Development of fatigue test method and improvement of fatigue life by new functional steel plates for welding of trough rib and deck plate of orthotropic decks

Under heavy traffic conditions, some fatigue cracks have been found at welding joints between U-shaped ribs “trough ribs” and deck plates. Fatigue cracks along thickness direction of deck plate from root tip are important because visual crack detection from outside is limited. In this paper, new functional steel plates with initiation resistance of fatigue crack at weldment and propagation resistance at base material are applied to deck plate to evaluate improvement of fatigue life. We conducted fixed-point fatigue tests with real scale partial models consisted with one trough rib and a transverse girder, and the elastic FEM (Finite Element Method) analysis corresponding to the fatigue test specimen. Based on these results, we studied the fatigue properties which focused on the difference between conventional steel plates and newly developed steel plates, FCA (Fatigue Crack Arrester). Fatigue cracks were initiated from root tip of welded joints between a trough rib and a deck plate. It is clarified that FCA steel plates instead of conventional steel plates can improve the fatigue life under the same welding conditions. This improvement effect becomes much clearer in the high cycle region, which is noticeable at the operation and management stage of bridges.     

Simultaneous Switching Noise Enabler in High-Speed Biomedical Systems by Integrated Plane Coupling

The performance of high-speed biomedical systems is adversely affected by switching noise caused by inductance in the power supply distribution network. In a high-speed medical system, signals are switched at rates up to 5 Gbps and discrete capacitors are ineffective in reducing the noise at this rate. The noise may affect patient care. Integrated plane coupling effectively minimized simultaneous switching noise by creating high capacitance between the planes. Although the suppression of electromagnetic interference due to switching noise on the component and printed circuit board is difficult, the integrated plane coupling at the front-end of the design cycle was shown to eliminate noise. The effect of switching noise coupling was investigated and a solution is reported. A test board was analyzed and the results were compared with simulations. This approach was shown to be effective in minimizing switching noise in high-speed biomedical systems.     

Improved lithium cyclability and storage in a multi-sized pore ("differential spacers") mesoporous SnO2

A wide pore distribution mesoporous morphology stabilizes SnO(2) structure during lithium insertion and removal and in the process remarkably enhances the lithium storage and cyclability.     

Study of issues in the development of surface EMG controlled human hand

In the process of improvement of prosthetic devices, there have been efforts to develop satisfactorily working artificial hands but still lots of work is to be done to meet the accuracy and requirements of the human hand movement. The EMG signal has been most promising signal in development of artificial limbs. The present review paper gives the historical developments in three main sections. First part describes the EMG signal properties. Second part deals with the mathematical models developed till now for EMG signal analysis. In the third part different design approaches have been reviewed for artificial hand. First approach discussed here is on the body-powered terminal devices which are controlled by the user's pull on the control cable to open the hand or hook and for the grip strength. Other being myoelectric controls type, an externally-powered system which uses electrical impulses, generated by contraction of the amputees own remaining muscles to operate a motor in a mechanical hand, hook or elbow. This paper presents a brief overview of above mentioned issues with regard to artificial hands.