The use of cluster analysis for plant grouping by their tolerance to soil contamination with hydrocarbons at the germination stage

Clustering was employed for the analysis of obtained experimental data set (42 plants in total) on seed germination in leached chernozem contaminated with kerosene. Among investigated plants were 31 cultivated plants from 11 families (27 species and 20 varieties) and 11 wild plant species from 7 families, 23 annual and 19 perennial/biannual plant species, 11 monocotyledonous and 31 dicotyledonous plants. Two-dimensional (two-parameter) clustering approach, allowing the estimation of tolerance of germinating seeds using a pair of independent parameters (s{cyrillic}75%, V7%) was found to be most effective. These parameters characterized the ability of seeds to both withstand high concentrations of contaminants without the significant reduction of the germination, and maintain high germination rate within certain contaminant concentrations. The performed clustering revealed a number of plant features, which define the relation of a particular plant to a particular tolerance cluster; it has also demonstrated the possibility of generalizing the kerosene results for n-tridecane, which is one of the typical kerosene components. In contrast to the "manual" plant ranking based on the assessment of germination at discrete concentrations of the contaminant, the proposed clustering approach allowed a generalized characterization of the seed tolerance/sensitivity to hydrocarbon contaminants. © 2014 Elsevier B.V

Synthesis of positively and negatively charged silver nanoparticles and their deposition on the surface of titanium

Bacterial infections related to dental implants are currently a significant complication. A good way to overcome this challenge is functionalization of implant surface with Ag nanoparticles (NPs) as antibacterial agent. This article aims at review the synthesis routes, size and electrical properties of AgNPs. Polyvinyl pyrrolidone (PVP) and polyethyleneimine (PEI) were used as stabilizers. Dynamic Light Scattering, Nanoparticle Tracking Analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDX) have been used to characterize the prepared AgNPs. Two types of NPs were synthesized in aqueous solutions: PVP-stabilized NPs with a diameter of the metallic core of 70 ± 20 nm, and negative charge of -20 mV, PEI-stabilized NPs with the size of the metallic core of 50 ± 20 nm and positive charge of +55 mV. According to SEM results, all the NPs have a spherical shape. Functionalization of the titanium substrate surface with PVP and PEI-stabilized AgNPs was carried out by dropping method. XRD patterns revealed that the AgNPs are crystalline with the crystallite size of 14 nm

Influence copolymers of ethylene with vinyl acetate on the physicochemical properties of Bitumen

The results of experiments are presented concerning the modification of road bitumen by ethylene copolymer with vinyl acetate (EVA). This polymeric additive make a strong structure-forming influence on bitumen. At that the penetration value changes most rapidly at 25 °C. The higher the concentration of copolymer and the content of the ester groups in it, the less the penetration depth of the binder needle. The introduction of excess amount of copolymers with vinyl acetate groups develops a spatial structure conjugated with asphaltene associates, and providing the stability of all bitumen heterogeneous system. The reduction of elongation and brittleness temperature is revealed at the introduction of low molecular EVA, which allows to obtain the binders with improved low temperature properties. The most intensive change of properties is achieved by the introduction of EVA into bitumen with the molecular weight of 25,000, which is manifested in softening temperature increase with brittleness temperature reduction, and the extension of plasticity range by 8-20 °C. At the same time the introduction of granulated EVA into bitumen with high molecular weight leads to a significant increase of softening and brittleness temperature and ductility interval decrease. The study results showed that the bituminous compositions modified by EVA with a high content of vinyl acetate groups are somewhat inferior to the softening temperature and the extensibility of the compositions, modified by EVA with a low content of ester groups, because of the greater initial plasticity of the copolymer in the second case

Surface functionalization of titanium with silver nanoparticles

This study aims to investigate the most efficient ways for metallic samples functionalization with silver nanoparticles (AgNPs). Three different techniques of surface functionalization have been used for the coating of titanium metal, i.e. the sessile drop method (evaporation), dip-coating and electrophoretic deposition (EPD). AgNPs stabilized with polyvinylpyrrolidone had a spherical shape and the metallic core diameter, charge and polydispersity index were 70±20 nm, -15 mV and 0.192, respectively. SEM analysis revealed that AgNPs were homogeneously distributed over the entire surface and did not form the particle agglomerates only in case of EPD. Thus, EPD method and spherical AgNPs can be used for further investigation concerning the preparation of biocomposites with antibacterial and bioactive properties

Surface functionalization of titanium with silver nanoparticles

This study aims to investigate the most efficient ways for metallic samples functionalization with silver nanoparticles (AgNPs). Three different techniques of surface functionalization have been used for the coating of titanium metal, i.e. the sessile drop method (evaporation), dip-coating and electrophoretic deposition (EPD). AgNPs stabilized with polyvinylpyrrolidone had a spherical shape and the metallic core diameter, charge and polydispersity index were 70±20 nm, -15 mV and 0.192, respectively. SEM analysis revealed that AgNPs were homogeneously distributed over the entire surface and did not form the particle agglomerates only in case of EPD. Thus, EPD method and spherical AgNPs can be used for further investigation concerning the preparation of biocomposites with antibacterial and bioactive properties

The use of cluster analysis for plant grouping by their tolerance to soil contamination with hydrocarbons at the germination stage

Clustering was employed for the analysis of obtained experimental data set (42 plants in total) on seed germination in leached chernozem contaminated with kerosene. Among investigated plants were 31 cultivated plants from 11 families (27 species and 20 varieties) and 11 wild plant species from 7 families, 23 annual and 19 perennial/biannual plant species, 11 monocotyledonous and 31 dicotyledonous plants. Two-dimensional (two-parameter) clustering approach, allowing the estimation of tolerance of germinating seeds using a pair of independent parameters (s{cyrillic}75%, V7%) was found to be most effective. These parameters characterized the ability of seeds to both withstand high concentrations of contaminants without the significant reduction of the germination, and maintain high germination rate within certain contaminant concentrations. The performed clustering revealed a number of plant features, which define the relation of a particular plant to a particular tolerance cluster; it has also demonstrated the possibility of generalizing the kerosene results for n-tridecane, which is one of the typical kerosene components. In contrast to the "manual" plant ranking based on the assessment of germination at discrete concentrations of the contaminant, the proposed clustering approach allowed a generalized characterization of the seed tolerance/sensitivity to hydrocarbon contaminants. © 2014 Elsevier B.V

The use of cluster analysis for plant grouping by their tolerance to soil contamination with hydrocarbons at the germination stage

Clustering was employed for the analysis of obtained experimental data set (42 plants in total) on seed germination in leached chernozem contaminated with kerosene. Among investigated plants were 31 cultivated plants from 11 families (27 species and 20 varieties) and 11 wild plant species from 7 families, 23 annual and 19 perennial/biannual plant species, 11 monocotyledonous and 31 dicotyledonous plants. Two-dimensional (two-parameter) clustering approach, allowing the estimation of tolerance of germinating seeds using a pair of independent parameters (s{cyrillic}75%, V7%) was found to be most effective. These parameters characterized the ability of seeds to both withstand high concentrations of contaminants without the significant reduction of the germination, and maintain high germination rate within certain contaminant concentrations. The performed clustering revealed a number of plant features, which define the relation of a particular plant to a particular tolerance cluster; it has also demonstrated the possibility of generalizing the kerosene results for n-tridecane, which is one of the typical kerosene components. In contrast to the "manual" plant ranking based on the assessment of germination at discrete concentrations of the contaminant, the proposed clustering approach allowed a generalized characterization of the seed tolerance/sensitivity to hydrocarbon contaminants. © 2014 Elsevier B.V

The use of cluster analysis for plant grouping by their tolerance to soil contamination with hydrocarbons at the germination stage

Clustering was employed for the analysis of obtained experimental data set (42 plants in total) on seed germination in leached chernozem contaminated with kerosene. Among investigated plants were 31 cultivated plants from 11 families (27 species and 20 varieties) and 11 wild plant species from 7 families, 23 annual and 19 perennial/biannual plant species, 11 monocotyledonous and 31 dicotyledonous plants. Two-dimensional (two-parameter) clustering approach, allowing the estimation of tolerance of germinating seeds using a pair of independent parameters (s{cyrillic}75%, V7%) was found to be most effective. These parameters characterized the ability of seeds to both withstand high concentrations of contaminants without the significant reduction of the germination, and maintain high germination rate within certain contaminant concentrations. The performed clustering revealed a number of plant features, which define the relation of a particular plant to a particular tolerance cluster; it has also demonstrated the possibility of generalizing the kerosene results for n-tridecane, which is one of the typical kerosene components. In contrast to the "manual" plant ranking based on the assessment of germination at discrete concentrations of the contaminant, the proposed clustering approach allowed a generalized characterization of the seed tolerance/sensitivity to hydrocarbon contaminants. © 2014 Elsevier B.V