TY  - JOUR
AU  - Kopanja, Lazar
AU  - Lončar, Boris B.
AU  - Žunić, Dragiša
AU  - Tadić, Marin
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5902
AB  - The goal of the nanoparticle synthesis is, first of all, the production of nanoparticles that will be more similar in size and shape. This is very important for the possibility of studying and applying nanomaterials because of their characteristics that are very sensitive to size and shape such as, for example, magnetic properties. In this paper, we propose the shape analysis of the nanoparticles using three shape descriptors – elongation, convexity and circularity. Experimental results were obtained by using TEM images of hematite nanoparticles that were, first of all, subjected to segmentation in order to obtain isolated nanoparticles, and then the values of elongation, convexity and circularity were measured. Convexity C x ( S ) is regarded as the ratio between shape’s area and area of the its convex hull. The convexity measure defines the degree to which a shape differs from a convex shape while the circularity measure defines the degree to which a shape differs from an ideal circle. The range of convexity and circularity values is (0, 1], while the range of elongation values is [1, ∞). The circle has lowest elongation (ε = 1), while it has biggest convexity and circularity values ( C x = 1; C = 1). The measures ε( S ), C x ( S ), C ( S ) proposed and used in the experiment have the few desirable properties and give intuitively expected results. None of the measures is good enough to describe all the shapes, and therefore it is suggested to use a variety of measures so that the shapes can be described better and then classify and control during the synthesis process.
T2  - Journal of Electrical Engineering
T1  - Nanoparticle shapes: Quantification by elongation, convexity and circularity measures
EP  - 50
IS  - 7
SP  - 44
VL  - 70
DO  - 10.2478/jee-2019-0040
ER  - 

@article{
author = "Kopanja, Lazar and Lončar, Boris B. and Žunić, Dragiša and Tadić, Marin",
year = "2019",
abstract = "The goal of the nanoparticle synthesis is, first of all, the production of nanoparticles that will be more similar in size and shape. This is very important for the possibility of studying and applying nanomaterials because of their characteristics that are very sensitive to size and shape such as, for example, magnetic properties. In this paper, we propose the shape analysis of the nanoparticles using three shape descriptors – elongation, convexity and circularity. Experimental results were obtained by using TEM images of hematite nanoparticles that were, first of all, subjected to segmentation in order to obtain isolated nanoparticles, and then the values of elongation, convexity and circularity were measured. Convexity C x ( S ) is regarded as the ratio between shape’s area and area of the its convex hull. The convexity measure defines the degree to which a shape differs from a convex shape while the circularity measure defines the degree to which a shape differs from an ideal circle. The range of convexity and circularity values is (0, 1], while the range of elongation values is [1, ∞). The circle has lowest elongation (ε = 1), while it has biggest convexity and circularity values ( C x = 1; C = 1). The measures ε( S ), C x ( S ), C ( S ) proposed and used in the experiment have the few desirable properties and give intuitively expected results. None of the measures is good enough to describe all the shapes, and therefore it is suggested to use a variety of measures so that the shapes can be described better and then classify and control during the synthesis process.",
journal = "Journal of Electrical Engineering",
title = "Nanoparticle shapes: Quantification by elongation, convexity and circularity measures",
pages = "50-44",
number = "7",
volume = "70",
doi = "10.2478/jee-2019-0040"
}

Kopanja, L., Lončar, B. B., Žunić, D.,& Tadić, M.. (2019). Nanoparticle shapes: Quantification by elongation, convexity and circularity measures. in Journal of Electrical Engineering, 70(7), 44-50.
https://doi.org/10.2478/jee-2019-0040

Kopanja L, Lončar BB, Žunić D, Tadić M. Nanoparticle shapes: Quantification by elongation, convexity and circularity measures. in Journal of Electrical Engineering. 2019;70(7):44-50.
doi:10.2478/jee-2019-0040 .

Kopanja, Lazar, Lončar, Boris B., Žunić, Dragiša, Tadić, Marin, "Nanoparticle shapes: Quantification by elongation, convexity and circularity measures" in Journal of Electrical Engineering, 70, no. 7 (2019):44-50,
https://doi.org/10.2478/jee-2019-0040 . .

TY  - JOUR
AU  - Kopanja, Lazar
AU  - Kralj, Slavko
AU  - Žunić, Dragiša
AU  - Lončar, Boris B.
AU  - Tadić, Marin
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5810
AB  - For the first time, particle shape analysis of silica coated iron oxide (maghemite/magnetite) nanoparticle clusters (core-shell nanostructures) is discussed using computational methods. We analyzed three samples of core-shell nanostructures synthesized with different thickness of the silica shell. A new computational method is presented and successfully applied to the segmentation of the core-shell nanoparticles, as one of the main problems in image analysis of the TEM micrographs. We have introduced the circularity coefficient, marked with k(circ) and defined as the ratio of circularity measure C-2(S) of nanoparticles core and circularity measure core-shell nanoparticles in order to answer the question how the shell affects the overall shape of the final core-shell structure, with respect to circularity. More precisely, the circularity coefficient determines whether the circularity of the core-shell nanoparticle is higher, lower or equal to the circularity of the core. We have also determined the shells share in the overall area of the core-shell nanoparticle. The core-shell nanoparticle clusters here investigated exhibit superparamagnetic properties at room temperature, thus emphasizing their potential for use in practical applications such as in biomedical and particle separation. We show that the saturation magnetization strength can be easily adjusted by controlling the thickness of the silica shell. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
PB  - Elsevier
T2  - Ceramics International
T1  - Core-shell superparamagnetic iron oxide nanoparticle (SPION) clusters: TEM micrograph analysis, particle design and shape analysis
EP  - 10984
IS  - 9
SP  - 10976
VL  - 42
DO  - 10.1016/j.ceramint.2016.03.235
ER  - 

@article{
author = "Kopanja, Lazar and Kralj, Slavko and Žunić, Dragiša and Lončar, Boris B. and Tadić, Marin",
year = "2016",
abstract = "For the first time, particle shape analysis of silica coated iron oxide (maghemite/magnetite) nanoparticle clusters (core-shell nanostructures) is discussed using computational methods. We analyzed three samples of core-shell nanostructures synthesized with different thickness of the silica shell. A new computational method is presented and successfully applied to the segmentation of the core-shell nanoparticles, as one of the main problems in image analysis of the TEM micrographs. We have introduced the circularity coefficient, marked with k(circ) and defined as the ratio of circularity measure C-2(S) of nanoparticles core and circularity measure core-shell nanoparticles in order to answer the question how the shell affects the overall shape of the final core-shell structure, with respect to circularity. More precisely, the circularity coefficient determines whether the circularity of the core-shell nanoparticle is higher, lower or equal to the circularity of the core. We have also determined the shells share in the overall area of the core-shell nanoparticle. The core-shell nanoparticle clusters here investigated exhibit superparamagnetic properties at room temperature, thus emphasizing their potential for use in practical applications such as in biomedical and particle separation. We show that the saturation magnetization strength can be easily adjusted by controlling the thickness of the silica shell. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.",
publisher = "Elsevier",
journal = "Ceramics International",
title = "Core-shell superparamagnetic iron oxide nanoparticle (SPION) clusters: TEM micrograph analysis, particle design and shape analysis",
pages = "10984-10976",
number = "9",
volume = "42",
doi = "10.1016/j.ceramint.2016.03.235"
}

Kopanja, L., Kralj, S., Žunić, D., Lončar, B. B.,& Tadić, M.. (2016). Core-shell superparamagnetic iron oxide nanoparticle (SPION) clusters: TEM micrograph analysis, particle design and shape analysis. in Ceramics International
Elsevier., 42(9), 10976-10984.
https://doi.org/10.1016/j.ceramint.2016.03.235

Kopanja L, Kralj S, Žunić D, Lončar BB, Tadić M. Core-shell superparamagnetic iron oxide nanoparticle (SPION) clusters: TEM micrograph analysis, particle design and shape analysis. in Ceramics International. 2016;42(9):10976-10984.
doi:10.1016/j.ceramint.2016.03.235 .

Kopanja, Lazar, Kralj, Slavko, Žunić, Dragiša, Lončar, Boris B., Tadić, Marin, "Core-shell superparamagnetic iron oxide nanoparticle (SPION) clusters: TEM micrograph analysis, particle design and shape analysis" in Ceramics International, 42, no. 9 (2016):10976-10984,
https://doi.org/10.1016/j.ceramint.2016.03.235 . .