Non-Destructive Evaluation of Composite Helmets Using IR Thermography and Ultrasonic Excitation

The paper presents selected results of non-destructive testing of composite helmets with deliberately introduced defects. Ultrasound pulsed infrared thermography was used for the tests. In order to determine the initial possibilities of this method, artificial defects made of Teflon featuring different area sizes and designed to simulate delamination were placed between layers of the aramid composite from which the helmet was made. The obtained results confirmed the effectiveness of the NDT method used in these tests.

Evaluation of Moisture Diffusion by IR Thermography

It is well known that IRT is among the preferred instruments in the qualitative monitoring of humidity in buildings. The evaporation of water leads to a sink of thermal energy that eventually manifests as a decreasing of the temperature. The imaging and non-contact characteristics of IRT make the monitoring of this temperature decrease particularly easy and effective. Nonetheless, the quantitative extraction of some figures that make the qualitative observation more reliable is still an open problem.

Thermographical study of geometry and phase change influence on PDMS Microchannel liquid cooling devices

This work proposes a methodology in which high speed camera imaging is combined with infrared (IR) thermography to look at the effect of geometric parameters and boiling in the effectiveness of these coolers. PDMS microchannels were manufactured with 3 channel widths: 250, 500 and 750µm. HFE7100 was used as the refrigerant. Pressure losses were significant for the thinnest geometry as clogging and flow reversal were observed. The dissipated heat flux, as measured by the IR camera was higher in the largest channels, due to the PDMS poor conductivity. Results obtained with HFE7100 were then compared with those obtained with water at single-phase flow. For the same geometry, HFE 7100 resulted in a higher heat transfer coefficient than water.

Can infrared camera images be used for screening in Adolescent Idiopathic Scoliosis?

Adolescent idiopathic scoliosis (AIS) is the most common type of scoliosis, and affects up to 4% of adolescents in early stages. The deformity can develop during any of the rapid periods of growth in children, and the time of pubertal growth spurt also plays a role in spinal curve progression. Hence it is crucial to detect the disease early, to provide timely intervention. Detection of scoliosis when it is mild or before the growth spurt can be conducted via various screening methods. Adam's forward bend test (FBT) and scoliometer measurement of the angle of trunk rotation (ATR) are commonly used, to observe lateral bending and rotation of the spine, causing a visible rib hump. Moire topography can also be used, but is reserved for second tier due to some degree of ambiguity. X-rays (XR) remain the best way to diagnose scoliosis, as it provides a clear image of the spine and allows measurement of Cobb angle; however it has risks associated including requirement of the use of ionising radiation. Infrared (IR) thermography can be used to measure surface temperature and is performed with an IR camera. The temperature distribution and data matrix can be visualised into a thermal map, which has previously been studied and associated with the thermal asymmetry in paraspinal muscles, as well as significant temperature differences between the convex and concave side of the spinal curvature for idiopathic scoliotic patients. We hypothesize that such asymmetry and temperature differences may produce a detectable pattern on IR thermography, which would prompt further confirmatory investigations to reach a fast and non-radiation screening of AIS.

Investigation of the Freezing Phenomenon in Vials Using an Infrared Camera

The freezing phenomenon has a dramatic impact on the quality of freeze-dried products. Several freezing models applied to solutions in vials have been proposed to predict the resulting product morphology and describe heat transfer mechanisms. However, there is a lack of detailed experimental observations of the freezing phenomenon in vials in the literature. Thus, the present work offers new experimental observations of the freezing phenomenon in vials by infrared (IR) thermography. IR imaging allowed each vial’s whole axial temperature profile to be collected during freezing, providing significant insights into the process. Spontaneous nucleation and vacuum-induced surface freezing (VISF), as a controlled nucleation technique, are investigated. Batches having vials in direct contact with the shelf (exchanging heat mainly through conduction) as well as suspended (exchanging heat mainly through natural convection and radiation) were tested. The study used three solutions: sucrose 5%, mannitol 5%, and dextran 10%. SEM images coupled with an automated image segmentation technique were also performed to examine possible correlations between the freezing observations and the resulting pore size distributions. IR thermography was found to be a promising tool for experimentally predicting the resulting product morphology in-line.

Thermogravimetric analysis of glue-welded joint with various adhesive materials

Using the IR-thermography methods, the experimental evaluation of temperature transitions in a steel and aluminum glue-welded joint made with applying various adhesive materials (epoxy, anaerobic, organic-silicon and hot melt glue) has been carried out. It was found out that viscosity of an adhesive material considerably effected on the temperature transitions in the glue-welded joint as well as on glue line thickness. The temperature transitions were demonstrated on different sections of the glue-welded joint. Conclusions were made about the influence of properties of adhesive materials on the glue-welded joint quality.

ARCHITECTURAL SURVEY TECHNIQUES FOR DEGRADATION DIAGNOSTICS. AN APPLICATION FOR THE CULTURAL HERITAGE

The great technological development in recent years in the field of architectural survey has made possible increasingly expeditious and less invasive investigations with the aim of acquiring a series of data related to the asset and fundamental for the protection of cultural heritage. In addition, the synergy between the various techniques represents an added value able, not only, to fill possible gaps and lacks arising from application limits of the instruments, but also to enhance the peculiarities of the same. This paper presents an integrated survey activity (range-based, image-based and IR thermography techniques) aimed at applying the combination and collaboration of multiple sensors for the analysis and study of historical buildings as well as for the generation of digital repository to support current and future investigations. In particular, the attention has been on the Chiesa dell’Annunziata located in the municipality of Sessa Aurunca in the province of Caserta (Italy). By carrying out a systematic process of survey, colorimetric-material analysis and thermographic investigations, the work has allowed to identify the main forms of degradation that characterize the structure and the causes that generate it. The work conducted through the combination of multiple technologies demonstrates, once again, the importance of synergy and integrations between several instrumentations useful for the documentation of the built heritage, characterized by complex analyses and investigations based on increasingly interdisciplinary approaches.