Impact Factor :
1.025
Q1(Year 2015)
ISSN : 1026-3098
e-ISSN : 2345-3605
Published Issues
The Effects of Laser Wavelength and Particle Size on Heating and Melting of Gold Nanoparticles Dispersed in Liquid
2016
Abstract :
In this research the heating process and melting of water surrounded homogenous gold nanospheres irradiated by nanosecond laser pulses at the wavelengths of 355, 532, 633, and 900 nm are studied. The estimation of absorbed energy by gold nanoparticles with radius range 1-40 nm and their maximum temperature is calculated using the absorption efficiency of the nanoparticles at corresponding laser wavelength. The dependency of the melting temperature of nanoparticles upon their size is also considered. It is seen that the progress in the melting process strongly depend on the laser wavelength and particle size. The laser wavelength of 532 nm has been found appropriate for effective photothermal heating of a large gold nanoparticle. Controlling the laser irradiation wavelength is crucial to achieve the best conditions for the desired applications such as localized heating and nanowelding.
Keywords :
Nanoparticle, Optical absorption, Laser wavelength, Melting, Photothermal heating
( 337 Visit ) ( 211 Download )

Relaxation time assessment in nanoparticle containing bimodal and mono-disperse shear thickening fluids
2016
Abstract :
When an applied shear to a fluid results in steep rise in its viscosity, it is referred to as Shear Thickening Fluid (STF). In this study, we investigate rheological response of bimodal against mono-dispersed nano sized silica particles in an STF system. Two sizes of nano-silica particles (50 nm fumed silica and 12 nm colloidal silica) were dispersed in polyethylene glycol in various compositions and were compared with monodispersed STF. Results showed lower critical shear rate for shear thickening in bimodal nanoparticle containing STF than mono-dispersed STF. Higher viscosities were also observed in di erent compositions of bimodal system. Examination of both STF systems under oscillatory stress condition revealed faster response by the bimodal system. Results also indicated that the storage and loss modulus for the bimodal STF system had low critical angular frequency compared to mono-dispersed STF. Study of relaxation time spectrum diagram for the two STFs showed that relaxation time for mono-dispersed STF was faster than that for bimodal STF system.
Keywords :
Shear thickening fluids; Mono-disperse; Bimodal; Nano; Relaxation time.
( 185 Visit ) ( 67 Download )

Nanofluid e ffects on peristaltic transport of a fourth grade fluid in the occurrence of inclined magnetic field
2016
Abstract :
This paper deals with the e ect of nanofluid and inclined magnetic field on peristaltic transport of a fourth grade uid model. Mathematical modelling of two dimensional fourth grade uid along with nanofluid model are given for channel. Assumptions of long wave length are employed to simplify the governing equations of momentum, temperature, and nano particle volume fraction. The exact solutions of temperature and nano particle volume fraction are calculated. Analytical solution is carried out to calculate the solution of stream function. Pressure rise and pressure gradient on the channel walls have been computed numerically. The graphical results are discussed to see the e ects of various emerging parameters on di erent wave forms.
Keywords :
Peristaltic flow; Nanofluid particles; Fourth grade fluid; Inclined magnetic fi eld; Asymmetric channel; Di erent wave forms.
( 193 Visit ) ( 27 Download )

The Effect of Catalyst Combination Ratioon Growth of Carbon Nanotubesover Fe-Co/nanometric SiCby Chemical Vapor Deposition
2016
Abstract :
Bimetallic Fe-Co catalysts supported on nanometric SiC powder were prepared by wet impregnation method and were used to catalyze CNTs from decomposition of acetylene at 850ͦ C by TCVD. The effect of Fe and Co combination ratio in catalytic basis on properties of end product CNTs was investigated using XRD, SEM, TEM and Raman spectroscopy. The results revealed that iron and cobalt are in oxide and cobalt ferrite form.The best growth of CNTs on catalyst sample with wt% Fe:Co:SiC=10:10:80 was achieved. It was observed that the ratio of Fe:Co loading in catalyst-substrate composition is an important factor which can affect the activity of catalytic basis and the characteristics of grown CNTs such as the density and average diameter. Bimetallic Fe-Co catalysts supported on nanometric SiC powder were prepared by wet impregnation method and were used to catalyze CNTs from decomposition of acetylene at 850ͦC by TCVD. The effect of Fe and Co combination ratio in catalytic basis on properties of end product CNTs was investigated using XRD, SEM, TEM and Raman spectroscopy. The results revealed that iron and cobalt are in oxide and cobalt ferrite forms.The best growth of CNTs on catalyst sample with wt% Fe:Co:SiC=10:10:80 was achieved. It was observed that the ratio of Fe:Co loading in catalyst-substrate composition is an important factor which can affect the activity of catalytic basis and the characteristics of grown CNTs such as the density and average diameter.
Keywords :
CNTs; CVD; Bimetallic catalyst; SiC; Combination ratio.
( 369 Visit ) ( 74 Download )

Second law analysis for radiative MHD slip flow of a nanofluid over a stretching sheet with non-uniform heat source e ffect
2016
Abstract :
The application of second law of thermodynamics to an electrically conducting incompressible nanofluid slip flow over a stretching sheet is investigated in the presence of thermal radiation and non-uniform heat source/sink, both analytically and numerically. The governing dimensionless equations for this investigation are solved analytically by hypergeometric function and numerically by using Runge-Kutta-Gill method with shooting technique. The e ects of magnetic parameter, nanosolid volume fraction parameter, slip parameter, and suction parameter on velocity pro le are discussed for Ag nanoparticles. Further, in addition to these parameters, the e ects of radiation parameter and non-uniform heat source/sink parameters on temperature pro le and entropy generation number are also discussed. Finally, the results of these pro les of Ag nanoparticles are compared with those of the Cu, Al2O3, and TiO2 nanoparticles. It is inferred that the e ect of slip and non-uniform heat source parameters decrease the entropy generation. The metallic nanoparticles create more entropy than the non-metallic nanoparticles.
Keywords :
Nanofluid; Entropy generation; MHD; Thermal radiation; Non-uniform heat source/sink; Stretching sheet; Partial slip
( 179 Visit ) ( 54 Download )

Effects of Elastic Contributions in Evolution of Nano-Structure Al3SC phase: A Phase-Field Study
2016
Abstract :
A micromechanical phase-field model is utilized to study the evolution of nano-structure Al3Sc phase in Al-Sc alloy.  We study the morphology of  Al3Sc precipitates in an Al-Sc alloy by phase-field simulations. Since the precipitates of Al3Sc phase are fully coherent to the Al matrix, the elastic energy will have an influence on the resulting morphology. We have studied numerically the effects of elastic strain energies on shape evolution of Al3Sc phase. The simulated nano-structures evolve from a spherical to cubic shapes. The equilibrium shape of the coherent phase was found to be determined by minimizing the sum of the elastic and interfacial energies through the phase-field equations. A coherency loss is observed when the precipitates reach a specific size. The simulation results show a good agreement with previous experimental studies. 
Keywords :
Phase-field model; Al3Sc precipitates ; Misfit stress; Coherency;
( 368 Visit ) ( 25 Download )

Retracted: Microwave irradiation synthesis of TiO2/graphene nano-hybrid using titanium butoxide with enhanced photocatalytic activity
2016
Abstract :
Nanoscale hybridization of graphene is a popular way to create highly conductive composite materials and surfaces with enhanced light absorption. In this study, TiO2/graphene nano-hybrid is prepared by direct growth of TiO2 nanoparticles on graphene oxide sheets. Graphene oxide was produced by an improved Hummer's method. In this study, titanium butoxide, an inorganic titanium source, is added into a water/ethanol mixture with graphene oxide to produce the TiO2/graphene-oxide nano-hybrid. Microwave irradiation was used to reduce graphene oxide in graphene and, therefore, the produced TiO2/graphene nano-hybrid. The synthesized hybrid shows almost two times higher photocatalytic performance compared to P25, i.e. commercial titania, in degradation of methylene blue. SEM, XRD, FTIR, and UV-vis spectroscopy were used to characterize the synthesized material. FTIR detection in Ti-O-C bond con rms the formation of nanohybrid graphene with titania nanoparticles.
Keywords :
Graphene; Titanium dioxide; Microwave irradiation method; TiO2/graphene nano-hybrid; Photocatalytic activity.
( 122 Visit ) ( 25 Download )

Higher Flexibililty of Recon gurable Digital Micro/Nano Fluidic Biochips using an FPGA-Inspired Architecture
2016
Abstract :
Significant improvements in bio-technology and bio-engineering have composed wonderful opportunities to understand and manipulate the bio-structures. Biochips are known as electronic platform for automating the bio-chemical operations in order to decrease time, cost and increase flexibility of operations. Digital micro/nano fluidic biochips are two dimensional arrays of controllable electrodes that can convey droplets around the chip to perform the assays. Each electrode is controlled via an external pins and decreasing the number of pins is very critical in feasibility of biochip construction. In this paper, a new FPGA-inspired architecture is proposed for micro-fluidic biochips in order to create the ability for configurability to improve the flexibility of biochip and reduce the number of controlling pins. Our simulations show that in the new architecture, number of required pins is improved 6.35x rather to than direct addressing method Griffith (2005) and total experiment time is reduced by 34% with higher level of configurability, flexibility.
Keywords :
Digital micro-fluidic biochip , Constrained-pin , Reconfigurable
( 303 Visit ) ( 50 Download )

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Published Issues
2017
Transactions on Civil Engineering
Transactions on Mechanical Engineering
Transactions on Industrial Engineering
2016
2015
Transactions on Civil Engineering
Transactions on Mechanical Engineering
Transactions on Chemistry and Chemical Engineering
Transactions on Computer Science & Engineering and Electrical Engineering
Transactions on Industrial Engineering
Transactions on Nanotechnology
2014
Transactions on Civil Engineering
Transactions on Mechanical Engineering
Transactions on Chemistry and Chemical Engineering
Transactions on Computer Science & Engineering and Electrical Engineering
Transactions on Industrial Engineering
Transactions on Nanotechnology
2013
Transactions on Civil Engineering
Transactions on Mechanical Engineering
Transactions on Chemistry and Chemical Engineering
Transactions on Computer Science & Engineering and Electrical Engineering
Transactions on Industrial Engineering
Transactions on Nanotechnology

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