A woven electrode with convex structure for electrical impedance tomography

We developed a silver/silver chloride (Ag/AgCl) woven electrode, which was woven in a convex high-density structure. The convex structure can decrease the motion artifacts caused by the slippage between human skin and the electrode. The high density can reduce the noise caused by the change of contact resistance. The model of the electrode–skin interface was proposed, and its equivalent circuit model was built, which can present an intuitive understanding of electrode design principles. Furthermore, AgCl particles were electrochemically deposited on the Ag electrode in terms of 23 schemes to optimize the deposition uniformity. The effects of deposition time, electrolyte concentration, and current/voltage magnitude were investigated. According to the result, the best combination is a constant current method, with the current at 0.01 A, the deposition time set to 300 s, and the electrolyte concentration as 0.05 M. The resistances of the deposited electrodes are qualified for impedance monitoring due to their small resistance. A bioimpedance system was assembled followed by the electrical impedance tomography mechanism. The frequency response and bioimpedance–time relationship were measured and analyzed in our bioimpedance system. The result reveals that the frequency response from [Formula: see text] to[Formula: see text] Hz presents a stable state for the convex woven electrode. The woven electrode system has a wider stable frequency band than the wet electrode. The bioimpedance of wet electrodes is stable in the initial time, whereas that of woven electrodes decreases with time. However, the wet electrode bioimpedance increases with time after 3 h, and the woven electrode bioimpedance is stable after 3 h. Both the interface capacitance and resistance have very important roles in the bioimpedance system. The woven electrode is better in long-term monitoring than the wet electrode. In addition, convex electrode bioimpedance presents less noise than the plain electrode. Therefore, the convex electrode is the best choice for the bioimpedance monitoring system.

Convex Structure in Generalized Fuzzy Metric Spaces

In this paper, we introduce the concept of convex structure in generalized fuzzy metric spaces and proved common fixed point theorems for a pair of self-mappings under sufficient contractive type conditions.

Simulation and Experimental Study on Improving Electrochemical Machining Stability of High Convex Structure on Casing Surface by Using Backwater Pressure

Casing parts are regarded as one of the key components in aero-engine components. Most casing parts are attached with different shapes of convex structures, and their heights range from hundreds of microns to tens of millimeters. The use of profiling blocky electrodes for electrochemical machining of casing parts is a widely used method, especially in the processing of high convex structures. However, with the increase of convex structure height, the flow field of machining areas will become more complex, and short circuits may occur at any time. In this study, a method to improve the flow field characteristics of machining area by adjusting the backwater pressure is proposed, the simulation and experiment are carried out respectively. The simulation results showed that the back-pressure mehtod can significantly improve the uniformity of the flow field around the convex structure compared with the extraction outlet mode and the open outlet mode, and then the optimized back-pressure of 0.5 MPa was obtained according to simulation results. The experimental results showed that under condition of the optimized back-pressure parameters, the cathode feed-rate increased from 0.6 mm/min to 0.8 mm/min, and the convex structure with a height of 18 mm was successfully machined. This indicated that the back-pressure method is suitable and effective for the electrochemical machining of high convex structure with blocky electrode.

Fixed Point Theorem for Multivalued Non-self Mappings in Partial Symmetric Spaces

In this paper, we proved a fixed point theorem for multi-valued non-self mappings in partial symmetric spaces. In doing so, we extended and generalized the results in literature by employing a convex structure for multi-valued non-self mappings using Rhoades type contractions. We also provided an illustrative example to support the results.

Convex structures in a new kind of ordered fuzzy group1

By means of a fuzzy binary operation defined on partially ordered sets, a new kind of ordered fuzzy group is proposed in this paper. Some properties of this ordered fuzzy group are studied. Following that, its substructures, such as subgroup and convex subgroup, as well as its homomorphisms, along with their properties are explored. It is shown that each family of these substructures forms a convex structure, where the convex hull of a subset is exactly the (convex) subgroup generated by itself, and the homomorphisms between two ordered fuzzy groups are convexity-preserving mappings between the corresponding convex spaces. In addition, when these substructures are extended to fuzzy setting, several L-convex structures are constructed and investigated.