Non-Destructive Inspection of Concrete Structures Using an Acceleration Pickup
The present paper proposes a method for detecting cracks or honeycombs in concrete structures using an acceleration pickup. The sensor on the concrete surface observes the stationary waves which are generated inside the structures depending on the depth of the crack (if there is a crack) or the bottom of the structure (if there are no cracks or honeycombs). The method measures the depths of the reflection planes (such as cracks or honeycombs) accurately by modeling the sensor output as an output of a linear dynamic system with unknown parameters and by applying a maximum likelihood method. The method is shown to be quite effectively applied to measure the depths of cracks and honeycombs
Intelligent BioRobot Platform for Integrated Clinical Test
Recently, automation in clinical test is raised as a fusion of bio and robotic technology. Particularly, automation in clinical test becomes a new application area of the robotic technology. In this paper, we present a robot platform for clinical test suitable for small or medium size of hospitals. The platform is designed to minimize the consumption of reagents, and easily integrate various testing equipments since it is functionally modularized. The platform is aimed for accommodating almost 70 kinds of clinical tests, which are the most frequently conducted in the hospitals. The platform consists of several major function blocks such as manipulation, transportation and detection, incubation, reservation, and each of them is designed as a module of the system. Basic ideas of the design are described and each functional block is explained in details
Microstructure of the solder-casting zone in bridges of dental gold alloys.
The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.