Papers by Keyword: Oscillation

Abstract: In this paper, by means of the method of mathematical analysis, a mechanical controlled system with time delay has been investigated. Some sufficient conditions have been provided to guarantee the oscillation of the system. Numerical simulation demonstrates the result.

Abstract: A new approach to information recording in distributed media based on the forced wave excitation involved by temperature fluctuations was proposed. The scheme of the device providing the implementation of the proposed approach is considered.

Abstract: Multi-function and all-electric rheometer (MAR) was designed by the authors to study the nonlinear viscoelasticity of polymer melts at high shear rate. It is important to design suitable size of capillary and barrel because it is the calculation basis for some other important parts and determines the shear rate range of MAR. Considering the shear rate range, the entrance pressure correction and the wall slip correction, the length and diameter of capillary and barrel of MAR were designed through particular analysis and precise calculation.

Abstract: The article deals with the influence of manufacturing and geometric asymmetry on the vertical oscillation of symmetric and asymmetric systems consisting of rigid bodies linked flexibly with different kinematic excitation. The solution was performed using experimental and numerical analysis (with application of oscillation of vehicles and flexibly coupled machines). Numerical solutions were carried out by finite element method (FEM) on a simple model and experimental solutions on laboratory model of a mechanical system. The aim of the work was to create a numerical model and its solution using the finite element method. The experimental solution was used to verify the numerical model.

Abstract: The oscillation for certain third-order nonlinear neutral delay dynamic equations on time scales is discussed in this article. By using the generalized Riccati transformation and the inequality technique, three new different sufficient conditions which ensure that every solution is oscillatory or converges to zero are established. The results obtained essentially generalize and improve earlier ones.

Abstract: Based on linear-response-like approach and simulations, the relationship between the strength of inhibitory feedback and the oscillation is explored by spectral properties of networks with leaky integrate-and-fire neurons under varying feedback strength. It is found that the network oscillation is enhanced sharply with increasing the feedback strength when the feedback is weak, but is insensitive to the feedback strength when the feedback is not weak. These results suggest that inhibitory feedback plays a limited role in enhancing the network oscillation. A qualitative analysis of the limited role of the inhibitory feedback in enhancing network oscillation is also presented.

Abstract: Numerical investigation on the fluid structure interaction in the cylindrical membrane inflation is performed by the Euler-Largrangian method. In membrane inflation, the vortex flow and wave system induced by the interaction between compressible jet flow and membrane appeared inside membrane. This phenomenon concentrates the stresses and generates a pair of bumps. The influences of oscillation and bumps on membrane working performance and safety are also investigated.

Abstract: Various problems of science and engineering that deal with dynamical systems can be described by partial difference equations. This article is concerned with a class of mixed partial difference equations with constant coefficients. We obtain necessary and sufficient conditions for all solutions of these equations to be oscillatory by finding the characteristic roots. An example is given to illustrate the results presented in this paper.

Abstract: Ultrasonic-assisted extraction of lead from red soil using EDTA was investigated, the experimental result was compared with that of oscillation extraction to evaluate the performance of ultrasonic-assisted extraction. The optimum extraction conditions were 0.006 mol/L of EDTA, 0.006 mol/L of EDTA and 90 min of ultrasonic-assisted extraction or 240 min of oscillation extraction. Under the optimum extraction conditions, the extraction rate of 76.33% and 74.30% was obtained for ultrasonic-assisted extraction and oscillation extraction, respectively. The ultrasonic-assisted extraction could shorter the extraction time with a improved extraction rate effectively.

Abstract: The importance of aeroelastic interaction in the design of bridge decks is nowadays apparent. Key role played by the Scruton number in wind engineering applications is discussed in this paper, the windtunnel tests carried out to estimate the aeroelastic parameters of this model are presented. We also demonstrates by means of numerical integrations the validity of the approximate solution and identification procedure, Finally, the results of the previously mentioned numerical identification procedure are presented.