Interparticle interaction and structure of deposits for competitive model in (2+1)- dimensions

A competitive (2+1)-dimensional model of deposit formation, based on the combination of random sequential absorption deposition (RSAD), ballistic deposition (BD) and random deposition (RD) models, is proposed. This model was named as RSAD$_{1-s}$(RD$_f$BD$_{1-f}$)$_s$. It allows to consider different cases of interparticle interactions from complete repulsion between near-neighbors in the RSAD model ($s=0$) to sticking interactions in the BD model ($s=1, f=0$) or absence of interactions in the RD model ($s=1$, $f=0$). The ideal checkerboard ordered structure was observed for the pure RSAD model ($s=0$) in the limit of $h \to \infty$. Defects in the ordered structure were observed at small $h$. The density of deposit $p$ versus system size $L$ dependencies were investigated and the scaling parameters and values of $p_\infty=p(L=\infty)$ were determined. Dependencies of $p$ versus parameters of the competitive model $s$ and $f$ were studied. We observed the anomalous behaviour of the eposit density $p_\infty$ with change of the inter-particle repulsion, which goes through minimum on change of the parameter $s$. For pure RSAD model, the concentration of defects decreases with $h$ increase in accordance with the critical law $\rho\propto h^{-\chi_{RSAD}}$, where $\chi_{RSAD} \approx 0.119 \pm 0.04$.Comment: 10 pages,4 figures, Latex, uses iopart.cl

Effect of Molecular Weight on the Properties of Polyethyleneglycols Doped with Multiwalled Carbon Nanotubes

The aim of this study is to analyze the changes in the structure, thermal properties and electrophysical behavior of polyethylene glycol doped with multiwalled carbon nanotubes. The differential scanning calorimetry and electrical conductivity methods were used to study influence of doping multiwalled carbon NTs on the properties of polyethylene glycol of different molecular weights, Mw (PEG-400, PEG-1000, PEG- 10000). Dependencies of the polymers degree of crystallinity and temperature behavior of conductivity on the concentration of NTs were researched. The obtained data indicates a strong influence of the molecular weight of PEG on the spatial distribution of NTs and electrical conductivity of researched systems

Effect of surfactant addition on the MWNT suspenzions stability in organic solvents

It is shown that multi-walled carbon nanotubes (MWNT) form stable suspensions in isopropanol solvent as a result of influence of ultra-sound in the weight range of concentrations from 0.0001% to 1% by weight. Nonionic surfactant Triton X-165 affects the microstructure of the MWNT aggregates in isopropanol, a small amount of surfac- tant increase the intervals between the aggregates and accelerate the sedimentation process. MWNT suspension in and toluene shows unstable behavior, their total precipi- tation time is less than 104 sec. Addition of 0.4% Triton X-165 to suspension of MWNT in p-xylene leads to its stabilization. Also, addition of 0.6% Triton X-165 leads to partial stabilization of suspensions of MWNT in toluene. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2061

Exciplexes of fullerene C60 with aromatic solvents

The solvent induced spectral shift method is applied to study stacking interactions between aromatic solvents molecules, such as benzene and toluene from one side, and solute fullerene C60. Ratios of high-energy transitions shifts to calculated shifts under dispersion interactions are considered. It is concluded that in contrast to aromatic molecules containing two or three rings which do not form complexes with aromatic solvents, fullerene forms exciplexes with high-energy excited states involved in more strong interactions rather than low-energy one. The higher is excited state, the stronger is interaction. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2062

Percolation in deposits for competitive models in (1+1)-dimensions

The percolation behaviour during the deposit formation, when the spanning cluster was formed in the substrate plane, was studied. Two competitive or mixed models of surface layer formation were considered in (1+1)-dimensional geometry. These models are based on the combination of ballistic deposition (BD) and random deposition (RD) models or BD and Family deposition (FD) models. Numerically we find, that for pure RD, FD or BD models the mean height of the percolation deposit $\bar h$ grows with the substrate length $L$ according to the generalized logarithmic law $\bar h\propto (\ln (L))^\gamma$, where $\gamma=1.0$ (RD), $\gamma=0.88\pm 0.020$ (FD) and $\gamma=1.52\pm 0.020$ (BD). For BD model, the scaling law between deposit density $p$ and its mean height $\bar h$ at the point of percolation of type $p-p_\infty \propto \bar h^{-1/\nu_h}$ are observed, where $\nu_h =1.74\pm0.02$ is a scaling coefficient. For competitive models the crossover, %in $h$ versus $L$ corresponding to the RD or FD -like behaviour at small $L$ and the BD-like behaviour at large $L$ are observed.Comment: 8 pages,4 figures, Latex, uses iopart.cl

Exploring metabolic responses of potato tissue induced by electric pulses

In this study, we investigated the metabolic responses of potato tissue induced by pulsed electric field (PEF). Potato tissue was subjected to field strengths ranging from 30 to 500 V/cm, with a single rectangular pulse of 10 μs, 100 μs, or 1 ms. Metabolic responses were monitored using isothermal calorimetry, changes on electrical resistance during the delivery of the pulse, as well as impedance measurements. Our results show that the metabolic response involves oxygen consuming pathways as well as other unidentified events that are shown to be insensitive to metabolic inhibitors such as KCN and sodium azide. The metabolic response is strongly dependent on pulsing conditions and is independent of the total permeabilization achieved by the pulse. Evidence shows that calorimetry is a simple and powerful method for exploring conditions for metabolic stimulation, providing information on metabolic responses that can not be obtained from electrical measurements. This study set the basis for further investigations on defense-related consequences of PEF-induced stress.Sparbanksstiftelsen Färs & Frosta (Sweden).Fundação para a Ciência e a Tecnologia (FCT).Lund University (Sweden).Department of Cell and Organism Biology; Department of Plant Biochemistry

Interaction between nucleoside and nucleotide with carbon nanotubes

Carbon nanotubes (CNTs) possess a number of unique properties; they are successfully applied as fillers for improving the mechanical, electric, thermophysical, and optical properties of composite materials. At present, CNTs are intensively used in the development of biosensor devices and materials designed for pharmaceutics and diagnostics. Functionalization of CNT surfaces with molecules playing important roles in biological processes, including proteinforming peptides, nucleic acids, etc., makes it possible to produce new systems capable of identifying iological objects. CNT surface can serve as a platform for the targeted transport of different molecules, including drugs (antibiotics or protein). Efficiency of this transport is governed by the unique adsorption ability of CNTs and the specific interaction of molecules with their surface. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2062

Optical transmittance and electric conductivity in nematic dispersions containing carbon nanotubes and organomodified montmorillonite

Optical transmission and electric conductivity were measured for dispersions of multiwalled carbon nanotubes (MWCNT), organomodified montmorillonite (MMT) and for hybrid dispersions of MWCNT+MMT in 5CB nematic liquid crystal (LC). The optical transmittance jump at the nematic-isotropic transition was observed in MMT+LC (~0.1 % wt. of MMT). This behaviour was qualitatively similar to that of reported earlier for MWCNT+LC (~0.1 % wt. of MWCNT) nanocomposites, suggesting exfoliation of the organoclay plate-like particles and their incorporation into the orientationally ordered nematic structure. In hybrid dispersions the effect of MWCNT and MMT on optical transmission was additive. Noticeable differences in the electric conductivity behaviour for composites filled with MWCNTs and organomodified MMT were observed. It was shown that MWCNTs facilitated and MMT hindered the electric field-induced transition from planar to homeotropic state in the LC cell.Досліджено оптичне пропускання та електропровідність дисперсій багатостінкових вуглецевих нанотрубок (НТ), органомодифікованого монтморилоніту (ММТ) та гібридних дисперсій НТ+ММТ у нематичному рідкому кристалі (РК) 5СВ. Спостерігали стрибок оптичного пропускання при нематико-ізотропному переході у ММТ+РК (~0.1 % ММТ). Така поведінка якісно подібна раніше описанії для нанокомпозитів НТ+ РК (~0.1 % НТ), що дозволяє припустити розшаровування пласких частинок органоглини та їх вбудовування в орієнтаційно впорядковану нематичну структуру. У гібридних дисперсіях вплив НТ та ММТ на оптичне пропускання був адитивним. Відзначено істотні відмінності у поведінці електропровідності між композитами, заповненими НТ та органомодифікованим ММТ. Показано, що НТ полегшують, а частинки ММТ утруднюють індукований електричним полем перехід від планарного до гомеотропного стану у рідкокристалічній комірці.Исследовано оптическое пропускание и электропроводность дисперсий многостеночных углеродных нанотрубок (НТ), органомодифицированного монтмориллонита (ММТ) и гибридных дисперсий НТ+ММТ в нематическом жидком кристалле (ЖК) 5СВ. Наблюдался скачок оптического пропускания при нематико-изотропном переходе в ММТ+ЖК (~0.1 % ММТ). Такое поведение качественно подобно ранее описанному для нанокомпозитов НТ+ЖК (~0.1 % НТ), что позволяет предположить расслаивание плоских частиц органоглины и их встраивание в ориентационно упорядоченную нематическую структуру. В гибридных дисперсиях влияние НТ и ММТ на оптическое пропускание аддитивно. Отмечены существенные различия в поведении электропроводности между композитами, заполненными НТ и органомодифицированным ММТ. Показано, что НТ облегчают, а частицы ММТ затрудняют индуцированный электрическим полем переход из планарного в гомеотропное состояние в жидкокристаллической ячейке

Optical transmittance and electric conductivity in nematic dispersions containing carbon nanotubes and organomodified montmorillonite

Optical transmission and electric conductivity were measured for dispersions of multiwalled carbon nanotubes (MWCNT), organomodified montmorillonite (MMT) and for hybrid dispersions of MWCNT+MMT in 5CB nematic liquid crystal (LC). The optical transmittance jump at the nematic-isotropic transition was observed in MMT+LC (~0.1 % wt. of MMT). This behaviour was qualitatively similar to that of reported earlier for MWCNT+LC (~0.1 % wt. of MWCNT) nanocomposites, suggesting exfoliation of the organoclay plate-like particles and their incorporation into the orientationally ordered nematic structure. In hybrid dispersions the effect of MWCNT and MMT on optical transmission was additive. Noticeable differences in the electric conductivity behaviour for composites filled with MWCNTs and organomodified MMT were observed. It was shown that MWCNTs facilitated and MMT hindered the electric field-induced transition from planar to homeotropic state in the LC cell.Досліджено оптичне пропускання та електропровідність дисперсій багатостінкових вуглецевих нанотрубок (НТ), органомодифікованого монтморилоніту (ММТ) та гібридних дисперсій НТ+ММТ у нематичному рідкому кристалі (РК) 5СВ. Спостерігали стрибок оптичного пропускання при нематико-ізотропному переході у ММТ+РК (~0.1 % ММТ). Така поведінка якісно подібна раніше описанії для нанокомпозитів НТ+ РК (~0.1 % НТ), що дозволяє припустити розшаровування пласких частинок органоглини та їх вбудовування в орієнтаційно впорядковану нематичну структуру. У гібридних дисперсіях вплив НТ та ММТ на оптичне пропускання був адитивним. Відзначено істотні відмінності у поведінці електропровідності між композитами, заповненими НТ та органомодифікованим ММТ. Показано, що НТ полегшують, а частинки ММТ утруднюють індукований електричним полем перехід від планарного до гомеотропного стану у рідкокристалічній комірці.Исследовано оптическое пропускание и электропроводность дисперсий многостеночных углеродных нанотрубок (НТ), органомодифицированного монтмориллонита (ММТ) и гибридных дисперсий НТ+ММТ в нематическом жидком кристалле (ЖК) 5СВ. Наблюдался скачок оптического пропускания при нематико-изотропном переходе в ММТ+ЖК (~0.1 % ММТ). Такое поведение качественно подобно ранее описанному для нанокомпозитов НТ+ЖК (~0.1 % НТ), что позволяет предположить расслаивание плоских частиц органоглины и их встраивание в ориентационно упорядоченную нематическую структуру. В гибридных дисперсиях влияние НТ и ММТ на оптическое пропускание аддитивно. Отмечены существенные различия в поведении электропроводности между композитами, заполненными НТ и органомодифицированным ММТ. Показано, что НТ облегчают, а частицы ММТ затрудняют индуцированный электрическим полем переход из планарного в гомеотропное состояние в жидкокристаллической ячейке