fractal clusters
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Doklady BGUIR ◽  
2022 ◽  
Vol 19 (8) ◽  
pp. 35-39
Author(s):  
A. V. Belko ◽  
N. N. Babarika ◽  
I. S. Zeylikovich ◽  
A. V. Nikitin

The paper proposes a modification of the diffusion-limited aggregation model to study the properties of a cluster system. A computational experiment to determine the mutual influence of the sticking probability and the volume concentration of particles on the formation of fractal clusters in a cluster system was carried out in accordance  with  the  second-order  orthogonal  central  compositional  plan  (OCCP).  As  a  result of a computational experiment in accordance with the OCCP, an equation was obtained for the dependence of the mass fractal dimension of clusters on the volume of particle concentration and the probability of adhesion of diffusing particles and cluster particles in the adhesion zone. This dependence was obtained in a range of volume concentration of particles from 2 to 5 % and the probability of adhesion of diffusing particles and particles of clusters in the adhesion zone from 0.2 to 1.


Author(s):  
L. Krichkovskaya ◽  
Essam Elnaggar ◽  
V. Dubonosov

In the present article importance of adsorptive purification of vegetable oils is shown as the most responsible technological stage. Insufficiency of scientific developments in the scope of domestic sorbents in Ukraine is pointed out. The phytosorbent with nanotubes from sunflower peel improving some quality parameters of non-refined sunflower and soybean oils to standard values for refined oils has been offered. Some literature data on the main characteristics of a number of sorption materials (carbonaceous, natural, fibrous, and sorbents obtained from agricultural waste - Corylus avellana Lambert nuts) as a result of heat treatment are analyzed. The main sorption properties are considered; dignity; limitations. The effect of temperature on the productivity of pyrolysis of plant raw materials and the properties of the resulting carbonizates in the temperature range 150-600 °C was investigated. The duration of exposure of materials at the final temperature of the process in all experiments was the same and amounted to 1 h. Analysis of the experimental data allows us to conclude that temperature is the main factor affecting the process of carbonization of the initial plant material. Regardless of the pyrolysis atmosphere, the yield of the product from plant raw materials decreases with a significant increase in temperature. At present, the main raw material for the industrial production of adsorbents is in many studies organic substances - wood, fossil coal, peat, remnants of the processing of agricultural raw materials due to their low cost and large amount. Solving the problem of creating sorbents based on plant raw materials with the inclusion of hydrated fullerenes in their composition solved the problem of creating sorbents and environmental problems, since the waste did not always find a useful application. Concentration of water solution of hydrated C60, fast C60FWS, є molecular-coloidal systems and spherical fractal clusters, structural unit of which is micro-hydrophilic, high-hydrophilic supramolecular complex, molecules can be folded to fit into ) 24-hydration of fullerene C60 (C60HyFn). The hydrated cultivation is set in its own well-ordered, structurally heterogeneous watery middle, in which the directness and kinetics of chemical processes are seen in such, that it is necessary to be washed in order to clean.


2021 ◽  
Vol 15 (2) ◽  
Author(s):  
L. Krichkovskaya ◽  
P. Lysak ◽  
M. Bobro ◽  
V. Dubonosov ◽  
Yu. Gritzaenko

cultivation of plant food objects, in particular, Brassica juncea czern (mustard seeds of the talisman variety). In addition, the issue of recycling of the most concentrated fermentation liquid, which is a waste after separation at the stage of growing a pure yeast culture, is solved. The growth-stimulating activity of "Humir-1", created on the basis of hydrated fullerenes (HyFn), (C60(H2O)n) and humates, as well "Humir-2" in which the mixture of hydrated fullerenes and humates was added to the supernatant of the fermentation fluid, in which a pure culture of yeast (strain Saccharomyces cerevisiae) was grown. Concentrated aqueous solutions of hydrated C60HyFn which are molecular colloidal systems of spherical fractal clusters, the structural unit of which is a strong, highly hydrophilic supramolecular complex consisting of a C60 fullerene molecule enclosed in the first hydrated shell containing 24 water molecules were used as a basis in “Humir” preparations. Humates, which is also part of the developed composition, in addition to stimulating growth, has a positive effect on the plant's immunity, helping to adapt to the environment and increase protection against its negative manifestations. The supernatant of the fermentation mixture, in which pure culture yeast was grown, is rich of vitamins, micro and macro elements, yeast residues, and also contains the dry matter of yeast rich in biologically active substances. The influence of the developed compositions on the efficiency of brassica juncea czern cultivation was studied in laboratory and field conditions on the basis of an experimental farm of the Dokuchaev Institute of Agriculture in Kharkiv region. As a result of research, it has been proved that the developed drug "Humir-2", in addition to increasing the yield of brassica juncea czern, increases photosynthetic activity, increases germination and germination energy. As a result, plants have a powerful developed root system and a significantly increased assimilation area of the Leaf.


Carbon ◽  
2020 ◽  
Vol 169 ◽  
pp. 349-356
Author(s):  
Piotr Kowalczyk ◽  
Elda-Zoraida Piña-Salazar ◽  
Jacob Judas Kain Kirkensgaard ◽  
Artur P. Terzyk ◽  
Ryusuke Futamura ◽  
...  

Fractals ◽  
2020 ◽  
Vol 28 (07) ◽  
pp. 2050137
Author(s):  
ASHWINI V. MAHAJAN ◽  
ABHAY V. LIMAYE ◽  
ARUN G. BANPURKAR ◽  
PRASHANT M. GADE

The spread of infectious disease, virus epidemic, fashion, religion and rumors is strongly affected by the nearest neighbor hence underlying morphologies of the colonies are crucial. Likewise, the morphology of naturally grown patterns ranges from fractal to compact with lacunarity. We analyze the contact process on the fractal clusters simulated by generalized Diffusion-limited Aggregation (g-DLA) model. In g-DLA model, randomly walking particle is added to the cluster with sticking probability [Formula: see text] depending on the local density of occupied sites in the neighborhood of radius [Formula: see text] from the center of active site. It takes values [Formula: see text], [Formula: see text] and [Formula: see text] ([Formula: see text]) for highly dense, moderately dense and sparsely occupied regions, respectively. The corresponding morphology varies from fractal to compact as [Formula: see text] varies from [Formula: see text] to [Formula: see text]. Interestingly, the contact process on the g-DLA clusters shows clear transition from active phase to absorbing phase and the exponent values fall between 1-d and 2-d in directed percolation (DP) universality class. The local persistence exponents at transition are studied and are found to be much smaller than that for 1-d and 2-d DP cases. We conjecture that infection in the fractal cluster does not easily reach far-flung or remote areas at the periphery of the cluster.


2020 ◽  
Vol 23 (2) ◽  
Author(s):  
Luigi Gentile ◽  
Helena Mateos ◽  
Antonia Mallardi ◽  
Marcella Dell’Aglio ◽  
Alessandro De Giacomo ◽  
...  

AbstractGold nanoparticles (AuNPs), synthesized by ns-pulsed laser ablation in liquid (ns-PLAL) in the absence of any capping agents, are potential model systems to study the interactions with biological structures unencumbered by interference from the presence of stabilizers and capping agents. However, several aspects of the physics behind these AuNPs solutions deserve a detailed investigation. The structure in solution of ns-PLAL-synthesized AuNPs was investigated in solution by means of small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS). Furthermore, the (dried) NPs have been examined using TEM. The analysis of the SAXS curve shows the presence of a large number of small aggregates with a fractal structure stabilized by strong long-range repulsive interactions. Fitting of the SAXS curve to a suitable “fractal model” allows the estimation of the features of the fractal including the fractal dimension d = 1.9. The latter allows to estimate the fraction of light scattered by fractals of different sizes and thus permits a fair comparison between the DLS and TEM data. Here, a stable abundant population of fractal clusters is reported reflecting a mechanism where primary AuNPs (size 7.6 nm) are forced to aggregate forming clusters during the collapse of the cavitation bubble. When these clusters are released in the aqueous phase, their large negative charge builds up repulsive interactions that prevent cluster-cluster aggregation imparting colloidal stability.


2019 ◽  
Vol 10 ◽  
pp. 305-314 ◽  
Author(s):  
Nikolai A Usov ◽  
Mikhail S Nesmeyanov ◽  
Elizaveta M Gubanova ◽  
Natalia B Epshtein

The low frequency hysteresis loops and specific absorption rate (SAR) of assemblies of magnetite nanoparticles with cubic anisotropy are calculated in the diameter range of D = 20–60 nm taking into account both thermal fluctuations of the particle magnetic moments and strong magneto–dipole interaction in assemblies of fractal-like clusters of nanoparticles. Similar calculations are also performed for assemblies of slightly elongated magnetite nanoparticles having combined magnetic anisotropy. A substantial dependence of the SAR on the nanoparticle diameter is obtained for all cases investigated. Due to the influence of the magneto–dipole interaction, the SAR of fractal clusters of nanoparticles decreases considerably in comparison with that for weakly interacting nanoparticles. However, the ability of magnetic nanoparticle assemblies to generate heat can be improved if the nanoparticles are covered by nonmagnetic shells of appreciable thickness.


2019 ◽  
Vol 224 ◽  
pp. 03007
Author(s):  
Ivan V. Stepanyan ◽  
Abbakar M. Khussein

Algorithms for scaling and visualization of nucleotide sequences developed in this study allow identifying relationships between the biochemical parameters of DNA and RNA molecules with scale invariance, fractal clusters, nonlinear ordering and symmetry and noise immunity of visual representations in orthogonal coordinate systems. The algorithms are capable of displaying structures of the nucleotide sequences of living organisms by visualizing them in spaces of various dimensions and scales. Approximately one hundred genes (protozoa, plants, fungi, animals, viruses) were analysed and examples of visualization of the nucleotide composition of genomes of various species have been presented. The developed method contributes to an in-depth understanding of the principles of genetic coding and simplifying the perception of genetic information due to the algorithmic interpretation of the basic properties of polynucleotide fragments with visualization of the final geometric structure of the genetic code.


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