Sensor Networks for Integration into Textile-Reinforced Composites
The integration of sensor networks into textile-reinforced composites enables monitoring of different physical values like strain, acceleration and temperature in a component. This paper presents a system concept of a modular sensor network supporting different sensor types and the wireless transmission of stored measurements. Sensor and transponder ASICs have been developed for realizing first demonstration examples. The feasibility of integration of discrete components and silicon chips was successfully verified in experiments with a composite made of glass fibers and polypropylene. Two demonstrators with fully functional integrated modules were fabricated in order to show the possibility of integrated strain monitoring and recording of impact events with wireless data transmission.
Integrated Sensor Network with Event-Driven Activation for Recording Impact Events in Textile-Reinforced Composites
This paper presents the system concept and first experimental results of the realization of a sensor network for monitoring suddenly occurring temporary events such as impacts. The system consists of modules with sensor and transponder ASIC that can be integrated into a composite component made of glass fibers and polypropylene. The power consumption in standby is very low because the power supply for the ASICs is only activated when a relevant event is detected by a startup sensor. A fast start of the data acquisition process at the beginning of the event is therefore extremely important. The achievable startup time is demonstrated with a test setup.
Studies on root enamel (2). Enamel pearls. A review of their morphology, localization, nomenclature, occurrence, classification, histogenesis and incidence.
Enamel pearls are one of a number of different enamel structures that can be found on the roots of deciduous and permanent teeth. They have a distinct predilection for the furcation areas of molar teeth, particularly the maxillary third and second molars. They can consist primarily of enamel, but in most instances, a core of dentin is contained within them. On rare occasions, even pulpal tissues can be found. Enamel pearls usually occur singularly, but up to 4 enamel pearls have been observed on the same tooth. Depending on the study, enamel pearls on permanent molar teeth have an incidence rate of between 1.1%-9.7% with distinct differences among racial and national groups. The incidence of enamel pearls increases greatly in histological studies, suggesting that they are often obscured by a covering of cementum.