Cylindrical Nanoparticles Research Articles

Theoretical Study of Gold Nanoparticles Randomly Dispersed on a Dielectric/Gold Substrate.

We theoretically study random arrangements of cylindrical gold nanoparticles (NPs) deposited on a dielectric/gold substrate. We use two methods, namely the Finite Element Method (FEM) and the Coupled Dipole Approximation (CDA) method. The FEM is increasingly used to analyze the optical properties of NPs, but calculations for arrangements containing a large number of NPs have a high computational cost. On the contrary, the CDA has the advantage to drastically reduce the computation time and the memory demand compared to the FEM. Nevertheless, as the CDA involves modeling each NP as a single electric dipole through the polarizability tensor of a spheroidal-shaped NP, it may be an insufficiently accurate method. Therefore, the main purpose of this article is to verify the validity of using the CDA in order to analyze such a kind of nanosystems. Finally, we capitalize on this methodology to draw some tendencies between statistics of NPs' distributions and the plasmonic properties.

FEM treatments for MHD highly mixed convection flow within partially heated double-lid driven odd-shaped enclosures using ternary composition nanofluids

A highly mixed convection due to the movements of two perpendicular walls of odd-shaped enclosures is examined. The upper and right boundaries are partially heated, and several heating situations based on the positions of the active parts are considered. Also, several directions of the lid-walls movements are examined. The inner medium is a heat generating and the considered Lorentz force is inclined with angle Φ. The mathematical formulations are based on the Brinkman-extended non-Darcy model. The containers are filled with ternary composition nanofluids. The components of the ternary nanofluids are spherical Al2O3 nanoparticles, MWCNT cylindrical nanoparticles and platelet graphene nanoparticles and suitable correlations for the thermophysical properties are introduced. The numerical simulations are carried out using the finite element method (FEM) based on the characteristics–based split (CBS) algorithm. The major outcomes revealed that the ternary composition nanofluids cause an enhancement in the heat transfer rate by 17.65% comparing to the mono-nanofluids. Also, to get the best mixed convection situation, it is recommended to locate the heat sources in the middle of the outer perpendicular walls, set Re≥100 and make the lower perpendicular walls move in anticlockwise direction to get the best mixed convection situation.

Hamilton–Crosser model impact for particle shape in a nanofluid flow influenced by variable thermal conductivity

Nanofluids with immersed metallic nanoparticles possess a higher thermal conductivity. The extent of this enhancement is largely dependent on the amount of the volume fraction, composition, nanoparticles’ shape, and size. The current study emphasizes nanofluid (gold-ethylene glycol) flow with different shapes past a horizontal infinite permeable conduit. The porous walls exhibit the fluid to move in or out of the channel as the walls expand or contract. The flow problem is modeled in a Cartesian coordinate system by employing the Tiwari-Das nanofluid model. Heat transfer is enhanced with the inclusion of Cattaneo–Christov combined with heat generation/absorption effect and temperature-dependent thermal conductivity. The Hamilton–Crosser model is adopted here for the cylindrical and platelet shapes nanoparticles. By invoking appropriate transformation, the equations are transmuted into ordinary differential equations and are solved numerically by employing the bvp4c approach. The influence of the key parameters is illustrated graphically. A protuberant decline is observed in the cylindrical shape nanoparticles in the thermal field on augmenting the thermal relaxation parameter. The drag force coefficient elevates on incrementing the volume fraction of nanoparticles. A significant correlation is noticed in the findings of the comparison with the existing literature.

Obesity and inflammation influence pharmacokinetic profiles of PEG-based nanoparticles.

Most patients that will be treated with soft nanoparticles (NPs) will be obese. Yet, NP testing, which begins with pharmacokinetic (PK) and toxicity studies, is carried out almost exclusively in lean rodents having healthy livers and low inflammation. To address this knowledge gap, we determined the PK and toxicity of tail-vein-injected, PEG-based cylindrical nanoparticles (CNPs) and PEGylated liposomes (PLs) as a function of obesity, liver health, and inflammation in leptin-deficient ob/ob and wild-type C57BL/6J mice. CNPs localized faster to obese livers than to healthy livers within 24h of injection. PLs localized faster to obese livers than to healthy livers but only 30min post-injection. Afterwards PL localization to lean livers was higher than localization to obese livers. Overall, PL liver signal peaked ∼6h post-injection in lean mice, ∼24h post-injection in heavy mice, and∼48h post-injection in obese mice. CNPs and PLs were non-toxic to mouse livers as assessed by histology; they reduced many cytokine and chemokine levels that were elevated by obesity. Liver macrophage depletion reduced CNP and PL liver localization as expected; liver sinusoidal endothelial cell (LSEC) depletion reduced PL liver localization but surprisingly increased CNP liver localization. The intensity of RAW264.7 macrophages was higher after CNP incubations than with PL incubations; conversely, the intensity of LSECs was higher after PL incubations than with CNP incubations. This shows the potential for key differences in NP-liver interactions. Triggering inflammation by administering lipopolysaccharide (LPS) to mice increased CNP liver localization but decreased PL liver localization. The results show that obesity and inflammation in a mouse model and in vitro affect soft PEG-based NP interaction with macrophages and LSECs, but also that these NPs can reduce pro-inflammatory pathways increased by obesity.

Application of various influences to obtain isolated or oriented nanoparticles

Heterostructural nanowires with alternating copper and nickel layers were obtained by matrix synthesis, then were cut into cylindrical magnetic nanoparticles of calibrated sizes. For their use in medicine, the tasks of their separation (overcoming agglomeration) and spatial orientation for targeted drug delivery and hyperthermia, respectively, were solved.

A STUDY OF MIXED CONVECTIVE TERNARY HYBRID NANOFLUID FLOW OVER A STRETCHING SHEET WITH RADIATION AND TRANSPIRATION

This study explains the motion of a mixed convective ternary hybrid nanofluid flow with radiation and transpiration. Ternary hybrid nanofluid is the colloidal mixture of three district types of particles, namely, Al<sub>2</sub>O<sub>3</sub>, single-wall CNT, and graphene. The ordinary differential equations (ODEs) of the equation is yielded by converting partial differential equations (PDEs) with the help of suitable variables for analyzing the spherical, cylindrical, and platelet nanoparticles. Then the analytical solution can be conducted by using different shapes of the nanoparticles, namely, spherical, cylindrical, and platelet, to get the solution domain. Main results on the applications of suction and results of four roots are investigated. Also by using this domain fluctuation of friction, heat and mass transfer across the flow can be analyzed with various physical parameters. Increasing knowledge of these ternary hybrid nanofluids helps to improve the heat transfer rate. This is useful in dynamics of fuel and coolant in automobiles. Furthermore, the goal and novelty of the present work mainly explains the ternary hybrid nanofluid flow with three different shapes of nanoparticles in the presence of mixed convection. The given mixed convective Navier-Stokes equations given in PDE form are converted into ODE form using suitable transformation. The analytical results are expressed in terms of Prandtl number and in terms of four roots. Finally, the impact of different shapes of nanoparticles and parameters can be discussed using a graphical scenario. The main finding is that the Dufour number is greater for more values of thermal radiation. Also, transverse and tangential velocities as well as temperature and concentration profiles are greater for more values of solution domain and Darcy number.

Combine influence of Hall effects and viscous dissipation on the motion of ethylene glycol conveying alumina, silica and titania nanoparticles using the non-Newtonian Casson model

<abstract> <p>A vital role of ternary hybrid nanofluid is visualized as a significant improvement of thermal performance and enhancement in thermal rate which is applicable in automobiles for coolant process, thermodynamics of fuel. This process of ternary hybrid nanofluid is utilized to enhance maximum performance of thermal energy and applicable in chemical products, solar power, melting process, wire paintings, biological products, solar system, cooling process, glasses melting, glass fiber, metal grinding etc. Three-dimensional motion of ternary hybrid nanoparticles in partially Casson fluid over a vertical stretching surface is addressed using Darcy's Forchheirmer theory. Further, effects of Joule heating, non-uniform thermal radiation and viscous dissipation are considered in the energy equation and motion of ethylene glycol contains alumina, silica, and titania nanoparticles with various shape effects. Similarity variables are utilized to derive the system of ODEs from PDEs. A system of ODEs is numerically solved by a finite element method. It was concluded that the thermal field for platelet nanoparticles is greater than the thermal field for cylindrical nanoparticles. Nusselt number increases versus change in ion slip, Hall and magnetic parameters. Maximum production of heat energy is obtained for the case of tri-hybrid nanomaterial rather than for the case of hybrid nanomaterial.</p> </abstract>

Two-Dimensionalnumerical Study of the Effect of Nanoparticles on the Fusion and Freezing Process of Phase Change Materials Using a Computing Method

In this paper, a scalar two-dimensional analysis was conducted on the influence of nanoparticles on the thawing and freezing rate of phase-change materials based on enthalpy method that is an innovative calculation method. To this end, carbon nanotubes (CNTs) and aluminum oxide nanoparticles (NPs) were employed as a model of cylindrical and spherical nanoparticles, respectively.Paraffin and a composite of hydrated salts was also utilized as the PCM. The numerical procedure involved the simulation of the phase change process based on finite difference using enthalpy approach. Because of the recent innovations in computer calculation and also its connection with mechanical engineering a computational code was written for this purpose.Simulation results indicated a reduction in time of thawing and freezing upon incorporation of nanoparticles into the phase change material. For both states, CNTs showed the better result due to acceleration of the heat transfer. The biggest increase (28%) in the rate of thawing and freezing was for CNT-paraffin system; while the lowest increase (6%) was observed in aluminum oxide-hydrated salt system. This result can be utilized to control the speed of energy storage and release.

OpenSANS: A Semi-Analytical solver for Nonlocal plasmonicS

Prompted by the renewed interest the past decade in the hydrodynamic model for the description of nanoplasmonic systems, we present OpenSANS, a MATLAB toolbox for the simulation of canonical (that is, standalone spherical and cylindrical) nanoparticles and planar stratified structures whose critical dimensions are of mere nanometres. The method comprises of a generalisation of Mie theory to properly address the hydrodynamic motion of free electrons in metals and a compact S matrix formulation for the efficient treatment of multiple layers. The toolbox is built in a modular manner; each part (routine) has its own important functionality and can be used independently from the others. Our primary goal is the presentation of a highly efficient and accessible solver for the nanoplasmonics community. This is achieved by the very semi-analyticity of the chosen method and by powerful vectorisation techniques optimised in a very popular environment, MATLAB. Program summaryProgram Title: OpenSANSCPC Library link to program files:https://doi.org/10.17632/hmk224xngb.1Code Ocean capsule:https://codeocean.com/capsule/2246190Licensing provisions: GPLv3Programming language: MATLAB R2018b and newer.Supplementary material: See Appendix A.Nature of problem: Solve the scattering problem from multilayered, dielectric, local or nonlocal metallic nanoparticles, excited by a plane wave and placed in a local (dielectric or metallic) background.Solution method: Mie theory, appropriately extended to incorporate nonlocal effects (longitudinal waves) as predicted by the Hard Wall-Hydrodynamic Model, combined with S matrix theory for efficient handling of the multilayered structure.

Effect of Couple Stress and Mass Transpiration on Ternary Hybrid Nanoliquid over a Stretching/Shrinking Sheet with Heat Transfer

The present article describes the unsteady flow of a couple stress via a ternary hybrid nanofluid on a stretching surface with porous media. The nanofluid exhibits important properties for increasing heat transmission, and it is widely used in manufacturing and industrial applications. The basic similarity equations have been discovered to accommodate both stretching/shrinking surfaces. Ternary hybrid nanofluid is a colloidal combination of three types of microspheres: Al2O3, single wall carbon nanotubes, and graphene. For investigating spherical, cylindrical, and platelet nanoparticles, the governing partial differential equations are converted into ordinary differential equations, expending appropriate transformations. The analytical solution can then be carried out using various forms of nanoparticles, such as spherical, cylindrical, and platelet, to obtain the solution domain. Heat transfer is used in an electrically conducting fluid and also including thermal radiation, as calculated with the Biot number. The focus of the present effort is the evaluation of the flow of ternary hybrid nanofluid over a porous media via thermal radiation, with couple stress, using an analytical process. For various physical parameters, the velocity and temperature conditions are shown graphically.

Statistical numerical investigation of translational-rotational ultrafast image-based dynamic light scattering to measure a bimodal Gaussian sample of cylindrical nanoparticles

In a translational-rotational ultrafast image-based dynamic light scattering (TR-UIDLS) experiment, nanoparticles in Brownian motion in a solvent are illuminated by a focused Gaussian beam and scatter the light toward a camera. If both vertical-vertical and vertical-horizontal polarization geometries are recorded at the same time, using a polarization camera, a distribution of “equivalent cylindrical particles” is determined from the cross-correlation coefficients between the pairs of pictures recorded by the camera in both polarization geometries. The equivalent cylindrical particles are the monodisperse cylindrical particles that scatter the same light fluctuations as the polydisperse particles in the measurement volume. The distribution of equivalent cylindrical particles is not strictly the distribution of the particles in the sample, and our purpose is to measure characteristic information about the size and shape of the particles in the sample from the distribution of the equivalent cylindrical particles. With this purpose, we propose in the present paper a model of numerical simulation of the TR-UIDLS experiment for polydisperse arbitrary distributions of cylindrical particles. The TR-UIDLS has been simulated for the bimodal Gaussian distribution of gold cylindrical nanorods immersed in water. In view of these simulations, a strategy is discussed to retrieve characteristic information about the bimodal Gaussian distribution of cylindrical particles.

Thermo-Hydraulic Optimization of Shell and Externally Finned Tubes Heat Exchanger by the Thermal Efficiency Method and Second Law of Thermodynamics

The application aims to determine the thermal and hydraulic performance of externally finned, counter-flow, Shell, and Tube Heat Exchangers (STHE). The application refers to the cooling of machine oil flowing in the annular region, including non-spherical cylindrical nanoparticles of Boehmite Alumina. The oil inlet temperature is equal to 80 °C. Sea water is a coolant with an inlet temperature of 20°C. The main parameter in the optimization process is the number of finned tubes used for oil cooling. Another optimization factor is the number of heat exchanger units connected by hairpin. The number of fins per tube is fixed, equal to 34. The oil flow is set and equal to 4.0 kg/s. The inlet water flow varies, with a maximum flow of 5.0 kg/s. The quantities determined for analysis are: the thermal effectiveness, the actual and maximum heat transfer rates, the pressure drops caused in the tubes and by the flow in the annular region and fin system, the thermal and viscous irreversibilities, and the fluid outlet temperatures, and the thermodynamic Bejan number. It was determined that increasing the number of finned tubes from two to six tubes leads to better thermal and hydrodynamic performance. That is, it produces a favorable cost-benefit, to the detriment of the high viscous dissipation caused by the oil in the annular region. As an object of analysis, the inclusion of nanoparticles showed a significant improvement in thermal performance and an increase in viscous dissipation, with a slight decline in the Bejan number.

Influence of suction and heat source on MHD stagnation point flow of ternary hybrid nanofluid over convectively heated stretching/shrinking cylinder

Heat flow may be improved using a new form of nanofluid known as ternary hybrid nanofluid. Magnetic field, mass suction, and heat source effects on the stagnation area of [Formula: see text]) ternary hybrid nanofluid toward convectively heated stretching/shrinking cylinder with cylindrical shape nanoparticles are studied in this work. There will be an equation modeled under the given assumptions. It is feasible, with the help of similarity transformation, to convert nonlinear partial differential equations that are not quite solvable into ordinary differential equations that can be resolved numerically. The prevailing role of heat transfer and the features of movement of ternary hybrid nanofluids have been found to be significantly affected by the combination of Runge–Kutta-IV and the shotting technique in Mathematica. Many variables, including suction, Reynold number, nanoparticle volume fraction, magnetic field, Biot number, heat source, and stretching/shrinking influenced temperature, velocity, skin friction, and the local heat transfer rate, as shown in the graphs in the study. When magnetic field, suction, and Reynold number are present velocity increases, but inverse is true for nanoparticle volume fraction and stretching/shrinking parameter. The greatest influence on the surface is shown by the ternary hybrid nanofluid. Additionally, the heat transfer rate of the ternary hybrid nanofluid is faster than that of the hybrid and regular nanofluids.

Heat transfer analysis in the peristaltic flow of Casson nanofluid through asymmetric channel with velocity and thermal slips: Applications in a complex system

This investigation articulately addresses the role of gold nanoparticles in medical sciences from a different perspective. Aiming to highlight the significant usage of nanoparticles, four different types such as spherical, platelets, cylindrical and brick-like nanoparticles are brought into consideration with the main focus to achieve maximum heat enhancement. This motivation leads to mathematically formulating an electroosmosis blood flow. Casson fluid is treated as physiological fluid through an asymmetric microchannel. The nonlinear term of radiative heat flux is added on the right-hand side of the heat equation to report the impact of radiation which is beneficial in skin diseases. A closed-form solution is achieved with the help of physical approximation. Moreover, analytical expressions for velocity distribution, temperature field, shear stress, heat transfer rate and pressure gradient have been provided. The expression of stream function is also presented and the trapping phenomena are discussed. Besides studying the tremendous capacity of gold particles to enhance the heat transfer rate for targeting the maligned tissues as a prime objective, the current survey will also assist readers to explore the other similar metallic particles which can effectively be used as an alternative.

Investigation of a novel surface inlay composite nanoparticle based on local surface plasmon resonance-enhanced solar absorption

The absorption performance of a direct absorption solar collector (DASC), as the main method of solar thermal application, affects the performance of the entire solar thermal utilization system. The enhancement of the solar energy absorption performance of DASC has received extensive attention. In this study, in order to simultaneously utilize the two absorption peaks of spherical and cylindrical core-shell nanoparticles in the solar spectrum, a new type of surface inlay composite nanoparticle (SICN) is constructed. The enhancement effect of the inlay on the absorption properties of nanoparticles is proven by the finite element method. The SICN for Au@SiO2@Cu achieves an absorption increase of 10.29% and gains a local high heat flux of 8.83 × 105 W/m3. It can be seen that under the same material, SICN has achieved a significant breakthrough in terms of performance compared with core-shell nanoparticles. Then, it is determined that local surface plasmon resonance (LSPR) is the cause of the absorption enhancement. In addition, the coupling nanoparticles can adjust the absorption peak through the change in the size parameters, and when the inlay depth r = 5 nm, two absorption peaks are excited near 630 nm and 710 nm. Therefore, a better absorption performance will be obtained by reasonably adjusting the structural parameters of the SICN. The results are of great significance in promoting the thermal application of solar energy.

The Cross-Scale Strengthening-Softening Behavior of Solids With the Pressurized Cylindrical Cell

Abstract A lot of research has shown that the strength of nanoparticle composites increases first and then decreases with the decrease of particle size when particle size is at nanoscale, which is the so-called positive-inverse Hall–Petch effects, or called the strengthening-softening characteristic. In this paper, the strengthening-softening behavior of cylindrical nanoparticle composites with periodic distribution of particles is studied. By selecting the representative single cylindrical cell model, the mechanic’s solution is obtained strictly by using the strain gradient viscoelastic theory established previously by the present authors. The results clearly show the strengthening-softening behavior of the nanoparticle composite. In the process of solution, first, the strain gradient elasticity theory is used to strictly solve the problem of the cylindrical cell under uniform external pressure. Then, using the correspondence principle of the strain gradient viscoelastic theory, the solution for the strain gradient viscoelastic theory is obtained through Laplace inversion transformation, and its dependence on the time-space two-scale parameters is analyzed. The results showed a significant positive-inverse Hall–Petch effects.

Dynamics of ternary-hybrid nanofluids due to dual stretching on wedge surfaces when volume of nanoparticles is small and large: forced convection of water at different temperatures

Management of heat energy and control of temperature distribution are major problems in the industry. With emphasis on the heat and mass transfer when the volume of nanoparticles is small and large, nothing is known on forced convection flow of water at different temperatures conveying platelet aluminum nanoparticles, cylindrical magnesium oxide nanoparticles, and titanium dioxide nanoparticles due to dual stretching on wedge surfaces. The mathematical model for the problem mentioned above is presented in this report, transformed using similarity variables, and solved numerically using the approach of shooting technique together with fourth order Runge-Kutta integration scheme. The analysis of results, justification, and discussion of results was established after the positive outcome of the reliability and validity. It is worth concluding that as time goes on in all the four cases of water at different temperature as in the case of four ternary-hybrid nanofluid flows, the local skin friction coefficients increases at the rate of 0.07 when the volume of nanoparticles is small and at a most minimum rate of 0.008 when the volume of nanoparticles is large. At 80°C temperature of water-based ternary hybrid nanofluid, as time grows large, the heat transfer decreases at the optimal rate of −0.354681119 when the volume of nanoparticles is small but the same heat transfer increases at the minima rate of 0.159722534 when the volume of nanoparticles is large.

Convective flow of a Williamson hybrid nanofluid in a porous medium through a cone and wedge with the effect of the shape of nanoparticles

AbstractThe performance of nanofluid in the heat transport phenomena showed satisfactory results, which have been considered by scientists and researchers. The dispersion of two nanoparticles to form a mixture which named as hybrid nanofluid. It has been proved experimentally that hybrid nanofluid has good thermal performance compared to unitary nanofluid. The present study inspected the convective flow of a Williamson hybrid nanofluid through a cone and wedge in a porous medium of different shapes of nanoparticles (cylindrical‐, spherical‐, blades‐, platelets‐, bricks‐) under the influence of a magnetic field. The partial differential equations were converted to an ordinary differential equation and the resulting equations were solved using the bvp4c MATLAB code. The effect of some important physical parameters on both the velocity and temperature profile was graphically plotted and the effect of the shape and size of nanoparticles was discussed, the numerical values of the friction coefficient and Nusselt number were obtained. As observed, the friction factor of Ag–TiO2–H2O hybrid nanofluid was more than that of TiO2–H2O nanofluid. A significant enhancement in bulk temperature is seen for the Ag–TiO2 hybrid and nanofluid formed by blade‐shaped nanoparticles followed by cylindrical, platelet, brick, and spherical nanoparticles. In addition, for a 5% volume fraction of using blade nanoparticles shape givean increase in skin friction factor about 4.8% compared tobrick hybrid nanoparticles. A comparative study of different forms for Ag‐TiO2was presented graphically.

Nonlinear optical heating of all-dielectric super-cavity: efficient light-to-heat conversion through giant thermorefractive bistability

Abstract Optical heating of resonant nanostructures is one of the key issues in modern nanophotonics, being either harmful or desirable effect depending on the applications. Despite a linear regime of light-to-heat conversion being well-studied both for metal and semiconductor resonant systems is generalized as a critical coupling condition, the clear strategy to optimize optical heating upon high-intensity light irradiation is still missing. This work proposes a simple analytical model for such a problem, taking into account material properties changes caused by the heating. It allows us to derive a new general critical coupling condition for the nonlinear case, requiring a counterintuitive initial spectral mismatch between the pumping light frequency and the resonant one. Based on the suggested strategy, we develop an optimized design for efficient nonlinear optical heating, which employs a cylindrical nanoparticle supporting the quasi bound state in the continuum mode (quasi-BIC or so-called ‘super-cavity mode’) excited by the incident azimuthal vector beam. Our approach provides a background for various nonlinear experiments related to optical heating and bistability, where self-action of the intense laser beam can change resonant properties of the irradiated nanostructure.

Mechanistic understanding of the charge storage processes in FeF2 aggregates assembled with cylindrical nanoparticles as a cathode material for lithium‐ion batteries by in situ magnetometry

AbstractTransition metal fluorides (TMFs) cathode materials have shown extraordinary promises for electrochemical energy storage, but the understanding of their electrochemical reaction mechanisms is still a matter of debate due to the complicated and continuous changing in the battery internal environment. Here, we design a novel iron fluoride (FeF2) aggregate assembled with cylindrical nanoparticles as cathode material to build FeF2 lithium‐ion batteries (LIBs) and employ advanced in situ magnetometry to detect their intrinsic electronic structure during cycling in real time. The results show that FeF2 cannot be involved in complete conversion reactions when the FeF2 LIBs operate between the conventional voltage range of 1.0–4.0 V, and that the corresponding conversion ratio of FeF2 can be further estimated. Importantly, we first demonstrate that the spin‐polarized surface capacitance exists in the FeF2 cathode by monitoring the magnetic responses over various voltage ranges. The research presents an original and insightful method to examine the conversion mechanism of TMFs and significantly provides an important reference for the future artificial design of energy systems based on spin‐polarized surface capacitance.