Comparative analysis of eddy current pulsed thermography and long pulse thermography for damage detection in metals and composites
NDT & E INTERNATIONAL
Authors: Wang, Zijun; Zhu, Junzhen; Tian, GuiYun; Ciampa, Francesco
Abstract
Eddy current pulsed thermography (ECPT) and long pulse thermography (LPT) are two emerging non-destructive evaluation techniques that have been recently used for sub-surface defect detection in both metallic and composite components. This paper provides a comparative analysis of these two methods by focussing on the detection of flat bottom holes (FBHs) in both aluminium and carbon fibre reinforced plastic samples. Principal component analysis was used for the post-processing of thermal data in order to enhance the detection of FBHs with various diameters and depths. Results showed that LPT had a better performance for detecting FBHs in low-thermally conductive materials such as carbon fibre-reinforced thermoplastic composites, whilst ECPT revealed a superior performance for detecting FBHs in materials with higher thermal and electrical conductivity such as aluminium.
Aesthetic characteristics of the orthodontic wire with silver plating
BIOMEDICAL RESEARCH-INDIA
Authors: Usui, Takashi; Miyake, Sinjiro; Iwata, Toshio; Otsuka, Takero; Koizumi, So; Shirakawa, Nobukazu; Kawata, Toshitsugu
Abstract
Introduction: The aesthetics of orthodontic appliances represents one of the main concerns of patients receiving orthodontic treatment. A large number of orthodontic appliances have been composed of silver and have a metallic color. The aim of this study is to prepare esthetic orthodontic wires using silver electroplating. The color of the aesthetic wires was assessed using a devised colorimetric measurement method as described later. Materials and methods: A silver-plated wire that we have developed and six brands of esthetic arch wires were assessed. These wires were measured three times using a colorimeter color system 1. Lightness (L*), 2. Hue (a* . b*), 3. Chroma (C*), were evaluated. The colors of these wires need to be compared with the natural tooth color. VITA shade A1 (VA1) as evaluation criteria was measured. Result: 1. In the L* value, the silver-plated wire was the closest to VA1 at 70.5 than (p<0.01). 2. Among the a* values, epoxy coating wire was the closest to VA1 at -1.3. 3. Among the b* and C* values, the silver-plated wire was the most approximate at 8.4 to VA1 (p<0.01). Discussion: The silver-plated wire was closest to the natural tooth color, lightness, chroma, hue. In the future, we are working on development of a more aesthetic wire.