Synchronization of simplest two-component Hartley’s chaotic circuits: influence of channel

Firstly, the synchronization problem of the simplest two-component Hartley chaotic systems is considered. A simple and effective controller is used to achieve synchronization between the drive and response systems. The proposed controller is built around a linear and a nonlinear parts with each contributing to the achievement of the synchronization process. The stability of the drive–response systems framework is proved through the Lyapunov stability theory. Secondly, the impact of channel on the signal coming from the drive system to synchronize the response system is taken into consideration. In this second part, the conditions to obtain synchronization between both master and slave systems are investigated. For the purpose of illustration, PSpice simulations are given as complement of the numerical analysis.     

Tris(2,2′-bipyridyl)ruthenium(II) electrochemiluminescent determination of ethyl formate

Analytical and Bioanalytical Chemistry - Ethyl formate is extensively used as food flavor, fungicide, and larvicide. It naturally exists in coffee, fruits, honey, brandy, and rum as well as dust...     

Sensitive and selective electrochemical detection of artemisinin based on its reaction with p-aminophenylboronic acid

The electrochemical detection of artemisinin generally requires high oxidation potential or the use of complex electrode modification. We find that artemisinin can react with p-aminophenylboronic acid to produce easily electrochemically detectable aminophenol for the first time. By making use of the new reaction, we report an alternative method to detect artemisinin through the determination of p-aminophenol. The calibration curve for the determination of artemisinin is linear in the range of 2 μmol L⁻¹ to 200 μmol L⁻¹ with the detection limit of 0.8 μmol L⁻¹, which is more sensitive than other reported electrochemical methods. The relative standard deviation is 4.83% for the determination of 10 μM artemisinin. Because the oxidation potential of p-aminophenol is around 0 V, the present method is high selective. When 40 μM, 90 μM and 140 μM of artemisinin were spiked to compound naphthoquine phosphate tablet samples, the recoveries are 107.6%, 105.4% and 101.7%, respectively. This detection strategy is attractive for the detection of artemisinin and its derivatives. The finding that artemisinin can react with aromatic boronic acid has the potential to be exploited for the development of other sensors, such as fluorescence artemisinin sensors.     

Screening effect on the polaron by plasmons in the field of self-action potential in a planar nanocrystal

We investigate the effect of plasmon screening on the polaron characteristics following the Feynman variational method and find that the screening considerably reduces the polaron characteristics, as plasmon density increases. We establish that the factor contributing to this screening not only depends on the concentration, but also on the anisotropy of the dielectric permittivities, the temperature, and charge as well as on the layer width. The contribution of the surface effects to the total polaron characteristics are exceedingly small and can therefore be safely neglected. The characteristics are found to be strongly dependent on the screen function referred to as the F-function, and when screening parameters vanish this F-function vanishes and the polaron characteristics reduce to the familiar non-screen ones. The decrease of the polaron characteristics with an increase of the screening parameter is not exactly exponential but mimics that of a pseudoatom which has a much more slow decrease.     

Finite-time synchronization of fractional-order simplest two-component chaotic oscillators

The problem of finite-time synchronization of fractional-order simplest two-component chaotic oscillators operating at high frequency and application to digital cryptography is addressed. After the investigation of numerical chaotic behavior in the system, an adaptive feedback controller is designed to achieve the finite-time synchronization of two oscillators, based on the Lyapunov function. This controller could find application in many other fractional-order chaotic circuits. Applying synchronized fractional-order systems in digital cryptography, a well secured key system is obtained. Numerical simulations are given to illustrate and verify the analytic results.     

Nanomaterials‐based Electrochemical Sensing of Cardiac Biomarkers for Acute Myocardial Infarction: Recent Progress

The development of the methods for early and accurate diagnosis of acute myocardial infarction are needed to facilitate immediate treatment of patients. One of the ways to achieve that is the detection of cardiac biomarkers for myocardial infarction, such as thrombin, cardiac troponins (I and T), myoglobin, etc. Nanotechnology has played an important role in the development of sensitive and efficient electrochemical sensors for cardiac biomarkers. In this review, we discuss recent progress on nanomaterial‐based electrochemical sensing of various cardiac biomarkers for acute myocardial infarction.     

Dynamics of the plane and solitary waves in a Noguchi network:Effects of the nonlinear quadratic dispersion

We consider a modified Noguchi network and study the impact of the nonlinear quadratic dispersion on the dynamics of modulated waves. In the semi-discrete limit, we show that the dynamics of these waves are governed by a nonlinear cubic Schrodinger equation. From the graphical analysis of the coefficients of this equation, it appears that the nonlinear quadratic dispersion counterbalances the effects of the linear dispersion in the frequency domain. Moreover, we establish that this nonlinear quadratic dispersion provokes the disappearance of some regions of modulational instability in the dispersion curve compared to the results earlier obtained by Pelap et al.(Phys. Rev. E 91 022925(2015)). We also find that the nonlinear quadratic dispersion limit considerably affects the nature, stability, and characteristics of the waves which propagate through the system. Furthermore, the results of the numerical simulations performed on the exact equations describing the network are found to be in good agreement with the analytical predictions.     

Bipolaron in a quasi-0D quantum dot

Bipolaron states in a quasi-0D quantum dot with a spherical parabolic confinement potential are investigated by applying the Feynman variational principle. The bipolaron coupling energy and self-action potential energy are found to increase with an increase in the Fröhlich electron–phonon-coupling constant. There is also a non-monotonic dependence of the bipolaron coupling energy on the quantum dot radius. With decreasing structure radius the bipolaron coupling energy increases. However, from a critical radius it starts decreasing as the radius decreases, due to the dominance of the coulomb-to-phonon mediated interaction. When electrons in the bipolaron are forcefully neighboured, the polarization of the structure is intensified and consequently there is Coulomb repulsion. The possibility of bipolaron formation depends on the strength of the direct Coulomb repulsion which, in turn, depends on the quantum dot radius. The main contribution to the bipolaron coupling energy comes from the self-action potential. This self-action potential energy influences the energy state of the bipolaron considerably. The ratio of optical-to-static dielectric constants significantly affects the bipolaron coupling energy.     

Interface Between an Old Concrete and a Bonded Overlay: Debonding Mechanism

The ageing of concrete structures creates the need for their repair. The thin bonded overlay technique is widely used; it is particularly suitable for the repair of large concrete areas. It is appropriate for slabs on grade (mainly industrial floors), pavements, bridge decks, walls and tunnels. Toppings and linings are similar applications. The aim of the overlay may be to smooth a damaged surface, and/or to improve the mechanical capacity of a structure by increasing its thickness, or to provide additional cover for corrosion protection.The durability of such repairs or overlays depends on the durability of their bond with the base structure; it is usually the critical aspect. Work, carried out in Laboratoire Matériaux et Durabilité des Constructions (Laboratory for building Materials and Constructions Durability) in Toulouse, France, is part of a larger programme started in 1990. The programme objective is to achieve a thorough knowledge of the debonding mechanisms of an overlay. Design rules and practical recommendations eliminating or drastically reducing durability hazards are expected to be developed. The work reported here focuses on the debonding propagation along an interface, notably the major influence of the interlocking between the two faces of the debonding interface. The study relies on finite elements modelling and on the comparison with experiments.Having evidenced the major role of interlocking in the example of a crack propagation, the paper focuses on the actual case of an interface. Debonding propagates in mixed mode, mode I combined with mode II, bringing an extra degree of complexity. Beyond the problem of the mixed mode, an important issue is how interlocking changes while debonding propagates. Indeed, mode I debonding opening damages interlocking for both mode I and mode II. A mode II slip has the same coupled effect on interlocking. A very significant problem is taking into account the coupling of mode I and II displacements to evaluate the actual value of the interlocking at any step of the propagation.The involved parameters have been identified and a method is proposed to take into account the coupling. The comparison with experimental results is promising. This research opens a new approach on the mechanism of the propagation of a debonding along an interface. The next step will consider evolution of the interlocking in the case of fatigue loading.