Discrete breathers assist energy transfer to ac driven nonlinear chains

One-dimensional chain of pointwise particles harmonically coupled with nearest neighbors and placed in six-order polynomial on-site potentials is considered. Power of the energy source in the form of single ac driven particles is calculated numerically for different amplitudes $A$ and frequencies $\omega$ within the linear phonon band. The results for the on-site potentials with hard and soft nonlinearity types are compared. For the hard-type nonlinearity, it is shown that when the driving frequency is close to (far from) the {\em upper} edge of the phonon band, the power of the energy source normalized to $A^2$ increases (decreases) with increasing $A$. In contrast, for the soft-type nonlinearity, the normalized power of the energy source increases (decreases) with increasing $A$ when the driving frequency is close to (far from) the {\em lower} edge of the phonon band. Our further demonstrations indicate that, in the case of hard (soft) anharmonicity, the chain can support movable discrete breathers (DBs) with frequencies above (below) the phonon band. It is the energy source quasi-periodically emitting moving DBs in the regime with driving frequency close to the DBs frequency, that induces the increase of the power. Therefore, our results here support the mechanism that the moving DBs can assist energy transfer from the ac driven particle to the chain.Comment: 11 pages, 13 figure

Corporate information management system and its influence on increase of changes productivity

The urgency of the problem under investigation due to constant changes in the external business environment requires organizations to establish a mechanism to manage change and increase the impact of these changes. The purpose of the article is to analyze the change management concepts and their applicability in the strategically important holdings in the region, as well as identifying features of reforming of the enterprises in the crisis through the creation of change management system. The leading approach to the study of this problem is a systematic approach to identify the main features allowing for the formation of the mechanism of change management in the regional holding companies. The main results: systematization and analysis of the existing change management concepts, and identified particular changes in the company based on the use of change management system. Article Submissions may be useful for the regional and federal holding companies with constant changes in the external business environment. © 2016 Krivtsov et al

On the Contributions of Pavel Andreevich Zhilin to Mechanics

This paper is dedicated to the memory of Pavel A. Zhilin (1942-2005), the great Russian scientist in the field of Rational Mechanics. He was educated and worked at the State Polytechnical University in St. Petersburg (Russian Federation), formerly known as the Polytechnical Institute. As Head of the Department of Theoretical Mechanics he supervised sixteen PhD theses (Candidate of Science theses) and six higher doctorates (Habilitations or Doctor of Science theses), some of them are shown on Fig. 2. His scientific interests covered various branches of Mechanics and Theoretical Physics. In his research he strived to pave a way based on Rational Mechanics to areas which are traditionally not associated with Mechanics, such as Physics of Microstructures and Electrodynamics. The paper gives a brief summary of the scientific biography and the main results obtained by Pavel A. Zhilin1

Effect of discrete breathers on macroscopic properties of the Fermi-Pasta-Ulam chain

The effect of discrete breathers (DBs) on macroscopic properties of the Fermi-Pasta-Ulam chain with symmetric and asymmetric potentials is investigated. The total to kinetic energy ratio (related to specific heat), stress (related to thermal expansion), and Young's modulus are monitored during the development of modulational instability of the zone boundary mode. The instability results in the formation of chaotic DBs followed by the transition to thermal equilibrium when DBs disappear due to energy radiation in the form of small-amplitude phonons. It is found that DBs reduce the specific heat for all the considered chain parameters. They increase the thermal expansion when the potential is asymmetric and, as expected, thermal expansion is not observed in the case of symmetric potential. The Young's modulus in the presence of DBs is smaller than in thermal equilibrium for the symmetric potential and for the potential with a small asymmetry, but it is larger than in thermal equilibrium for the potential with greater asymmetry. Our results can be useful for setting experiments on the identification of DBs in crystals by measuring their macroscopic properties.Comment: 9 pages, 10 figures; v3: some changes in the text, references added; matches the published versio

Further development of The Ebbsfleet Water Management System Dynamics Model: Adjusting representation of processes and system boundaries, incentivising stakeholder re-engagement, and exploring the potential for University teaching

This is the final version. Available from WIT Press via the DOI in this record. System Dynamics Model (SDM) that explores sustainable urban water management. The model is open-source compiled using Vensim software, which is free for non-commercial use. This paper demonstrates that the current SDM and the modelling approach are open to adjustment, which is illustrated by introducing a link between water tariffs and environmental awareness. The increase in water tariffs leads not only to the obvious increase in water bills, but also to an increase in Environmental Awareness, and consequently, to increases in the use of water efficiency devices, grey water acceptability, and grey water reuse. A range of further modifications is suggested, including expanding representation of sustainable drainage systems (SuDS) to consider resultant improvements in stormwater quality as well as quantity. This would recognise the indirect benefits of improved stormwater quality on biodiversity in the River Ebbsfleet, which is the receiving watercourse. This study intends to encourage knowledge transfer, by facilitating and incentivising the use and further development of the SDM by stakeholders and a wider community of end-users, including practitioners, academics and the public. While SDM is particularly suited to analysis of indirect relations, benefits and trade-offs among system constituents, other approaches provide viable alternatives and we discuss the potential for re-implementing our findings in other interactive modelling software packages and programming languages. We also explore the scope for linking the adapted SDM to other models. Finally, we consider the utility of the Ebbsfleet SDM in teaching, learning and knowledge transfer. We conclude that students, practitioners and other stakeholders could not only enhance their understanding of urban water management complexity, but also gain valuable system modelling skills based on using the SDM to support kinaesthetic learning. Ultimately, society benefits when the level of knowledge and analytical thinking skills of its members are enhanced.Engineering and Physical Sciences Research Council (EPSRC)Engineering and Physical Sciences Research Council (EPSRC)Engineering and Physical Sciences Research Council (EPSRC

Derivation of the conditions for equivalent positions in crystals: The dissymmetrization of barite by electron spin resonance spectra

The conditions for equivalent positions on the (hkl) face of growing crystal are derived using sym- metry elements of the space group. It is shown by the example of the sp. gr.D2h 16 that the conditions of equiv- alent position formation coincide with conditions of the reflection of diffracted beams by crystal. It is estab- lished that electron spin resonance (ESR) centers in barite, SO4 -(I) and SO4 -(II), with only two conjugate spectra with equal intensity out of four, and SO4 -(III), with a different intensity of conjugate spectra KaM = 2, are localized into the growth pyramid of the (001) face with a [010] step. SO2 -,SO3 -, and (IV) centers, having an identical intensity of the conjugate ESR spectra with KαM = 2, are localized into the growth pyramid of the (210) face with a growth step [001]. © Pleiades Publishing, Inc., 2012

EXPERIMENTAL MODELING OF APOPTOSIS UNDER CONDITIONS OF STABLE STRONTIUM EXPOSURE

Apoptosis is defined as a highly regulated form of programmed cell death with typical morphological and biochemical features. A variety of factors, including heavy metals, may influence the intensity of programmed cell death. The aim of the work was to simulate apoptosis in an in vitrosystem under the conditions of stable strontium exposure. The children’s population consuming drinking water with high strontium (Sr2+) content (n = 49) was observed. The level of lymphocyte apoptosis was determined with flow cytometry technique, by means of labeled annexin V-FITC conjugate (AnnV-FITC) and propidium iodide (PI) staining. AnnV-FITC+PI- cells were regarded as early apoptotic forms, whereas late apoptotic and/or necrotic cells were AnnV-FITC+PI+. The isolated leukocytes were incubated with Sr2+ at a concentration of 7.0 mg/l, the maximal permitted concentration (MPC) for water of aqueous objects, for 4 hours at 37 ºC. Expression of CD95 and p53 apoptosis markers was performed by flow cytometry using labeled monoclonal antibodies.In vitroexposure to strontium was associated with significantly decreased expression of apoptosisregulating factors, i.e., membrane marker CD95 and intracellular transcription protein p53, 1.56- and 1.68-fold, respectively. Meanwhile, we revealed a significantly (4.68-fold) decreased amounts of AnnV-FITC+PI--cells, as well as a statistically significant (1.35-fold) increase of the AnnV-FITC+PI+-cells. Moreover, the amounts of AnnV-FITC+ PI--lymphocytes in all samples were below the physiological ranges and control values. The number of samples with higher contents of AnnV-FITC+PI+-lymphocyte exceeding the established standards and control values, was 30.8%. Thus, it has been experimentally proven that strontium, at a concentration corresponding to MPC for water objects may significantly inhibit cell death along apoptotic pathways, with switching to necrotic cell death mechanisms, according to phosphatidylserine contents, as detected by annexin V binding test. The data have revealed an ability of strontium to have a significant effect upon the parameters of regulation and maintenance of cellular homeostasis, by influencing the apoptosis intensity, due to shifting a balance towards necrosis and reducing expression of apoptosis-regulating factors. The results of this study may be used in order to identify some marker indexes of immune disorders potentially induced by external influence of strontium upon human health under specific environmental factors

A drifting impact oscillator with periodic impulsive loading: Application to percussive drilling

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