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1.
Heliyon ; 9(11): e21807, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38027973

RESUMO

Micro polar fluids have a wide variety of applications in biomedical, manufacturing, and technical activities, such as nuclear structures, biosensors, electronic heating and cooling, etc. The aim of this study is to investigate the properties of heat transfer on a magnetohydrodynamic free convection movement of micro polar fluid over an exponentially stretchable curved surface. The flow is non-turbulent and steady. The effects of Joule heating, varying thermal conductivity, irregular heat reservoir, and non-linear radiation are anticipated. The modelled PDEs are converted to ODEs via transformation, and the integration problems are then addressed using ND-Solve method along with bvp4c package. It is observed that velocity is reduced and the micro rotation field is increased as the micro rotation parameter is increased. It is witnessed that the temperature of the fluid enhances as the Eckert number is augmented. The velocity is increasing function of the curvature parameter while the decreases with increasing magnetic factor. The distribution of temperature is improved by a rise in temperature-dependent thermal conductivity characteristic. It is investigated that as the values of temperature ratio, Prandtl number, and the Biot number are increased the temperature distribution is enhanced. For the stability of the numerical results, the mean square residue error (MSRE) and total mean square residue error (TMSRE) are computed. For the confirmation of the present analysis, a comparison is done with the published study and excellent settlement is found.

2.
Nanoscale Adv ; 5(22): 6216-6227, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37941957

RESUMO

Applications: the study of highly advanced hybrid nanofluids has aroused the interest of academics and engineers, particularly those working in the fields of chemical and applied thermal engineering. The improved properties of hybrid nanoliquids are superior to those of earlier classes of nanofluids (which are simply referred to as nanofluids). Therefore, it is essential to report on the process of analyzing nanofluids by passing them through elastic surfaces, as this is a typical practice in engineering and industrial applications. Purpose and methodology: the investigation of hybrid nanoliquids was the sole focus of this research, which was conducted using a stretched sheet. Using supporting correlations, an estimate was made of the improved thermal conductivity, density, heat capacitance, and viscosity. In addition, the distinctiveness of the model was increased by the incorporation of a variety of distinct physical limitations, such as thermal slip, radiation, micropolarity, uniform surface convection, and stretching effects. After that, a numerical analysis of the model was performed, and the physical results are presented. Core findings: the results of the model showed that it is possible to attain the desired momentum of hybrid nanofluids by keeping the fluidic system at a uniform suction, and that this momentum may be enhanced by increasing the force of the injecting fluid via a stretched sheet. Surface convection, thermal radiation, and high dissipative energy are all great physical instruments that can be used to acquire heat in hybrid nanofluids. This heat acquisition is significant from both an applied thermal engineering perspective and a chemical engineering perspective. The features of simple nano and common hybrid nanoliquids have been compared and the results indicate that hybrid nanofluids exhibit dominant behavior when measured against the percentage concentration of nanoparticles, which enables them to be used in large-scale practical applications.

3.
Sci Rep ; 13(1): 20059, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37973960

RESUMO

The entropy generation analysis for the nanofluid flowing over a stretching/shrinking curved region is performed in the existence of the cross-diffusion effect. The surface is also subjected to second-order velocity slip under the effect of mixed convection. The Joule heating that contributes significantly to the heat transfer properties of nanofluid is incorporated along with the heat source/sink. Furthermore, the flow is assumed to be governed by an exterior magnetic field that aids in gaining control over the flow speed. With these frameworks, the mathematical model that describes the flow with such characteristics and assumptions is framed using partial differential equations (PDEs). The bvp4c solver is used to numerically solve the system of non-linear ordinary differential equations (ODEs) that are created from these equations. The solutions of obtained through this technique are verified with the available articles and the comparison is tabulated. Meanwhile, the interpretation of the results of this study is delivered through graphs. The findings showed that the Bejan number was decreased by increasing Brinkman number values whereas it enhanced the entropy generation. Also, as the curvature parameter goes higher, the speed of the nanofluid flow diminishes. Furthermore, the increase in the Soret and Dufour effects have enhanced the thermal conduction and the mass transfer of the nanofluid.

4.
Heliyon ; 9(11): e21107, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37928015

RESUMO

The magnetohydrodynamic (MHD) rotating flow that occurs across a stretching surface has numerous practical applications in a variety of domains. These fields include astronomy, engineering, the material sciences, and space exploration. The combined examination of magnetohydrodynamics rotating flow across a stretching surface, taking into consideration fluctuating viscosity and nanoparticle aggregation, has significant ramifications across several different domains. It is essential for both the growth of technology and the attainment of deeper insights into the complicated fluid dynamics to maintain research in this field. Given the aforementioned motivation, the principal aim of this study is to examine the effects of variable viscosity on the bidirectional rotating magnetohydrodynamic flow over a stretching surface. Aggregation effects on nanoparticles are used in the analysis. Titania (TiO2) is taken nanoparticle and ethylene glycol as base fluid. The nonlinear ordinary differential equations and the boundary conditions that correspond to them can be transformed into a dimensionless form by using a technique called similarity transformation. To get a numerical solution to the transformed equation, the Runge-Kutta 4th order (RK-4) method is utilized, and this is done in conjunction with the shooting method. The impact of various leading variables on dimensionless velocity, the coefficients of temperature, skin friction and local Nusselt number are graphically represented. Velocity profiles in both direction increases with increasing values of φ. The Nusselt number increases with increasing values of the radiation and temperature ratio parameters. When a 1 % volume fraction of nanoparticles is introduced, the Nusselt number exhibits a 0.174 % increase for the aggregation model compared to the regular fluid in the absence of radiation effects. When the aggregation model is used with a 1 % volume fraction of nanoparticles, the skin friction increases by 0.1153 % in the x direction and by 0.1165 % in the y direction compared to the regular fluid. Tables show the variation in Nusselt numbers, as well as a comparison of the effects of nanoparticle's aggregation model without and with radiation. Moreover, the numerical results obtained were compared with previously published data, demonstrating a satisfactory agreement. We firmly believe that this finding will have extensive implications for engineering and various industries.

5.
Sci Rep ; 13(1): 7180, 2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37137919

RESUMO

The analysis of the energy transport mechanism received much attention from scientists and researchers. Conventional fluids like vegetable oils, water, ethylene glycol, and transformer oil play a vital role in numerous industrial activities. In certain industrial operations, the low heat conductivity of base fluids causes significant difficulties. This inevitably led to the advancement of critical aspects of nanotechnology. The tremendous significance of nanoscience is in improving the thermal transfer process in different heating transmitting equipment. Therefore, the MHD spinning flow of hybrid nanofluid (HNF) across two permeable surfaces is reviewed. The HNF is made of silver (Ag) and gold (Au) nanoparticles (NPs) in the ethylene glycol (EG). The modeled equations are non-dimensionalized and degraded to a set of ODEs through similarity substitution. The numerical procedure parametric continuation method (PCM) is used to estimate the 1st order set of differential equations. The significances of velocity and energy curves are derived versus several physical parameters. The results are revealed through Tables and Figures. It has been determined that the radial velocity curve declines with the varying values of the stretching parameter, Reynold number, and rotation factor while improving with the influence of the suction factor. Furthermore, the energy profile enhances with the rising number of Au and Ag-NPs in the base fluid.

6.
Sci Rep ; 13(1): 6423, 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37076537

RESUMO

The primary goal of this article is to explore the radiative stagnation point flow of nanofluid with cross-diffusion and entropy generation across a permeable curved surface. Moreover, the activation energy, Joule heating, slip condition, and viscous dissipation effects have been considered in order to achieve realistic results. The governing equations associated with the modeling of this research have been transformed into ordinary differential equations by utilizing appropriate transformation variable. The resulting system of equations was solved numerically by using Bvp4c built-in package in MATLAB. The impact of involved parameters have been graphically examined for the diverse features of velocity, temperature, and concentration profiles. Throughout the analysis, the volume fraction is assumed to be less than [Formula: see text] while the Prandtl number is set to be [Formula: see text]. In addition, the entropy generation, friction drag, Nusselt, and Sherwood numbers have been plotted for describing the diverse physical aspects of the underlying phenomena. The major outcomes reveal that the curvature parameter reduces the velocity profile and skin friction coefficient whereas the magnetic parameter, temperature difference parameter, and radiation parameter intensify the entropy generation.

7.
Heliyon ; 9(4): e14740, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37025838

RESUMO

The current study aims to assess the augmentation of energy transmission in the presence of magnetic dipole through trihybrid Carreau Yasuda nanofluid flow across a vertical sheet. The rheological properties and thermal conductivity of the based fluids are improved by framing an accurate combination of nanoparticles (NPs). The trihybrid nanofluid (Thnf) has been synthesized by the addition of ternary nanocomposites (MWCNTs, Zn, Cu) to the ethylene glycol. The energy and velocity conveyance has been observed in the context of the Darcy Forchhemier effect, chemical reaction, heat source/sink, and activation energy. The trihybrid nanofluid flow across a vertical sheet has been accurately calculated for velocity, concentration, and thermal energy in the form of a system of nonlinear PDEs. The set of PDEs is reduced to dimensionless ODEs by using suitable similarity replacements. The obtained set of non-dimensional differential equations is numerically computed through the Matlab package bvp4c. It has been perceived that the energy curve enhances by the influence of heat generation factor and viscous dissipation. It is also noted that the magnetic dipole has a momentous contribution to raising the transmission of thermal energy of trihybrid nanofluid and declines the velocity curve. The inclusion of multi-wall carbon nanotubes (MWCNTs), zinc (Zn), and copper (Cu) nano particulates to the base fluid "ethylene glycol", augments the energy and velocity outlines.

8.
Molecules ; 27(21)2022 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-36364434

RESUMO

The whitefly, Bemisia tabaci, is the main pest for many field and horticultural crops, causing main and significant problems. The efficiency of imidacloprid insecticide as seed treatment and foliar spray at three rates against the whitefly, B. tabaci, was evaluated in tomato plants under field conditions; in addition, insecticide residues were determined in tomato leaves and fruits. The obtained results revealed that the seedlings produced from treated seeds with imidacloprid were the most effective treatment in decreasing whitefly stages. Reduction percentages of whitefly stages in seedlings produced from treated seeds and sprayed with ½, ¾ and 1 field rates of imidacloprid were more than that produced from untreated seeds. Tomato fruit yield in seedlings produced from treated seeds and sprayed with one recommended rate of imidacloprid was more than that of untreated seeds. The residues of imidacloprid in leaves and fruits in seedlings produced from treated seeds and sprayed with field rate were more than that of untreated seeds; additionally, the residues were higher in leaves than in fruits. The residual level in fruits was less than the maximum residual level (MRL = 1 mg kg-1) of the Codex Alimentarius Commission. The half-life (t ½) was 6.99 and 6.48 days for leaves and fruits of seedlings produced from treated seeds and 5.59 and 4.59 days for untreated seeds. Residues in tomato fruits were less than the MRL, therefore, imidacloprid is considered an unconventional insecticide appropriate for B. tabaci control that could be safe for the environment.


Assuntos
Hemípteros , Inseticidas , Solanum lycopersicum , Animais , Inseticidas/farmacologia , Imidazóis/farmacologia , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Plântula
9.
Sci Rep ; 12(1): 19374, 2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36371535

RESUMO

The important feature of the current work is to consider the pressure variation, heat transport, and friction drag in the hydromagnetic radiative two-dimensional flow of a hybrid nanofluid depending on the viscous dissipation and Joule heating across a curved surface. The curved surface has been considered with the binary heating process called as prescribed heat flux and surface temperature. The basic partial differential equation (PDEs) has been converted into the non-dimensional ordinary differential equations (ODEs) by applying some specified dimensionless transformations. The bvp4c built-in package in MATLAB has been considered to find the numerical solution of the consequential equations. The graphical results have been plotted in terms of pressure, friction drag, velocity, temperature, and heat transport. Several important results have also been plotted for the plan level surface [Formula: see text]The condition of [Formula: see text]. It is found that the heat transport rate respectively reduces and enhances with the enhancement of radiation parameter and Hartmann number as well as the friction drag is enhancing with the high-volume fraction of nanoparticles and Hartmann number. Moreover, enhancing curvature parameter, enhances the friction drag and declines the heat transport rate. The current work renders uncountable applications in several engineering and industrial systems like electronic bulbs, electric ovens, geysers, soil pollution, electric kettle, fibrous insulation, etc. Moreover, the heating as well as the cooling systems of electrical, digital, and industrial instruments, are controlled by the heat transport in fluids. Thus, it is important to use such flows in these types of instruments.

10.
Micromachines (Basel) ; 14(1)2022 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-36677110

RESUMO

The present computational model is built to analyze the energy and mass transition rate through a copper and cobalt ferrite water-based hybrid nanofluid (hnf) flow caused by the fluctuating wavy spinning disk. Cobalt ferrite (CoFe2O4) and copper (Cu) nanoparticles (nps) are incredibly renowned in engineering and technological research due to their vast potential applications in nano/microscale structures, devices, materials, and systems related to micro- and nanotechnology. The flow mechanism has been formulated in the form of a nonlinear set of PDEs. That set of PDEs has been further reduced to the system of ODEs through resemblance replacements and computationally solved through the parametric continuation method. The outcomes are verified with the Matlab program bvp4c, for accuracy purposes. The statistical outputs and graphical evaluation of physical factors versus velocity, energy, and mass outlines are given through tables and figures. The configuration of a circulating disk affects the energy transformation and velocity distribution desirably. In comparison to a uniform interface, the uneven spinning surface augments energy communication by up to 15%. The addition of nanostructured materials (cobalt ferrite and copper) dramatically improves the solvent physiochemical characteristics. Furthermore, the upward and downward oscillation of the rotating disc also enhances the velocity and energy distribution.

11.
Biomed Res Int ; 2017: 8094947, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28691034

RESUMO

In this research article, a new mathematical model of delayed differential equations is developed which discusses the interaction among CD4 T cells, human immunodeficiency virus (HIV), and recombinant virus with cure rate. The model has two distributed intracellular delays. These delays denote the time needed for the infection of a cell. The dynamics of the model are completely described by the basic reproduction numbers represented by R0, R1, and R2. It is shown that if R0 < 1, then the infection-free equilibrium is locally as well as globally stable. Similarly, it is proved that the recombinant absent equilibrium is locally as well as globally asymptotically stable if 1 < R0 < R1. Finally, numerical simulations are presented to illustrate our theoretical results. Our obtained results show that intracellular delay and cure rate have a positive role in the reduction of infected cells and the increasing of uninfected cells due to which the infection is reduced.


Assuntos
Infecções por HIV/terapia , Infecções por HIV/virologia , HIV-1/fisiologia , Modelos Biológicos , Simulação por Computador , Humanos , Análise Numérica Assistida por Computador , Fatores de Tempo
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