Key Engineering Materials Vol. 826

Abstract: Electrochemical copolymerization of 2,5-bis[4-(p-aminophenoxy)phenylene]-1,3,4-oxadiazole (Ox) with fluorene (Fl) was carried out via consecutive multisweep cyclic voltammetry. The electrogrowth process was conducted in the potential range between 0 and 1.8 V, at a scan rate of 50 mV/s. The FTIR spectroscopy was used to solve the issues concerning the way of monomers linkage in the copolymer structure. A deep investigation of the electrogenerated copolymer film characteristics was performed by scanning electron microscopy, UV-Vis and fluorescence spectroscopy, and cyclic voltammetry.

Abstract: Among the organic materials widely studied for applications in advanced techniques, imine-based compounds (or azomethines) have received considerable attention due to their ability to reversibly change the color under the action of an external stimulus. The halochromic or photochromic behavior of imines is based on the protonation or photoizomerization ability of the imine linkage, the color changing effect occurring in response to the change in pH of the surrounding medium or electromagnetic radiation absorption. Starting from these aspects, three imine-based oligomers with a donor-acceptor-donor topology containing phenoxazine as the donor unit and diphenyl-1,3,4-oxadiazole, 9,9-diphenylfluorene or fluorene as an acceptor moiety were thoroughly investigated with respect to their protonation and photoiradiation behavior, evaluated by means of photo-physics analysis.

Abstract: This paper deals with the design of an apparatus based on tensegrity structures for the transmission of special solitary waves with adjustable profile into a material or structure, and the detection of such waves from a material or structure. The advantages of using tensegrity building blocks in place of granular materials or different structural units for the fabrication of novel nondestructive evaluation and monitoring tools and acoustic lenses are illustrated.

Abstract: A human motion prediction system can be used to estimate human gestures in advance to the actual action for reducing delays in interactive system. We have already reported a method of simple and easy fabrication of strain sensors and wearable devices using pyrolytic graphite sheets (PGSs). The wearable electronics could detect various types of human motion, with high durability and fast response. In this study, we have demonstrated hand motion prediction by neural networks (NNs) using hand motion data obtained from data gloves based on PGSs. In our experiments, we measured hand motions of subjects for learning. We created 4-layered NNs to predict human hand motion in real-time. As a result, the proposed system successfully predicted hand motion in real-time. Therefore, these results suggested that human motion prediction system using NNs is able to forecast various types of human behavior using human motion data obtained from wearable devices based on PGSs.

Abstract: The paper relates to the field of measuring technologies and deals with the enhancement of thermoconvective method when it is applied for the experimental determination of such hydrodynamics indicators as mass flow rate and velocity of flow by their indirect parameters - capacity of the heater and the temperatures obtained from two thermal sensors, provided that they are located on the hermetic piping system surface. The issue of determination of correction factor on heterogeneity of liquid temperature distribution in the pipe cross section depending on pipe diameter and fluid movement velocity was clarified. According to the results of numerical calculations, the dependencies of temperature gradient on the pipe surface and the correction factor on the heterogeneity of the temperature distribution along the pipe cross-section under the heater in the function of the velocity of flow in pipes of different diameters are plotted. These dependencies specify the thermal method of studying the fluid flow in the pipes, simplify the experiment conduction, are useful in processing of the obtained results and can be applied in measuring engineering.