Pub Date : 2024-10-01DOI: 10.1016/j.rinp.2024.107996
Multiple planes with different properties are exposed after the comminution of molybdenite because of the anisotropy of molybdenite. Study on the properties of different planes is of great significance to enhance the comprehensive utilization of molybdenite, especially in flotation. In order to explore the properties of different planes, the two main planes of molybdenite (basal plane and edge plane) are respectively taken as the research object in this paper, and the properties of planes are expressed using DFT through the adsorption behaviors of a new reagent named DTC-CTS and water molecules. The results show that edge plane has higher activity than basal plane. This is because there are exposed molybdenum atoms on the edge plane, and the sulfur atoms in DTC-CTS and oxygen atoms in water molecules are easy to react with the exposed molybdenum atoms. While the activity of basal plane is low because of the hinderance effect of sulfur atoms in the skin layer. The different adsorption behaviors of water molecules on molybdenite planes verified the hydrophobicity of different planes. In addition, the results also show that the water can affect the DTC-CTS adsorption on edge plane. Water can enhance interaction between single-bond sulfur atom and molybdenum atom, and weaken the interaction between double-bond sulfur atom and molybdenum atom on edge plane.
{"title":"The anisotropy of molybdenite planes: Analysis based on the adsorption behaviors of reagent and H2O","authors":"","doi":"10.1016/j.rinp.2024.107996","DOIUrl":"10.1016/j.rinp.2024.107996","url":null,"abstract":"<div><div>Multiple planes with different properties are exposed after the comminution of molybdenite because of the anisotropy of molybdenite. Study on the properties of different planes is of great significance to enhance the comprehensive utilization of molybdenite, especially in flotation. In order to explore the properties of different planes, the two main planes of molybdenite (basal plane and edge plane) are respectively taken as the research object in this paper, and the properties of planes are expressed using DFT through the adsorption behaviors of a new reagent named DTC-CTS and water molecules. The results show that edge plane has higher activity than basal plane. This is because there are exposed molybdenum atoms on the edge plane, and the sulfur atoms in DTC-CTS and oxygen atoms in water molecules are easy to react with the exposed molybdenum atoms. While the activity of basal plane is low because of the hinderance effect of sulfur atoms in the skin layer. The different adsorption behaviors of water molecules on molybdenite planes verified the hydrophobicity of different planes. In addition, the results also show that the water can affect the DTC-CTS adsorption on edge plane. Water can enhance interaction between single-bond sulfur atom and molybdenum atom, and weaken the interaction between double-bond sulfur atom and molybdenum atom on edge plane.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.rinp.2024.107995
The secondary consequences of predator species on prey species have substantial implications for population dynamics. A deeper comprehension of the dynamics between prey and predator can be achieved through the examination of indirect consequences. This work examines the dynamic behavior of a modified Holling-Tanner model. The interactions between the species are characterized by a functional response of the Beddington–DeAngelis type. Factors such as prey refuge, fear factor, disturbance intensity, and cross diffusion have been taken into account. The boundedness, feasibility of equilibrium points, their stability and restrictions for Hopf bifurcation of non-spatial model system are derived. The study explores the combined effects of prey refuge presence and fear factors on population dynamics. Furthermore, the investigation focuses on the stability of spatial self-diffusion and cross-diffusion model systems, as well as the specific conditions that lead to Turing instability. Ultimately, it has been shown that in the context of self-diffusion, a moderate level of fear promotes the survival of prey, whereas an excessive level of dread hinders the survival of prey. Concurrently, the mean density of prey exhibited a gradual decline as the refuge parameters increased. The spatial patterns of the population have also been investigated. As the mutual interference between prey populations intensifies, the spatial distribution of the prey population transitions from a clustered pattern to a combination of striped and clustered patterns, ultimately settling into a striped pattern. With the gradual growth of the half saturation constant, the prey population reached a state of uniform distribution. In the scenario of cross diffusion, when the prey is heavily impacted by the pursuit of predators, the fear effect, when appropriately used, did not have a significant impact on the survival of the prey. This work adds to the existing body of knowledge by revealing novel insights into the influence of indirect factors on the behavior of predator and prey populations.
{"title":"Modified Holling Tanner diffusive and non-diffusive predator–prey models: The impact of prey refuge and fear effect","authors":"","doi":"10.1016/j.rinp.2024.107995","DOIUrl":"10.1016/j.rinp.2024.107995","url":null,"abstract":"<div><div>The secondary consequences of predator species on prey species have substantial implications for population dynamics. A deeper comprehension of the dynamics between prey and predator can be achieved through the examination of indirect consequences. This work examines the dynamic behavior of a modified Holling-Tanner model. The interactions between the species are characterized by a functional response of the Beddington–DeAngelis type. Factors such as prey refuge, fear factor, disturbance intensity, and cross diffusion have been taken into account. The boundedness, feasibility of equilibrium points, their stability and restrictions for Hopf bifurcation of non-spatial model system are derived. The study explores the combined effects of prey refuge presence and fear factors on population dynamics. Furthermore, the investigation focuses on the stability of spatial self-diffusion and cross-diffusion model systems, as well as the specific conditions that lead to Turing instability. Ultimately, it has been shown that in the context of self-diffusion, a moderate level of fear promotes the survival of prey, whereas an excessive level of dread hinders the survival of prey. Concurrently, the mean density of prey exhibited a gradual decline as the refuge parameters increased. The spatial patterns of the population have also been investigated. As the mutual interference between prey populations intensifies, the spatial distribution of the prey population transitions from a clustered pattern to a combination of striped and clustered patterns, ultimately settling into a striped pattern. With the gradual growth of the half saturation constant, the prey population reached a state of uniform distribution. In the scenario of cross diffusion, when the prey is heavily impacted by the pursuit of predators, the fear effect, when appropriately used, did not have a significant impact on the survival of the prey. This work adds to the existing body of knowledge by revealing novel insights into the influence of indirect factors on the behavior of predator and prey populations.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.rinp.2024.107994
The space–time fractional Landau-Ginzburg-Higgs equation and coupled Boussinesq-Burger equation describe the behavior of nonlinear waves in the tropical and mid-latitude troposphere, exhibiting weak scattering, extended connections, arising from the interactions between equatorial and mid-latitude Rossby waves, fluid flow in dynamic systems, and depicting wave propagation in shallow water. The improved Bernoulli sub-equation function method has been used to achieve new and wide-ranging closed-form solitary wave solutions to the mentioned nonlinear fractional partial differential equations through beta-derivative. A wave transformation is applied to renovate the fractional-order equation into an ordinary differential equation. Some standard wave shapes of multiple soliton type, single soliton, kink shape, double soliton shape type, triple soliton shape, anti-kink shape, and other types of solitons have been established. The more updated software Python is used to display the solutions by using 3D and contour plotlines to describe the physical significances of attained solutions more clearly. The findings of this study are straightforward, adaptable, and quicker to simulate. It has been notable that the improved Bernoulli sub-equation function method is practical, effective, and offers more sophisticated solutions that can help to generate a large number of wave solutions for various models.
{"title":"Diverse soliton wave profile assessment to the fractional order nonlinear Landau-Ginzburg-Higgs and coupled Boussinesq-Burger equations","authors":"","doi":"10.1016/j.rinp.2024.107994","DOIUrl":"10.1016/j.rinp.2024.107994","url":null,"abstract":"<div><div>The space–time fractional Landau-Ginzburg-Higgs equation and coupled Boussinesq-Burger equation describe the behavior of nonlinear waves in the tropical and mid-latitude troposphere, exhibiting weak scattering, extended connections, arising from the interactions between equatorial and mid-latitude Rossby waves, fluid flow in dynamic systems, and depicting wave propagation in shallow water. The improved Bernoulli sub-equation function method has been used to achieve new and wide-ranging closed-form solitary wave solutions to the mentioned nonlinear fractional partial differential equations through beta-derivative. A wave transformation is applied to renovate the fractional-order equation into an ordinary differential equation. Some standard wave shapes of multiple soliton type, single soliton, kink shape, double soliton shape type, triple soliton shape, anti-kink shape, and other types of solitons have been established. The more updated software Python is used to display the solutions by using 3D and contour plotlines to describe the physical significances of attained solutions more clearly. The findings of this study are straightforward, adaptable, and quicker to simulate. It has been notable that the improved Bernoulli sub-equation function method is practical, effective, and offers more sophisticated solutions that can help to<!--> <!-->generate a large number of wave solutions for various models.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.rinp.2024.107989
Medium-entropy alloys (MEA) have potential load-bearing applications as high-performance structural materials. In this work, the plastic deformations in NiCoFe MEAs were investigated using nanoindentation atomistic simulations. The nanoindentation responses of three typical orientations of NiCoFe single-crystals were investigated, i.e., [001], [011] and [111]. The results show that, during nanoindentation, Shockley partials on (111) slip planes remarkably affect dislocation-related activities including nucleation, gliding, and interactions. The form of atomic pile-ups is highly non-uniform and strongly asymmetrical due to the presence of multi-principal elements. The dislocation nucleation mechanism of the alloys during nanoindentation is proposed in detail. We find evidence that a hexagonal close-packed phase is formed from the face-centered cubic structure during nanoindentation.
{"title":"Plastic deformations in NiCoFe medium-entropy alloy investigated using nanoindentation simulations","authors":"","doi":"10.1016/j.rinp.2024.107989","DOIUrl":"10.1016/j.rinp.2024.107989","url":null,"abstract":"<div><div>Medium-entropy alloys (MEA) have potential load-bearing applications as high-performance structural materials. In this work, the plastic deformations in NiCoFe MEAs were investigated using nanoindentation atomistic simulations. The nanoindentation responses of three typical orientations of NiCoFe single-crystals were investigated, i.e., [001], [011] and [111]. The results show that, during nanoindentation, Shockley partials on (111) slip planes remarkably affect dislocation-related activities including nucleation, gliding, and interactions. The form of atomic pile-ups is highly non-uniform and strongly asymmetrical due to the presence of multi-principal elements. The dislocation nucleation mechanism of the alloys during nanoindentation is proposed in detail. We find evidence that a hexagonal close-packed phase is formed from the face-centered cubic structure during nanoindentation.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.rinp.2024.107999
Electron emission from cathodes in high field gradients is a quantum tunneling effect. The 1928 Fowler–Nordheim field emission (FE) equation and the 1956 Murphy–Good FE equation have traditionally been key in describing cold field emissions, offering estimates for emitters for almost a century. Nevertheless, applying FE theory in practice is often constrained by the lack of data on the distribution and geometry of the emission sites. Predictions become more challenging with an uneven electric field distribution at the cathode surface. Consequently, FE formulations are frequently calibrated using current–voltage data after test, limiting their efficacy as true predictive models.
This study develops an alternative model for field emission using a data-driven predictive approach based on (1) vast experimental data, (2) electrostatic simulations of the cathode surface, and (3) detailed material and geometry properties, which together overcome these limitations. The objective of this work is to develop and harness this comprehensive dataset to train a machine learning model capable of providing precise predictions of the cathode current in order to further the understanding and application of field emission phenomena. More than 259 h of experimental data have been processed to train and benchmark some of the well-known machine learning models. After two stages of optimization, a coefficient of determination is achieved in the prediction total field emission current using ensemble models.
高场梯度阴极电子发射是一种量子隧道效应。1928 年的 Fowler-Nordheim 场发射 (FE) 方程和 1956 年的 Murphy-Good FE 方程历来是描述冷场发射的关键，为发射器提供了近一个世纪的估计值。然而，由于缺乏有关发射点分布和几何形状的数据，在实践中应用 FE 理论往往受到限制。在阴极表面电场分布不均匀的情况下，预测变得更具挑战性。因此，FE 公式经常在测试后使用电流-电压数据进行校准，从而限制了其作为真正预测模型的功效。本研究采用数据驱动的预测方法，基于（1）大量实验数据、（2）阴极表面的静电模拟以及（3）详细的材料和几何特性，开发了另一种场发射模型，从而克服了这些限制。这项工作的目的是开发和利用这一全面的数据集来训练一个能够精确预测阴极电流的机器学习模型，以进一步了解和应用场发射现象。我们处理了超过 259 小时的实验数据，对一些著名的机器学习模型进行了训练和基准测试。经过两个阶段的优化，利用集合模型预测总场发射电流的确定系数达到了 98%。
{"title":"A data-driven model for the field emission from broad-area electrodes","authors":"","doi":"10.1016/j.rinp.2024.107999","DOIUrl":"10.1016/j.rinp.2024.107999","url":null,"abstract":"<div><div>Electron emission from cathodes in high field gradients is a quantum tunneling effect. The 1928 Fowler–Nordheim field emission (FE) equation and the 1956 Murphy–Good FE equation have traditionally been key in describing cold field emissions, offering estimates for emitters for almost a century. Nevertheless, applying FE theory in practice is often constrained by the lack of data on the distribution and geometry of the emission sites. Predictions become more challenging with an uneven electric field distribution at the cathode surface. Consequently, FE formulations are frequently calibrated using current–voltage data after test, limiting their efficacy as true predictive models.</div><div>This study develops an alternative model for field emission using a data-driven predictive approach based on (1) vast experimental data, (2) electrostatic simulations of the cathode surface, and (3) detailed material and geometry properties, which together overcome these limitations. The objective of this work is to develop and harness this comprehensive dataset to train a machine learning model capable of providing precise predictions of the cathode current in order to further the understanding and application of field emission phenomena. More than 259 h of experimental data have been processed to train and benchmark some of the well-known machine learning models. After two stages of optimization, a coefficient of determination <span><math><mrow><mo>></mo><mn>98</mn><mtext>%</mtext></mrow></math></span> is achieved in the prediction total field emission current using ensemble models.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.rinp.2024.108003
In this paper, an efficiency tunable reflective metasurface (MS) consisting of a dielectric substrate sandwiched between hollow Z-shaped (HZS) structure graphene and a metallic ground plane is proposed for single/dual-focusing effects based on Pancharatnam-Berry (PB) in terahertz (THz) region. Numerical simulations demonstrate that the designed HZS graphene can achieve a circular polarization (CP) conversion with efficiency of approximately 98 % at a Fermi energy level (EF) of 1.0 eV. Moreover, by adjusting the rotation angle of the HZS graphene, a full 0-2π phase coverage can be achieved. Of note, the simulation results also reveal that the reflective CP conversion efficiency is highly dependent on the value of the EF. By carefully designing the spatial phase distribution of the graphene MS, tunable reflective single/dual-focusing effects can be realized, with focusing efficiency controlled by the EF. It is anticipated that the proposed tunable graphene MS will have broad applications in communications, imaging, and others in THz domains.
本文提出了一种效率可调的反射元表面 (MS)，它由夹在空心 Z 形 (HZS) 结构石墨烯和金属地平面之间的介质基板组成，用于太赫兹 (THz) 区域基于 Pancharatnam-Berry (PB) 的单/双聚焦效应。数值模拟证明，在费米能级（EF）为 1.0 eV 时，所设计的 HZS 石墨烯可实现圆偏振（CP）转换，效率约为 98%。此外，通过调整 HZS 石墨烯的旋转角度，还可以实现 0-2π 相位的全覆盖。值得注意的是，模拟结果还表明，反射式 CP 转换效率与 EF 值有很大关系。通过精心设计石墨烯 MS 的空间相位分布，可以实现可调的反射式单/双聚焦效果，聚焦效率由 EF 控制。预计所提出的可调石墨烯 MS 将在太赫兹领域的通信、成像和其他方面有广泛的应用。
{"title":"Efficiency tunable terahertz graphene metasurfaces for reflective single/dual-focusing effects based on Pancharatnam-Berry phase","authors":"","doi":"10.1016/j.rinp.2024.108003","DOIUrl":"10.1016/j.rinp.2024.108003","url":null,"abstract":"<div><div>In this paper, an efficiency tunable reflective metasurface (MS) consisting of a dielectric substrate sandwiched between hollow Z-shaped (HZS) structure graphene and a metallic ground plane is proposed for single/dual-focusing effects based on Pancharatnam-Berry (PB) in terahertz (THz) region. Numerical simulations demonstrate that the designed HZS graphene can achieve a circular polarization (CP) conversion with efficiency of approximately 98 % at a Fermi energy level (<em>E<sub>F</sub></em>) of 1.0 eV. Moreover, by adjusting the rotation angle of the HZS graphene, a full 0-2π phase coverage can be achieved. Of note, the simulation results also reveal that the reflective CP conversion efficiency is highly dependent on the value of the <em>E<sub>F</sub></em>. By carefully designing the spatial phase distribution of the graphene MS, tunable reflective single/dual-focusing effects can be realized, with focusing efficiency controlled by the <em>E<sub>F</sub></em>. It is anticipated that the proposed tunable graphene MS will have broad applications in communications, imaging, and others in THz domains.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.rinp.2024.107993
This paper delves into the numerical investigation of aluminum oxide–water nanofluid thermal and dynamic performances under the influences of magnetic field application and chemical reaction, utilizing the Finite Element Method within a circular enclosure containing three inner tubes, as an application to the heat exchanging phenomenon between the reactive shell of the cavity and the surface of the triple tubes. Various governing parameters were studied for their interaction on the nanofluid flow and heat transmission rate within the proposed geometry, including the Rayleigh parameter (), Hartmann parameter (), nanoparticles concentration (), magnetic rotational angle (), and Frank-Kamenetskii parameter (). The results indicated that raising Ra from 103 to 105 results in expediting the nanofluid velocity by 10.62 % and 100 % respectively as well as raising the total heat transfer efficiency. The nanofluid speed was also increased by 28.57 % when Fk has to further increase to a value of 3. When there was no exothermic activity present, the rate of heat transmission was at its lowest, and it was greater when the Fk value was 3. Similarly, there were discernible impacts in various areas of the geometry as the Ha number intensified and the Nuavg decreased. Improvements in local and mean Nusselt parameters are observed when the concentration of nanoparticles is increased, suggesting better heat transfer, achieving an increase by 7 % in the average Nusselt number. This research emphasizes the importance of nanoparticle concentration in raising the medium’s rates of heat transmission, contributing to advancements in energy storage development.
本文采用有限元法，对氧化铝-水纳米流体在磁场应用和化学反应影响下的热性能和动态性能进行了数值研究，并将其应用于包含三根内管的圆形外壳中，以研究空腔的反应外壳与三根内管表面之间的热交换现象。研究了各种调节参数，包括瑞利参数（103≤Ra≤105）、哈特曼参数（0≤Ha≤61）、纳米颗粒浓度（0≤∅≤6×10-2）、磁旋转角（0o≤γ≤90o）和弗兰克-卡缅涅茨基参数（0≤Fk≤3），以了解它们对拟议几何形状内纳米流体流动和热传递率的影响。结果表明，将 Ra 值从 103 提高到 105 后，纳米流体的速度分别提高了 10.62 % 和 100 %，总传热效率也提高了。当 Fk 值进一步增加到 3 时，纳米流体的速度也提高了 28.57%。 当没有放热活动时，热量传输率最低，而当 Fk 值为 3 时，热量传输率更高。同样，随着 Ha 值的增加和 Nuavg 的降低，几何体的各个区域都受到了明显的影响。当纳米粒子的浓度增加时，局部和平均努塞尔特参数都有所改善，表明传热效果更好，平均努塞尔特数增加了 7%。这项研究强调了纳米粒子浓度在提高介质热传导率方面的重要性，有助于推动储能技术的发展。
{"title":"Numerical analysis of unsteady free convection of Al2O3 inside a tubular reactor under the influences of exothermic reaction, and inclined MHD as an application to chemical reactor","authors":"","doi":"10.1016/j.rinp.2024.107993","DOIUrl":"10.1016/j.rinp.2024.107993","url":null,"abstract":"<div><div>This paper delves into the numerical investigation of aluminum oxide–water nanofluid thermal and dynamic performances under the influences of magnetic field application and chemical reaction, utilizing the Finite Element Method within a circular enclosure containing three inner tubes, as an application to the heat exchanging phenomenon between the reactive shell of the cavity and the surface of the triple tubes. Various governing parameters were studied for their interaction on the nanofluid flow and heat transmission rate within the proposed geometry, including the Rayleigh parameter (<span><math><mrow><msup><mrow><mn>10</mn></mrow><mn>3</mn></msup><mo>≤</mo><mi>R</mi><mi>a</mi><mo>≤</mo><msup><mrow><mn>10</mn></mrow><mn>5</mn></msup></mrow></math></span>), Hartmann parameter (<span><math><mrow><mn>0</mn><mo>≤</mo><mi>H</mi><mi>a</mi><mo>≤</mo><mn>61</mn></mrow></math></span>), nanoparticles concentration (<span><math><mrow><mn>0</mn><mo>≤</mo><mi>∅</mi><mo>≤</mo><mn>6</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>-</mo><mn>2</mn></mrow></msup></mrow></math></span>), magnetic rotational angle (<span><math><mrow><msup><mrow><mn>0</mn></mrow><mi>o</mi></msup><mo>≤</mo><mi>γ</mi><mo>≤</mo><msup><mrow><mn>90</mn></mrow><mi>o</mi></msup></mrow></math></span>), and Frank-Kamenetskii parameter (<span><math><mrow><mn>0</mn><mo>≤</mo><msub><mi>F</mi><mi>k</mi></msub><mo>≤</mo><mn>3</mn></mrow></math></span>). The results indicated that raising Ra from 10<sup>3</sup> to 10<sup>5</sup> results in expediting the nanofluid velocity by 10.62 % and 100 % respectively as well as raising the total heat transfer efficiency. The nanofluid speed was also increased by 28.57 % when F<sub>k</sub> has to further increase to a value of 3. When there was no exothermic activity present, the rate of heat transmission was at its lowest, and it was greater when the F<sub>k</sub> value was 3. Similarly, there were discernible impacts in various areas of the geometry as the Ha number intensified and the Nu<sub>avg</sub> decreased. Improvements in local and mean Nusselt parameters are observed when the concentration of nanoparticles is increased, suggesting better heat transfer, achieving an increase by 7 % in the average Nusselt number. This research emphasizes the importance of nanoparticle concentration in raising the medium’s rates of heat transmission, contributing to advancements in energy storage development.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.rinp.2024.107985
In this study, we designed ranging parameters and refined a loop filtering algorithm to solve the problem of parameter compatibility with the phasemeter and low ranging accuracy under bidirectional communication conditions. This enables the ranging and communication system to be integrated directly into the phasemeter as an auxiliary module. Experimental results compare fiber measurement lengths under different clock sources, indicating that the system achieves an ranging accuracy of 82.1 cm with an rms error of 9.14 cm. Additionally, the data communication rate reaches 19.5 kbps with a bit error rate below , all while ensuring that the implementation of the laser ranging and data communication system utilizes only 1% of the optical power to avoid introducing excessive phase noise to the scientific interferometer.
{"title":"Experimental demonstration of bi-directional laser ranging and data communication for space gravitational wave detection","authors":"","doi":"10.1016/j.rinp.2024.107985","DOIUrl":"10.1016/j.rinp.2024.107985","url":null,"abstract":"<div><div>In this study, we designed ranging parameters and refined a loop filtering algorithm to solve the problem of parameter compatibility with the phasemeter and low ranging accuracy under bidirectional communication conditions. This enables the ranging and communication system to be integrated directly into the phasemeter as an auxiliary module. Experimental results compare fiber measurement lengths under different clock sources, indicating that the system achieves an ranging accuracy of 82.1 cm with an rms error of 9.14 cm. Additionally, the data communication rate reaches 19.5 kbps with a bit error rate below <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>6</mn></mrow></msup></mrow></math></span>, all while ensuring that the implementation of the laser ranging and data communication system utilizes only 1% of the optical power to avoid introducing excessive phase noise to the scientific interferometer.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.rinp.2024.107978
This paper proposes the utility of interpretable ensemble learning models for predicting the mechanical properties (bulk, shear and Young moduli) of ABX3 perovskite compounds with the A, B, and X referring to the 3 elements that make the cubic 3-dimensional framework of the perovskite compounds. These models consist of 3 ensemble learning techniques namely CatBoost, Random Forest, and XGBoost. To expand the feature space, robust first-principles density functional theory calculations were used to generate some of the input features, namely elastic constants, density, volume per atom, and ground state energy per atom. The order of the input feature ranking that influences the machine learning (ML) model decisions was then determined. For this, we performed correlation analysis on the multi-dimensional input feature space, suppressed features with high collinearity, and selected features with limited correlation. We trained the three ensemble learning techniques on the desired vectorial input feature representation to predict the mechanical properties. Furthermore, we employed the Shapley Additive Explanations (SHAP) algorithm for analysing the intrinsic decision-making rationality of the ensemble learning models. We measured the performance in the context of the error metrics and coefficient of determination, R2. The results show that XGBoost outperforms other approaches when predicting the shear modulus or Young modulus of the perovskite compounds yielding the least error metrics and the highest R2 value (0.97) in the testing phase. However, both CatBoost and Random Forest outperformed XGBoost when attempting to predict the bulk modulus in the testing phase. The deficiency of the XGBoost in predicting the bulk modulus can be ascribed to an overfitting problem which can occur when the ML model gives accurate predictions for training data but not for test data. Furthermore, the SHAP algorithm provides an insight into the order of feature importance (from highest to lowest). Additionally, we conducted a post-analysis using a holistic ranking to analyse the relative importance of the SHAP feature impact comprehension for the examined ensemble learning techniques. Our findings indicate that the elastic constants are the most important input features influencing the predictive decision of the ensemble learning models.
{"title":"Interpretable machine learning methods to predict the mechanical properties of ABX3 perovskites","authors":"","doi":"10.1016/j.rinp.2024.107978","DOIUrl":"10.1016/j.rinp.2024.107978","url":null,"abstract":"<div><div>This paper proposes the utility of interpretable ensemble learning models for predicting the mechanical properties (bulk, shear and Young moduli) of ABX<sub>3</sub> perovskite compounds with the A, B, and X referring to the 3 elements that make the cubic 3-dimensional framework of the perovskite compounds. These models consist of 3 ensemble learning techniques namely CatBoost, Random Forest, and XGBoost. To expand the feature space, robust first-principles density functional theory calculations were used to generate some of the input features, namely elastic constants, density, volume per atom, and ground state energy per atom. The order of the input feature ranking that influences the machine learning (ML) model decisions was then determined. For this, we performed correlation analysis on the multi-dimensional input feature space, suppressed features with high collinearity, and selected features with limited correlation. We trained the three ensemble learning techniques on the desired vectorial input feature representation to predict the mechanical properties. Furthermore, we employed the Shapley Additive Explanations (SHAP) algorithm for analysing the intrinsic decision-making rationality of the ensemble learning models. We measured the performance in the context of the error metrics and coefficient of determination, R<sup>2</sup>. The results show that XGBoost outperforms other approaches when predicting the shear modulus or Young modulus of the perovskite compounds yielding the least error metrics and the highest R<sup>2</sup> value (0.97) in the testing phase. However, both CatBoost and Random Forest outperformed XGBoost when attempting to predict the bulk modulus in the testing phase. The deficiency of the XGBoost in predicting the bulk modulus can be ascribed to an overfitting problem which can occur when the ML model gives accurate predictions for training data but not for test data. Furthermore, the SHAP algorithm provides an insight into the order of feature importance (from highest to lowest). Additionally, we conducted a post-analysis using a holistic ranking to analyse the relative importance of the SHAP feature impact comprehension for the examined ensemble learning techniques. Our findings indicate that the elastic constants are the most important input features influencing the predictive decision of the ensemble learning models.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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