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Velocity and Thermal Slips Impact on the Williamson Fluid Flow above a Stretching Sheet in the Existence of Radiation and Inclined Magnetic Field 速度和热滑移对存在辐射和倾斜磁场的拉伸片上威廉姆森流体流动的影响
Q2 Mathematics Pub Date : 2024-03-04 DOI: 10.37934/cfdl.16.7.118135
Srinu Anagandula, K. Sreeram Reddy
Research has been conducted on the study of the velocity and thermal slips' impact on the Williamson fluid flow above a stretching sheet in the existence of an inclined magnetic field and Radiation. By applying the proper similarity conversions, the governing equations (PDEs) are reduced to a set of non-linear ODEs, and a numerical solution is produced by using MATLAB in-built solver bvp4c package. The impacts of the dimensionless characteristics on the flow patterns are analyzed visually, and the values of the friction, Nusselt, and mass transfer quantities are tabulated to exemplify how the various physical factors have an influence. We noted that the velocity profile enhances the rising estimations of velocity slip and the temperature profile increases with Q increase.
研究了在存在倾斜磁场和辐射的情况下,速度和热滑移对拉伸片上威廉姆森流体流动的影响。通过应用适当的相似性转换,将支配方程(PDEs)简化为一组非线性 ODEs,并使用 MATLAB 内置求解器 bvp4c 软件包进行数值求解。我们直观地分析了无量纲特征对流动模式的影响,并将摩擦、努塞尔特和传质量的值列表,以说明各种物理因素的影响。我们注意到,速度剖面增强了对速度滑移的上升估计,而温度剖面则随着 Q 值的增加而增加。
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引用次数: 0
Hydrodynamic Performance Analysis of Camber Ratio Variations on B-series Propeller Types B 系列螺旋桨倾角比变化的水动力性能分析
Q2 Mathematics Pub Date : 2024-03-04 DOI: 10.37934/cfdl.16.7.3953
Mahendra Indiaryanto Hendra, Ketut Suastika, Taufiq Arif Setyanto
The hydrodynamic performance of the B-series propeller can be determined by calculating the polynomial equation published by MARIN. Furthermore, analysis and evaluation of B-series propeller modifications can be done by varying the camber ratio of the foil. The camber ratio affects the lift force on the propeller foil, directly affecting the propeller thrust and torque. Numerical calculations were carried out using Computational Fluids Dynamics (CFD), based on Reynolds Averaged Navier Stokes Equations (RANSE) and turbulence model in the form of explicit algebraic stress models (EASM). The overall results of this study show an increase in efficiency of 4.182 on the foil with a camber ratio of 2.2% when compared to the foil camber ratio of 0%.
B 系列螺旋桨的水动力性能可通过计算 MARIN 公布的多项式方程来确定。此外,还可以通过改变桨叶的外倾角比来分析和评估 B 系列螺旋桨的改型。外倾角比会影响螺旋桨箔片上的升力,直接影响螺旋桨的推力和扭矩。计算流体动力学(CFD)基于雷诺平均纳维-斯托克斯方程(RANSE)和显式代数应力模型(EASM)形式的湍流模型进行了数值计算。研究的总体结果表明,与外倾率为 0% 的箔片相比,外倾率为 2.2% 的箔片的效率提高了 4.182%。
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引用次数: 0
Performance Analysis of Wet Porous Moving Fin under the Influence of Spherical Shaped TiO2- Ag Hybrid Nanoparticles in a Water Based Fluid 球形 TiO2- Ag 混合纳米粒子影响下的湿式多孔移动鳍片在水基流体中的性能分析
Q2 Mathematics Pub Date : 2024-03-04 DOI: 10.37934/cfdl.16.7.105117
Ammembal Gopalkrishna Pai, Rekha G. Pai, Lavanya B, Vinay Madhusudanan, Sanjana T.D
The study investigates the flow characteristics of spherical shaped TiO2 –Ag hybrid nanofluid with water as a base fluid passing through a wet porous rectangular moving fin with a focus on understanding the effects of nanoparticle concentration on the heat transfer rate. The fin under consideration are subjected to boundary conditions, insulated and convective tips. Hybrid nanofluid that combine nanoparticles with conventional base fluids have potentially enhanced thermal conductivity and heat transfer properties in engineering applications. The energy balance equation containing the parameters that effect the flow of heat transfer rate is non- dimensionalized and solved numerically using 3-stage Lobatto - IIIa formula with appropriate boundary conditions. The simulation result shows the impact of different parameters on the flow and heat transfer properties of the hybrid nanofluid obtained by mixing spherical shaped TiO2 –Ag hybrid nanoparticles with water as base fluid. It is observed that the fin shows significant heat transfer rate in a convective tip relative to an insulated tip. The findings contribute to the understanding of hybrid nanofluid flow and its potential application in the design and optimization of thermal management system. It also facilitates the ground work for research in the field of nano fluid based cooling system. The observation from the graphical illustration shows that the rise in the thermal conductivity of the base fluid by 23% increases the conduction heat transfer as well as the temperature distribution by 10%. The natural convection and radiation are the key parameters that determines the heat transfer rate from the surface to the surrounding. In our investigation, enhancing the Nc,Nr parameters by 50% and 25%, the temperature distribution profile is reduced by about 13% and 6% respectively. The increase in the Pe number by 100% results in a rise in the temperature distribution by 8%.
本研究探讨了以水为基本流体的球形 TiO2 -Ag 混合纳米流体通过湿式多孔矩形移动鳍片的流动特性,重点是了解纳米粒子浓度对传热速率的影响。所考虑的翅片受到边界条件、绝缘和对流尖端的影响。将纳米粒子与传统基础流体相结合的混合纳米流体在工程应用中具有潜在的增强导热性和传热特性。能量平衡方程包含影响热传导率流动的参数,采用 3 级洛巴托-IIIa 公式和适当的边界条件对其进行非尺寸化和数值求解。模拟结果表明了不同参数对混合纳米流体的流动和传热性能的影响,混合纳米流体是通过将球形 TiO2 -Ag 混合纳米粒子与水作为基础流体混合得到的。据观察,相对于绝热顶端,翅片在对流顶端显示出显著的传热率。研究结果有助于理解混合纳米流体流动及其在热管理系统设计和优化中的潜在应用。它还为基于纳米流体的冷却系统领域的研究奠定了基础。从图解中可以看出,基础流体的导热系数增加 23%,传导热量和温度分布就会增加 10%。自然对流和辐射是决定从表面向周围传热的关键参数。在我们的研究中,将 Nc、Nr 参数分别提高 50%和 25%,温度分布曲线分别降低了约 13%和 6%。Pe 值增加 100%,温度分布会上升 8%。
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引用次数: 0
Bi-directional Forced Convective Stagnation Points Flow of Oldroyd-B Liquid with Joule Heating Effects: A Finite Difference Simulations 具有焦耳加热效应的 Oldroyd-B 液体双向强制对流停滞点流动:有限差分模拟
Q2 Mathematics Pub Date : 2024-03-04 DOI: 10.37934/cfdl.16.7.2238
Bilal Ahmed
The impact of Joule heating for the three-dimensional stagnation point flow of non-Newtonian liquid (namely Oldroyd-B) nanomaterial has been inspected. The influence of mixed convection and the magnetic force is also considered. The flow is induced by the bidirectional stretched surface which moves linearly. The partial differential equations for the developed model are altered into dimensionless statements first. The numerical simulations with the implementation of a finite difference scheme are used for the numerical description. The physical description of parameters is presented against the flow parameters. The results reveal that there is a reverse change in velocity observed for both the relaxation time constant and the retardation constant. Furthermore, the heat transfer rate decreases as the ratio parameter increases. The thickness of the boundary layer increases due to the retardation time and can also be regulated by the application of a magnetic field. An increase in the magnetic parameter leads to an enhancement in temperature and an increase in thermal boundary layer thickness.
研究了焦耳加热对非牛顿液体(即 Oldroyd-B)纳米材料三维停滞点流动的影响。同时还考虑了混合对流和磁力的影响。流动由线性移动的双向拉伸表面引起。首先将所开发模型的偏微分方程转换为无量纲语句。数值模拟采用有限差分方案进行数值描述。参数的物理描述与流动参数相对应。结果表明,在弛豫时间常数和迟滞常数方面都观察到了速度的反向变化。此外,传热速率随着比率参数的增加而降低。边界层的厚度因延迟时间而增加,也可以通过施加磁场来调节。磁参数的增加会导致温度升高和热边界层厚度增加。
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引用次数: 0
Characteristics of MHD Jeffery Fluid Past an Inclined Vertical Porous Plate 穿过倾斜垂直多孔板的 MHD 杰弗里流体的特征
Q2 Mathematics Pub Date : 2024-01-23 DOI: 10.37934/cfdl.16.6.6889
Obulesu Mopuri, A.Sailakumari, Aruna Ganjikunta, Sudhakara E, VenkateswaraRaju K, Ramesh P, Charankumar Ganteda, B.Ramakrishna Reddy, S. V. K. Varma
This paper is concerned with the study of an unsteady, MHD natural convective boundary layer flow of a viscous, incompressible and electrically conducting, non-Newtonian Jeffery fluid over a semi-infinite vertically inclined permeable moving plate embedded in a porous medium in the presence of thermal radiation, heat absorption and thermal diffusion, heat and mass transfer. . The permeability of the porous medium and the suction velocity are considered to be an exponentially decreasing function of time. The fundamental governing equations for this investigation are solved numerically using the perturbation technique. The results are presented graphically and in tabular form for various controlling parameters. The behavior of different physical parameters is shown graphically. The numerical values of Skin friction, Nusselt number, and Sherwood number are presented in a tabular form. Obtained outcomes are compared with earlier studies in the special case and strong agreement is noted. From graphical representation, it is concluded that velocity and temperature distribution increases with the mixed convection parameter and buoyancy force parameter. An increasing value of magnetic field parameter, slip parameter, and Jeffery parameter tends to reduced velocity and also raising the values of Prandtl number, radiation parameter and heat absorption parameter tends to downfallen temperature profiles. This study may be useful in several industrial applications, for example, polymer production, manufacturing of ceramics or glassware and food processing, and so forth.
本文主要研究在存在热辐射、吸热、热扩散、传热和传质的情况下,粘性、不可压缩、导电、非牛顿杰弗里流体在嵌入多孔介质的半无限垂直倾斜可渗透移动板上的非稳态、MHD 自然对流边界层流动。.多孔介质的渗透性和抽吸速度被认为是时间的指数递减函数。采用扰动技术对本研究的基本控制方程进行了数值求解。结果以图形和表格形式显示了各种控制参数。图形显示了不同物理参数的行为。表皮摩擦力、努塞尔特数和舍伍德数的数值以表格形式列出。将获得的结果与之前在特殊情况下的研究结果进行了比较,发现两者非常一致。从图表中可以得出结论,速度和温度分布随着混合对流参数和浮力参数的增加而增加。磁场参数、滑移参数和杰弗里参数值的增加会导致速度减小,普朗特数、辐射参数和吸热参数值的增加会导致温度分布减小。这项研究可用于多种工业应用,例如聚合物生产、陶瓷或玻璃器皿制造以及食品加工等。
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引用次数: 0
Investigation of Modified EMST Micromixing Model Performance on Lagrangian PDF Transported in Lifted Hydrogen/Air Fames 改良 EMST 微混合模型对提升氢气/空气火焰中拉格朗日传输 PDF 性能的研究
Q2 Mathematics Pub Date : 2024-01-23 DOI: 10.37934/cfdl.16.6.2031
Mohamed Senouci, Ahmed Amine Larbi, Habib Rouan Serik, Abdehamid Bounif, Habib Merouane
This article presents a numerical simulation of high hydrogen/air flames using the Lagrangian transported PDF method. This method enables the calculation of fluid composition changes resulting from convection and reaction without the need for modelling, while requiring modelling for molecular mixing. Consequently, the accuracy of calculations in this L-PDF method heavily relies on an accurate representation of the mixture model term. The Euclidean model, which provides a better description of physical mixing processes, is well-suited for modelling the molecular mixing term EMST. Additionally, the accuracy of this model depends on the value of the mixing constant, representing the ratio between the mechanical time scale and the scalar time scale. Two algebraic models for the mixing constant have been implemented in the computational code, employing a well-defined function to calculate this ratio for each cell. These models contribute to memory and CPU time savings. To account for turbulence and its interaction with physical phenomena, the RSM model is employed due to its ability to identify different areas of turbulent stresses. Hence, the primary objective of this study is to evaluate the capabilities of these algebraic models in predicting scalar fields within such flames. Overall, the predictions align well with experimental data, affirming the validity of these models.
本文采用拉格朗日传输 PDF 方法对高氢气/空气火焰进行了数值模拟。该方法无需建模即可计算对流和反应引起的流体成分变化,而分子混合则需要建模。因此,这种 L-PDF 方法的计算精度在很大程度上取决于混合模型项的准确表示。欧氏模型能更好地描述物理混合过程,非常适合建立分子混合项 EMST 模型。此外,该模型的准确性还取决于混合常数的值,它代表了机械时间尺度和标量时间尺度之间的比率。混合常数的两个代数模型已在计算代码中实施,采用一个定义明确的函数来计算每个单元的这一比率。这些模型有助于节省内存和 CPU 时间。为了解释湍流及其与物理现象的相互作用,采用了 RSM 模型,因为该模型能够识别湍流应力的不同区域。因此,本研究的主要目的是评估这些代数模型预测此类火焰中标量场的能力。总体而言,预测结果与实验数据非常吻合,从而肯定了这些模型的有效性。
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引用次数: 0
MHD Flow Darcy Forchheimeter of Jeffrey Nanofluid over a Stretching Sheet Considering Melting Heat Transfer and Viscous Dissipation heat transfe 考虑熔融传热和粘性耗散的杰弗里纳米流体在拉伸片上的 MHD 流动达西-福赫海姆计
Q2 Mathematics Pub Date : 2024-01-23 DOI: 10.37934/cfdl.16.6.131145
Naresh Kumar, Gandrakota Srinivasu, Balagnoor Srikantha setty, Mani Ramanuja
This work investigates the MHD flow of a Jeffery nanofluid through a non-linear stretching sheet, considering melting heat transfer and the combined influences of concentration and thermal radiation. A variable magnetic effect normal to the flow direction is enforced to reinforce the conductivity of the Jeffery nanofluid. The governing non-linear PDEs with convective boundary conditions are transformed into the non-dimensional ODEs, and we apply appropriate similarity variables. The further similarity transformation is determined with the 4th-order Runge-Kutta shooting technique facilitated. The approach is implemented for convergent relations of the rate field, temperature, and nano-particle concentration. However, small magnetic Reynolds is considered to decline the induced magnetic impact. Melting parameter enhances temperature and concentration. Finally, the effect of fluid parameters such as thermophoresis, melting parameter, Deborah number, chemical reaction, Brownian motion, inertia parameter, Darcy number, and thermophoresis on the MHD flow profiles is examined graphically.
本文研究了杰弗里纳米流体流经非线性拉伸片的 MHD 流动,考虑了熔融传热以及浓度和热辐射的综合影响。为了加强杰弗里纳米流体的传导性,对流动方向的法向施加了可变磁效应。带有对流边界条件的非线性 PDE 被转换为非二维 ODE,我们应用了适当的相似性变量。进一步的相似性转换由四阶 Runge-Kutta 射击技术确定。该方法适用于速率场、温度和纳米粒子浓度的收敛关系。然而,小磁力雷诺被认为会降低诱导磁场的影响。熔化参数会提高温度和浓度。最后,以图形方式研究了热泳、熔化参数、德博拉数、化学反应、布朗运动、惯性参数、达西数和热泳等流体参数对 MHD 流动剖面的影响。
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引用次数: 0
Energy Evaluation of Synthesis Gas in a Turbocharger System Employing CFD Tools 利用 CFD 工具对涡轮增压器系统中的合成气进行能量评估
Q2 Mathematics Pub Date : 2024-01-23 DOI: 10.37934/cfdl.16.6.109119
Jorge Alvarez, Jonathan Fabregas Villegas, Mauricio Márquez, Javier Carpintero
Renewable energy sources derived from biomass, such as synthesis gases, represent an opportunity to take advantage of available waste resources and contribute to global energy rationing. This study developed an analysis with computational fluid dynamics (CFD) to estimate the energy behavior of synthesis gases through a turbocharger system. The synthesis gas used to drive the turbocharger turbine was extracted from the gasification of biomass from the Colombian Caribbean. The application of models for rigid body motion, as well as models of momentum, turbulence, energy, and conservation transport of species, suggest that the energy potential available by the turbine ranges from 0.4 kW to 5.2 kW of power generation, concerning mass flow rates entering the simulated system. The main findings of the study were temperature profiles, speed profiles, rotational speed variation, torque, and mechanical power generated in the turbocharger. It is emphasized that the synthesis gas studied presents a good behavior to generate energy through a turbine system of a turbocharger device.
从生物质中提取的可再生能源(如合成气)是利用现有废物资源的一个机会,并有助于全球能源配给。本研究利用计算流体动力学(CFD)进行了分析,以估算合成气通过涡轮增压器系统时的能量行为。用于驱动涡轮增压器涡轮的合成气是从哥伦比亚加勒比海地区的生物质气化过程中提取的。刚体运动模型以及动量、湍流、能量和物种守恒传输模型的应用表明,就进入模拟系统的质量流量而言,涡轮可产生的能量潜力从 0.4 千瓦到 5.2 千瓦不等。研究的主要发现是涡轮增压器中产生的温度曲线、速度曲线、转速变化、扭矩和机械功率。研究强调,所研究的合成气在通过涡轮增压器装置的涡轮系统产生能量方面表现良好。
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引用次数: 0
CFD Analysis for Valve-Holding Camber Permanent Inhaler Spacer (AerospaAcer) with Different Valves 采用不同气门的气门固定凸面永久吸入器垫片(AerospaAcer)的 CFD 分析
Q2 Mathematics Pub Date : 2024-01-23 DOI: 10.37934/cfdl.16.6.5367
Riyadhthusollehan Khairulfuaad, Norzelawati Asmuin, Juntakan Taweekun, Azizan Ismail, Nabil Izzuddin Shahhidan
During the COVID-19 pandemic, data statistics showed that patients with respiratory problems become infected. One of the therapy techniques for the respiratory condition was the use of a metered-dose inhaler and spacer. The objective of this paper is to determine the flow parameters of three types of valves which is duckbill valve, cross slit valve and umbrella valve in inhaler spacer to compare fluid flow between valve Previous researchers chose the duckbill valve to control fluid flow in inhaler spacer. The flow characteristics are unaffected by the materials used in the new disposable inhaler spacers, such as paper and polylactic acid (PLA). Several design valves reduced the skewness below 0.94 by suppressing the fillet and chamfer. ANSYS Workbench Fluent 19.2 is used to calculate flow parameters such as turbulence kinetic energy (TKE), turbulence eddy dissipation (TED), velocity, particle velocity magnitude, streamline, and vector velocity. The setup input data is based on the previous researcher's specified parameters such as viscosity model, drug characteristics (salbutamol and propellant), discrete phase model (DPM) equal to 80, boundary condition model, and SIMPLE technique. For the three types of valves, the nozzle injection used a 0.50-millimetre dimension. The simulation work is cross-checked against the results of prior simulations. Within each iteration, the transient flow employed a time step size of 0.01 for 200 steps. The results show that computational analysis can distinguish between models of varying complexity. The TED, TKE, and velocity graphs showed the approximate value between the model geometries. Overall, the study was successful in achieving the desired velocity magnitude in terms of visual and graph representations of the various valve.
在 COVID-19 大流行期间,数据统计显示,有呼吸道问题的病人会受到感染。呼吸系统疾病的治疗技术之一是使用计量吸入器和间隔器。本文的目的是测定三种阀门(鸭嘴阀、十字缝阀和伞形阀)在吸入器间隔器中的流量参数,比较不同阀门之间的流体流量。新型一次性吸入器垫片所使用的材料,如纸和聚乳酸(PLA),对流动特性没有影响。几个设计阀通过抑制圆角和倒角将偏斜度降至 0.94 以下。ANSYS Workbench Fluent 19.2 用于计算湍流动能 (TKE)、湍流涡耗散 (TED)、速度、颗粒速度大小、流线和矢量速度等流动参数。设置输入数据基于之前研究人员指定的参数,如粘度模型、药物特性(沙丁胺醇和推进剂)、等于 80 的离散相模型(DPM)、边界条件模型和 SIMPLE 技术。对于三种类型的阀门,喷嘴的喷射尺寸均为 0.50 毫米。模拟工作与之前的模拟结果进行了交叉检查。在每次迭代中,瞬态流的时间步长为 0.01,共 200 步。结果表明,计算分析可以区分不同复杂程度的模型。TED、TKE 和速度图显示了模型几何形状之间的近似值。总体而言,该研究成功地在各种阀门的视觉和图形表示方面达到了预期的速度大小。
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引用次数: 0
Numerical Simulation of Graphene-Nanoplatelet Nanofluid Convection in Millimeter-Sized Automotive Radiator 毫米级汽车散热器中石墨烯-纳米板纳米流体对流的数值模拟
Q2 Mathematics Pub Date : 2024-01-23 DOI: 10.37934/cfdl.16.6.3252
Leslie Kok Lik Toh, Tiew Wei Ting
The depletion of fossil fuels and environmental considerations in transportation sector motivate the researchers to enhance the efficiency and performance of the automotive systems. However, the poor thermal performance of conventional coolant poses a limitation in the development of energy-efficient vehicle due to the cooling constraint. In the present study, a comprehensive numerical study is conducted to scrutinize the convective performance of graphene nanoplatelets (GnP) nanofluid in millimeter-sized automotive radiator, aiming to enhance the understandings on the underlying physical significance of the suspension of graphene-based nanoparticle in water for the performance enhancement of automotive radiator. The temperature-dependent thermophysical properties of GnP-water nanofluid is predicted via existing correlations, while a modified viscosity correlation is developed. ANSYS Fluent is employed in the present numerical simulation to investigate the effects of various pertinent parameters such as Reynolds number, nanoparticles aspect ratio, tube aspect ratio and tube hydraulic diameter on the heat transfer performance of the radiator. Double precision and second-order upwind scheme with inclusion of viscous heating, and convergent criteria of 10˗6 are adopted for the present simulation. It is observed that the convective performance of the radiator is significantly enhanced by increasing Reynolds number and nanoparticle volume fraction while decreasing the aspect ratios of nanoparticle and radiator tube, with an enhancement rate as much as 1816%. Therefore, it is evident that the suspension of GnP intensifies the heat transfer performance of millimeter-sized automotive radiator, which could possibly lead to a more efficient radiator that is smaller and lighter.
化石燃料的枯竭和交通领域的环保考虑促使研究人员提高汽车系统的效率和性能。然而,由于冷却方面的限制,传统冷却剂的热性能较差,限制了高能效汽车的发展。本研究对石墨烯纳米颗粒(GnP)纳米流体在毫米级汽车散热器中的对流性能进行了全面的数值研究,旨在加深对悬浮在水中的石墨烯基纳米颗粒对提高汽车散热器性能的潜在物理意义的理解。通过现有相关性预测了 GnP-水纳米流体随温度变化的热物理性质,同时开发了一种改进的粘度相关性。本数值模拟采用 ANSYS Fluent 来研究雷诺数、纳米颗粒长宽比、管子长宽比和管子液压直径等各种相关参数对散热器传热性能的影响。本次模拟采用了包含粘性加热的双精度和二阶上风方案,收敛标准为 10˗6。结果表明,通过增加雷诺数和纳米粒子体积分数,同时降低纳米粒子和散热器管的长宽比,散热器的对流性能显著增强,增强率高达 1816%。因此,GnP 的悬浮显然增强了毫米级汽车散热器的传热性能,从而有可能使散热器的体积更小、重量更轻,效率更高。
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引用次数: 0
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