scholarly journals Optical Nanocomposites Based on High Nanoparticles Concentration and Its Holographic Application

10.5772/47737 ◽  
2012 ◽  
Author(s):  
Igor Yu. ◽  
Julia A. ◽  
Sandor Kokenyesi ◽  
Vera G. ◽  
Mari Iv.
Keyword(s):  
Nanoparticles Concentration

Peristaltic Carreau-Yasuda nanofluid flow and mixed heat transfer analysis in an asymmetric vertical and tapered wavy wall channel

2020 ◽  
Vol 1 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Mohammad Hatami ◽  
◽  
D Jing ◽  
Keyword(s):  
Heat Transfer ◽  
Least Square Method ◽  
Weissenberg Number ◽  
Least Square ◽  
Heat Transfer Analysis ◽  
Phase Method ◽  
Nanofluid Flow ◽  
Two Phase ◽  
Nanoparticles Concentration ◽  
The Right

In this study, two-phase asymmetric peristaltic Carreau-Yasuda nanofluid flow in a vertical and tapered wavy channel is demonstrated and the mixed heat transfer analysis is considered for it. For the modeling, two-phase method is considered to be able to study the nanoparticles concentration as a separate phase. Also it is assumed that peristaltic waves travel along X-axis at a constant speed, c. Furthermore, constant temperatures and constant nanoparticle concentrations are considered for both, left and right walls. This study aims at an analytical solution of the problem by means of least square method (LSM) using the Maple 15.0 mathematical software. Numerical outcomes will be compared. Finally, the effects of most important parameters (Weissenberg number, Prandtl number, Brownian motion parameter, thermophoresis parameter, local temperature and nanoparticle Grashof numbers) on the velocities, temperature and nanoparticles concentration functions are presented. As an important outcome, on the left side of the channel, increasing the Grashof numbers leads to a reduction in velocity profiles, while on the right side, it is the other way around.

scholarly journals The synergistic interference effect of silica nanoparticles concentration and the wavelength of ELISA on the colorimetric assay of cell toxicity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fariba Abbasi ◽  
Hassan Hashemi ◽  
Mohammad Reza Samaei ◽  
Amir SavarDashtaki ◽  
Abooalfazl Azhdarpoor ◽  
...  
Keyword(s):  
Mtt Assay ◽  
Interference Effect ◽  
Polynomial Regression ◽  
Colorimetric Assay ◽  
Synergistic Effects ◽  
Cell Toxicity ◽  
Diphenyltetrazolium Bromide ◽  
Nanoparticles Concentration ◽  
Artificial Neural Network Ann ◽  
First Time

AbstractThe 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay is the most common method for the determination of cell toxicity, but some factors limit the sensitivity of this method, such as pH. Less attention had been paid to the interference effect of optical and plasmonic properties of SiO2 nanoparticles (NPs) in the wavelength range assigned to MTT. This study investigated the synergistic interference effect of SiO2 NPs and wavelength on MTT assay for the first time. The examined variables included the type of SiO2 NPs concentrations (1, 10, and 100 mM) and different wavelengths (470, 490, 520, and 570 nm). The results showed that optical density (OD) increased (p < 0.05) when wavelength and the concentration of crystalline SiO2 NPs increased. So, the maximum OD at 10 and 100 mM were attributed to crystalline SiO2 NPs (p < 0.05) due to the functional group, whereas it was related to amorphous at 1 mM (p > 0.05). According to polynomial regression modeling (PRM), the maximum interference effect was predicted at crystalline SiO2 NPs and wavelength > 550 nm. Besides, the synergistic effects of SiO2 NPs, wavelength, and concentration of NPs had been a good fitting with first-order PRM. Thus, the concentration of SiO2 NPs had a confounder factor in colorimetric for MTT assay. The best artificial neural network (ANN) structure was related to the 3:7:1 network (Rall = 0.936, MSE = 0.0006, MAPE = 0.063). The correlation between the actual and predicted data was 0.88. As SiO2 NPs presence is an interfering factor in MTT assay concerning wavelength, it is suggested wavelength use with minimum confounding effect for MTT assay.

scholarly journals Nanoscopic interactions of colloidal particles can suppress millimetre drop splashing

Soft Matter ◽  
2021 ◽  
Author(s):  
Marie-Jean Thoraval ◽  
Jonas Schubert ◽  
Stefan Karpitschka ◽  
Munish Chanana ◽  
François Boyer ◽  
...  
Keyword(s):  
Solid Surface ◽  
Colloidal Particles ◽  
Liquid Drop ◽  
Nanoparticles Concentration

The presence of nanoparticles in a millimetric liquid drop impacting on a solid surface can suppress splashing at higher impact velocities. This mechanism is affected by the nanoparticles concentration and the coating molecules at their surface.

EXPERIMENTAL STUDY ON THERMAL TRANSPORT PHENOMENON OF NANOFLUIDS AS WORKING FLUID IN HEAT EXCHANGER

2014 ◽  
Vol 22 (01) ◽  
pp. 1450005 ◽  
Author(s):  
SHUICHI TORII
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Performance ◽  
Pure Water ◽  
Horizontal Tube ◽  
Constant Heat Flux ◽  
Working Fluid ◽  
Transfer Performance ◽  
Nanoparticles Concentration ◽  
Transfer Behavior

This paper aims to study the convective heat transfer behavior of aqueous suspensions of nanoparticles flowing through a horizontal tube heated under constant heat flux condition. Consideration is given to the effects of particle concentration and Reynolds number on heat transfer enhancement and the possibility of nanofluids as the working fluid in various heat exchangers. It is found that (i) significant enhancement of heat transfer performance due to suspension of nanoparticles in the circular tube flow is observed in comparison with pure water as the working fluid, (ii) enhancement is intensified with an increase in the Reynolds number and the nanoparticles concentration, and (iii) substantial amplification of heat transfer performance is not attributed purely to the enhancement of thermal conductivity due to suspension of nanoparticles.

Structural and Optical Properties of (PVA/PVP:Sr2NO3) Nanocomposites

2021 ◽  
Vol 19 (4) ◽  
pp. 27-37
Author(s):  
Doaa E. Al-Kateb ◽  
Ali R. Abdulridha
Keyword(s):  
Optical Properties ◽  
Energy Gap ◽  
Ftir Spectra ◽  
Structural And Optical Properties ◽  
Casting Method ◽  
Forbidden Transitions ◽  
Nanoparticles Concentration

In this study preparing and investigating of the (PVA/PVP:Sr2NO3) nanocomposites films by using casting method with different concentration of Sr2NO3 as (0, 1, 3, 5, and 7 wt. %). Optical properties obtained by UV-Vis spectrometer, OM and FTIR spectra have been revealed in this study, the absorbance increased by increasing of Sr2NO3 nanoparticles concentrations, the energy-gap (allowed and forbidden) transitions decreased by increasing of the nanoparticles concentration.

scholarly journals Numerical Analysis of Nanofluids in Differentially Heated Enclosure Undergoing Orthogonal Rotation

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
H. Saleh ◽  
I. Hashim
Keyword(s):  
Heat Transfer ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Convection Heat Transfer ◽  
Staggered Grid ◽  
Governing Equations ◽  
Nanoparticles Concentration ◽  
Quantity Of Heat ◽  
Velocity Pressure

Natural convection heat transfer in a rotating, differentially heated enclosure is studied numerically in this paper. The rotating enclosure is filled with water-Ag, water-Cu, water-Al2O3, or water-TiO2nanofluids. The governing equations are in velocity, pressure, and temperature formulation and solved using the staggered grid arrangement together with MAC method. The governing parameters considered are the solid volume fraction,0.0 ≤ ϕ ≤ 0.05, and the rotational speeds,3.5≤ Ω ≤ 17.5 rpm, and the centrifugal force is smaller than the Coriolis force and both forces were kept below the buoyancy force. It is found that the angular locations of the local maximums heat transfer were sensitive to rotational speeds and nanoparticles concentration. The global quantity of heat transfer rate increases about 1.5%, 1.1%, 0.8%, and 0.6% by increasing 1%ϕof the nanoparticles Ag, Cu, Al2O3, and TiO2, respectively, for the considered rotational speeds.

scholarly journals An Experimental and Theoretical Study on the Effect of Silver Nanoparticles Concentration on the Structural, Morphological, Optical, and Electronic Properties of TiO2 Nanocrystals

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1488
Author(s):  
Faheem Ahmed ◽  
Mohammed Benali Kanoun ◽  
Chawki Awada ◽  
Christian Jonin ◽  
Pierre-Francois Brevet
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Anatase Phase ◽  
Density Functional Theory Calculations ◽  
Tio2 Nanocrystals ◽  
Uniform Size ◽  
Chemical Route ◽  
Structural And Electronic Properties ◽  
Nanoparticles Concentration ◽  
Gap States

In this work, pure and silver (Ag)-loaded TiO2 nanocrystals (NCs) with various concentrations of Ag were prepared by soft chemical route and the effect of Ag nanoparticles (NPs) on the functional properties of TiO2 was studied. X-ray diffraction (XRD) and Raman studies confirmed that the synthesized product had single-phase nature and high crystalline quality. The crystallite size was decreased from 18.3 nm to 13.9 nm with the increasing in concentration of Ag in TiO2 NCs. FESEM micrographs showed that the pure and AgNPs-loaded TiO2 have spherical morphology and uniform size distribution with the size ranging from 20 to 10 nm. Raman spectroscopy performed on pure and AgNPs-loaded TiO2 confirms the presence of anatase phase and AgNPs. Optical properties show the characteristics peaks of TiO2 and the shifting of the peaks position was observed by changing the concentration of Ag. The tuning of bandgap was found to be observed with the increase in Ag, which could be ascribed to the synergistic effect between silver and TiO2 NCs. Density functional theory calculations are carried out for different Ag series of doped TiO2 lattices to simulate the structural and electronic properties. The analysis of the electronic structures show that Ag loading induces new localized gap states around the Fermi level. Moreover, the introduction of dopant states in the gap region owing to Ag doping can be convenient to shift the absorption edge of pristine TiO2 through visible light.

Influence of metal oxide nanoparticles concentration on their zeta potential

2013 ◽  
Vol 407 ◽  
pp. 22-28 ◽  
Author(s):  
Nan Wang ◽  
Chien Hsu ◽  
Lihua Zhu ◽  
Shiojenn Tseng ◽  
Jyh-Ping Hsu
Keyword(s):  
Zeta Potential ◽  
Metal Oxide ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Nanoparticles Concentration
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