consist of various energy resources such as thermal power, solar energy, wind energy, energy storage, and so on. These energy resources have different characteristics and fluctuations. By utilizing the characteristics of different energy resources in a complementary and synergistic manner, their energy utilization efficiency can be promoted and the system stability can be improved. This paper considers the energy storage device in the completion of a single charge and discharge loss, that is, the single-use cost. Special attention to the impact of start-stop costs of unit combinations on microgrid operations. It proposes that in the daily dispatch and operation of microgrids, sinking costs can be reasonably reduced within a reasonable range, and power supply reliability can be appropriately lowered to improve the economic performance of power systems. Using the single-use cost of energy storage devices and the start-stop costs of unit combinations as variables, their impact on the economic operation of isolated microgrids is analyzed. For grid-connected microgrids with the objectives of minimizing operating costs and achieving optimal environmental protection, an optimal balance between economic and environmental performance is achieved through solving by Anti-Entropy weight method and Particle Swarm Optimization combination.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"11 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141846824","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: 10.1088/1742-6596/2793/1/012002
Talal Al-Ameen, Maythem Mahmud, Imad Muhi
The binomial (Taylor) expansion of the Lorentz factor has been reconsidered here in an attempt to find out whether the Newtonian kinetic energy and the Einsteinian rest-mass energy are implicitly embedded in the mathematical structure of the binomial expansion of the Lorentz factor (as Einstein postulated in his Special Theory of Relativity). Advocates of Standard Special Relativity show that it is possible to obtain these two kinds of energy by multiplying both sides of the expansion of the Lorentz factor by the moving object’s rest mass m0 and the square of the speed of light c2. This study shows that the apparent reconciliation between classical and relativistic physics made possible by employing the binomial expansion of the Lorentz factor γ=[1−(v2c2)]−12, where
这里重新考虑了洛伦兹系数的二项式（泰勒）展开，试图找出牛顿动能和爱因斯坦静止质量能是否隐含在洛伦兹系数二项式展开的数学结构中（如爱因斯坦在他的狭义相对论中所假设的那样）。标准狭义相对论的倡导者指出，将洛伦兹系数展开的两边分别乘以运动物体的静止质量 m 0 和光速 c 2 的平方，就可以得到这两种能量。这项研究表明，利用洛伦兹系数 γ = [ 1 - ( v 2 c 2 ) 的二项式展开，可以在表面上调和经典物理学和相对论物理学。 ] - 1 2，其中 v 是运动物体的速度，这一点值得商榷。此外，爱因斯坦著名的静止质量能量方程 E = m 0 c 2（从动能网 = mrelativistic c 2 - m 0 c 2 得出）如何用于计算核裂变释放的能量？
{"title":"Can Newtonian kinetic energy and Einsteinian rest-mass energy be expressed by the binomial expansion of the Lorentz factor? And how valid is using Einstein’s E = mc2 to calculate the nuclear fission energy?","authors":"Talal Al-Ameen, Maythem Mahmud, Imad Muhi","doi":"10.1088/1742-6596/2793/1/012002","DOIUrl":"https://doi.org/10.1088/1742-6596/2793/1/012002","url":null,"abstract":"\u0000 <jats:p>The binomial (Taylor) expansion of the Lorentz factor has been reconsidered here in an attempt to find out whether the <jats:italic>Newtonian kinetic energy</jats:italic> and the <jats:italic>Einsteinian rest-mass energy</jats:italic> are implicitly embedded in the mathematical structure of the binomial expansion of the Lorentz factor (as Einstein postulated in his Special Theory of Relativity). Advocates of Standard Special Relativity show that it is possible to obtain these two kinds of energy by multiplying both sides of the expansion of the Lorentz factor by the moving object’s rest mass <jats:italic>m</jats:italic>\u0000 <jats:sub>0</jats:sub> and the square of the speed of light <jats:italic>c</jats:italic>\u0000 <jats:sup>2</jats:sup>. This study shows that the <jats:italic>apparent</jats:italic> reconciliation between classical and relativistic physics made possible by employing the binomial expansion of the Lorentz factor <jats:inline-formula>\u0000 <jats:tex-math/>\u0000 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\">\u0000 <mml:mrow>\u0000 <mml:mi>γ</mml:mi>\u0000 <mml:mo>=</mml:mo>\u0000 <mml:msup>\u0000 <mml:mrow>\u0000 <mml:mo stretchy=\"false\">[</mml:mo>\u0000 <mml:mn>1</mml:mn>\u0000 <mml:mo>−</mml:mo>\u0000 <mml:mo stretchy=\"false\">(</mml:mo>\u0000 <mml:mfrac>\u0000 <mml:mrow>\u0000 <mml:msup>\u0000 <mml:mi>v</mml:mi>\u0000 <mml:mn>2</mml:mn>\u0000 </mml:msup>\u0000 </mml:mrow>\u0000 <mml:mrow>\u0000 <mml:msup>\u0000 <mml:mi>c</mml:mi>\u0000 <mml:mn>2</mml:mn>\u0000 </mml:msup>\u0000 </mml:mrow>\u0000 </mml:mfrac>\u0000 <mml:mo stretchy=\"false\">)</mml:mo>\u0000 <mml:mo stretchy=\"false\">]</mml:mo>\u0000 </mml:mrow>\u0000 <mml:mrow>\u0000 <mml:mo>−</mml:mo>\u0000 <mml:mfrac>\u0000 <mml:mn>1</mml:mn>\u0000 <mml:mn>2</mml:mn>\u0000 </mml:mfrac>\u0000 </mml:mrow>\u0000 </mml:msup>\u0000 </mml:mrow>\u0000 </mml:math>\u0000 </jats:inline-formula>, where <ja","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"30 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141838971","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: 10.1088/1742-6596/2806/1/012001
Y. R. Ming, S. B. Liu
Branch pipes are widely found in complex equipment, and its layout planning and design has an important impact on the quality and efficiency of equipment design. In this paper, a branch pipe layout planning method based on machine learning and improved grey wolf algorithm is proposed. Firstly, the branch pipe layout problem is decomposed into a series of “between two points” pipe layout and “point to line” pipe layout problems to reduce the complexity of the problem. Secondly, the Q-learning algorithm is applied to solve the “between two points” pipe layout path solving problem, and then combined with the improved grey wolf algorithm to optimize the “point to line” pipe path solving. Finally, a simulation system is built based on Siemens NX and MATLAB platform, and the validity of the proposed method is verified by simulation cases.
{"title":"Complex Branch Pipe Layout Optimization Based on Machine Learning and Improved Grey Wolf Algorithm","authors":"Y. R. Ming, S. B. Liu","doi":"10.1088/1742-6596/2806/1/012001","DOIUrl":"https://doi.org/10.1088/1742-6596/2806/1/012001","url":null,"abstract":"\u0000 Branch pipes are widely found in complex equipment, and its layout planning and design has an important impact on the quality and efficiency of equipment design. In this paper, a branch pipe layout planning method based on machine learning and improved grey wolf algorithm is proposed. Firstly, the branch pipe layout problem is decomposed into a series of “between two points” pipe layout and “point to line” pipe layout problems to reduce the complexity of the problem. Secondly, the Q-learning algorithm is applied to solve the “between two points” pipe layout path solving problem, and then combined with the improved grey wolf algorithm to optimize the “point to line” pipe path solving. Finally, a simulation system is built based on Siemens NX and MATLAB platform, and the validity of the proposed method is verified by simulation cases.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"169 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141840428","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: 10.1088/1742-6596/2774/1/012065
Qiying Li, Yumeng Xie, Lei Yang, Kun Yang, Dongsheng Xu, Dongwei Qiao, Shuyuan Wang
While PV-battery hybrid grid integration has been recognized as an effective approach to enhance transient stability, the high operational and maintenance costs of energy storage systems constrain their reliability across various operating scenarios. To overcome this challenge, this paper takes the application of PV-battery subsystems in a distribution grid supply scenario as an example and conducts an in-depth analysis of the transient stability of PV systems during fault conditions. In cases where system demands are not adequately met, this research proposes a solution based on shared energy storage to enhance system supportability while maintaining economic feasibility. By appropriately allocating and sharing energy storage capacity, the system can better respond to sudden load fluctuations and fault conditions, ensuring a stable power supply. Simulation results demonstrate that the proposed shared energy storage solution significantly enhances the transient stability of PV systems during fault conditions, effectively mitigating the destabilizing effects of PV grid integration. Furthermore, from an economic perspective, this solution can reduce energy storage operation and maintenance costs, enhancing overall system sustainability. In conclusion, this study presents a feasible and effective support solution for the application of PV systems in distribution grids, providing valuable insights to advance the reliability and sustainability of clean energy sources.
{"title":"Shared Energy Storage Scheme for Photovoltaic Energy Storage Power Supply System","authors":"Qiying Li, Yumeng Xie, Lei Yang, Kun Yang, Dongsheng Xu, Dongwei Qiao, Shuyuan Wang","doi":"10.1088/1742-6596/2774/1/012065","DOIUrl":"https://doi.org/10.1088/1742-6596/2774/1/012065","url":null,"abstract":"\u0000 While PV-battery hybrid grid integration has been recognized as an effective approach to enhance transient stability, the high operational and maintenance costs of energy storage systems constrain their reliability across various operating scenarios. To overcome this challenge, this paper takes the application of PV-battery subsystems in a distribution grid supply scenario as an example and conducts an in-depth analysis of the transient stability of PV systems during fault conditions. In cases where system demands are not adequately met, this research proposes a solution based on shared energy storage to enhance system supportability while maintaining economic feasibility. By appropriately allocating and sharing energy storage capacity, the system can better respond to sudden load fluctuations and fault conditions, ensuring a stable power supply. Simulation results demonstrate that the proposed shared energy storage solution significantly enhances the transient stability of PV systems during fault conditions, effectively mitigating the destabilizing effects of PV grid integration. Furthermore, from an economic perspective, this solution can reduce energy storage operation and maintenance costs, enhancing overall system sustainability. In conclusion, this study presents a feasible and effective support solution for the application of PV systems in distribution grids, providing valuable insights to advance the reliability and sustainability of clean energy sources.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"18 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141848666","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: 10.1088/1742-6596/2796/1/012009
R. Araguillin, Ángel Méndez, José González, C. Costa-Vera
The growing demand for compound characterization has stimulated research, particularly in surface plasmon resonance technology. This technique monitors changes in the light-reflecting properties of a sample medium in close contact and in interaction with a plasmonic surface (typically a metal such as gold) due to shifts in the fundamental plasmon resonance of the surface. The Otto and Kretschmann configurations are commonly used in this method. When an analyte is expensive, scarce, or hazardous, it is advantageous to reduce the sample required for testing, making optimization of sample use interesting. This challenge requires trade-offs between sensitivity and LoD. This work compares two sensors in the indicated configurations designed for minimal analyte requirement (in this case, Ag nanoparticle suspensions) using the wavelength scanning technique. The results show that the Kretschmann configuration is the most efficient for characterizing nanoparticle suspensions due to its construction characteristics, ease of use, and the characteristics of the obtained response. The final arrangement is a quasi-point sensor that only requires 6μL of analyte and has a sensitivity of 4.17x10−4 RIU/λ (RIU is the refractive index unit). This study contributes to the exploration of advantages and limitations in the design and operation of SPR sensors. The work also underlies the need for future research to enhance the selectivity and versatility of these devices.
{"title":"Comparative evaluation of wavelength-scanning Otto and Kretschmann configurations of SPR biosensors for low analyte concentration measurement","authors":"R. Araguillin, Ángel Méndez, José González, C. Costa-Vera","doi":"10.1088/1742-6596/2796/1/012009","DOIUrl":"https://doi.org/10.1088/1742-6596/2796/1/012009","url":null,"abstract":"\u0000 The growing demand for compound characterization has stimulated research, particularly in surface plasmon resonance technology. This technique monitors changes in the light-reflecting properties of a sample medium in close contact and in interaction with a plasmonic surface (typically a metal such as gold) due to shifts in the fundamental plasmon resonance of the surface. The Otto and Kretschmann configurations are commonly used in this method. When an analyte is expensive, scarce, or hazardous, it is advantageous to reduce the sample required for testing, making optimization of sample use interesting. This challenge requires trade-offs between sensitivity and LoD. This work compares two sensors in the indicated configurations designed for minimal analyte requirement (in this case, Ag nanoparticle suspensions) using the wavelength scanning technique. The results show that the Kretschmann configuration is the most efficient for characterizing nanoparticle suspensions due to its construction characteristics, ease of use, and the characteristics of the obtained response. The final arrangement is a quasi-point sensor that only requires 6μL of analyte and has a sensitivity of 4.17x10−4 RIU/λ (RIU is the refractive index unit). This study contributes to the exploration of advantages and limitations in the design and operation of SPR sensors. The work also underlies the need for future research to enhance the selectivity and versatility of these devices.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141705070","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: 10.1088/1742-6596/2791/1/012053
Zhenlei Fu, Wen Wang
We designed a novel herringbone groove sliding bearing suitable for gallium-based liquid metal lubrication, taking advantage of the excellent fluidity, high thermal conductivity, and strong stability of gallium-based liquid metal at room temperature. We used the finite element method to analyze how eccentricity affected the bearing pressure variation and chose the best structural parameters by comparing how different groove parameters affected the peak pressure and carrying capacity. The results show that the herringbone groove reduces bearing friction resistance and causes the bearing pressure variation to exhibit a herringbone pattern. The herringbone groove structural parameters have a significant impact on the peak pressure and carrying capacity of the bearing. The gallium-based liquid metal bearing works well when the herringbone angle is 50°, the groove depth is between 15 μm and 25 μm, and the groove ratio is between 0.7 and 0.9.
{"title":"Structural design and simulation of herringbone groove bearing lubricated with liquid metal","authors":"Zhenlei Fu, Wen Wang","doi":"10.1088/1742-6596/2791/1/012053","DOIUrl":"https://doi.org/10.1088/1742-6596/2791/1/012053","url":null,"abstract":"\u0000 We designed a novel herringbone groove sliding bearing suitable for gallium-based liquid metal lubrication, taking advantage of the excellent fluidity, high thermal conductivity, and strong stability of gallium-based liquid metal at room temperature. We used the finite element method to analyze how eccentricity affected the bearing pressure variation and chose the best structural parameters by comparing how different groove parameters affected the peak pressure and carrying capacity. The results show that the herringbone groove reduces bearing friction resistance and causes the bearing pressure variation to exhibit a herringbone pattern. The herringbone groove structural parameters have a significant impact on the peak pressure and carrying capacity of the bearing. The gallium-based liquid metal bearing works well when the herringbone angle is 50°, the groove depth is between 15 μm and 25 μm, and the groove ratio is between 0.7 and 0.9.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"68 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141711112","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: 10.1088/1742-6596/2796/1/012014
Ana Teran, Cesar Costa Vera
Thermal lensing is a local effect produced by the incidence of a light beam that heats a part of an absorbent material. Mathematical modeling of this photothermal phenomenon allows the determination of the medium’s thermal diffusivity. A pumping-modulated laser (405nm) induces the thermal lensing effect, and a test laser (650nm) generates the photothermal signal measured as a function of the modulation. The thermal diffusivity is obtained from a curve fit of the signal (calibrated for ethanol). In this work, the thermal diffusion coefficients of low-absorbance nanoparticle suspensions are established. This was achieved through the application of a standard addition method. The added analyte, enhance the optical response of SiO 2 nanoparticle suspensions. Different aliquots of tartrazine (analyte) resulted in different values for the thermal diffusion of the samples. It was found that the experimental coefficients of this colloids agree with the theoretical model. Finally, a linear regression allowed to find the thermal coefficient in the zero concentration point.
{"title":"Study of the thermal diffusivity in low-response optical systems combining a thermal lensing approach with a standard addition method","authors":"Ana Teran, Cesar Costa Vera","doi":"10.1088/1742-6596/2796/1/012014","DOIUrl":"https://doi.org/10.1088/1742-6596/2796/1/012014","url":null,"abstract":"\u0000 Thermal lensing is a local effect produced by the incidence of a light beam that heats a part of an absorbent material. Mathematical modeling of this photothermal phenomenon allows the determination of the medium’s thermal diffusivity. A pumping-modulated laser (405nm) induces the thermal lensing effect, and a test laser (650nm) generates the photothermal signal measured as a function of the modulation. The thermal diffusivity is obtained from a curve fit of the signal (calibrated for ethanol). In this work, the thermal diffusion coefficients of low-absorbance nanoparticle suspensions are established. This was achieved through the application of a standard addition method. The added analyte, enhance the optical response of SiO\u0000 2 nanoparticle suspensions. Different aliquots of tartrazine (analyte) resulted in different values for the thermal diffusion of the samples. It was found that the experimental coefficients of this colloids agree with the theoretical model. Finally, a linear regression allowed to find the thermal coefficient in the zero concentration point.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"1 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141711402","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: 10.1088/1742-6596/2791/1/012017
Xinhua Tao, Fan Gan, Jiang Yu, Linchong Huang, Yu Chen
The underground distribution of complex karst geology in the Zhangjiajie region of China poses a significant threat to the construction safety of tunnels, not only increasing project investments but also severely impacting the stable operation of engineering construction. This paper, based on ABAQUS numerical simulation, explores the influence of karst caves around tunnels in different orientations of surrounding rock environments through the rock strength, stress field, and dimension of surrounding rock mass. The results are as follows: (1) With the decrease in cohesive strength of the cave surrounding rock, the stability of the tunnel is enhanced. (2) The maximum displacement of the lower cave is 0.02011 m, greater than that of the side cave, which is 0.01965 m; the maximum principal stress of the lower cave is 7.457 MPa, greater than that of the side cave, which is 7.423 MPa. The lower cave has a greater impact on tunnel construction and can further reduce the stability of the karst tunnel surrounding rock. This paper has researched the influence of caves on tunneling through surrounding rock and investigated the effects of cave orientation, cohesive strength, and other parameters on tunnel construction. It provides theoretical guidance for tunnel alignment and pre-processing of concealed caves.
{"title":"Numerical simulation analysis of the influence of karst cave orientation and surrounding rock properties on tunnel excavation","authors":"Xinhua Tao, Fan Gan, Jiang Yu, Linchong Huang, Yu Chen","doi":"10.1088/1742-6596/2791/1/012017","DOIUrl":"https://doi.org/10.1088/1742-6596/2791/1/012017","url":null,"abstract":"\u0000 The underground distribution of complex karst geology in the Zhangjiajie region of China poses a significant threat to the construction safety of tunnels, not only increasing project investments but also severely impacting the stable operation of engineering construction. This paper, based on ABAQUS numerical simulation, explores the influence of karst caves around tunnels in different orientations of surrounding rock environments through the rock strength, stress field, and dimension of surrounding rock mass. The results are as follows: (1) With the decrease in cohesive strength of the cave surrounding rock, the stability of the tunnel is enhanced. (2) The maximum displacement of the lower cave is 0.02011 m, greater than that of the side cave, which is 0.01965 m; the maximum principal stress of the lower cave is 7.457 MPa, greater than that of the side cave, which is 7.423 MPa. The lower cave has a greater impact on tunnel construction and can further reduce the stability of the karst tunnel surrounding rock. This paper has researched the influence of caves on tunneling through surrounding rock and investigated the effects of cave orientation, cohesive strength, and other parameters on tunnel construction. It provides theoretical guidance for tunnel alignment and pre-processing of concealed caves.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"47 45","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141689934","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: 10.1088/1742-6596/2791/1/012065
Junan Li, Jun Hu, Lisong Wang, Kangxing Wang, Jialei Dai
As complex safety-critical system software becomes more powerful, so does the complexity of its design requirements. Modeling and analyzing design requirements at an early stage has become an integral part of the entire development process for complex safety-critical system software. Simulink is a system modeling and simulation tool used in aviation and other fields. Its model is stored in the form of MDL files. ART (Avionics Requirement Tools) is a requirement modeling and analysis verification tool for the aviation field. It uses VRM (Variable Relation Model) as the theoretical model and can accept VRM and its extended subsets as input models and verify them in the tool. The work of this paper is oriented to the typical software requirements in the field of avionics systems and proposes a formal modeling and verification method for Simulink-MDL models. First, the composition form and structure of the MDL model are analyzed in the article. The functions and semantics of various elements in the model are given. Then a formal modeling method of the MDL model is given. Finally, a simplified version of the flight guidance control system is used for modeling and verification to demonstrate the usability and effectiveness of this method.
{"title":"Formal modeling and verification method for Simulink-MDL requirement model","authors":"Junan Li, Jun Hu, Lisong Wang, Kangxing Wang, Jialei Dai","doi":"10.1088/1742-6596/2791/1/012065","DOIUrl":"https://doi.org/10.1088/1742-6596/2791/1/012065","url":null,"abstract":"\u0000 As complex safety-critical system software becomes more powerful, so does the complexity of its design requirements. Modeling and analyzing design requirements at an early stage has become an integral part of the entire development process for complex safety-critical system software. Simulink is a system modeling and simulation tool used in aviation and other fields. Its model is stored in the form of MDL files. ART (Avionics Requirement Tools) is a requirement modeling and analysis verification tool for the aviation field. It uses VRM (Variable Relation Model) as the theoretical model and can accept VRM and its extended subsets as input models and verify them in the tool. The work of this paper is oriented to the typical software requirements in the field of avionics systems and proposes a formal modeling and verification method for Simulink-MDL models. First, the composition form and structure of the MDL model are analyzed in the article. The functions and semantics of various elements in the model are given. Then a formal modeling method of the MDL model is given. Finally, a simplified version of the flight guidance control system is used for modeling and verification to demonstrate the usability and effectiveness of this method.","PeriodicalId":506941,"journal":{"name":"Journal of Physics: Conference Series","volume":"113 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141713026","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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