Quantitative Three-Dimensional Imaging of Heterogeneous Materials by Thermal Tomography

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
J. G. Sun
Keyword(s):  
Thermal Imaging ◽  
Three Dimensional ◽  
Heterogeneous Materials ◽  
Thermal Effusivity ◽  
Test Sample ◽  
Imaging Data ◽  
Entire Volume ◽  
Multilayer Material ◽  
Infrared Thermal Imaging ◽  
Thermal Tomography

Infrared thermal imaging based on active thermal excitations has been widely used for nondestructive evaluation (NDE) of materials. While the experimental systems have remained essentially the same during the last few decades, development of advanced data-processing methods has significantly improved the capabilities of this technology. However, many limitations still exist. One fundamental limitation is the requirement, either explicitly or implicitly, of the tested material to be homogeneous such that detected thermal contrasts may be used to determine an average material property or attributed to flaws. In this paper, a new thermal tomography (TT) method is introduced, which for the first time can evaluate heterogeneous materials by directly imaging their thermal-property variations with space. It utilizes one-sided flash thermal-imaging data to construct the three-dimensional (3D) distribution of thermal effusivity in the entire volume of a test sample. Theoretical analyses for single and multilayer material systems were conducted to validate its formulation and to demonstrate its performance. Experimental results for a ceramic composite plate and a thermal barrier coating (TBC) sample are also presented. It was shown that thermal diffusion is the primary factor that degrades the spatial resolution with depth for TT; the spatial resolutions in the lateral and axial directions were quantitatively evaluated.

scholarly journals An investigation of the Temperature Distribution of a Thin Steel Strip during the Quenching Step of a Hardening Process

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 675 ◽  
Author(s):  
Pouyan Pirouznia ◽  
Nils Å. I. Andersson ◽  
Anders Tilliander ◽  
Pär G. Jönsson
Keyword(s):  
Temperature Distribution ◽  
Numerical Model ◽  
Thermal Imaging ◽  
Steel Strip ◽  
Imaging Data ◽  
Infrared Thermal Imaging ◽  
Hardening Process ◽  
Real Process ◽  
Significant Temperature

The dimension quality of the strip within the hardening process is an essential parameter, which great attention needs to be paid. The flatness of the final product is influenced by the temperature distribution of the strip, specifically across the width direction. Therefore, based on physical theories, a numerical model was established. The temperature of the strip for the section before the martensitic transformation was objected in the predicted model by using a steady state approach. In addition an infrared thermal imaging camera was applied in the real process in order to validate the results and to improve the boundary conditions of the numerical model. The results revealed that the temperature of strip decreased up to 250 °C within the area between the furnace and the quenching bath. This, in turn, resulted in significant temperature difference across the width of the strip. This difference can be up to 69 °C and 41 °C according to the numerical results and thermal imaging data, respectively. Overall, this study gave a better insight into the cooling step in the hardening process. In addition, this investigation can be used to improve the hardening process as well as an input for future thermal stress investigations.

scholarly journals Model Smoke Stream Adsorption over Cellulose Acetate Stick with Three-dimensional Temperature Gradient by Combining in-situ DRIFTS with Infrared Thermal Imaging

2021 ◽  
Author(s):  
Xin Xu ◽  
Xi Du ◽  
Feng Zheng ◽  
Lisheng Guo ◽  
Panwei Shi ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Cellulose Acetate ◽  
Human Health ◽  
Thermal Imaging ◽  
Three Dimensional ◽  
Adsorption Properties ◽  
Mathematical Explanation ◽  
Infrared Thermal Imaging ◽  
Different Temperatures

Abstract Understanding the adsorption of the smoke stream (SR) on cellulose acetate stick as cigarette filter with different temperatures is beneficial for controlling chemical emissions and reducing the toxic effect of smoking on human health. However the investigation of corresponding adsorption properties was missing because the adsorption of smoke stream (SR) on cigarette cellulose acetate stick is sensitive with the three-dimensional temperature gradient. In this work, the adsorption of typical smoke stream substances, such as CO, propylene glycol, formaldehyde, and acetone, on cellulose acetate stick were studied by in-situ diffuse reflectance Fourier transform infrared spectroscopy with different temperatures assisted by the infrared thermal imaging method. The adsorption capacities of cellulose acetate stick to these typical smoke stream substances is dependent on the adsorption time and temperature. The adsorption properties all fitted well with the Freundlich model. By a spectroscopic and mathematical explanation, quantifying contours of adsorption was performed. The 3D model of the normalized CO adsorption of cellulose acetate stick versus the spatial coordinates and time was established. This study gives unparalleled insight into smoking release characteristics of tobacco filtered by cellulose acetate and regulating cellulose acetate stick for reducing the negative effect of smoke on human health.

scholarly journals Effects of salicylic acid elicitor against aphids on wheat and detection of infestation using infrared thermal imaging technique in Ismailia, Egypt

2015 ◽  
Vol 30 (2) ◽  
pp. 91-97 ◽  
Author(s):  
Farag Mahmoud ◽  
Hatem Mahfouz
Keyword(s):  
Salicylic Acid ◽  
Thermal Imaging ◽  
Insect Pests ◽  
Foliar Application ◽  
Imaging Technique ◽  
Wheat Yield ◽  
Yield Reduction ◽  
Imaging Data ◽  
Infrared Thermal Imaging ◽  
Aphid Infestation

Wheat (Triticum sativum L.) is one of the most important cereal crops in Egypt. Insect pests, such as aphids, are major threats in terms of yield reduction. Induced resistance in wheat using salicylic acid as a foliar application was tested on the farm of the Faculty of Agriculture, Suez Canal University during 2012/2013 and 2013/2014 seasons. Three wheat cultivars, Gemeza 9, Sakha 93 and Giza 168, were sprayed three times with two concentrations of salicylic acid (SA), 200 mg/l and 100 mg/l, after early detection of aphid infestation by infrared thermal imaging. The infrared thermal imaging technique is based on significant differences in surface temperature between infested and healthy leaves. Imaging data are digital, and a computer program can be used to detect infestation rapidly. The results showed that aphid infestation raised the temperature of infested leaves, compared to healthy leaves. The range temperature difference between maximum and minimum temperatures (At) was 1.1 ?C in healthy leaves and 3.9 ?C in infected leaves. The results of SA application showed significant differences in the mean number of aphids and in reduction of infestation among treatments and cultivars. The higher of the two SA rates (200 mg/l) gave higher efficacy in the three cultivars than the lower rate (100 mg/l) over the five weeks of trial. The highest efficacy against aphids was reached one week after application (86.28% for Giza, 85.89% for Gemesa and 70.54% for Sakha). Moreover, SA treatment enhanced the wheat yield of all three cultivars, compared with control plants. The three cultivars (Giza, Gemesa and Sakha) produced higher yields than the control when sprayed with 200 mg/l SA. Their grain yield was 2,491.5, 2,455.0, and 2,327.25 kg/feddan (1 fed = 0.42 ha), respectively. In conclusion, infrared thermal imaging can be employed in identification of infected leaves. Also, the application of SA on wheat induced plant resistance to aphids.

scholarly journals A Defect Detection Method for the Surface of Metal Materials Based on an Adaptive Ultrasound Pulse Excitation Device and Infrared Thermal Imaging Technology

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yibo Ai ◽  
Yingjie Zhang ◽  
Xingzhao Cao ◽  
Weidong Zhang
Keyword(s):  
Thermal Imaging ◽  
Crack Detection ◽  
Control Method ◽  
Three Dimensional ◽  
Resonance State ◽  
Ultrasonic Pulse ◽  
Operating Conditions ◽  
Pulse Excitation ◽  
Infrared Thermal Imaging ◽  
Imaging Technology

Ultrasonic excitation has been widely used in the detection of microcracks on metal surfaces, but there are problems such as poor excitation effect of ultrasonic pulse, long time to reach the best excitation, and difficult to find microcracks. In this paper, an adaptive ultrasonic pulse excitation device and infrared thermal imaging technology have been combined, as well as their control method, to solve the problem. The adaptive ultrasonic pulse excitation device adds intelligent modules to realize automatic adjustment of detection parameters, which can quickly obtain reliable excitation; the multidegree-of-freedom base realizes the three-dimensional direction change of the ultrasonic gun to adapt to different excitation occasions. When the appropriate ultrasonic excitation makes microcracks in the resonance state, the microcracks can be frictionated, which produce heat rise with the temperature. Then, the microcrack defect can be detected by the infrared thermal instrument through the different surface temperatures with imaging recognition method. Our detection experiments of the titanium alloy plates and the aluminum alloy profiles of marine engineering show that the method can get reliable detection parameters in a short time and measure the crack length effectively. It can be used in many aspects such as crack detection in mechanical structures or complex equipment operating conditions and industrial production processes.

Preliminary Studies on the Functional and Structural Design of Forest Fire Helmet

2011 ◽  
Vol 228-229 ◽  
pp. 605-609
Author(s):  
Bo Li ◽  
Bin Li ◽  
Hong Ze Yang
Keyword(s):  
Wireless Communication ◽  
Forest Fire ◽  
Fire Protection ◽  
Structural Design ◽  
Thermal Imaging ◽  
Three Dimensional ◽  
Security Requirements ◽  
Infrared Thermal Imaging ◽  
Processing Software ◽  
Forest Fire Protection

In order to improve the performance of forest fire protection equipment, this paper proposes a new design concept of modern forest fire helmet. The scheme combines the functions of infrared thermal imaging, wireless communication and emergency oxygen making, which not only meets the security requirements in firemen’s present working, but also accords with the development of fire helmets at home and abroad. This helmet adopts the design conception of integration structurally, its weight and operation difficulty are both reduced, at the same time, accords with the Man-Machine Engineering. Moreover, using the three-dimensional processing software, this study realizes a simulation model of the designed forest fire helmet.

scholarly journals Effects of interfaces and current spreading on the thermal transport of micro-LEDs for kA-per-square-cm current injection levels

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24203-24211
Author(s):  
Chengcheng Li ◽  
Zhizhong Chen ◽  
Fei Jiao ◽  
Jinglin Zhan ◽  
Yifan Chen ◽  
...  
Keyword(s):  
Thermal Imaging ◽  
Light Emitting Diodes ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Forward Voltage ◽  
Infrared Thermal Imaging ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Thermal Transient ◽  
Transient Measurements

The three-dimensional thermal characteristics of micro-light-emitting diodes (μLEDs) on GaN and sapphire substrates were studied with forward-voltage methods, thermal transient measurements, and infrared thermal imaging.

scholarly journals INFRARED THERMAL IMAGING AS AN INNOVATIVE APPROACH FOR EARLY DETECTION INFESTATION OF STORED PRODUCT INSECTS IN CERTAIN STORED GRAINS

2020 ◽  
Vol 52 (4) ◽  
pp. 321-331
Author(s):  
A. I. IBRAHIM ◽  
M. A. YOUSRY ◽  
M. I. SAAD ◽  
M. F. MAHMOUD ◽  
Maysa SAID ◽  
...  
Keyword(s):  
Early Detection ◽  
Thermal Imaging ◽  
Large Scale ◽  
Negative Impact ◽  
Imaging Data ◽  
Infrared Thermal Imaging ◽  
Stored Product Insects ◽  
Stored Grains ◽  
White Bean

Grains of field crops, such as wheat, maize, faba bean and white bean, are considered strategic food for humanity worldwide and Egypt. Unfortunately, percent losses of grains quantity may reach to 15-30%, as a result of stored product insect damage, and the losses increased dramatically in the last years, as an outcome of quickly productions of these pests. Experiments were conducted on infrared thermal imaging that demonstrate early detection of infestation by stored product insects in wheat, maize, broad bean, white bean and bean grains. The imaging is dependent on subtle significant differences in temperature between infested and healthy grains. Because the thermal imaging data are digital, computer programs can be used to analysis differences in temperature and mining figures explained for that. Results revealed that the use of thermal imaging offers an alternative method to detect an insect infestation. Data concluded that thermal imaging has the potential to identify whether the grains of crops that tested are infested or not, but is less effective in identifying which developmental stage is present. Moreover, it could apply this technique easily on a large scale in silos, storage, mills and granaries without negative impact on quality of stored grains.

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