Journal articles: 'Nanoparticle transfer'

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Scull, Christopher M., Ruben Kuruvilla, Thomas H. Fischer, and Timothy C. Nichols. "Gene Transfer to Macrophages with Nanoparticle-Loaded Platelets." Blood 106, no. 11 (November 16, 2005): 3043. http://dx.doi.org/10.1182/blood.v106.11.3043.3043.

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Abstract Hemorrhagic fever, traumatic brain injury, and inflammatory bowel syndrome are among a wide range of pathologies involving inflammation that results in bleeding. The vascular injury that occurs in these conditions is closely associated with macrophage activation. An inherent function of macrophages is to phagocytose platelets that have adhered to sites of vascular injury, and thus platelets are an ideal vehicle for site-specific delivery of anti-inflammatory genes to macrophages at wound sites. Here we report the preparation of reporter gene nanoparticle-platelet conjugates and gene transfer to macrophages. Plasmid-containing nanoparticles were prepared by condensing cDNA for β-galactosidase, green fluorescent protein, or luciferase with polyethyleneimine. Scanning electron microscopic analysis showed that this anion/cation agglomeration reaction yields spherical particles with diameters of 100 to 300 nm. Plasmid-containing nanoparticles were then incubated with platelets that were isolated from human blood by differential centrifugation. Flow cytometric and transmission electron microscopic analysis demonstrated that the nanoparticles associated with the surface-connected canalicular system with most platelets containing one or more particles. The ability of the nanoparticle-loaded platelets to transfer the reporter genes to macrophages was tested in tissue culture using monocyte-derived macrophages incubated with the nanoparticle-loaded platelets. Subsequent fluorescent microscopic, luminescent and histological analysis demonstrated that the macrophages readily phagocytosed the nanoparticle-loaded platelets and expressed the reporter genes. This result provides the basis for studies to deliver anti-inflammatory genes to macrophages in animal model systems.

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Jiang, Jia-Zong, Song Zhang, Lei Liu, and Bao-Min Sun. "A microscopic experimental study of nanoparticle motion for the enhancement of oxygen absorption in nanofluids." Nanotechnology Reviews 7, no. 6 (December 19, 2018): 529–39. http://dx.doi.org/10.1515/ntrev-2018-0072.

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AbstractThe behavior of nanoparticle motion has a great influence on gas-liquid mass transfer. However, it has been very difficult to characterize the motion of nanoparticles from a micro view in mass transfer experiments. In this study, a novel method was proposed to investigate nanoparticle Brownian motion through the application of the total internal reflection fluorescence microscope in a self-designed sample (a quasi-static liquid micro-groove) and the mass transfer enhancement of nanoparticles. Nanoparticle movement behavior was photographed using an electron-multiplying charge coupled device, and 100 consecutive images were recorded using Micro-Manager software at a rate of 20 fps. The images were processed through the particle tracking velocimetry algorithm to calculate two-dimensional motion rates of nanoparticles caused by Brownian movement. It showed that nanoparticle loadings influenced the motion rates significantly, and the motion rates were larger with smaller particle sizes under the same operating condition. The mass transfer coefficients in the quasi-static gas-liquid mass transfer system were calculated and analyzed through microscopic measurement. Based on the above thought, three important non-dimensional numbers [Sherwood (Shp), Reynolds (Rep), and Schmidt (Scp) numbers] for mass transfer theory were studied.

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Majeed, Noor Sabeeh, Shaymaa Mahdi Salih, Hussam Nadum Abda Lraheemal Ani, Basma Abbas Abdulmajeed, Paul Constantin Albu, and Gheorghe Nechifor. "Study the Effect of SiO2 Nanofluids on Heat Transfer in Double Pipe Heat Exchanger." Revista de Chimie 71, no. 5 (May 29, 2020): 117–24. http://dx.doi.org/10.37358/rc.20.5.8119.

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In this paper the effect of nanofluid is studied in the double pipe heat exchanger counter current flow, the viscosity of nanofluids are measured at different temperatures and different particle sizes. SiO2 nanoparticles are dispersed at different concentrations (0.2-2) % with different particle sizes of (50-25) nm in base fluid of water. The friction factor and heat transfer coefficient are calculated at different nanoparticle sizes, the results showed that the viscosity was increased as nanoparticle concentration increased. The friction factor is increased as SiO2 nanoparticles concentration and increased as nanoparticles size decreased. The heat transfer coefficient increased as nanoparticle concentration increased and particles size decrease.

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Yacob, Nor Azizah, Anuar Ishak, Roslinda Nazar, and Ioan Pop. "Mixed Convection Flow Adjacent to a Stretching Vertical Sheet in a Nanofluid." Journal of Applied Mathematics 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/696191.

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The characteristics of fluid flow and heat transfer over a stretching vertical sheet immersed in a nanofluid are investigated numerically in this paper. Three different types of nanoparticles, namely, copper Cu, alumina Al2O3, and titania TiO2, are considered, using water as the base fluid. It is found that nanofluid with titania nanoparticles has better enhancement on the heat transfer rate compared to copper and alumina nanoparticles. For a particular nanoparticle, increasing the nanoparticle fraction is to reduce the skin friction coefficient and the heat transfer rate at the surface.

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Ranjbar, A. A., S. Kashani, S. F. Hosseinizadeh, and M. Ghanbarpour. "Numerical heat transfer studies of a latent heat storage system containing nano-enhanced phase change material." Thermal Science 15, no. 1 (2011): 169–81. http://dx.doi.org/10.2298/tsci100412060r.

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The heat transfer enhancement in the latent heat thermal energy storage system through dispersion of nanoparticle is reported. The resulting nanoparticle-enhanced phase change materials (NEPCM) exhibit enhanced thermal conductivity in comparison to the base material. The effects of nanoparticle volume fraction and some other parameters such as natural convection are studied in terms of solid fraction and the shape of the solid-liquid phase front. It has been found that higher nanoparticle volume fraction result in a larger solid fraction. The present results illustrate that the suspended nanoparticles substantially increase the heat transfer rate and also the nanofluid heat transfer rate increases with an increase in the nanoparticles volume fraction. The increase of the heat release rate of the NEPCM shows its great potential for diverse thermal energy storage application.

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Doifode, Nitin, Sameer Gajghate, Abdul Najim, Anil Acharya, and Ashok Pise. "Effect of Uniformly and Nonuniformly Coated Al2O3 Nanoparticles over Glass Tube Heater on Pool Boiling." Journal of Nanoparticles 2016 (November 15, 2016): 1–6. http://dx.doi.org/10.1155/2016/8763171.

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Effect of uniformly and nonuniformly coated Al2O3 nanoparticles over plain glass tube heater on pool boiling heat transfer was studied experimentally. A borosilicate glass tube coated with Al2O3 nanoparticle was used as test heater. The boiling behaviour was studied by using high speed camera. Result obtained for pool boiling shows enhancement in heat transfer for nanoparticle coated surface heater and compared with plain glass tube heater. Also heat transfer coefficient for nonuniformly coated nanoparticles was studied and compared with uniformly coated and plain glass tube. Coating effect of nanoparticles over glass tube increases its surface roughness and thereby creates more nucleation sites.

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Prajapati, Om Shankar, and A. K. Rajvanshi. "Al₂O₃-Water Nanofluids in Convective Heat Transfer." Applied Mechanics and Materials 110-116 (October 2011): 3667–72. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.3667.

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Anofluids are suspensions of metallic or nonmetallic nanopowders in base liquid and can be employed to increase heat transfer rate in various applications. In this work turbulent flow forced convection heat transfer of Al2O3-water nanofluid inside an annular tube with variable wall temperature was investigated experimentally. The Nusselt number of nanofluid was obtained for various Reynolds numbers and nanoparticle concentrations at atmospheric pressure. The addition of nanoparticles in water enhances heat transfer coefficient and the enhancement increases with increase in the nanoparticle concentration and flow rate. Experimental results emphasize the enhancement of heat transfer due to nanoparticles presence in the fluid.

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Cui, Jinhui, Haixin Cui, Yan Wang, Changjiao Sun, Kui Li, Hongyan Ren, and Wei Du. "Application of PEI-Modified Magnetic Nanoparticles as Gene Transfer Vector for the Genetic Modification of Animals." Advances in Materials Science and Engineering 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/764521.

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To evaluate the performance of the magnetic nanoparticles as gene transfer vector for breeding transgenic animals, we investigated a new approach to deliver green fluorescent protein (GFP) gene to porcine kidney 15 (PK-15) and porcine embryonic fibroblast (PEF) cells using PEI-modified magnetic nanoparticles as gene vector. The morphology of the nanoparticles and nanoparticle/DNA complexes was characterized using scanning electron microscopy. It was found that the surface of the particles becomes coarse and rough with increased average diameter, which implied the effective conjugating between nanoparticles with DNA. The zeta potential of nanoparticle/DNA complexes drops down from +29.4 mV to +23.1 mV comparing with pure nanoparticles. Agarose gel electrophoresis experiments show that DNA plasmids can be protected effectively against degradation of exonuclease and endonuclease. The efficiency of gene delivery was affected by the mass ratio of nanoparticle/DNA and the amount of nanoparticle/DNA complexes. We confirm that the most optimal mass ratio of nanoparticle/DNA is 1 : 1 by conducting a series of experiments. This work provides important experimental basis for the application of the magnetic nanoparticles on gene delivery to porcine somatic cells, which is significant for the achieving of breeding new transgenic cloned pigs by using somatic cell nuclear transfer technique.

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Che Sidik, Nor Azwadi, Lee Yoke Keen, and Alireza Fazeli. "Computational Investigation of Heat Transfer of Nanofluids in Domestic Water Heat Exchanger." Applied Mechanics and Materials 695 (November 2014): 423–27. http://dx.doi.org/10.4028/www.scientific.net/amm.695.423.

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Recent development of nanotechnology led to the concept of using suspended nanoparticles in the heat transfer fluids to improve the heat transfer properties of the base fluids. The heat transfer enhancement by nanofluids is the significant concerns in the efficiency of domestic water heat exchanger system. A computational investigation of the heat transfer in a domestic water heat exchanger is conducted on the water and water-based nanofluids. Copper (Cu) nanoparticle and Alumina (Al2O3) nanoparticle are selected in the water-based nanofluids. Volume fraction of nanoparticle in the nanofluids is set at 0.5 %, 1.0 %, 1.5 %, 2.0 %, 2.5 %, and 3.0 %. Heat exchanger has been invented for the heat transfer from one medium to another medium in many heat transfer systems. Domestic water heat exchanger can be used in a heat pump domestic water heating system. The density, the thermal conductivity, and the dynamic viscosity of the water base fluid are increased while the specific heat capacity of the water base fluid is reduced with the addition of copper as well as alumina nanoparticle. Addition of copper nanoparticle into the water-based heat transfer fluid significantly increases the domestic hot water temperature. The efficiency of domestic water heat exchanger system is optimum when 1.5 % copper or alumina nanoparticle is added into the water-based heat transfer fluid.

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Karimi-Maleh, Hassan, Fatemeh Karimi, Abdollah FallahShojaei, Khalil Tabatabaeian, Mohammad Arshadi, and Morteza Rezapour. "Metal-based Nanoparticles as Conductive Mediators in Electrochemical Sensors: A Mini Review." Current Analytical Chemistry 15, no. 2 (February 19, 2019): 136–42. http://dx.doi.org/10.2174/1573411014666180319152126.

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Background: Modified electrodes are a new approach to improving the characteristics of the electrochemical sensors. The high conductivity and low charge transfer resistance are the major properties of new mediators for improving electrochemical sensors. Metal-based nanoparticles showed good electrical conductivity and can be selected as the suitbale mediator for modified electrodes. Objective: Recently, metal-based nanoparticles, such as Au nanoparticle, TiO2 nanoparticle, Fe3O4 nanoparticle and etc. were suggested as the suitable mediator for modification of solid electrodes. The high surface area and low charge transfer resistance of metal-based nanoparticles, suggested the exceptional intermediate in the electrochemical sensors. Here, we tried to consider these exceptional effects through reviewing some of the recently published works.

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Liu, I. Chung, Hung Hsun Wang, and Chia Nan Liu. "Flow and Heat Transfer of Nanofluids near a Rotating Disk." Advanced Materials Research 664 (February 2013): 859–65. http://dx.doi.org/10.4028/www.scientific.net/amr.664.859.

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The study of boundary layer flow and heat transfer near a rotating disk with nanofluids is investigated numerically. Three types of nanoparticles, namely, silver Ag, copper Cu and alumina Al2O3with water as the base fluid are considered. The results show that the momentum boundary layer thicknesses shortens as the nanoparticle volume fraction increases, whereas thermal boundary layer thickness elongates for increasing ϕ. It is found that the reduced skin-friction coefficients and heat transfer rateat the rotating surface increase linearly with nanoparticle volume fractionϕ. The surface heat transfer rate for Cu-water nanofluid is higher than those of the otherswhen ϕ>0.02, even though the nanoparticle Ag has higher thermal conductivity than that of copper Cu.

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Chen, Wei, Shaowei Chen, Feizhi Ding, Haobin Wang, Lauren E. Brown, and Joseph P. Konopelski. "Nanoparticle-Mediated Intervalence Transfer." Journal of the American Chemical Society 130, no. 36 (September 10, 2008): 12156–62. http://dx.doi.org/10.1021/ja803887b.

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Azimi, Seyyed Shahabeddin, Mansour Kalbasi, and Mohammad Hosain Namazi. "Effect of nanoparticle diameter on the forced convective heat transfer of nanofluid (water + Al2O3) in the fully developed laminar region." International Journal of Modeling, Simulation, and Scientific Computing 05, no. 03 (May 5, 2014): 1450008. http://dx.doi.org/10.1142/s1793962314500081.

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Nanofluid is a suspension of nanoparticles (solid particles with diameters below 100 nm) in a conventional base fluid with significantly improved heat transfer characteristics compared to the original fluid. The heat transfer coefficient is a quantitative characteristic of the convective heat transfer. The purpose of this paper is to study the effect of the nanoparticle size (diameter) on the heat transfer coefficient of forced convective heat transfer of nanofluid in the fully developed laminar region of a horizontal tube. Using thermal conductivity model which is a function of the nanoparticle size, flow of a nanofluid (water + Al 2 O 3) in a circular tube submitted to a constant wall temperature is numerically investigated with two particle sizes of 11 nm and 47 nm. The calculated results show that the nanoparticle size does not significantly affect the heat transfer coefficient, however, the heat transfer coefficient decreases as the particle size increases.

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Tanner, Eden E. L., Stanislav V. Sokolov, Neil P. Young, and Richard G. Compton. "DNA capping agent control of electron transfer from silver nanoparticles." Physical Chemistry Chemical Physics 19, no. 15 (2017): 9733–38. http://dx.doi.org/10.1039/c7cp01721a.

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Sebti, Seyed, Mohammad Mastiani, Sina Kashani, Hooshyar Mirzaei, and Ahmad Sohrabi. "Numerical study of melting in an annulur enclosure filled with nano-enhanced phase change material." Thermal Science 19, no. 3 (2015): 1067–76. http://dx.doi.org/10.2298/tsci120720022s.

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Heat transfer enhancement during melting in a two-dimensional cylindrical annulus through dispersion of nanoparticle is investigated numerically. Paraffin-based nanofluid containing various volume fractions of Cu is applied. The governing equations are solved on a non-uniform O type mesh using a pressure-based finite volume method with an enthalpy porosity technique to trace the solid and liquid interface. The effects of nanoparticle dispersion into pure fluid as well as the influences of some significant parameters, namely, nanoparticle volume fraction and natural convection on the fluid flow and heat transfer features are studied. The results are presented in terms of streamlines, isotherms, temperatures and velocity profiles and dimensionless heat flux. It is found that the suspended nanoparticles give rise to the higher thermal conductivity as compared to the pure fluid and consequently the heat transfer is enhanced. In addition, the heat transfer rate and the melting time increases and decreases, respectively, as the volume fraction of nanoparticle increases.

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Aliev, Gazi N., Jamaree Amonkosolpan, and Daniel Wolverson. "Observation of oxygen dimers via energy transfer from silicon nanoparticles." Physical Chemistry Chemical Physics 18, no. 2 (2016): 690–93. http://dx.doi.org/10.1039/c5cp04192a.

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Simpson, Sarah, Austin Schelfhout, Chris Golden, and Saeid Vafaei. "Nanofluid Thermal Conductivity and Effective Parameters." Applied Sciences 9, no. 1 (December 26, 2018): 87. http://dx.doi.org/10.3390/app9010087.

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Due to the more powerful and miniaturized nature of modern devices, conventional heat-transfer working fluids are not capable of meeting the cooling needs of these systems. Therefore, it is necessary to improve the heat-transfer abilities of commonly used cooling fluids. Recently, nanoparticles with different characteristics have been introduced to base liquids to enhance the overall thermal conductivity. This paper studies the influence of various parameters, including base liquid, temperature, nanoparticle concentration, nanoparticle size, nanoparticle shape, nanoparticle material, and the addition of surfactant, on nanofluid thermal conductivity. The mechanisms of thermal conductivity enhancement by different parameters are discussed. The impact of nanoparticles on the enhanced thermal conductivity of nanofluids is clearly shown through plotting the thermal conductivities of nanofluids as a function of temperature and/or nanoparticle concentration on the same graphs as their respective base liquids. Additionally, the thermal conductivity of hybrid nanofluids, and the effects of the addition of carbon nanotubes on nanofluid thermal conductivity, are studied. Finally, modeling of nanofluid thermal conductivity is briefly reviewed.

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Al Khafaji, Ammar S., and Maureen D. Donovan. "Endocytic Uptake of Solid Lipid Nanoparticles by the Nasal Mucosa." Pharmaceutics 13, no. 5 (May 20, 2021): 761. http://dx.doi.org/10.3390/pharmaceutics13050761.

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Nanoparticles may provide unique therapeutic opportunities when administered via the nasal cavity, yet the primary uptake and transfer pathways for these particles within the nasal mucosa are not well understood. The endocytic pathways involved in the uptake of fluorescently labeled, (Nile Red) solid lipid nanoparticles (SLNs) of different sizes (~30, 60, and 150 nm) were studied using excised bovine olfactory and nasal respiratory tissues. Endocytic activity contributing to nanoparticle uptake was investigated using a variety of pharmacological inhibitors, but none of the inhibitors were able to completely eliminate the uptake of the SLNs. The continued uptake of nanoparticles following exposure to individual inhibitors suggests that a number of endocytic pathways work in combination to transfer nanoparticles into the nasal mucosa. Following exposure to the general metabolic inhibitors, 2,4-DNP and sodium azide, additional, non-energy-dependent pathways for nanoparticle uptake were also observed. While the smallest nanoparticles (30 nm) were the most resistant to the effects of pharmacologic inhibitors, the largest (150 nm) were still able to transfer significant amounts of the particles into the tissues. The rapid nanoparticle uptake observed demonstrates that these lipid particles are promising vehicles to accomplish both local and systemic drug delivery following nasal administration.

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Patrice, Fato Tano, Kaipei Qiu, Yi-Lun Ying, and Yi-Tao Long. "Single Nanoparticle Electrochemistry." Annual Review of Analytical Chemistry 12, no. 1 (June 12, 2019): 347–70. http://dx.doi.org/10.1146/annurev-anchem-061318-114902.

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Experimental techniques to monitor and visualize the behaviors of single nanoparticles have not only revealed the significant spatial and temporal heterogeneity of those individuals, which are hidden in ensemble methods, but more importantly, they have also enabled researchers to elucidate the origin of such heterogeneity. In pursuing the intrinsic structure-function relations of single nanoparticles, the recently developed stochastic collision approach demonstrated some early promise. However, it was later realized that the appropriate sizing of a single nanoparticle by an electrochemical method could be far more challenging than initially expected owing to the dynamic motion of nanoparticles in electrolytes and complex charge-transfer characteristics at electrode surfaces. This clearly indicates a strong necessity to integrate single nanoparticle electrochemistry with high-resolution optical microscopy. Hence, this review aims to give a timely update of the latest progress for both electrochemically sensing and seeing single nanoparticles. A major focus is on collision-based measurements, where nanoparticles or single entities in solution impact on a collector electrode and the electrochemical response is recorded. These measurements are further enhanced with optical measurements in parallel. For completeness, advances in other related methods for single nanoparticle electrochemistry are also included.

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Shalimba, Veikko, and Vít Sopko. "JATROPHA OIL WITH IRON NANOPARTICLES APPLICATION IN DRILLING PROCESSES." Acta Polytechnica 59, no. 3 (July 1, 2019): 299–304. http://dx.doi.org/10.14311/ap.2019.59.0299.

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A performance of heat transfer fluids has a substantial influence on the size, weight and cost of heat transfer systems, therefore, a high-performance heat transfer fluid is very important in many industries. Over the last decades, nanofluids have been developed. According to many researchers and publications on nanofluids, it is evident that nanofluids have a high thermal conductivity. The aim of this experimental study was to investigate the change of the workpiece temperature during drilling using Jatropha oil with iron nanoparticles and water with iron nanoparticles as lubricating and cooling fluids. These experiments were carried out with samples of nanofluid with different nanoparticles volume ratio, such as samples JN1, JN5 and JN10 of iron nanoparticles in the base Jatropha oil with a nanoparticle volume fraction of 1 %, 5% and 10% respectively and samples WN1, WN5 and WN10 of iron nanoparticles in the base water with a nanoparticle volume fraction of 1 %, 5% and 10% respectively.

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He, Boshu, and Zhaoping Ying. "Numerical investigation of molten salt-based nanofluid laminar heat transfer in a circular tube using Eulerian-Lagrangian method." Thermal Science, no. 00 (2020): 199. http://dx.doi.org/10.2298/tsci191101199h.

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Molten salt-based nanofluid in a laminar region of a circular tube with constant wall heat flux was numerically investigated. An Eulerian- Lagrangian method, discrete phase model, was used to predict the heat transfer performance of nanofluid, considering the factors of inlet Reynolds number, the mass concentration of the nanoparticles and nanoparticle diameter. Validation results were found in a good match with experimental results obtained from the literature. Numerical results showed that the heat transfer performance of nanofluid was considerably better than that of pure molten salt. The local heat transfer coefficient and Nusselt number of nanofluid are about 30% higher than these of pure molten salt and increase with an increase of Reynolds number and nanoparticle concentration. Moreover, the heat transfer performance of nanofluid with the small size of the nanoparticles (10~100 nm) is improved significantly.

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Ellahi, Rahmat, Mohsin Hassan, and Ahmad Zeeshan. "A study of heat transfer in power law nanofluid." Thermal Science 20, no. 6 (2016): 2015–26. http://dx.doi.org/10.2298/tsci150524129e.

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The purpose of this paper is to study the effects of nanoparticles on mixed convection flow of power law fluid. The shear thinning fluid is considered as base fluid. The nanoparticles of copper for nanofluid are taken into account. To analysis the flow and temperature behavior, various mass concentrations of polyvinyl alcohol in water, different sizes and concentrations of nanoparticles are used. The effects of nanoparticle concentrations on shear stress, heat flux and thermal resistance are also presented.

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Rajabnia, Hossein, Ehsan Abedini, Ali Tahmasebi, and Amin Behzadmehr. "Experimental investigation of subcooled flow boiling of water/TiO2 nanofluid in a horizontal tube." Thermal Science 20, no. 1 (2016): 99–108. http://dx.doi.org/10.2298/tsci130929122r.

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Subcooled flow boiling heat transfer of water/TiO2 nanofluid in a horizontal tube is experimentally investigated. To validate the experimental apparatus as well as the experimental procedure, data for distilled water were compared with the available results on the literature in both single phase and subcooled flow boiling regime. Experimental investigations were carried out at three nanoparticles volumetric concentrations of 0.01%, 0.1%, and 5%. It was found that the nanofluid heat transfer coefficient in single-phase flow regime augments with the nanoparticle concentration. However, in the case of subcooled flow boiling regime the heat transfer coefficient decreases with the nanoparticle volume fractions.

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G., Sowmya, Gireesha B.J., and Prasannakumara B.C. "Scrutinization of different shaped nanoparticle of molybdenum disulfide suspended nanofluid flow over a radial porous fin." International Journal of Numerical Methods for Heat & Fluid Flow 30, no. 7 (November 18, 2019): 3685–99. http://dx.doi.org/10.1108/hff-08-2019-0622.

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Purpose The purpose of this paper is to study the thermal behaviour of radial porous fin wetted with nanofluid containing different shaped nanoparticles in the presence of natural convection and radiation. Here, the nanofluid suspended with molybdenum disulfide nanoparticle with base fluid as water is considered. The influence of non-spherical nanoparticles such as platelet, cylinder, brick and blade shapes is also investigated. Design/methodology/approach The modeled equations are non-dimensionalized and solved numerically via Runge–Kutta–Fehlberg method combined with shooting scheme. Findings The flow natures of the pertinent parameter are represented graphically and discussed their physical significance. From the validation of obtained outcome, it is found that the use nanofluid has significant influence on heat transfer rate. Among platelet, cylinder, brick and blade shapes, brick-shaped nanoparticle shows better heat transfer rate. Originality/value The present paper deals with an analysis of the flow of molybdenum disulfide nanoparticles suspended in water over a porous fin of a radial profile. The effect of differently shaped nanoparticles on the heat transfer enhancement through the radial porous fin is investigated for the first time. The natural convection and radiation effects are also considered. The modeled equations are non-dimensionalized and solved numerically via Runge–Kutta–Fehlberg method combined with shooting scheme. The effect of pertinent parameters on temperature field is examined. From the validation of obtained outcome it is found that the use nanofluid has significant influence on heat transfer rate. Among platelet, cylinder, brick and blade shapes, brick-shaped nanoparticle shows better heat transfer rate.

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Periasamy, Manikandan, and Rajoo Baskar. "Experimental heat transfer studies on copper nanofluids in a plate heat exchanger." Chemical Industry and Chemical Engineering Quarterly, no. 00 (2020): 20. http://dx.doi.org/10.2298/ciceq191220020p.

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The objective of the present work is to study the influence of Copper nanoparticle concentration on heat transfer performance of mixed base fluid. In the present study, the performance of copper nanoparticles in (Ethylene Glycol (EG) + Propylene Glycol (PG) + Water (W)) base fluid was analyzed in the chevron-type Plate Heat Exchanger. The sol-gel method was used to prepare Copper nanoparticles (100 nm); dispersed in two different mixed base fluids of volume fractions 5%EG + 5%PG + 90%W and 15%EG +5%PG +80%W. Experiments were performed by varying the nanoparticle concentration from 0.2 to 1.0 vol %. Three different hot fluid inlet temperatures were used (55?C, 65?C and 75?C). It is revealed from the study that the rate of heat transfer increased significantly with the mixed base fluid. Result shows that at 75?C, 9%, and 14.9% enhancement in Nusselt number is obtained for 5%EG + 5%PG + 90%W and 15%EG +5%PG +80%W base fluid respectively for the nanoparticle concentration of 1%.

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Cieśliński, Janusz T., Slawomir Smolen, and Dorota Sawicka. "Effect of Temperature and Nanoparticle Concentration on Free Convective Heat Transfer of Nanofluids." Energies 14, no. 12 (June 15, 2021): 3566. http://dx.doi.org/10.3390/en14123566.

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A theoretical analysis of the influence of temperature and nanoparticle concentration on free convection heat transfer from a horizontal tube immersed in an unbounded nanofluid was presented. The Nusselt (Nu) number and heat transfer coefficient were parameters of the intensity of the convective heat transfer. For free convection, the Nu number was a function of the Rayleigh (Ra) number and Prandtl (Pr) number. The Rayleigh (Ra) number and Prandtl (Pr) number were functions of the thermophysical properties of nanofluids. The thermophysical properties of nanofluids varied with temperature and nanoparticle concentration. Therefore, an analysis was conducted to evaluate the effects on the performance of nanofluids due to variations of thermal conductivity, viscosity, thermal expansion, density, and specific heat, which are functions of nanoparticle concentration and temperature. Water- and ethylene glycol (EG)-based nanofluids with dispersed alumina (Al2O3) nanoparticles at mass concentrations of 0.01%, 0.1%, and 1% were considered. Calculated Nu numbers and heat transfer coefficients were compared with experimental values taken from the published literature.

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Domenikou, Natalia, Ioannis Thanopulos, Vassilios Yannopapas, and Emmanuel Paspalakis. "Stimulated Raman Adiabatic Passage in a Quantum Emitter Near to a Gold Nanoparticle." Materials Proceedings 4, no. 1 (November 11, 2020): 7. http://dx.doi.org/10.3390/iocn2020-07867.

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In the last three decades, stimulated Raman adiabatic passage (STIRAP) has been proven a robust and high-efficient technique for population transfer in a three-level quantum system and beyond that. As coupled quantum-plasmonic nanostructures are widely used in recent nanophotonics for the superior properties that the coupled structures have over their constituents, a series of studies have analyzed the influence of a spherical metallic nanoparticle, which is a basic plasmonic nanosystem, on coherent population transfer methods in nearby quantum systems. For several recent proposals, it is important to understand the behavior of STIRAP near metallic nanoparticles. Therefore, in this work we present numerical results on the influence of a spherical metallic nanoparticle to the population transfer in a Λ-type quantum system under conditions of STIRAP. For the study of the system’s dynamics, we use the density matrix approach for the quantum system, where the parameters for the electric field amplitudes and the spontaneous decay rates have been calculated using ab initio electromagnetic calculations for the plasmonic nanoparticle. We then present results for the evolution of the populations of the different levels of the quantum system as a function of different parameters, in the presence and the absence of the plasmonic nanoparticle. We find that the presence of the plasmonic nanoparticle and the polarization of the pump and Stokes fields with respect to the surface of the nanoparticle, affect the efficiency of the population transfer inside the three-level quantum system. For the right combination of the values of the free space spontaneous decay rates and the fields intensities, high efficiency population transfer is obtained in the quantum system near a plasmonic nanoparticle using the STIRAP process.

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Malvandi, Amir, Saeed Heysiattalab, Amirmahdi Ghasemi, D. D. Ganji, and Ioan Pop. "Nanoparticle migration effects at film boiling of nanofluids over a vertical plate." International Journal of Numerical Methods for Heat & Fluid Flow 27, no. 2 (February 6, 2017): 471–85. http://dx.doi.org/10.1108/hff-01-2016-0007.

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Purpose The purpose of this paper is to theoretically investigate the effects of nanoparticle migration on the heat transfer enhancement at film boiling of nanofluids. The modified Buongiorno model is used for modeling the nanofluids to observe the effects of nanoparticle migration. Design/methodology/approach The governing partial differential equations including continuity, momentum, energy and nanoparticle continuity are transformed to ordinary ones and solved numerically. For nanoparticle distribution, an analytical expression has been found. The results have been obtained for different parameters, including the Brownian motion to thermophoretic diffusion NBT, saturation nanoparticle volume fraction ϕsat and normal temperature difference. Findings A closed-form expression for nanoparticle distribution is obtained, and it is indicated that nanoparticle migration significantly affects the flow fields and thermophysical properties of nanofluids. It was shown that temperature gradient at heated wall grows as the migration of nanoparticles increases, which has positive effects on the heat transfer rate. However, decrement of thermal conductivity at heated wall because of nanoparticle depletion plays a negative role in heat transfer enhancement. In fact, there is a tradeoff between thermal conductivity reduction and an increment in temperature gradient at the wall, which determines the net enhancement/deterioration of the heat transfer rate. Research limitations/implications Flow has been assumed to be laminar, and the vapor temperature is constant such that boiling is the only heat transfer mechanism between the liquid-vapor interface. Also, the shear stress at the liquid-vapor interface is assumed to be negligible. The film thickness is small relative to the plate length to justify the boundary layer assumptions. Inertia forces are neglected relative to shear stress forces. Practical implications Outcomes of the present study are suitable for several heat exchange purposes such as evaporation and condensation in heat pipes, immersion, microchannel cooling of microelectronics and crystal growth. Originality/value The novelty of this paper has three aspects: modeling the film boiling of nanofluids considering the effects of nanoparticle migration; how it influences the cooling performance; and an analytical expression for the nanoparticle distribution at film boiling of nanofluids.

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Gireesha, BJ, G. Sowmya, and Rama Subba Reddy Gorla. "Nanoparticle shape effect on the thermal behaviour of moving longitudinal porous fin." Proceedings of the Institution of Mechanical Engineers, Part N: Journal of Nanomaterials, Nanoengineering and Nanosystems 234, no. 3-4 (May 2, 2020): 115–21. http://dx.doi.org/10.1177/2397791420915139.

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A numerical examination of nanoliquid flow over a longitudinal porous fin moving with constant speed is undertaken in the current study. Nickel alloy is used as a nanoparticle, and engineered fluid [Formula: see text] is used as a based fluid. In addition, various shapes of nanoparticles like sphere, disc and needle shapes are considered. The generated ordinary differential equation has been nondimensionalized and integrated by using the Runge–Kutta–Fehlberg method. The influence of suitable parameters on the enhancement of heat transfer has been discussed with the help of plotted graphs. Also, the influence of diverse shaped nanoparticle is analysed mathematically. It is found that sphere shaped nanoparticles show better transfer of heat than the disc and needle shapes.

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Xi, Qing, Yunyun Li, Jun Zhou, Baowen Li, and Jun Liu. "Role of radiation in heat transfer from nanoparticles to gas media in photothermal measurements." International Journal of Modern Physics C 30, no. 04 (April 2019): 1950024. http://dx.doi.org/10.1142/s0129183119500244.

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The heat transfer from nanoparticles (NPs) to gas of photothermal effect is investigated by taking into account both conduction and radiation. The steady-state and unsteady-state heat transfer processes are studied analytically and numerically, respectively. In contrast to the photothermal effect in liquid with metal NPs, in which the radiation is negligible, we found that the thermal radiation must be taken into account in the nanoparticle–gas system. The reason is that the thermal boundary conductance (TBC) of gas–solid interface is several orders of magnitude smaller than the TBC of liquid–solid interface, especially when the diameter of nanoparticle is comparable to or smaller than the mean free path of gas molecules. We propose a method to measure the ultra-low TBC of interface between nanoparticle and gas based on our investigations.

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Komissarenko, Filipp, George Zograf, Sergey Makarov, Mikhail Petrov, and Ivan Mukhin. "Manipulation Technique for Precise Transfer of Single Perovskite Nanoparticles." Nanomaterials 10, no. 7 (July 3, 2020): 1306. http://dx.doi.org/10.3390/nano10071306.

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In this article, we present the pick-and-place technique for the manipulation of single nanoparticles on non-conductive substrates using a tungsten tip irradiated by a focused electron beam from a scanning electron microscope. The developed technique allowed us to perform the precise transfer of single BaTiO3 nanoparticles from one substrate to another in order to carry out measurements of elastic light scattering as well as second harmonic generation. Also, we demonstrate a fabricated structure made by finely tuning the position of a BaTiO3 nanoparticle on top of a dielectric nanowaveguide deposited on a glass substrate. The presented technique is based on the electrostatic interaction between the sharp tungsten tip charged by the electron beam and the nanoscale object. A mechanism for nanoparticle transfer to a non-conductive substrate is proposed and the forces involved in the manipulation process are evaluated. The presented technique can be widely utilized for the fabrication of nanoscale structures on optically transparent non-conductive substrates, which presents a wide range of applications for nanophotonics.

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Xu, Duo, Dong Liu, Tao Xie, Yue Cao, Jun-Gang Wang, Zhi-jun Ning, Yi-Tao Long, and He Tian. "Plasmon resonance scattering at perovskite CH3NH3PbI3 coated single gold nanoparticles: evidence for electron transfer." Chemical Communications 52, no. 64 (2016): 9933–36. http://dx.doi.org/10.1039/c6cc04283j.

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We demonstrate the electron transfer between gold nanoparticles and perovskite CH₃NH₃PbI₃ at a single nanoparticle level by plasmon resonance Rayleigh scattering spectroscopy.

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Abdelmalek, Zahra, Annunziata D’Orazio, and Arash Karimipour. "The Effect of Nanoparticle Shape and Microchannel Geometry on Fluid Flow and Heat Transfer in a Porous Microchannel." Symmetry 12, no. 4 (April 8, 2020): 591. http://dx.doi.org/10.3390/sym12040591.

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Microchannels are widely used in electrical and medical industries to improve the heat transfer of the cooling devices. In this paper, the fluid flow and heat transfer of water–Al2O3 nanofluids (NF) were numerically investigated considering the nanoparticle shape and different cross-sections of a porous microchannel. Spherical, cubic, and cylindrical shapes of the nanoparticle as well as circular, square, and triangular cross-sections of the microchannel were considered in the simulation. The finite volume method and the SIMPLE algorithm have been employed to solve the conservation equations numerically, and the k-ε turbulence model has been used to simulate the turbulence fluid flow. The models were simulated at Reynolds number ranging from 3000 to 9000, the nanoparticle volume fraction ranging from 1 to 3, and a porosity coefficient of 0.7. The results indicate that the average Nusselt number (Nuave) increases and the friction coefficient decreases with an increment in the Re for all cases. In addition, the rate of heat transfer in microchannels with triangular and circular cross-sections is reduced with growing Re values and concentration. The spherical nanoparticle leads to maximum heat transfer in the circular and triangular cross-sections. The heat transfer growth for these two cases are about 102.5% and 162.7%, respectively, which were obtained at a Reynolds number and concentration of 9000 and 3%, respectively. However, in the square cross-section, the maximum heat transfer increment was obtained using cylindrical nanoparticles, and it is equal to 80.2%.

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Cieśliński, Janusz T. "Effect of nanofluid concentration on two-phase thermosyphon heat exchanger performance." Archives of Thermodynamics 37, no. 2 (June 1, 2016): 23–40. http://dx.doi.org/10.1515/aoter-2016-0011.

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Abstract An approach - relaying on application of nanofluid as a working fluid, to improve performance of the two-phase thermosyphon heat exchanger (TPTHEx) has been proposed. The prototype heat exchanger consists of two horizontal cylindrical vessels connected by two risers and a downcomer. Tube bundles placed in the lower and upper cylinders work as an evaporator and a condenser, respectively. Distilled water and nanofluid water-Al2O3 solution were used as working fluids. Nanoparticles were tested at the concentration of 0.01% and 0.1% by weight. A modified Peclet equation and Wilson method were used to estimate the overall heat transfer coefficient of the tested TPTHEx. The obtained results indicate better performance of the TPTHEx with nanofluids as working fluid compared to distilled water, independent of nanoparticle concentration tested. However, increase in nanoparticle concentration results in overall heat transfer coefficient decrease of the TPTHEx examined. It has been observed that, independent of nanoparticle concentration tested, decrease in operating pressure results in evaporation heat transfer coefficient increase.

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Buongiorno, J. "Convective Transport in Nanofluids." Journal of Heat Transfer 128, no. 3 (August 15, 2005): 240–50. http://dx.doi.org/10.1115/1.2150834.

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Nanofluids are engineered colloids made of a base fluid and nanoparticles (1-100nm). Nanofluids have higher thermal conductivity and single-phase heat transfer coefficients than their base fluids. In particular, the heat transfer coefficient increases appear to go beyond the mere thermal-conductivity effect, and cannot be predicted by traditional pure-fluid correlations such as Dittus-Boelter’s. In the nanofluid literature this behavior is generally attributed to thermal dispersion and intensified turbulence, brought about by nanoparticle motion. To test the validity of this assumption, we have considered seven slip mechanisms that can produce a relative velocity between the nanoparticles and the base fluid. These are inertia, Brownian diffusion, thermophoresis, diffusiophoresis, Magnus effect, fluid drainage, and gravity. We concluded that, of these seven, only Brownian diffusion and thermophoresis are important slip mechanisms in nanofluids. Based on this finding, we developed a two-component four-equation nonhomogeneous equilibrium model for mass, momentum, and heat transport in nanofluids. A nondimensional analysis of the equations suggests that energy transfer by nanoparticle dispersion is negligible, and thus cannot explain the abnormal heat transfer coefficient increases. Furthermore, a comparison of the nanoparticle and turbulent eddy time and length scales clearly indicates that the nanoparticles move homogeneously with the fluid in the presence of turbulent eddies, so an effect on turbulence intensity is also doubtful. Thus, we propose an alternative explanation for the abnormal heat transfer coefficient increases: the nanofluid properties may vary significantly within the boundary layer because of the effect of the temperature gradient and thermophoresis. For a heated fluid, these effects can result in a significant decrease of viscosity within the boundary layer, thus leading to heat transfer enhancement. A correlation structure that captures these effects is proposed.

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Liu, Ching-Ping, Shih-Hsun Cheng, Nai-Tzu Chen, and Leu-Wei Lo. "Intra/Inter-Particle Energy Transfer of Luminescence Nanocrystals for Biomedical Applications." Journal of Nanomaterials 2012 (2012): 1–9. http://dx.doi.org/10.1155/2012/706134.

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Elaborate design of energy transfer systems in luminescent nanocrystals revealed tremendous advantages in nanotechnology, especially in biosensing and drug delivery systems. Recently, upconversion nanoparticles have been discussed as promising probes as labels in biological assays and imaging. This article reviews the works performed in the recent years using quantum dot- and rare-earth doped nanoparticle-based energy transfer systems for biomedical applications.

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Malvandi, A., and D. D. Ganji. "Effects of Nanoparticle Migration on Water/Alumina Nanofluid Flow Inside a Horizontal Annulus with a Moving Core." Journal of Mechanics 31, no. 3 (August 12, 2014): 291–305. http://dx.doi.org/10.1017/jmech.2014.56.

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AbstractThe present study is a theoretical investigation of the laminar flow and convective heat transfer of water/alumina nanofluid inside a horizontal annulus with a streamwise moving inner cylinder. A modified, two-component, four-equation, nonhomogeneous equilibrium model is employed for the alumina/water nanofluid, which fully accounts for the effect of the nanoparticle volume fraction distribution. To determine the effects of thermal boundary conditions on the migration of the nanoparticles, two cases are considered: constant heat flux at the outer wall with an adiabatic inner wall (Case A) and constant heat flux at the inner wall with an adiabatic outer wall (Case B). The numerical results indicate that the thermal boundary conditions at the pipe walls significantly affect the nanoparticle distribution, particularly in cases where the ratio of Brownian motion to thermophoretic diffusivities is small. Moreover, increasing the velocity of the moving inner cylinder reduces the heat transfer rate for Case A. Conversely, in Case B, the movement of the inner cylinder enhances the heat transfer rate, and anomalous heat transfer enhancement occurs when the thermophoretic force is dominant (in larger nanoparticles).

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Nagata, Akihiko, Takeo Oku, Tsuyoshi Akiyama, Atsushi Suzuki, Yasuhiro Yamasaki, and Tomohiro Mori. "Effects of Au Nanoparticle Addition to Hole Transfer Layer in Organic Photovoltaic Cells Based on Phthalocyanines and Fullerene." Journal of Nanotechnology 2011 (2011): 1–6. http://dx.doi.org/10.1155/2011/869596.

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Phthalocyanines/fullerene organic photovoltaic cells were fabricated and characterized. Effects of Au nanoparticle addition to a hole transfer layer were also investigated, and power conversion efficiencies of the photovoltaic cells were improved after blending the Au nanoparticle into PEDOT:PSS. Nanostructures of the Au nanoparticles were investigated by transmission electron microscopy and X-ray diffraction. Energy levels of molecules were calculated by molecular orbital calculations, and the nanostructures and electronic property were discussed.

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Rabby, Md Insiat Islam, Farzad Hossain, S. A. M. Shafwat Amin, Tazeen Afrin Mumu, MD Ashraf Hossain Bhuiyan, and A. K. M. Sadrul-Islam. "CONVECTIVE HEAT TRANSFER AND POWER SAVING APPLICATION OF SI BASED NANOPARTICLES IN A CIRCULAR PIPE." Latin American Applied Research - An international journal 50, no. 4 (September 25, 2020): 321–27. http://dx.doi.org/10.52292/j.laar.2020.593.

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A numerical study of laminar forced convection heat transfer for the fully developed region inside a circular pipe filled with Si based nanoparticle is presented for investigating the parameters of heat transfer. Four Si based nanoparticles Si, SiC, SiO2, Si3N4 with 1-5% volume fraction have been mixed with water to prepare nanofluids which is used for working fluid to flow over a circular pipe with 5mm diameter and 700mm length. Heat transfer characteristics and pumping power have been calculated at fully developed region with constant heat flux condition on pipe wall to identify the heat transfer enhancement ratio and pumping power reduction ratio among base fluid water and each nanofluids. It is worth mentioning that utilizing SiC nanoparticle shows not only the highest increment of Nusselt number and convective heat transfer coefficient but also the highest decrement of pumping power requirement and FOM in comparison to the base fluid.

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Arslan, Kamil. "Three-dimensional computational fluid dynamics modeling of TiO2/R134a nanorefrigerant." Thermal Science 21, no. 1 Part A (2017): 175–86. http://dx.doi.org/10.2298/tsci140425002a.

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In this study, numerical investigations were carried out for R134a based TiO2 nanorefrigerants. Forced laminar flow and heat transfer of nanorefrigerants in a horizontal smooth circular cross-sectioned duct were investigated under steady-state condition. The nanorefrigerants consist of TiO2 nanoparticles suspended in R134a as a base fluid with four particle volume fractions of 0.8, 2.0 and 4.0%. Numerical studies were performed under laminar flow conditions where Reynolds numbers range from 8?102 to 2.2?103. Flow is flowing in the duct with hydrodynamically and thermally developing (simultaneously developing flow) condition. The uniform surface heat flux with uniform peripheral wall heat flux (H2) boundary condition was applied on the duct wall. Commercial CFD software, Ansys Fluent 14.5, was used to carry out the numerical study. Effect of nanoparticle volume fraction on the average convective heat transfer coefficient and average Darcy friction factor were analyzed. It is obtained in this study that increasing nanoparticle volume fraction of nanorefrigerant increases the convective heat transfer in the duct; however, increasing nanoparticle volume fraction does not influence the pressure drop in the duct. The velocity and temperature distribution in the duct for different Reynolds numbers and nanoparticle volume fractions were presented.

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Srinivas, S., A. Vijayalakshmi, and A. Subramanyam Reddy. "Flow and Heat Transfer of Gold-Blood Nanofluid in a Porous Channel with Moving/Stationary Walls." Journal of Mechanics 33, no. 3 (November 9, 2016): 395–404. http://dx.doi.org/10.1017/jmech.2016.102.

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AbstractThe present study investigates the flow and heat transfer characteristics of blood carrying gold nanoparticles in a porous channel with moving/stationary walls in the presence of thermal radiation. Blood is considered as Newtonian fluid which is the base fluid and gold (Au) as nanoparticles. The governing equations are transformed into system of ordinary differential equations by using similarity transformations. The analytical solutions are obtained for the flow variables by employing homotopy analysis method (HAM). The analytical solutions are compared with the numerical solutions which are obtained by shooting technique along with Runge-Kutta scheme. It was noticed that there is a good agreement between analytical and numerical results. The influence of various parameters on velocity, temperature and heat transfer rate of gold-blood nanofluid has been discussed in detail. The temperature of the nanofluid increases with increasing the nanoparticle volume fraction. The heat transfer rate at the top wall increases with increasing nanoparticle volume fraction while it decreases for a given increase in radiation parameter.

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Barbillon, Grégory. "Latest Novelties on Plasmonic and Non-Plasmonic Nanomaterials for SERS Sensing." Nanomaterials 10, no. 6 (June 19, 2020): 1200. http://dx.doi.org/10.3390/nano10061200.

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An explosion in the production of substrates for surface enhanced Raman scattering (SERS) has occurred using novel designs of plasmonic nanostructures (e.g., nanoparticle self-assembly), new plasmonic materials such as bimetallic nanomaterials (e.g., Au/Ag) and hybrid nanomaterials (e.g., metal/semiconductor), and new non-plasmonic nanomaterials. The novel plasmonic nanomaterials can enable a better charge transfer or a better confinement of the electric field inducing a SERS enhancement by adjusting, for instance, the size, shape, spatial organization, nanoparticle self-assembly, and nature of nanomaterials. The new non-plasmonic nanomaterials can favor a better charge transfer caused by atom defects, thus inducing a SERS enhancement. In last two years (2019–2020), great insights in the fields of design of plasmonic nanosystems based on the nanoparticle self-assembly and new plasmonic and non-plasmonic nanomaterials were realized. This mini-review is focused on the nanoparticle self-assembly, bimetallic nanoparticles, nanomaterials based on metal-zinc oxide, and other nanomaterials based on metal oxides and metal oxide-metal for SERS sensing.

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Gobinath, Natarajan, and C. P. Karthikeyan. "Heating and Cooling Mechanisms of Nano Fluids: Experimental Investigation." Nano Hybrids and Composites 17 (August 2017): 44–54. http://dx.doi.org/10.4028/www.scientific.net/nhc.17.44.

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Heat transfer mechanisms and migration characteristics of volatile nanoparticles in a boiling fluid are complex phenomenon to understand. Boiling heat transfer mechanisms of the nanofluid (Al2O3/n-pentane) and migration characteristics of volatile Al2O3 nanoparticle are studied in this paper. Experiments were carried out using a sealed glass beaker partially filled with the nanofluid. Heat flux conditions and mass fractions of nanoparticles were varied to study the heat transfer mechanisms and migration characteristics of particles. Accuracy of experiments was checked using heat transfer correlations and repeated iterations. Also, in the present research, the solidification rate of pure water and water suspended with alumina nanoparticles is investigated to understand the freezing characteristics of nanofluids.

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Tarybakhsh, Mohammad Reza, Ali Akbar Lotfi Neyestanak, and Hamed Tarybakhsh. "CFD Study on Wall/Nanoparticle Interaction in Nanofluids Convective Heat Transfer." Advances in Materials Science and Engineering 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/651365.

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The Brownian motion of the nanoparticles in nanofluid is one of the potential contributors to enhance effective thermal conductivity and the mechanisms that might contribute to this enhancement are the subject of considerable discussion and debate. In this paper, the mixing effect of the base fluid in the immediate vicinity of the nanoparticles caused by the Brownian motion was analyzed, modeled, and compared with existing experimental data available in the literature. CFD was developed to study the effect of wall/nanoparticle interaction on forced convective heat transfer in a tube under constant wall temperature condition. The results showed that the motion of the particle near the wall which can decrease boundary layer and the hydrodynamics effects associated with the Brownian motion have a significant effect on the convection heat transfer of nanofluid.

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Chai, Jasman Y. H., and Basil T. Wong. "Study of Light Scattering by TiO₂, Ag, and SiO₂ Nanofluids with Particle Diameters of 20-60 nm." Journal of Nano Research 60 (November 2019): 1–20. http://dx.doi.org/10.4028/www.scientific.net/jnanor.60.1.

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In this research, we detailed how the following factors affect the scattering of light by nanofluids: (1) nanoparticle sizes, (2) volume fraction of nanoparticles, and (3) nanoparticle materials. Mie theory was used to calculate the radiative properties of the nanofluids. The radiative properties were then applied into the Radiative Transfer Equation (RTE) to solve for the transmittance and reflectance of light through the nanofluids. The RTE was solved using the Monte Carlo method. Results showed that when the size of nanoparticles and the volume fraction increase, absorption and scattering coefficients increase as well. For silver nanofluids, absorption and scattering coefficients decrease beyond nanoparticle size of about 50 nm. Transmittance of light decreased when nanoparticle sizes increased. When comparing between TiO2, Ag, and SiO2 nanofluids, Ag nanofluids exhibit the highest light absorption followed by TiO2 and SiO2.

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Cai, Weihua, Zhifeng Zheng, Changye Huang, Yue Wang, Xin Zheng, and Hongna Zhang. "Lattice Boltzmann simulation of Rayleigh-Benard convection in enclosures filled with Al2O3-water nanofluid." Thermal Science 22, Suppl. 2 (2018): 535–45. http://dx.doi.org/10.2298/tsci171023038c.

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In order to clarify the controversies for the role of nanoparticles on heat transfer in natural convection, lattice Boltzmann method is used to investigate Rayleigh-Benard convection heat transfer in differentially-heated enclosures filled with Al2O3-water nanofluids. The results for streamline and isotherm contours, vertical velocity, and temperature profiles as well as the local and average Nusselt number are discussed for a wide range of Rayleigh numbers and nanoparticle volume fractions (0 ? ? ? 5%). The results show that with the increase of Rayleigh number and nanoparticles loading, Nuave increases. It is suggested that the addition of nanoparticles can enhance the heat transfer in Rayleigh-Benard convection.

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Guangbin, Yu, Gao Dejun, Chen Juhui, Dai Bing, Liu Di, Song Ye, and Chen Xi. "Experimental Research on Heat Transfer Characteristics of CuO Nanofluid in Adiabatic Condition." Journal of Nanomaterials 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/3693249.

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The laminar convective heat transfer behavior of CuO nanoparticle dispersions in glycol with the average particle sizes (about 70 nm) was investigated experimentally in a flow loop with constant heat flux. To enhance heat exchange under high temperature condition and get the more accurate data, we try to improve the traditional experimental apparatus which is used to test nanofluid heat transfer characteristics. In the experiment five different nanoparticle concentrations (0.25%, 0.50%, 0.80%, 1.20%, and 1.50%) were investigated in a flow loop with constant heat flux. The experimental results show that the heat transfer coefficient of nanofluid becomes higher than that of pure fluid at the same Reynolds number and increased with the increasing of the mass fraction of CuO nanoparticles. Results also indicate that at very low volume concentrations nanofluid has no major impact on heat transfer parameters and the pressure of nanofluids increased by the mass fraction increase.

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Савин, А. В. "Термофорез углеродных наночастиц (нанолент и нанотрубок) на плоской многослойной подложке гексагонального нитрида бора (h-BN)." Физика твердого тела 63, no. 12 (2021): 2217. http://dx.doi.org/10.21883/ftt.2021.12.51687.178.

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Using the method of molecular dynamics and a 2D chain model, it is shown that thermophoresis of carbon nanoparticles (nanoribbons and nanotubes) on a flat multilayer substrate (on a flat surface of a hexagonal boron nitride crystal) has high efficiency. Placing a nanoparticle on a flat surface of a substrate involved in heat transfer leads to its movement in the direction of the heat flow. The heat flow along the substrate leads to the formation of constant forces acting on the nanoparticle nodes (thermophoresis forces). The main effect of the force is exerted on the edges of graphene nanoribbons, exactly where the main interaction of the nanoribbon with the bending phonons of the substrate occurs. These phonons have a long free path, so the effective transfer of nanoparticles using thermophoresis can occur at sufficiently large distances. The motion of carbon nanoparticles under the action of a heat flow has the form of particle motion in a viscous medium under the action of a constant force. Over time, the nanoparticles always enter the mode of movement at a constant speed. The velocity of the stationary motion is almost the same for all sizes and types of carbon nanoparticles, which is explained by the fact that the thermophoresis force and effective friction have the same source – the interaction of the nanoparticle with the bending thermal vibrations of the substrate layers.

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Minea, Alina Adriana. "State of the Art in PEG-Based Heat Transfer Fluids and Their Suspensions with Nanoparticles." Nanomaterials 11, no. 1 (January 3, 2021): 86. http://dx.doi.org/10.3390/nano11010086.

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Research on nanoparticle enhanced fluids has increased rapidly over the last decade. Regardless of several unreliable reports, these new fluids have established performance in heat transfer. Lately, polyethylene glycol with nanoparticles has been demarcated as an innovative class of phase change materials with conceivable uses in the area of convective heat transfer. The amplified thermal conductivity of these nanoparticle enhanced phase change materials (PCMs) over the basic fluids (e.g., polyethylene glycol—PEG) is considered one of the driving factors for their improved performance in heat transfer. Most of the research, however, is centered on the thermal conductivity discussion and less on viscosity variation, while specific heat capacity seems to be fully ignored. This short review abridges most of the recent investigations on new PEG-based fluids and is dedicated especially to thermophysical properties of the chemicals, while a number of PEG-based nanofluids are compared in terms of base fluid and/or nanoparticle type and concentration. This review outlines the possibility of developing promising new heat transfer fluids. To conclude, this research is in its pioneering phase, and a large amount of experimental and numerical work is required in the coming years.

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AKBAR, NOREEN SHER, DHARMENDRA TRIPATHI, and O. ANWAR BÉG. "MODELING NANOPARTICLE GEOMETRY EFFECTS ON PERISTALTIC PUMPING OF MEDICAL MAGNETOHYDRODYNAMIC NANOFLUIDS WITH HEAT TRANSFER." Journal of Mechanics in Medicine and Biology 16, no. 06 (September 2016): 1650088. http://dx.doi.org/10.1142/s0219519416500883.

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Magnetic nanofluid technologies are emerging in numerous areas including medicine, lubrication (smart tribology), pharmacology, etc. In this paper, we examine heat diffusion in hydromagnetic nanofluids in a peristaltic system, motivated by applications in medical drug delivery systems and gastric magnetographic monitoring. The mathematical formulation encompasses momentum and heat conservation equations with appropriate boundary conditions for compliant walls. Sophisticated correlations are employed for thermal conductivity of the nanoparticles. The nonlinear boundary value problem is normalized with appropriate variables and closed-form solutions are derived for stream function, pressure gradient and temperature profile. Analytical solutions are evaluated numerically with MATHEMATICA symbolic software. Validation of computations is performed for the nonlinear moving boundary value problem via a Chebyschev spectral collocation method (CSM). A detailed study is performed for the influence of various nanoparticle geometries (bricks, cylinders and platelets). With greater magnetic field, flow velocity is enhanced for platelet nanoparticles whereas it is depressed for brick particles. Temperature is dramatically modified with nanoparticle geometry and greater thermal conductivity is achieved with brick-shaped nanoparticles in the fluid, with implications for optimized medical device systems.

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Journal articles on the topic 'Nanoparticle transfer'

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