Ultrasonic phased array technology for the non-destructive testing of marble sculptures

The medical ultrasonic phased array technology was modified for the non-destructive testing of marble sculptures and the feasibility of the approach was evaluated. For this purpose, 1?MHz, 64-channel phased array electronic and phased array transducers were developed. The specifications of the electronics and the transducers are presented and discussed. Ultrasound images of inner structures of a marble sculpture are presented. The problem of the acoustic matching layers for different states of deterioration is discussed and the developments in view of a suitable matching layer solution are presented. This matching layer is combined with a new coupling technique that protects the marble surface. The results of experiments on ultrasound phantoms and on a marble sculpture are presented.     

Beyond Reflection: Perception,virtue, and teacher knowledge

In this article, I aim to vindicate the belief that many teachers have that their intuitions, insights, or perceptions are legitimate—and indispensible—guides for their teaching. Perceptions can constitute knowledge. This runs counter to some number of views that emphasize ‘reflective practice’ and teachers as ‘reflective practitioners.’ I do not deny that reflection can be important, but it is a derivative task, dependent on teachers being the ‘right sort of subject,’ having the ‘right orientation’ to their work, at the service of achieving that orientation. That orientation is a matter of virtue, where virtue is manifested in the capacity to read situations correctly for what is required to serve persons’ welfare, for them to do well. This entails that good teaching is more experienced-based than research-based. Ultimately, it is life experience that provides for teachers’ ability to see well.     

Feedback Analysis of the Movement Mechanisms of Handwriting

To extend the feedback analysis of legibility in handwriting, a coordinate force transducer has been devised that makes possible the separate sensing of the right-left and near-far directions of writing motions and the converting of these movements to their electrical analogs. This method of transducing handwriting motions made possible systematic measurement of the effects of feedback displacement and delay of the visual feedback of writing movements and of analyzing the types of variation in legibility related to variable feedback factors. Results showed that differential directional defects and general disturbances in legibility and timing of writing movements occurred in relation to both visual feedback displacement and delay of writing motions. The findings give added support to the view that writing is not a form of discrete stimulus-response behavior or stimulus tracking, but consists of self-generated forms of response comparable to steering, in which accuracy, legibility, and learning are directly determined by feedback time factors and directional specificity of particular right-left and near-far coordinates of movement that dynamically control and project visual input in the writing act.