scholarly journals New Proposal for Size and Size-Distribution Evaluation of Nanoparticles Synthesized via Ultrasonic Spray Pyrolysis Using Search Algorithm Based on Image-Processing Technique

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 38 ◽  
Author(s):  
Elif Emil Kaya ◽  
Ozan Kaya ◽  
Gözde Alkan ◽  
Sebahattin Gürmen ◽  
Srecko Stopic ◽  
...  

Nanoparticle properties are correlated to their size, size distribution, and shape; it is essential to accurately measure these features in the field of nanoscience. In this study, silver nanoparticles (AgNPs) were synthesized with the ultrasonic-spray-pyrolysis (USP) method from a water solution of silver nitrate. The synthesized AgNPs were characterized by Dynamic Light Scattering (DLS) analysis and Scanning Electron Microscopy (SEM) to reveal their size and size distribution. A search algorithm based on an image-processing technique to obtain particle size and particle-size distribution from SEM micrographs is proposed. In order to obtain more quantitative information and data with respect to the morphology of particles synthesized under different process parameters, SEM micrographs with a nonhomogeneous background contrast were examined via image-processing techniques in MATLAB. Due to the inhomogeneous contrast of SEM micrographs, defining an overall threshold value was insufficient in the detection of whole nanoparticles. Thus, subimages were directly created according to the maximum and minimum particle size specified by the user to determine local threshold values. The obtained results were automatically combined to represent both particle dimension and location in the SEM micrographs. We confirmed that the results of our DLS analysis, theoretical calculation, and image-processing technique were correlated with our expected results.

2008 ◽  
Vol 47 (5) ◽  
pp. 1650-1659 ◽  
Author(s):  
Wei-Ning Wang ◽  
Agus Purwanto ◽  
I. Wuled Lenggoro ◽  
Kikuo Okuyama ◽  
Hankwon Chang ◽  
...  

2014 ◽  
Vol 32 (14) ◽  
pp. 1655-1663 ◽  
Author(s):  
Leila Kavoshi ◽  
Mohammad S. Hatamipour ◽  
Amir Rahimi ◽  
Mehdi Momeni

2015 ◽  
Vol 7 (11) ◽  
pp. 920-929 ◽  
Author(s):  
Peter Majerič ◽  
Darja Jenko ◽  
Bojan Budič ◽  
Sergej Tomić ◽  
Miodrag Čolić ◽  
...  

2013 ◽  
Vol 59 (4) ◽  
pp. 469-482 ◽  
Author(s):  
M. Guerrieri ◽  
G. Parla

Abstract The mechanical characteristics of the railway superstructure are related to the properties of the ballast, and especially to the particle size distribution of its grains. Under the constant stress-strain of carriages, the ballast can deteriorate over time, and consequently it should properly be monitored for safety reasons. The equipment which currently monitors the railway superstructure (like the Italian diagnostic train Archimede) do not make any “quantitative” evaluation of the ballast. The aim of this paper is therefore to propose a new methodology for extracting railway ballast particle size distribution by means of the image processing technique. The procedure has been tested on a regularly operating Italian railway line and the results have been compared with those obtained from laboratory experiments, thus assessing how effective is the methodology which could potentially be implemented also in diagnostic trains in the near future.


Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6879
Author(s):  
Tangirala Venkata Krishna Karthik ◽  
María de la Luz Olvera ◽  
Arturo Maldonado ◽  
Rajesh Roshan Biswal ◽  
Heberto Gómez-Pozos

Undoped and nickel-doped zinc oxide thin films were deposited on sodalime glass substrates by utilizing dip coating and ultrasonic spray pyrolysis deposition techniques. In both cases zinc acetate and nickel acetylacetonate were used as zinc precursor and nickel dopant source, respectively. XRD analysis confirms the ZnO wurtzite structure with (002) as the preferential orientation.SEM studies show the formation of two types of morphologies, primarily a porous spherical grains with a grain size distribution from 40 to 150 nm and another, rose-like structures with size distribution from 30 to 200 nm, based on different deposition techniques utilized. The elemental depth profiles across the films were investigated by the secondary-ion mass spectrometry (SIMS). Different gas sensing responses of all ZnO films were obtained for both propane and carbon monoxide gases, at different gas concentrations and operating temperatures. The highest sensing response (~6) for undoped ZnO films was obtained for films deposited by ultrasonic spray pyrolysis (USP). Nevertheless, the highest sensing response (~4 × 104) for doped ZnO films was obtained for films deposited by dip coating method. The behavior of sensing responses is explained in detail based on the morphological properties and the amount of Ni impurities incorporated into the crystal lattice.


2021 ◽  
Vol 59 (5) ◽  
pp. 289-294
Author(s):  
Hyeonhui Jo ◽  
Jeong Hyun Kim ◽  
Young-In Lee ◽  
Young-Keun Jeong ◽  
Sung-Tag Oh

The powder microstructure and sintering behavior of W prepared by ultrasonic spray pyrolysis and spark plasma sintering were investigated. Fine-grained W powders were synthesized by ultrasonic spray pyrolysis using an ammonium metatungstate hydrate solution and hydrogen reduction. The XRD analysis of the powder, pyrolyzed below 600 oC, showed tungsten oxide hydrate and WO3 peaks, while the powder pyrolyzed at 700 oC was composed of only the WO3 phase. As the precursor concentration increased, the particle size of the WO3 powder increased, which was interpreted to be due to an increase in the amount of solute in the droplet. The hydrogen-reduced powder showed a spherical shape with fine pores inside. XRD and XPS analysis revealed that the WO3 powder was completely reduced to metallic W by hydrogen reduction, and some oxide layers existed on the powder surface. The consolidated specimen prepared by spark plasma sintering of hydrogen-reduced W powder exhibited a relative density of 94.1% and a Vickers hardness value of 3.89 GPa. The relative density and hardness of the specimens prepared by ultrasonic spray pyrolysis showed relatively lower values than when commercial W powder, with an average particle size of 1.22 μm, was sintered under the same conditions. These results were explained by the formation of agglomerates in the W powder prepared by the ultrasonic spray pyrolysis method.


2015 ◽  
Vol 15 (10) ◽  
pp. 8062-8069 ◽  
Author(s):  
Tea-Yeon Hwang ◽  
Guk-Hwan An ◽  
Jeong-Ho Cho ◽  
Jongryoul Kim ◽  
Yong-Ho Choa

Strontium ferrite (hexaferrite), SrFe12O19, was successfully fabricated in sizes ranging from hundreds of nanometers to several micrometers by salt-assisted ultrasonic spray pyrolysis-calcination using different salt media. All samples were single phases of SrFe12O19 without the intermediate phase, α-Fe2O3, and their morphology was hexagonal. As calcination temperature increased, the size of as-calcined samples and saturation magnetization, Ms, increased while coercivity decreased. The particle size of the obtained nanoparticles varied depending on the salt media and calcination temperatures. The best magnetic properties obtained in this experiment were a coercivity of 6973 Oe with a saturation magnetization of 68.3 emu/g. To the best of our knowledge, these coercivity values are the highest ever obtained. We propose a detailed mechanism explaining the growth of these particles and conclude that the resulting single-domain particle size is about 70 nm, taking into account of factors affecting coercivity in ferrite nano- to micro-sized particles.


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