Can infrared thermography be used to monitor fatigue during exercise? A case study

Background: Infrared thermographic imaging(IRTG) is a safe and reliable technology used to monitor skin temperature. The main aim of our study was to evaluate the relationship between skin temperature changes and muscle fatigue in order to answer the main research question if IRTG can be used to monitor muscle fatigue.Methods: This was a case study performed on a 23-year-old trained middle distance runner. After warm-up the subject was exercising on the dynamometer for 7.5 min at 120?/s performing only concentric contractions of quadriceps. At the same time IRTG recording of both(exercising and non-exercising) quadriceps was performed.Results: A correlational analysis that was performed in order to quantify the relationship between power and temperature change over time has shown that there is a significant negative correlation between skin temperature increase and power decrease(r = -0.543, p = 0.036) of exercising quadriceps. In linear regression model the exercising quadriceps power could be predicted from skin temperature. No such relationships were noted for the non-exercising limb that served as a control.Conclusion: We believe that correlation between skin temperature change and muscle power output as described in this case study deserves further analysis on the larger sample including subjects of the different ages, health status, and physical abilities in order to create a new tool for monitoring the muscle fatigue.

Thermal Diagnosis of Heat Conduction and Combustion Time of Fruits of the Brazil Nut Tree (<i>Bertholletia excelsa</i>Bonpl.)

The objective of this work was to evaluate the spatial and temporal dynamics of the process of combustion of fruits of the Brazil nut tree (Bertholletia excelsa Bonpl.) using thermographic images in order to characterize the potential of this biomass as an energy source for use in ceramic kilns. Infrared thermography was used as a diagnostic tool, and the trial was conducted in November 2018, in two blocks with two repetitions in each, with the fruits organized so that the cavity was oriented upward and also downward. The thermograms were analyzed using Flir Tools (6.3 v). The temperatures were the highest in the center of the fruits (>160&deg;C), attaining incandescence in 6 min 30 s. Heat was propagated from the center to the edge, and this process was quicker for fruits with their cavities pointed upward. A second order polynomial model explained combustion time with a maximum duration of 7.2 minutes. The thermographic diagnostic has the potential to be used in management strategies for this biomass as an energy source, thus aggregating value to the residuals that are normally left in the forest during harvest by extractivists.

Effect of undercut defect on deformation behavior TC4 titanium alloy laser welded butt joint under static tensile loading

By measuring and analyzing infrared thermal image of the specimen in static load tensile test process, it was studied that the influence of the undercut defects and double-sided dressing method on the deformation behavior of the laser welded joint specimens of TC4 titanium alloy. The results showed that for the unmodified specimens, the yield phenomenon occurs first in the region of the joint, but the undercut value has an effect on the stress and strain of starting to yield phenomenon, and a great effect on the plastic deformation behavior.When the undercut is less than a certain value, the large plastic deformation occurs in the base metal region and the plasticity of the specimen is comparable to that of the base metal, but the larger undercut defect results in a concentrated plastic deformation in the joint region and rapidly failed in this region. But the double-sided dressing specimen is significantly different. The physical yield is no longer concentrated in the joint region, but at the same time occurs in the several regions including joint and the base metal. And the plastic deformation mainly occurs in the base material area, similar to that of the base material.

Integrated Condition Monitoring of Large Captive Power Plants and Aluminum Smelters

Condition monitoring is implementation of the advanced diagnostic techniques to reduce downtime and to increase the efficiency and reliability.The research is for determining the usage of advanced techniques like Vibration analysis,Oil analysis and Thermography to diagnose ensuing problems of the Plant and Machinery at an early stage and plan to take corrective and preventive actions to eliminate the forthcoming breakdown and enhancing the reliability of the system.Nowadays,the most of the industries have adopted the condition monitoring techniques as a part of support system to the basic maintenance strategies.Major condition monitoring technique they follow is Vibration Spectrum Analysis,which can detect faults at a very early stage.However implementation of other techniques like Oil analysis or Ferrography,Thermography etc.can further enhance the data interpretation as they would detect the source of abnormality at much early stage thus providing us with a longer lead time to plan and take the corrective actions.In Large Captive Power Plants and Aluminium Smelters,Integrated Condition Monitoring techniques play an important role as stoppage of primary system and its auxiliaries(boiler,steam turbine,generator,coal and ash handling plants etc.)results into the stoppage of the entire plant,which in turn leads to loss of productivity.From economical and operational point of view,it is desirable to ensure optimum level of system availability.

Infrared experiment on the wall temperature distribution for a particle packed channel with constant heat flux

With constant heat flux, wall temperature distribution for a particle filled channel was measured using infrared thermal vision technology. It was found that non-uniform relative high-temperature regions were randomly distributed on the heating wall, possibly due to the lower flow velocity, or even due to the blocked flow near the points where particles contact with the heating wall directly. Not only porosity but also the size and shape of the pores are changed in the wall region of particle-packed structures, because of the limitation of the wall, and the changes affect largely the fluid flow and heat transfer. The transition of the flow pattern in pores can be inferred according to the variation of Nu with Re, where the area weighted wall temperature is adopted to calculate the Nu.