Zeitschriftenartikel: „General Dufour“

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Durojaye, M. O., J. A. Kazeem, F. O. Ogunfiditimi und I. J. Ajie. „Method of Lines Analysis of Soret and Dufour Effects on an Unsteady Heat and Mass Transfer MHD Natural Convection Couette Flow“. Physical Science International Journal 27, Nr. 2 (05.06.2023): 10–18. http://dx.doi.org/10.9734/psij/2023/v27i2780.

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This study examines the numerical solutions of an unsteady natural convection Couette flow of a viscous, incompressible and electrically conducting fluid between the two vertical parallel plates in the presence of thermal radiation, Soret and Dufour. The fundamental dimensionless governing partial differential equations for the impulsive movement of the plate are solved by method of lines (MOL). The numerical simulations for the effects of Soret and Dufour on the velocity profile, the temperature profile and the concentration profile of the flow are shown graphically. The analysis indicates that the fluid velocity is an increasing function of Soret and Dufour numbers. Also, the concentration profile and the temperature profile increase with increase in the Soret number and Dufour number respectively.

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Kavitha, S., und A. Selvaraj. „Rotation and Dufour Impact on Unsteady Flow Past a Parabolic Accelerated Vertical Plate with Uniform Temperature and Mass Diffusion“. Indian Journal Of Science And Technology 17, Nr. 24 (25.06.2024): 2482–93. http://dx.doi.org/10.17485/ijst/v17i24.1422.

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Objective : Fluid dynamics and heat transfer theory examine the Dufour phenomenon and the rotational influence of unstable parabolic flow across an accelerating infinite vertical plate. This scenario involves several parameters, including the "mass Grashof number (Gr), thermal Grashof number (Gc), Prandtl number (Pr), Hartmann number (Ha), Schmidt number (Sc), Dufour number (Dc), and acceleration parameter". Method : We have applied the Laplace transform method to the resulting PDE. This method converts the equations to algebraic form, making it easier to solve for velocity, temperature, and concentration in terms of time and space. Graphs can show the relationship between the acceleration parameter and numerous parameters such as mass and thermal Grashof, Hartmann (Ha), and Dufour (Df), as well as the consequent velocity profile. If the velocity increases when these variables change, we'll look at the physical reasons that generate this behaviour. We will examine the conclusions using experimental data or existing theoretical models, considering the model's assumptions and limits. Finally, highlight the significant facts and insights gained from the analysis. We will discuss potential future research possibilities, such as exploring more complex geometries or accounting for new physical effects. Findings : The increase in Dufour parameter value causes an increase in temperature and level trends, demonstrating the significant influence of these factors on the researched phenomena. Novelty: This research advances our understanding of heat and mass transfer phenomena by isolating the Dufour effect in a novel scenario involving unsteady flow around a rotating vertical plate, filling a gap in the existing body of knowledge that is dominated by MHD-inclusive investigations. Suggestions: This approach is fairly general and may be applied to find analysis of heat and mass transfer on Dufour effect for other effects such as Soret effect, Hall current of heat and mass transfer. Keywords: Uniform Temperature, Thermo diffusion (Dufour), Inverse Laplace, Rotational, Constant Mass

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Jha, Basant K., und Yusuf Y. Gambo. „Transient natural convention heat and mass transfer flow in a vertical channel in the presence of Soret and Dufour effects: An analytical approach“. International Journal of Modern Physics C 31, Nr. 02 (15.01.2020): 2050032. http://dx.doi.org/10.1142/s0129183120500321.

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This paper presents an analytical solution for transient natural convection heat and mass transfer flow in a vertical channel with Soret and Dufour effects. Due to the presence of these two effects, energy and concentration equations are coupled. The dimensionless governing equations for momentum, energy and concentration are first decoupled using perturbation method and then solved using Laplace Transform Technique (LTT) under relevant initial and boundary conditions. The expressions for temperature, concentration, velocity, rate of heat transfer, rate of mass transfer and skin-friction are obtained. Numerical solutions are also obtained using pdepe in MATLAB so as to validate the accuracy of the proposed analytical method. The effects of Soret parameter, Dufour parameter, Grashof number, modified Grashof number, Prandtl number, Schmidt number and dimensionless time are presented graphically and discussed. It is observed that the temperature and velocity increase with increase in Dufour number, while concentration decreases with increase of Dufour number. The Dufour effect is more significant on the temperature and velocity in comparison to concentration. Moreover, it is observed that the concentration and velocity increase with increase in Soret number while the impact of Soret number is just contrast on temperature variation.

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Siti Suzilliana Putri Mohamed Isa, Hazirah Mohd Azmi, Nanthini A/P Balakrishnan, Norihan Md. Arifin und Haliza Rosali. „Soret-Dufour Effects on Heat and Mass Transfer of Newtonian Fluid Flow over the Inclined Sheet and Magnetic Field“. Journal of Advanced Research in Numerical Heat Transfer 14, Nr. 1 (11.10.2023): 39–48. http://dx.doi.org/10.37934/arnht.14.1.3948.

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Newtonian fluid is ideal for lubrication purposes because the viscosity of this fluid remains as a function of the shear. Besides, the heat and mass transfer are an important study area in fluid dynamics due to its vast applications in industrial processes. The heat-mass transfer can be defined as the Soret and Dufour effect, which implemented in many industrial applications such as in chemical engineering and geosciences field. In addition, the fluid flow over an extending/compressing sheet has significant industrial applications such as the cooling of continuous strips, glass fibre production, the extrusion of plastic sheets from a die, etc. As a response, this study aims to investigate the impacts of Soret and Dufour parameters on the Newtonian fluid flow over an inclined stretching/shrinking sheet. The methodology of this mathematical model are stated as follow: 1) the transformation of partial differential equations (PDEs) to the ordinary differential equations (ODEs), and 2) The ODEs are solved using bvp4c solver in MATLAB software. The bvp4c solver is a MATLAB program directory that solves general form and multi-point boundary layer problems. The main sections of bvp4c are: 1) The solution of the ODEs, 2) The related boundary conditions that can produce the expected results, and 3) An initial guess to run the bvp4c solver. As a result, the numerical and graphical results show that the Soret effect increases the concentration profile whereas decreases the temperature profile. The vice versa occurrence is true for Dufour effect. The convective mass transfer caused by a temperature gradient is known as thermal-diffusion (Soret) effect. The convective heat transfer produced by concentration differences is known as diffusion-thermo (Dufour) effect. However, since the process of heat and mass transfers are related to each other, the Soret and Dufour effects are able to influence both of this process simultaneously. In conclusion, the convective heat transfer is enhanced by increasing Soret and Dufour number while the convective mass transfer is declined by increasing the two numbers.

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Filahi, Ismail, Mohamed Bourich, Mohammed Hasnaoui und Abdelkhalek Amahmid. „Analytical and Numerical Study of Soret and Dufour Effects on Thermosolutal Convection in a Horizontal Brinkman Porous Layer with a Stress-Free Upper Boundary“. Mathematical Problems in Engineering 2020 (31.03.2020): 1–17. http://dx.doi.org/10.1155/2020/4046570.

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In this paper, thermo-diffusion (Soret effect) and diffusion-thermo (Dufour effect) effects on double-diffusive natural convection induced in a horizontal Brinkman porous layer with a stress-free upper boundary are investigated. The cavity is filled with a binary fluid and subjected to uniform fluxes of heat and mass on its long sides. An analytical solution based on the parallel flow approximation is developed for the problem considered in order to allow prompt determination of the thresholds of stationary and finite amplitude solutions and also heat and mass transfer characteristics. The analytical solution is validated numerically by using a finite difference method. The combined effects of the Soret and Dufour parameters, the thermal Rayleigh number, the buoyancy ratio, and the Darcy number on the flow intensity and heat and mass transfer are illustrated graphically, and some particular behaviors observed are discussed. The analytical solution proves the existence of different regions in the buoyancy ratio-Dufour parameter plane, corresponding to different parallel flow behaviors. The number, the location, and the extent of these regions, which are impossible to predict numerically, depend strongly on Soret and Dufour parameters. The effect of thermo-diffusion and diffusion-thermo on flow intensity and heat and mass transfer is found to be important.

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Zeb, Salman, Suliman Khan, Zakir Ullah, Muhammad Yousaf, Ilyas Khan, Nawa Alshammari, Nur Alam und Nawaf N. Hamadneh. „Lie Group Analysis of Double Diffusive MHD Tangent Hyperbolic Fluid Flow over a Stretching Sheet“. Mathematical Problems in Engineering 2022 (21.02.2022): 1–14. http://dx.doi.org/10.1155/2022/9919073.

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In this study, we have used Lie group analysis procedure to propose a novel model for transforming the governing equations of double diffusive MHD hyperbolic tangent fluid flow model into a system of nonlinear ordinary differential equations (ODEs). The solution of these equations is then investigated numerically by employing Shooting method. We also reported and presented our results graphically illustrating the results and analysis of physical parameters on concentration, velocity, and temperature profiles and on other physical quantities present in the flow model. The results show that fluid temperature increases with rise in the modified Dufour and velocity slip parameters whereas opposite behavior is observed for thermal slip parameter. Moreover, the Nusselt number declines with enhanced values of modified Dufour parameter whereas its opposite effect has been observed for Dufour-solutal Lewis number and Prandtl number.

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Kefayati, Gholamreza. „Soret and Dufour effects on double diffusive mixed convection of Newtonian and shear-thinning fluids in a two sided lid-driven cavity“. Engineering Computations 33, Nr. 7 (03.10.2016): 2117–48. http://dx.doi.org/10.1108/ec-10-2015-0300.

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Purpose The thermal-diffusion (Soret) and the diffusion-thermo (Dufour) effects play a crucial role in double diffusive mixed convection in a lid-driven cavity; but they have not been studied properly by researchers. The purpose of this paper is to investigate effects of Soret and Dufour parameters on double diffusive laminar mixed convection of shear-thinning and Newtonian fluids in a two-sided lid-driven cavity. Design/methodology/approach Finite Difference Lattice Boltzmann method (FDLBM) has been applied to solve the complex problem. This study has been conducted for the certain pertinent parameters of Richardson number (Ri=0.00062-1), power-law index (n=0.2-1), Soret parameter (Sr=−5-5) as Dufour number effects have been investigated from Dr=−5 to 5 at Buoyancy ratio of N=1 and Lewis number of Le=5. Findings Results indicate that the augmentation of Richardson number causes heat and mass transfer to decrease. The fall of the power-law index declines heat and mass transfer at Ri=0.00062 and 0.01 in various Dufour and Soret parameters. At Ri=1, the heat and mass transfer rise with the increment of power-law index for Dr=0 and Sr=0. The least effect of power-law index on heat and mass transfer among the studied Richardson numbers was observed at Ri=1. The positive Dufour numbers augment the heat transfer gradually as the positive Soret numbers enhance the mass transfer. The Dr=−5 and Sr=−5 provokes the negative average Nusselt and Sherwood numbers, respectively, to be generated. The least magnitude of the average Nusselt and Sherwood numbers were obtained at Dr=−1 and Sr=−1, respectively. Originality/value Soret and Dufour effects in double diffusive mixed convection has not been studied in a lid-driven cavity. In addition. this study has been conducted also for shear-thinning fluids.

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Santos, Francisco Junior Lemes. „Da obra do gozo ou do sentido do sintoma: desordem simbólica e mínimo de Outro“. Estilos da Clinica 28, Nr. 2 (20.08.2023): 264–76. http://dx.doi.org/10.11606/issn.1981-1624.v28i2p264-276.

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No fundamento do que o filósofo Dany-Robert Dufour chama de dessimbolização está o esvaecimento do grande Sujeito, o desaparecimento do Outro. Este, um conceito eminentemente psicanalítico, considerável no ensino do psicanalista Jacques-Marie Émile Lacan, do qual o filósofo francês se serve. Se foi possível a Dufour indicar um processo de dessimbolização, não é porque a questão do Outro permaneceu intacta. O fato é que, na psicanálise lacaniana, também não. Esta pesquisa bibliográfica toma o singular paradoxo apresentado por Dufour, que aventa um regozijo frente ao sofrimento imiscuído na dessimbolização, mas contornando-o sobretudo desde o último Lacan, isto é, a partir do Seminário 20, e de seus aliados, a fim de fornecer outros operadores que possam problematizar essa leitura. Os desdobramentos e resultados alcançam a inconsistência do Outro frente ao protagonismo do modo de gozar do parlêtre.

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Krementz, David G., Richard J. Barker, William A. Link, James E. Hines, Pat O. Corr und Ray B. Owen. „Response to Dufour and Ankney“. Ornis Scandinavica 21, Nr. 4 (Dezember 1990): 301. http://dx.doi.org/10.2307/3676398.

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Rashidi, Mohammad Mehdi, Mohamed Ali, Behnam Rostami, Peyman Rostami und Gong-Nan Xie. „Heat and Mass Transfer for MHD Viscoelastic Fluid Flow over a Vertical Stretching Sheet with Considering Soret and Dufour Effects“. Mathematical Problems in Engineering 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/861065.

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The homotopy analysis method (HAM) with two auxiliary parameters is employed to examine heat and mass transfer in a steady two-dimensional magneto hydrodynamic viscoelastic fluid flow over a stretching vertical surface by considering Soret and Dufour effects. The two-dimensional boundary-layer governing partial differential equations are derived by considering the Boussinesq approximation. The highly nonlinear ordinary differential forms of momentum, energy, and concentration equations are obtained by similarity transformation. These equations are solved analytically in the presence of buoyancy force. The effects of different involved parameters such as magnetic field parameter, Prandtl number, buoyancy parameter, Soret number, Dufour number, and Lewis number on velocity, temperature, and concentration profiles are plotted and discussed. The effect of the second auxiliary parameter is also illustrated. Results show that the effect of increasing Soret number or decreasing Dufour number tends to decrease the velocity and temperature profiles (increase in Sr cools the fluid and reduces the temperature) while enhancing the concentration distribution.

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G, Lakshmi Devi, und Niranjan Hari. „INFLUENCE OF SORET AND DUFOUR, ACTIVATION ENERGY ON MHD CHEMICALLY REACTING NANOFLUID FLOW PAST A VERTICAL SURFACE WITH RADIATION“. Latin American Applied Research - An international journal 52, Nr. 3 (21.06.2022): 239–46. http://dx.doi.org/10.52292/j.laar.2022.926.

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The current article aims to investigate Soret and Dufour's effects on MHD flow of heat and mass transfer nanofluid over a vertical stretching sheet with activation energy and radiation. Using Similarity transformations, the non-linear momentum, energy, solute, and nanoparticle concentration boundary layer equations are simplified. The resulting boundary layer equations are solved numerically with bvp4c and along with the shooting technique. The impact of various parameters on velocity, temperature, concentration, and nanoparticle volume fraction, Skin friction, local Sherwood and local Nusselt numbers are presented through graphs. It is found that the temperature, fluid velocity, and nanoparticle volume fraction enhanced with both Dufour and Soret effects.

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Hussain, Muzamil, Umer Farooq, Gulfam Bano, Jifeng Cui und Taseer Muhammad. „Bioconvection Unsteady Magnetized Flow in a Horizontal Channel with Dufour and Soret Effects“. Mathematical Problems in Engineering 2022 (29.01.2022): 1–15. http://dx.doi.org/10.1155/2022/4771282.

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In the current decade, bioconvection phenomenon has received a lot of attention in research because of its applications in the biological polymer synthesis, biosensors and biotechnology, pharmaceutical industry, microbial enhanced oil recovery, environmentally friendly applications, and continuous refinements in mathematical modeling. Therefore, this article is prepared to address the unsteady mixed bioconvection in electrically conducting fluid flow between two infinite parallel plates with magnetic field and first-order chemical reaction impacts. Furthermore, the heat and mass transfer study has taken Dufour and Soret effects into account. The nonlinear coupled systems representing the continuity, momentum, energy, mass diffusion, and microorganisms’ equations are renewed into an ordinary differential equation (ODE) by employing the similarity renovation. The renovated ODEs are interpreted by the Homotopy Analysis Method (HAM). Impacts of the different emerging parameters, namely, magnetic field parameter ( M ), heat generation parameter ( Q ), Dufour number ( D u ), Soret number ( S r ), Schmidt number ( S c ), chemical reaction parameter ( K 0 ), Prandtl number ( P r ), squeezing parameter ( β ), Peclet number ( P e ), and Lewis number ( L e ) on the dimensionless velocity, temperature, concentration, and microorganism profiles as well as the frictional drag, Nusselt number, Sherwood number, and microorganisms mass flux are presented. The main outcomes of this investigation are that the velocity profile rises as the squeezing parameter is increased, and clear enhancement is noticed in the temperature profile for augmented estimations of chemical reaction, heat generation/absorption, and Dufour parameters. There is a significant downward trend in the concentration profile and microorganism density for elevated values of Dufour and Soret parameters.

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Ahmed, N. „MHD convection with Soret and Dufour effects in a three-dimensional flow past an infinite vertical porous plate“. Canadian Journal of Physics 88, Nr. 9 (September 2010): 663–74. http://dx.doi.org/10.1139/p10-056.

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In this paper, the Soret and Dufour effects on a mixed convective mass transfer flow past an infinite vertical porous plate with transverse sinusoidal suction velocity in presence of a uniform transverse magnetic field have been studied analytically. The magnetic Reynolds number is assumed to be so small that the induced magnetic field can be neglected. The nondimensional equations governing the flow and heat and mass transfer are solved by regular perturbation technique, on the assumption that the solution consists of two parts: a mean part and a perturbed part. The expressions for the velocity, temperature and concentration fields, skin friction at the plate in the direction of the free stream, Nusselt number and Sherwood number at the plate, and the current density are obtained in nondimensional forms. The effects of the Hartmann number M, the Soret number Sr, the Dufour number Du, the Reynolds number Re, Schmidt number Sc, and the Prandtl number Pr on the flow and transport characteristics are discussed through graphs and tables. It is seen that viscous drag on the plate is reduced under the effect of thermal-diffusion (Soret) and diffusion-thermo (Dufour). On the other hand, the rate of heat transfer from the plate to the fluid falls because of the Dufour effect and rises under the Soret effect, whereas the mass flux from the plate to the fluid is delayed under the thermal-diffusion effect, but the reverse occurs under the effect of diffusion-thermo.

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Srinivasacharya, D., und K. Kaladhar. „Soret and dufour effects on free convection flow of a couple stress fluid in a vertical channel with chemical reaction“. Chemical Industry and Chemical Engineering Quarterly 19, Nr. 1 (2013): 45–55. http://dx.doi.org/10.2298/ciceq111231041s.

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The Soret and Dufour effects in the presence of chemical reaction on natural convection heat and mass transfer of a couple stress fluid in a vertical channel formed by two vertical parallel plates is presented. The governing non-linear partial differential equations are transformed into a system of ordinary differential equations using similarity transformations. The resulting equations are then solved using Homotopy Analysis Method (HAM). Profiles of dimensionless velocity, temperature and concentration are shown graphically for various values of Dufour number, Soret number, Couple stress parameter and chemical reaction parameter.

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Jagan, Kandasamy, und Sivanandam Sivasankaran. „Soret & Dufour and Triple Stratification Effect on MHD Flow with Velocity Slip towards a Stretching Cylinder“. Mathematical and Computational Applications 27, Nr. 2 (09.03.2022): 25. http://dx.doi.org/10.3390/mca27020025.

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The phenomenon of convective flow with heat and mass transfer has been studied extensively due to its applications in various fields. The effects of nonlinear thermal radiation (NLTR), slip, thermal-diffusion (Soret) and diffusion-thermo (Dufour) on magenoto-hydrodynamic (MHD) flow towards a stretching cylinder in the presence of triple stratification (TSF) are investigated in this paper. The governing equations are transformed into an ODE by suitable transformations. The homotopy analysis method (HAM) is used to solve the ODE. The revamping of fluid flow, and heat transfer due to the presence of the Soret and Dufour effect, concentration slip and concentration stratification are analyzed. The temperature and local Sherwood number increases as the Dufour number rises, whereas the local Nusselt number decreases. While elevating the Soret number, the Sherwood number diminishes, whereas the concentration profile rises. The thermal boundary layer thickness enhances when thermal radiation increases. The rate of solute transport reduces while the concentration slip increases.

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Alexandre, Alain. „Richard Dufour, sculpteur et statuaire rouennais“. Études Normandes 61, Nr. 1 (2012): 29–38. http://dx.doi.org/10.3406/etnor.2012.1865.

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Hasen, Saba S., und Ahmed M. Abdulhadi. „Analytical Study of Soret and Dufour effect in the Electro-osmotic peristaltic flow of Rabinowitsch fluid model“. Ibn AL- Haitham Journal For Pure and Applied Sciences 34, Nr. 2 (20.04.2021): 70–86. http://dx.doi.org/10.30526/34.2.2629.

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The present paper concerned with study the of combined electro-osmotic peristaltic transport with heat and mass transfer which is represented by the Soret and Dufour phenomenon with the presence of the Joule electrothermal heating through a microchannel occupy by Rabinowitsch fluid. The unsteady two-dimensional governing equations for flow with energy and concentration conservation have been formed in a Cartesian coordinate system and the lubrication theory is applied to modify the relevant equations to the problem. The Debye-Hukel linearization approximation is utilizing to modify the electrohydrodynamics problem. The expressions for the axial velocity, the temperature profile, the concentration profile, and the volumetric flow rate are obtained analytically to gain exact solutions, while the numerical integration is used to analyze the pressure rise. The attitude of the Helmholtz-Smoluchowski velocity, the electro-osmotic parameter, the Joule electrothermal heating, the Dufour number, the Soret number, is studied and graphically analyzed. It is showed that the presence of the electric field increased the velocity of the fluid and pressure rise, and it is revealed that the temperature and concentration profile congregate in the center of the channel with increase in the Soret and Dufour number.

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Jaber, Khaled K. „Influence of Dofour and Soret on Eyrig-Powell Nanofluid Flow from A Circular Cylinder with Viscous Dissipation“. European Journal of Mathematics and Statistics 4, Nr. 4 (31.08.2023): 69–77. http://dx.doi.org/10.24018/ejmath.2023.4.4.181.

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The impact of Viscous dissipation on the heat and mass transfer characteristics of an Eyring Powell nanofluid flow past a horizontal circular cylinder is intensively investigated in the presence of Dufour and Soret effects. The free laminar flow is subject to a uniform transverse magnetic field. The continuity, momentum, energy, and concentrations equations are transformed into a nonlinear system of partial differential equations using appropriate non-similarity variables. The transformed system was solved numerically using the fourth order Runge Kutta method. The effect of parameters including Prandtl number, Dufour effect, Soret effect and Schmidt number were studied and presented graphically. Nusselt and Sherwood numbers have also been derived and discussed numerically.

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Shateyi, Stanford, Sandile Sydney Motsa und Precious Sibanda. „The Effects of Thermal Radiation, Hall Currents, Soret, and Dufour on MHD Flow by Mixed Convection over a Vertical Surface in Porous Media“. Mathematical Problems in Engineering 2010 (2010): 1–20. http://dx.doi.org/10.1155/2010/627475.

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The study sought to investigate the influence of a magnetic field on heat and mass transfer by mixed convection from vertical surfaces in the presence of Hall, radiation, Soret (thermal-diffusion), and Dufour (diffusion-thermo) effects. The similarity solutions were obtained using suitable transformations. The similarity ordinary differential equations were then solved by MATLAB routinebvp4c. The numerical results for some special cases were compared with the exact solution and those obtained by Elgazery (2009) and were found to be in good agreement. A parametric study illustrating the influence of the magnetic strength, Hall current, Dufour, and Soret, Eckert number, thermal radiation, and permeability parameter on the velocity, temperature, and concentration was investigated.

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Mohan, Hari, Pardeep Kumar und Pawittar Singh. „On generalized hydromagnetic thermosolutal convection: The Dufour-effect“. Thermal Science 9, Nr. 1 (2005): 139–50. http://dx.doi.org/10.2298/tsci0501139m.

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The effect of uniform magnetic field on the Dufour-driven thermosolutal convection of an electrically conducting fluid completely confined in an arbitrary region bounded by rigid walls is considered. Some general qualitative results concerning the character of marginal state, stability of oscillatory motions and limitations on the oscillatory motions of growing amplitude, are derived. The results for the horizontal layer geometry in the present case follow as a consequence.

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Mohammad, Saddam Atteyia. „Effects of Soret and Dufour on Mixed Convection over a Cone in a Non-Darcy Porous Medium with Chemical Reaction“. International Research Journal of Innovations in Engineering and Technology 06, Nr. 02 (2022): 86–93. http://dx.doi.org/10.47001/irjiet/2022.602015.

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This work explore the boundary layer behavior under the effects of Soret and Dufour on the mixed convection adjacent to inverted cone immersed within non-Darcian porous milieu together with chemical reaction action. The natural and forced convection limits are also considered in this study. The equations governing the problem together with the boundary conditions are converted to non-similar non-dimensional shape and solved numerically using finite difference method. It was found that enhances the value of the Soret number will increase the amount of heat transport and decrease the amount of mass transport. Enhances the value of Dufour number or chemical reaction parameter will reduce the amount of heat transfer and raise the amount of mass transfer.

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DAS, U. J. „SORET AND DUFOUR EFFECTS ON THREE DIMENSIONAL MIXED CONVECTIVE HYDROMAGENTIC FLOW OF A VISCO-ELASTIC FLUID PAST AN INFINITE INCLINED PLATE“. Latin American Applied Research - An international journal 49, Nr. 1 (31.01.2019): 7–12. http://dx.doi.org/10.52292/j.laar.2019.278.

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This study focuses analytically on a steady three dimensional mixed convective hydromagnetic flow of an incompressible, electrically conducting, visco-elastic fluid past an infinite inclined porous plate with transverse sinusoidal suction velocity, incorporating Soret and Dufour effects. The expressions for the velocity, temperature field, concentration field, skin friction at the plate, Nusselt number and Sherwood number at the plate are obtained. It is seen that fluid velocity decreases under the effects of Soret number and visco-elastic parameter. Also, it is seen that skin friction increases under the effects of visco-elastic parameter whereas Soret number and Dufour number reduces the viscous drag on the plate for both Newtonian and visco-elastic cases.

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Noreen, Waheed, Hussanan und Lu. „Entropy Analysis in Double-Diffusive Convection in Nanofluids through Electro-osmotically Induced Peristaltic Microchannel“. Entropy 21, Nr. 10 (10.10.2019): 986. http://dx.doi.org/10.3390/e21100986.

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A theoretical study is presented to examine entropy generation in double-diffusive convection in an Electro-osmotic flow (EOF) of nanofluids via a peristaltic microchannel. Buoyancy effects due to change in temperature, solute concentration and nanoparticle volume fraction are also considered. This study was performed under lubrication and Debye-Hückel linearization approximation. The governing equations are solved exactly. The effect of dominant hydrodynamic parameters (thermophoresis, Brownian motion, Soret and Dufour), Grashof numbers (thermal, concentration and nanoparticle) and electro-osmotic parameters on double-diffusive convective flow are discussed. Moreover, trapping, pumping, entropy generation number, Bejan number and heat transfer rate were also examined under the influence of pertinent parameters such as the thermophoresis parameter, the Brownian motion parameter, the Soret parameter, the Dufour parameter, the thermal Grashof number, the solutal Grashof number, the nanoparticle Grashof number, the electro-osmotic parameter and Helmholtz–Smoluchowski velocity. The electro-osmotic parameter powerfully affected the velocity profile. The magnitude of total entropy generation increased as the thermophoresis parameter and Brownian motion parameter increased. Soret and the Dufour parameter had a strong tendency to control the temperature profile and Bejan number. The findings of the present analysis can be used in clinical purposes such as cell therapy, drug delivery systems, pharmaco-dynamic pumps and particles filtration.

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Favard, Florent. „Éric Dufour, Le Cinéma de science-fiction“. Essais, Nr. 2 (15.11.2012): 120–24. http://dx.doi.org/10.4000/essais.10560.

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Chand, Ramesh, und Gian Chand Rana. „Dufour and Soret Effects on the Thermosolutal Instability of Rivlin– Ericksen Elastico–Viscous Fluid in Porous Medium“. Zeitschrift für Naturforschung A 67, Nr. 12 (01.12.2012): 685–91. http://dx.doi.org/10.5560/zna.2012-0074.

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Dufour and Soret effects on the convection in a horizontal layer of Rivlin-Ericksen elastico- viscous fluid in porous medium are considered. For the porous medium, the Darcy model is used. A linear stability analysis based upon normal mode analysis is employed to find a solution of the fluid layer confined between two free boundaries. The onset criterion for stationary and oscillatory convection has been derived analytically, and graphs have been plotted, giving various numerical values to various parameters, to depict the stability characteristics. The effects of the Dufour parameter, Soret parameter, solutal Rayleigh number, and Lewis number on stationary convection have been investigated.

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Choudhuri, K., Nazibuddin Ahmed und Pranab Jyoti Parashar. „SORET AND DUFOUR EFFECTS IN A THREE-DIMENSIONAL MHD FLOW PAST A SEMI-INFINITE UNIFORMLY MOVING VERTICAL PLATE WITH CONSTANT HEAT FLUX“. Latin American Applied Research - An international journal 53, Nr. 3 (24.06.2023): 263–70. http://dx.doi.org/10.52292/j.laar.2023.1000.

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In this paper, we have considered the three-dimensional MHD flow past a semi-infinite uniformly moving porous plate with Soret and Dufour effects. The plate is subjected to a sinu-soidal suction velocity and constant heat flux. It is assumed that a uniform magnetic field is applied normal to the plate and directed into the fluid region. But the induced magnetic field is neglected in the study on the assumption that the magnetic Reynolds number is very small. The analytic solutions are obtained by adopting the method of perturbation technique. The influence of magnetic field parameter, thermal diffusion and diffusion-thermo effects on the flow, heat and mass transfer characteristics are mainly focused on the study. It is found from our study that fluid velocity increases under the influence of Soret and Dufour effects.

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Sengupta, Sanjib, und Nazibuddin Ahmed. „MHD free convective mass transfer flow of radiative uniform heat generation (absorption) fluid through a wavy permeable channel in the presence of Soret and Dufour effects“. Canadian Journal of Physics 95, Nr. 1 (Januar 2017): 44–58. http://dx.doi.org/10.1139/cjp-2014-0599.

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The paper aims to present analytically the parametric effect of thermo-diffusion (Soret) and diffusion-thermo (Dufour) effects on a two-dimensional steady magnetohydrodynamic (MHD) free convective heat and mass transfer flow of a reasonably viscous incompressible electrically conducting fluid in the presence of thermal radiation and zeroth-order heat generation (absorption) effects. The governing system of partial differential equations with favorable boundary conditions is first non-dimensionalized and then solved by splitting the solution into a mean part and a perturbed part. Ostrach’s static fluid model is used to solve the mean part of the solution, while long wave approximations are employed to deal with the perturbed part of the solution. It is observed that an increase in parametric values of Soret and Dufour numbers as well as wall temperature and wall concentration parameters increase the primary velocity, while the cross flow velocity is found to be decreasing because of the increase in values of Soret and Dufour numbers. The primary and the cross flow velocities are both found to be increasing because of the increase in the thermal radiation parameter. The Nusselt number at the plates decreases because of the increase in the wall temperature parameter. It is also interesting to observe that the temperature and concentration of fluid particles near a plate are regulated by the influence of wall temperature and wall concentration parameters.

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Kune, Ramesh, Hari Singh Naik, Borra Shashidar Reddy und Christophe Chesneau. „Role of Nanoparticles and Heat Source/Sink on MHD Flow of Cu-H2O Nanofluid Flow Past a Vertical Plate with Soret and Dufour Effects“. Mathematical and Computational Applications 27, Nr. 6 (28.11.2022): 102. http://dx.doi.org/10.3390/mca27060102.

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The study is devoted to investigating the effect of an unsteady non-Newtonian Casson fluid over a vertical plate. A mathematical analysis is presented for a Casson fluid by taking into consideration Soret and Dufour effects, heat generation, heat radiation, and chemical reaction. The novelty of the problem is the physical interpretation of Casson fluid before and after adding copper water-based nanoparticles to the governing flow. It is found that velocity was decreased and the temperature profile was enhanced. A similarity transformation is used to convert the linked partial differential equations that control flow into non-linear coupled ordinary differential equations. The momentum, energy, and concentration formulations are cracked by means of the finite element method. The thermal and solute layer thickness growth is due to the nanoparticles’ thermo-diffusion. The effects of relevant parameters such as the Casson fluid parameter, radiation, Soret and Dufour effects, chemical reaction, and Prandtl number are discussed. A correlation of the average Nusselt number and Sherwood number corresponding to active parameters is presented. It can be noticed that increasing the Dufour number leads to an uplift in heat transfer. Fluid velocity increases with Grashof number and decreases with magnetic effect. The impact of heat sources and radiation is to increase the thermal conductivity. Concentration decreases with the Schmidt number.

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Frogerais, André, Dominique Kassel und Annik Sultan-Paré. „Le laboratoire des Cachets Sandol, Dufour and Paré“. Revue d'histoire de la pharmacie 105, Nr. 399 (2018): 343–50. http://dx.doi.org/10.3406/pharm.2018.23665.

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Desjardins, France, und Jeanne Simard. „Émilie Dufour, conseillère en développement collectif chez Communagir“. Revue Organisations & territoires 31, Nr. 3 (09.01.2023): 151–57. http://dx.doi.org/10.1522/revueot.v31n3.1526.

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31

Olagbemiro, T. O., K. M. Sani, L. Lajide, M. O. Agoh, B. W. Staddon und C. E. Chukwu. „trans-4-Phenyl-3-buten-2-one from the African Harvester Ant Messor galla (Mayr) (Hymenoptera: Formicidae)“. Zeitschrift für Naturforschung B 43, Nr. 3 (01.03.1988): 339–42. http://dx.doi.org/10.1515/znb-1988-0317.

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By gas chromatography mass spectrometry and synthesis of authentic standard, trans-4-phenyl-3- buten-2-one for the first time as well as known hydrocarbons have been identified in the Dufour′s gland secretion of the African harvester ant Messor galla (Mayr).

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Mahajan, R. L., und C. Wei. „Buoyancy, Soret, Dufour, and Variable Property Effects in Silicon Epitaxy“. Journal of Heat Transfer 113, Nr. 3 (01.08.1991): 688–95. http://dx.doi.org/10.1115/1.2910619.

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In most of the previous numerical and semi-analytical studies of silicon epitaxial deposition, a common practice has been to neglect the buoyancy flow, Dufour, Soret, and property variation effects. In this paper, we take a critical look at the validity of that approach and point out some fallacies. The geometric configuration studied is a horizontal reactor for the susceptor tilt angles of 0 and 2.9 deg. The full Navier-Stokes equations coupled with those for the energy and species transfer are solved numerically for a range of parameters typical of commercial silicon epitaxial deposition systems. The effects of ignoring terms due to buoyancy, Dufour, Soret, and variable properties on the mass transfer rate are systematically evaluated. The results indicate that for typical horizontal epitaxial deposition parameters, the buoyancy and Dufour effects have negligible effect on the mass transfer rate, while the Soret and property variation have a large impact. In light of this information, it is shown that the agreement reported in the past between the experimental and numerical/analytical studies is coincidental. The implication is that these assumptions must be critically examined for a given CVD system and not ignored a priori. Finally, the effects of important parameters—reactor height, inlet velocity, inlet concentration, and susceptor temperature—on the deposition characteristics are included to provide guidelines for controlling the epitaxial layer thickness and uniformity.

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Wahid, Nur Syahirah, Norihan Md Arifin, Najiyah Safwa Khashi’ie, Ioan Pop, Norfifah Bachok und Mohd Ezad Hafidz Hafidzuddin. „Hybrid Nanofluid Radiative Mixed Convection Stagnation Point Flow Past a Vertical Flat Plate with Dufour and Soret Effects“. Mathematics 10, Nr. 16 (17.08.2022): 2966. http://dx.doi.org/10.3390/math10162966.

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The widespread application of hybrid nanofluid in real applications has been accompanied by a large increase in computational and experimental research. Due to the unique characteristics of hybrid nanofluid, this study aspires to examine the steady two-dimensional mixed convection stagnation point flow of a hybrid nanofluid past a vertical plate with radiation, Dufour, and Soret effects, numerically. The formulations of the specific flow model are presented in this study. The model of fluid flow that is expressed in the form of partial differential equations is simplified into ordinary differential equations via the transformation of similarity, and then solved numerically by using the boundary value problem solver known as bvp4c in MATLAB, which implements the finite difference scheme with the Lobatto IIIa formula. Two possible numerical solutions can be executed, but only the first solution is stable and meaningful from a physical perspective when being evaluated via a stability analysis. According to the findings, it is sufficient to prevent the boundary layer separation by using 2% copper nanoparticles and considering the lesser amount of Dufour and Soret effects. The heat transfer rate was effectively upgraded by minimizing the volume fraction of copper and diminishing the Dufour effect. Stronger mixed convection would lead to maximum skin friction, mass transfer, and heat transfer rates. This important preliminary research will give engineers and scientists the insight to properly control the flow of fluids in optimizing the related complicated systems.

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ABDALLA, F. C., und C. da CRUZ-LANDIM. „Dufour glands in the hymenopterans (Apidae, Formicidae, Vespidae): a review“. Revista Brasileira de Biologia 61, Nr. 1 (Februar 2001): 95–106. http://dx.doi.org/10.1590/s0034-71082001000100013.

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Associated to the sting apparatus of the aculeate hymenopterans is found the poison gland, originated from the glands associated to the ovipositor of the non-aculeate hymenopterans and the less derived Dufour gland, homologue of the coletterial gland of other insects, and found in all hymenopteran females. The Dufour gland functions is mostly uncertain in hymenopterans but in ants it is involved with communication and defense and in non social bees with the nest building and protection. In wasps possibly with kin-recognition. Differences in morphology and chemical composition of the gland secretion were observed among species, in the same species, between the castes in the social species and among individual of the same caste playing different tasks or belonging to different nest. Its original function of egg-protective substance producing, or favoring the oviposition, appear to have been replaced or complemented in hymenopterans by the production of semiochemicals with function in communication.

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Verma, Krishnandan, und B. R. Sharma. „SORET AND DUFOUR EFFECTS ON MHD FLOW WITH HEAT AND MASS TRANSFER PAST AN EXPONENTIALLY STRETCHING SHEET“. Latin American Applied Research - An international journal 52, Nr. 2 (25.03.2022): 83–88. http://dx.doi.org/10.52292/j.laar.2022.795.

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The current study aims to explore the impact of Soret and Dufour effects past a stretching surface with heat and mass transfer on MHD fluid flow including the effects of heat sink and radiation. Similarity transformations are employed to deduce the governing partial differential equations of flow, heat and mass transfer to system of nonlinear ODEâ€™s. The equations together with boundary conditions so obtained are solved using numerical technique by employing Matlabâ€™s solver bvp4c. The graph of fluid velocity, temperature and concentration distributions are obtained for different parameters for the deep analysis of the problem. It is observed that Soret and Dufour effects show notable contribution towards heat and mass transfer where the latter boosts the rate of mass transfer, and the former raises the heat transfer rate. The accuracy of the numerical solution is confirmed by comparing our results with the outcomes of previous work on stretching sheet and the results show good agreement.

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Nisar, Kottakkaran Sooppy, Umair Khan, Aurang Zaib, Ilyas Khan und Dumitru Baleanu. „Exploration of Aluminum and Titanium Alloys in the Stream-Wise and Secondary Flow Directions Comprising the Significant Impacts of Magnetohydrodynamic and Hybrid Nanofluid“. Crystals 10, Nr. 8 (06.08.2020): 679. http://dx.doi.org/10.3390/cryst10080679.

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This exploration examines the nonlinear effect of radiation on magnet flow consisting of hybrid alloy nanoparticles in the way of stream-wise and cross flow. Many experimental, as well as theoretical explorations, demonstrated that the thermal conductivity of the regular liquid increases by up to 15 to 40% when nanomaterials are mixed with the regular liquid. This change of the thermal conductivity of the nanoliquid depends on the various characteristics of the mixed nanomaterials like the size of the nanoparticles, the agglomeration of the particles, the volume fraction, etc. Researchers have used numerous nanoparticles. However, we selected water-based aluminum alloy (AA7075) and titanium alloy (Ti6Al4V) hybrid nanomaterials. This condition was mathematically modeled by capturing the Soret and Dufour impacts. The similarity method was exercised to change the partial differential equations (PDEs) into nonlinear ordinary differential equations (ODEs). Such nonlinear ODEs were worked out numerically via the bvp4c solver. The influences of varying the parameters on the concentration, temperature, and velocity area and the accompanying engineering quantities such as friction factor, mass, and heat transport rate were obtained and discussed using graphs. The velocity declines owing to nanoparticle volume fraction in the stream-wise and cross flow directions in the first result and augment in the second result, while the temperature and concentration upsurge in the first and second results. In addition, the Nusselt number augments due to the Soret number and declines due to the Dufour number in both results, whereas the Sherwood number uplifts due to the Dufour number and shrinks due to the Soret number in both results.

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Bertei, Antonio, Andrea Lamorgese und Roberto Mauri. „Constitutive Relations of Thermal and Mass Diffusion“. Journal of Non-Equilibrium Thermodynamics 45, Nr. 1 (28.01.2020): 27–38. http://dx.doi.org/10.1515/jnet-2019-0055.

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AbstractNon-equilibrium thermodynamics provides a general framework for the description of mass and thermal diffusion, thereby including also cross-thermal and material diffusion effects, which are generally modeled through the Onsager coupling terms within the constitutive equations relating heat and mass flux to the gradients of temperature and chemical potential. These so-called Soret and Dufour coefficients are not uniquely defined, though, as they can be derived by adopting one of the several constitutive relations satisfying the principles of non-equilibrium thermodynamics. Therefore, mass diffusion induced by a temperature gradient and heat conduction induced by a composition gradient can be implicitly, and unexpectedly, predicted even in the absence of coupling terms. This study presents a critical analysis of different formulations of the constitutive relations, with special focus on regular binary mixtures. It is shown that, among the different formulations presented, the one which adopts the chemical potential gradient at constant temperature as the driving force for mass diffusion allows for the implicit thermo-diffusion effect to be strictly absent while the resulting Dufour effect is negligibly small. Such a formulation must be preferred to the other ones since cross-coupling effects are predicted only if explicitly introduced via Onsager coupling coefficients.

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Motsa, S. S., und S. Shateyi. „Successive Linearization Analysis of the Effects of Partial Slip, Thermal Diffusion, and Diffusion-Thermo on Steady MHD Convective Flow due to a Rotating Disk“. Mathematical Problems in Engineering 2012 (2012): 1–15. http://dx.doi.org/10.1155/2012/397637.

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We proposed a general formulation of the successive linearization method for solving highly nonlinear boundary value problem arising in rotating disk flow. The problem was studied under the effects of partial slip, thermal diffusion, and diffusion-thermo. The governing fundamental conservation equations of mass, momentum, angular momentum, energy, and concentration are transformed into a system of ordinary differential equations by means of similarity transformations. A parametric study illustrating the influence of the magnetic field, slip factor, Eckert number, Dufour and Soret numbers was carried out.

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Kaigalula, Victor, und Samuel Mutua. „Soret and Dufour Effects on MHD Fluid Flow Through a Collapssible Tube Using Spectral Based Collocation Method“. Applied and Computational Mathematics 13, Nr. 1 (28.02.2024): 8–28. http://dx.doi.org/10.11648/j.acm.20241301.12.

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This paper examine numerical study for soret and dufour effects on unsteady Newtonian MHD fluid flow with mass and heat transfer in a collapsible elastic tube using Spectral Collocation technique. The objective of the study is to determine the velocity, temperature and concentration profiles together with heat and mass transfer rates. The governing equations are continuity, momentum, energy and concentration equation. The system of nonlinear partial differential equations governing the flow solved numerically by applying collocation method and implemented in MATLAB. The numerical solution of the profiles displayed both by graphically and numerically for different values of the physical parameters. The effects of varying various parameters such as Reynolds number, Hartmann number, Soret number, Dufour number and Prandtl number on velocity, temperature and concentration profiles also the rates of heat and mass transfer are discussed. The findings of this study are important due to its wide range of application including but not limited to medical fields, biological sciences and other physical sciences where collapsible tubes are applied.

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Khan, Sohail A., und Tasawar Hayat. „Entropy Analysis for Hydromagnetic Darcy–Forchheimer Flow Subject to Soret and Dufour Effects“. Mathematical and Computational Applications 27, Nr. 5 (19.09.2022): 80. http://dx.doi.org/10.3390/mca27050080.

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Here, our main aim is to examine the impacts of Dufour and Soret in a radiative Darcy–Forchheimer flow. Ohmic heating and the dissipative features are outlined. The characteristics of the thermo-diffusion and diffusion-thermo effects are addressed. A binary chemical reaction is deliberated. To examine the thermodynamical system performance, we discuss entropy generation. A non-linear differential system is computed by the finite difference technique. Variations in the velocity, concentration, thermal field and entropy rate for the emerging parameters are scrutinized. A decay in velocity is observed for the Forchheimer number. Higher estimation of the magnetic number has the opposite influence for the velocity and temperature. The velocity, concentration and thermal field have a similar effect on the suction variable. The temperature against the Dufour number is augmented. A decay in the concentration is found against the Soret number. A similar trend holds for the entropy rate through the radiation and diffusion variables. An augmentation in the entropy rate is observed for the diffusion variable.

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Hayat, Tasawar, Meraj Mustafa und Said Mesloub. „Mixed Convection Boundary Layer Flow over a Stretching Surface Filled with a Maxwell Fluid in Presence of Soret and Dufour Effects“. Zeitschrift für Naturforschung A 65, Nr. 5 (01.05.2010): 401–10. http://dx.doi.org/10.1515/zna-2010-0505.

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This article looks at the heat and mass transfer characteristics in mixed convection boundary layer flow about a linearly stretching vertical surface. An incompressible Maxwell fluid occupying the porous space takes into account the diffusion-thermo (Dufour) and thermal-diffusion (Soret) effects. The governing partial differential equations are transformed into a set of coupled ordinary differential equations, by invoking similarity transformations. The involved nonlinear differential system is solved analytically using the homotopy analysis method (HAM) to determine the convergent series expressions of velocity, temperature, and concentration. The physical interpretation to these expressions is assigned through graphs and tables for the Nusselt number θ '(0) and the Sherwood number φ '(0). The dependence of suction parameter S, mixed convection parameter λ, Lewis number Le, Prandtl number Pr, Deborah number β , concentration buoyancy parameter N, porosity parameter γ , Dufour number Df, and Soret number Sr is seen on the flow quantities.

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Anusha, P., M. Naga Swapna Sri, V. V. Venu Madhav, Ch Sri Chaitanya, V. V. Spandana, Kuldeep K. Saxena, Dalael Saad Abdul-Zahra et al. „Dynamics of MHD Convection of Walters B Viscoelastic Fluid through an Accelerating Permeable Surface Using the Soret–Dufour Mechanism“. Applied Sciences 12, Nr. 19 (20.09.2022): 9431. http://dx.doi.org/10.3390/app12199431.

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The MHD convective Walters-B memory liquid flow past a permeable accelerating surface with the mechanism of Soret-Dufour is considered. The flow equation constitutes a set of partial differential equations (PDEs) to elucidate the real flow of a non-Newtonian liquid. The radiation thermo-physical parameters were employed based on the use of Roseland approximation. This implies the fluid employed in this exploration is optically thick. Utilizing suitable similarity terms, the flow equation PDEs were simplified to become total differential equations. The spectral homotopy analysis method (SHAM) was utilized to provide outcomes to the model. The SHAM involves the addition of the Chebyshev pseudospectral approach (CPM) alongside the homotopy analysis approach (HAM). The outcomes were depicted utilizing graphs and tables for the quantities of engineering concern. The mechanisms of Soret and Dufour were separately examined. The imposed magnetism was found to lessen the velocity plot while the thermal radiation term elevates the temperature plot because of the warm particles of the fluid.

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Costa, O. L. V., und F. Dufour. „The Vanishing Discount Approach for the Average Continuous Control of Piecewise Deterministic Markov Processes“. Journal of Applied Probability 46, Nr. 4 (Dezember 2009): 1157–83. http://dx.doi.org/10.1239/jap/1261670695.

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This work is concerned with the existence of an optimal control strategy for the long-run average continuous control problem of piecewise-deterministic Markov processes (PDMPs). In Costa and Dufour (2008), sufficient conditions were derived to ensure the existence of an optimal control by using the vanishing discount approach. These conditions were mainly expressed in terms of the relative difference of the α-discount value functions. The main goal of this paper is to derive tractable conditions directly related to the primitive data of the PDMP to ensure the existence of an optimal control. The present work can be seen as a continuation of the results derived in Costa and Dufour (2008). Our main assumptions are written in terms of some integro-differential inequalities related to the so-called expected growth condition, and geometric convergence of the post-jump location kernel associated to the PDMP. An example based on the capacity expansion problem is presented, illustrating the possible applications of the results developed in the paper.

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Rodrigues da Silva, André. „A Ausência Como Presença:Uma Discussão Sobre O Dispositivo Pronominal Trinitário“. PERcursos Linguísticos 12, Nr. 31 (03.10.2022): 126–39. http://dx.doi.org/10.47456/pl.v12i31.38647.

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Neste artigo, me proponho a discutir e refletir sobre o dispositivo trinitário pronominal de Dany-Robert Dufour, a fim de pensar o seu uso na análise do texto literário. Com isso, utilizaram-se excertos da obra O Estrangeiro (1942), de Albert Camus, a fim de pensar na reversibilidade pronominal, o eu e o tu, diante da oposição que se instaura ao ele, no texto literário. Dividida em duas partes, O Estrangeiro traz Meursault, que sofre uma reviravolta em sua vida após cometer um assassinato no final da primeira parte do livro. A partir disso, na segunda parte, Meursault se vê cada vez mais distante do seu lugar no discurso, fora da reversibilidade entre eu-tu, na medida em que ele é relegado ao papel de não-pessoa, o ele. Pretendo, portanto, mostrar como a ausência re-presentada nesse campo discursivo da reversibilidade, pode ser caracterizada como uma presença desse ausente, o ele, a partir de Dufour (2000), na instância discursiva e intersubjetivante entre os falantes eu-tu, assim como trazer um ponto de vista particular para a análise da obra, mostrando o personagem-narrador em meio à alternância pronominal instaurada na obra de Camus.

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Khalid, I. K., N. F. M. Mokhtar, I. Hashim, Z. B. Ibrahim und S. S. A. Gani. „Effect of Internal Heat Source on the Onset of Double-Diffusive Convection in a Rotating Nanofluid Layer with Feedback Control Strategy“. Advances in Mathematical Physics 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/2789024.

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A linear stability analysis has been carried out to examine the effect of internal heat source on the onset of Rayleigh–Bénard convection in a rotating nanofluid layer with double diffusive coefficients, namely, Soret and Dufour, in the presence of feedback control. The system is heated from below and the model used for the nanofluid layer incorporates the effects of thermophoresis and Brownian motion. Three types of bounding systems of the model have been considered which are as follows: both the lower and upper bounding surfaces are free, the lower is rigid and the upper is free, and both of them are rigid. The eigenvalue equations of the perturbed state were obtained from a normal mode analysis and solved using the Galerkin method. It is found that the effect of internal heat source and Soret parameter destabilizes the nanofluid layer system while increasing the Coriolis force, feedback control, and Dufour parameter helps to postpone the onset of convection. Elevating the modified density ratio hastens the instability in the system and there is no significant effect of modified particle density in a nanofluid system.

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CRUZ-LANDIM, C., und R. D. REGINATO. „Exocrine glands of Schwarziana quadripunctata (Hymenoptera, Apinae, Meliponini)“. Brazilian Journal of Biology 61, Nr. 3 (August 2001): 497–505. http://dx.doi.org/10.1590/s1519-69842001000300020.

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This article describes the location, anatomy, histology and ontogeny of adult Schwarziana quadripunctata exocrine glands. These glands appear either as individualized organs (salivary gland system and Dufour gland) or as epidermis differentiation (tegumentary glands). Variations in the occurrence and degree of development among colony components with regard to their degree of maturity are also described.

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Das, Utpal Jyoti. „MHD POISEUILLE FLOW WITH SORET AND DUFOUR EFFECTS UNDER SLIP BOUNDARY CONDITIONS“. Latin American Applied Research - An international journal 51, Nr. 3 (25.06.2021): 159–63. http://dx.doi.org/10.52292/j.laar.2021.615.

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A steady MHD flow is analyzed in presence of Soret and Dufour effects with consideration of induced magnetic field under slip boundary conditions. The walls of the channel are porous, isothermal and subjected to injection/suction at a constant velocity. The effects of various flow parameters on velocity, magnetic field intensity, temperature, concentration, skin friction, Nusselt number and Sherwood number are discussed.

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Jamir, Temjennaro, und Hemanta Konwar. „Unsteady Magnetohydrodynamic Slip Flow, Heat and Mass Transfer over a Permeable Stretching Cylinder with Soret and Dufour Effects in Porous Medium“. Defect and Diffusion Forum 424 (08.05.2023): 143–54. http://dx.doi.org/10.4028/p-jwdu0s.

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This study considers the unsteady magnetohydrodynamic slip flow past a permeable stretching cylinder by taking into account the Soret and Dufour effects. Using similarity transformations, the partial differential equations governing the flow, heat, and mass transfers are transformed into a system of ordinary differential equations. These equations are numerically solved for a variety of governing parameter values using the boundary value problem solved package, bvp4c, which is available in the MATLAB software. The outcomes of the governing parameters on the skin friction coefficient, Nusselt and Sherwood numbers are also examined. Upon observation, the unsteadiness parameter influences a positive growth on the momentum, thermal and concentration boundary layers. Slip parameter can be enhanced to improve the friction drag force about 28% and the rate of cooling around 3%. Also, larger effects of Dufour leads to around 9% decay in heat transfer rate and Soret effect to cause around 11% drop in mass transfer rate. Comparison with existing results show excellent agreement which justifies the reliability of the obtained results.

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Mohan, Hari, und Pardeep Kumar. „On hydromagnetic thermosolutal convection coupled with cross-diffusion in completely confined fluids“. Theoretical and Applied Mechanics 38, Nr. 1 (2011): 17–36. http://dx.doi.org/10.2298/tam1101017m.

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The instability of thermosolutal convection coupled with crossdiffusion of an electrically conducting fluid completely confined in an arbitrary region bounded by rigid wall in the presences of a uniform magnetic field applied in an arbitrary direction is investigated. Some general qualitatively results concerning the character of marginal state, stability of oscillatory motions and limitations on the oscillatory motions of growing amplitude are derived. The results for the thermosolutal convection problems with or without the individual consideration of Dufour and Soret effects follow as a consequence.

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Vasu, B., V. R. Prasad und O. Anwar Bég. „Thermo-Diffusion and Diffusion-Thermo Effects on MHD Free Convective Heat and Mass Transfer from a Sphere Embedded in a Non-Darcian Porous Medium“. Journal of Thermodynamics 2012 (30.08.2012): 1–17. http://dx.doi.org/10.1155/2012/725142.

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The problem of combined heat and mass transfer by natural convection over a sphere in a homogenous non-Darcian porous medium subjected to uniform magnetic field is numerically studied, taking Soret/Dufour effects into account. The coupled, steady, and laminar partial differential conservation equations of mass, momentum, energy, and species diffusion are normalized with appropriate transformations. The resulting well-posed two-point boundary value problem is solved using the well-tested, extensively validated Keller-Box implicit finite difference method, with physically realistic boundary conditions. A parametric study of the influence of Soret number (Sr), Dufour number (Du), Forchheimer parameter (Λ), Darcy parameter (Da), buoyancy ratio parameter (), Prandtl number (Pr), Schmidt number (Sc), magnetohydrodynamic body force parameter (), wall transpiration () is the blowing/suction parameter, and streamwise variable (ξ) on velocity, temperature, and concentration function evolution in the boundary layer regime is presented. Shear stress, Nusselt number, and Sherwood number distributions are also computed. Applications of the study arise in hydromagnetic flow control of conducting transport in packed beds, magnetic materials processing, geophysical energy systems, and magnetohydrodynamic chromatography technology.

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