scholarly journals Application of active thermography in study of the rotors dynamics

2021 ◽  
Vol 3 (1) ◽  
pp. 9-16
Author(s):  
Jarosław Bednarz
Keyword(s):  
Fault Detection ◽  
Research Design ◽  
Thermal Imaging ◽  
Imaging Techniques ◽  
Measurement Techniques ◽  
Dynamic State ◽  
Active Thermography ◽  
Infrared Measurement ◽  
Imaging Research ◽  
Real Objects

The article presents the infrared measurement techniques for analyzing and monitoring the dynamic state of the structure using advanced thermal imaging techniques. The article present an overview of the infrared measurement techniques and algorithms proposed research design based on the selected infrared measurement techniques. The article presents the results of a series of studies on the possibility of applying the vibrothermography methods in SHM systems. In particular it focuses on the analysis of the possibility of studying the dynamics of the rotor and the detection of its failures during operation. The results of vibrothermography studies of impeller made of plastic are presented. The results of studies based on algorithms developed by the authors. The article also presents the concept of the use of thermal imaging research in fault detection and monitoring of the dynamic state of real objects.

Evaluation of Package Defects by Thermal Imaging Techniques

2002 ◽  
Author(s):  
Yongmei Liu ◽  
Rajen Dias
Keyword(s):  
Infrared Thermography ◽  
Thermal Imaging ◽  
High Speed ◽  
Imaging Techniques ◽  
Thermal Response ◽  
Analysis Tool ◽  
Nondestructive Analysis ◽  
Ir Camera ◽  
External Heating

Abstract Study presented here has shown that Infrared thermography has the potential to be a nondestructive analysis tool for evaluating package sublayer defects. Thermal imaging is achieved by applying pulsed external heating to the package surface and monitoring the surface thermal response as a function of time with a high-speed IR camera. Since the thermal response of the surface is affected by the defects such as voids and delamination below the package surface, the technique can be used to assist package defects detection and analysis.

scholarly journals Techniques for In Vivo Measurement of Ligament and Tendon Strain: A Review

2020 ◽  
Vol 49 (1) ◽  
pp. 7-28
Author(s):  
Qiang Zhang ◽  
Naomi C. Adam ◽  
S. H. Hosseini Nasab ◽  
William R. Taylor ◽  
Colin R. Smith
Keyword(s):  
Soft Tissue ◽  
Strain Measurement ◽  
Sports Medicine ◽  
Imaging Techniques ◽  
Cruciate Ligament ◽  
Measurement Techniques ◽  
Tendon Repair ◽  
Strain Sensors ◽  
Superficial Tissues

AbstractThe critical clinical and scientific insights achieved through knowledge of in vivo musculoskeletal soft tissue strains has motivated the development of relevant measurement techniques. This review provides a comprehensive summary of the key findings, limitations, and clinical impacts of these techniques to quantify musculoskeletal soft tissue strains during dynamic movements. Current technologies generally leverage three techniques to quantify in vivo strain patterns, including implantable strain sensors, virtual fibre elongation, and ultrasound. (1) Implantable strain sensors enable direct measurements of tissue strains with high accuracy and minimal artefact, but are highly invasive and current designs are not clinically viable. (2) The virtual fibre elongation method tracks the relative displacement of tissue attachments to measure strains in both deep and superficial tissues. However, the associated imaging techniques often require exposure to radiation, limit the activities that can be performed, and only quantify bone-to-bone tissue strains. (3) Ultrasound methods enable safe and non-invasive imaging of soft tissue deformation. However, ultrasound can only image superficial tissues, and measurements are confounded by out-of-plane tissue motion. Finally, all in vivo strain measurement methods are limited in their ability to establish the slack length of musculoskeletal soft tissue structures. Despite the many challenges and limitations of these measurement techniques, knowledge of in vivo soft tissue strain has led to improved clinical treatments for many musculoskeletal pathologies including anterior cruciate ligament reconstruction, Achilles tendon repair, and total knee replacement. This review provides a comprehensive understanding of these measurement techniques and identifies the key features of in vivo strain measurement that can facilitate innovative personalized sports medicine treatment.

Fruit Ripeness Estimation for Avocado Using Thermal Imaging

2018 ◽  
Author(s):  
Sathish K. Gurupatham ◽  
Erhan Ilksoy ◽  
Nick Jacob ◽  
Kevin Van Der Horn ◽  
Fahad Fahad
Keyword(s):  
Thermal Imaging ◽  
Imaging Techniques ◽  
Scientific Enterprise ◽  
Thermal Images ◽  
Novel Technologies ◽  
Different Temperatures ◽  
Visible Images ◽  
Specific Heat Capacities ◽  
Analytical Approaches ◽  
Non Destructive

Novel technologies have always been an indispensable part of the scientific enterprise and a catalyst for new discoveries. The invisible radiation patterns of objects are converted into visible images called thermograms or thermal images. Thermal images can be utilized to estimate the ripeness of some fruits which do not change their color from yellow to green when they are ripe. Thermal imaging techniques are very helpful since color and fluorescent analytical approaches cannot be applied to these fruits. In this work, it is shown that different ripeness levels of avocado (Hall type) using a non-destructive method called thermal imaging, in two dimensional spaces. The work is based on the fact that fruits have different specific heat capacities at different temperatures, thus making their thermal images clear indicators of ripeness.

scholarly journals Non-Destructive Characterization of Railway Materials and Components with Infrared Thermography Technique

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4077 ◽  
Author(s):  
Jeongguk Kim
Keyword(s):  
Infrared Thermography ◽  
Thermal Imaging ◽  
High Speed ◽  
Hot Spot ◽  
Imaging Techniques ◽  
Brake Disc ◽  
Ir Thermography ◽  
Contact Mode ◽  
Non Destructive Evaluation ◽  
Non Destructive

Infrared (IR) thermography technology is one of the leading non-destructive evaluation (NDE) techniques based on infrared detection. Infrared thermography, in particular, has the advantage of not only being used in non-contact mode but also provides full images, real-time inspection, and relatively fast results. These advantages make it possible to perform thermal imaging analysis of railway materials and/or components, such as brake disc simulation, monitoring of abnormal heat generation, and monitoring of temperature changes, during mechanical tests. This study introduces the current state of research on railway materials and/or components using IR thermography technology. An attempt was made to characterize the deterioration of electrical equipment of diesel electric locomotives using infrared thermal imaging techniques. In addition, surface temperature monitoring was performed during tensile testing of railway steels using a high-speed infrared camera. Damage evolution due to the hot spot generation of railway brake discs was successfully monitored using high-speed IR cameras. In this paper, IR thermal imaging technology, used as a non-destructive evaluation analysis in the railway field, was introduced, and the results of recent research are presented.

CS02-03 - Imaging depression

2011 ◽  
Vol 26 (S2) ◽  
pp. 1773-1773
Author(s):  
J.-l. Martinot
Keyword(s):  
Brain Function ◽  
Imaging Techniques ◽  
Meta Analysis ◽  
Significant Proportion ◽  
White Matter Microstructure ◽  
Imaging Research ◽  
Spatial Coordinates ◽  
Patient Groups ◽  
Resistant Depression ◽  
Subcortical Regions

ContextPET and MRI investigations performed in patient groups with major depressive disorder (MDD) by our team in Orsay searched for differences of regional brain measures during treatments.ResultsIn the patient samples investigated, thorough analysis of cortical surface and metabolism suggested marked deviations in patients with resistant depression, while abnormalities of white matter microstructure were still present in euthymic patients (1–4). Relationship with treatment response was investigated (5). Recent ALE meta-analysis of Talairach’ spatial coordinates reported in the literature on adolescent MDD confirms that imaging techniques of brain function and brain structure revealed a consistent network of frontal limbic and subcortical regions (1)ConclusionWhile the diagnosis of MDD is symptom-based by definition, brain imaging research provided a bunch of convergent information on the regions mediating the depressive syndrome, and supports a significant proportion of MDD patients have brain deviations in both regional function and regional structure measurements.

Transient Thermal Response of Skin Tissue

2008 ◽  
Author(s):  
Muge Pirtini Cetingul ◽  
Cila Herman
Keyword(s):  
Temperature Distribution ◽  
Surface Temperature ◽  
Thermal Imaging ◽  
Imaging Techniques ◽  
Thermal Response ◽  
Sensitivity Study ◽  
Subsurface Structures ◽  
Surface Temperature Distribution ◽  
Transient Thermal ◽  
Transient Thermal Response

The increased availability of thermal imaging cameras has led to a growing interest in the application of infrared imaging techniques to the detection and identification of subsurface structures. These imaging techniques are based on the following principle: when a surface is heated or cooled, variations in the thermal properties of a structure located underneath the surface result in identifiable temperature contours on it. These contours are characteristic of the structure’s shape, depth, and its thermal properties. We study the use of the transient thermal response of skin layers to determine to which extent the surface temperature distribution reflects the properties of subsurface structures, such as lesions. A numerical model using the finite element method is described to obtain this response and key results are reported in the paper. A sensitivity study is conducted first to better understand the thermal response of the system and the role of various system and model parameters. We explore the extent to which we are able to draw conclusions regarding the size, depth and nature of subsurface structures and accuracy of these conclusions based on the surface temperature response alone. This work validates the idea of examining the transient thermal response and using thermal imaging as a solution for lesion identification. A sensitivity study of surface temperature distribution to variations of thermophysical properties, blood perfusion rate, and thicknesses of skin layers is performed. It is observed that variations in these parameters have little impact on the surface temperature distribution. The work reported in the paper is a portion of a comprehensive research effort involving experiments on a phantom model as well as measurements on patients. Future work will focus on comparing the results of our 2D numerical modeling efforts with the experimental results using a skin tissue-mimicking phantom. Knowledge gained from the modeling and experimental efforts will be utilized in characterizing lesions in patient studies. The focus of this paper is the computational sensitivity analysis.

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