Wyniki wyszukiwania - BazTech

1

Ion Distributions in Water/Graphene Interface: A Molecular Dynamics Study

Dweik J., Koabaz M., Younis J., Ghaddar A.

Computational Methods in Science and Technology

|

2021

|

Vol. 27, No. 1

29--35

EN

Classical Molecular Dynamics (MD) with a non-polarizable force field is used to quantify the ion size effect on structure and dynamics of the confined electrolyte solution by considering the series of sodium halides (NaX with X = = F, Cl, Br, and I). Ions and water transport were simulated through a rigid and neutral atomistic carbon wall (graphene). The results showed that the solid surface has a major effect on the ion distribution in nano-aqueous solutions near interfaces. Cl, Br, and I tend to be repelled from the regions where the density of water is high, while F was found to be significantly solvated by water. Due to confinement, the dynamical properties of the electrolyte solution were also observed on the anions and cations pairing through determining the self-diffusion coefficient.

2

Study on constitutive behavior of Ti-45Nb alloy under transversal ultrasonic vibration-assisted compression

Wang Xingxing, Qi Zhenchao, Chen Wenliang

Archives of Civil and Mechanical Engineering

|

2021

|

Vol. 21, no. 1

518--532

EN

Ultrasonic vibration technology has been widely applied in plastic forming processes due to its advantages of material properties improvement. In this study, a transverse ultrasonic vibration-assisted compression (TUVC) system with the range of vibration amplitude from 16 to 48 µm is developed to compress the difficult-to-deformation materials. The experiment found that the temperature of the compressed sample with the vibration amplitude of 38 µm arrived at 164 ℃, hence the current constitutive models are deficient for the description of TUVC deformation behavior with the large vibration amplitudes. The results show that the flow stress declines under the coupling action of volume effect and surface effect, especially the amplitude is larger than 38 µm. To accurately depict the constitutive behavior of titanium alloy under TUVC, a hybrid constitutive model considering the difference of softening mechanism was proposed based on crystal plasticity theory, and the predicted curves are in good agreement with experimental results. Finally, the microstructure further revealed the differences of softening mechanism in TUVC, and numerous secondary α phase was precipitated. Consequently, the studies provide an insight into the deformation mechanism of TUVC and promote the application of ultrasonic vibration-assisted forming for the difficult-to-deformation alloy.

3

Surface Effect on the Buckling of a Stretchable Electronic Structure

Zhang X., Ou Z., Yao X.

Przegląd Elektrotechniczny

|

2012

|

R. 88, nr 9b

137-140

EN

The structure of a stiff thin film on a compliant substrate has important applications in stretchable electronics. However, such structures are micro-nano-order of magnitude, where surface effects cannot be ignored. Gurtin-Murdoch theory is applied to model the thin film including surface effects. Through energy method, the size-dependent relations between the buckling features, material properties and geometric parameters are deduced. At last the influence of surface effects is illustrated by the case of silicon film and PDMS substrate.

PL

Badano strukturę cienkiej warstwy nałożonej na podłoże. Taka struktura może mieć rząd nanometrów kiedy efekt podłoża nie może być ignorowany. Zaproponowano model matematyczny struktury bazując na teorii Gurtin-Murdoch.

4

Estimation of supply lines impedance in low-ohmic furnaces using numerical method of elementary conductors

Novak P., Janośćik J., Medved D.

Jakość i Użytkowanie Energii Elektrycznej

|

2004

|

T. 10, z. 1/2

33-40

EN

This article deals with another exhibition of possible using numerical method of elementary conductors. It is applied in the course of analyze impedance relations of one and three phases supply lines to low-ohmic furnaces, in configurations of single and bundled lines. Results of analysis can be used for cross section form optimalisation and spatial configuration of objective supply lines. Optimalisation of particular conductors leads to reduction of electric loss and to improvement of some process properties of electrical furnaces working in low ohmic mode.

PL

W artykule przedstawiono kolejny przypadek możliwego wykorzystania numerycznej metody przewodników elementarnych. Zastosowano ją w trakcie analizy zależności impedancyjnych jedno- i trójfazowych przewodów zasilających piece o niskiej impedancji, w układzie przewodów pojedynczych i przewodów wiązkowych. Wyniki analizy mogą być wykorzystane do optymalizacji przekrojów i konfiguracji przestrzennej omawianych przewodów zasilających. Optymalizacja poszczególnych przewodników prowadzi do zmniejszenia strat elektrycznych i do poprawy niektórych własności technologicznych pieców elektrycznych pracujących w stanie niskiej impedancji.