Inspection of Reinforced Concrete Structures Using Active Infrared Thermography

Reinforced concrete is currently the most widely used construction material. The wide field of applications forces the usage of the advanced techniques for quality control and tests of these structures. Most frequently it is required, that such tests should be possible to perform after the reinforced concrete hardening, during its usage and without damaging the structure. Therefore, various non-destructive testing techniques are here the natural choice. There are several aspects of possible non-destructive evaluation of reinforced concrete structures. One of them is the detection and assessment of the rebars. The authors propose here selected active thermography techniques. In case of the active thermography, an external energy source has to be used to induce the thermal response of the tested specimen. For concrete structures heating source based on the radiation phenomena (like halogen lamps, flash lamps, infrared radiators and similar) may be not effective due to, usually, large size of the examined structures. Therefore, authors propose two different heating techniques: a microwave heating and an induction heating. The microwave heating has volumetric character and its ratio depends not only on thermal properties of the material, but also on electrical properties. In case of metals (rebars made of a steel) microwave heating is not effective, thus the colder spots observed on the specimens’ surface will indicate presence of the rebars. On the contrary, the induction heating, generates the heat by eddy currents only in the metal objects. The hot spots will indicate the rebars’ positions. In this article authors will present selected experimental results, which will allow to evaluate and compare the proposed two techniques of heating suitability of each one to assess the reinforced concrete by using the active thermography will be discussed

Study of Electron Transport in Fullerene (C60) Quantum Confined Channel Layer Based Field Effect Transistor

In this work, we modelled a simple n-channel Si Metal-Quantum confined layer-Semiconductor Field Effect Transistor (MQSFET), which resembles exactly as the conventional Si Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) where SiO2 dielectric layer is replaced with a wide band gap C60 quantum confined layer of thickness 3nm and gold (Ψ=5.1eV) as metal contact. The capacitance and voltage characteristics at different temperatures from 100 K to 500 K and energy band gap are studied using Multi-dielectric Energy Band Diagram Program (MEBDP) simulation software, performed current-voltage transistor characteristics and analyzed the mobility of the charge carrier in the MQS sandwiched device structure using the Caughey-Thomas high saturation mobility model and the Lombardi surface mobility model. In these studies, we inferred a very low threshold voltage, when the donor concentration in the p-Si substrate is tuned between 1E16 to 1E17 cm-3 and a saturated flow of nanoamperes range of charge carrier at a low gate potential is even possible

Epicardial adipose tissue - a new metabolic marker?

Autorzy niniejszej pracy zwracają uwagę na rosnące zainteresowanie pozatrzewnymi magazynami tłuszczu, które mogą być wskaźnikami zaburzeń metabolicznych. Prowadzone badania nad tkanką tłuszczową nasierdziową wskazują na jej ścisłe anatomiczne i funkcjonalne powiązanie z mięśniem sercowym, a także udział w jego metabolizmie. Dostępność i wiarygodność badania echokardiograficznego w ocenie tkanki tłuszczowej nasierdziowej najprawdopodobniej pozwoli wykorzystać dane z badania do oceny leczenia zespołu metabolicznego.Extravisceral stores of adipose tissue arise increasing interest as they can be markers of metabolic disturbances. Studies on epicardial adipose tissue indicate its close anatomical and functional relationship with the heart muscle, as well as its role in the cardiac metabolism. Availability and reliability of the echocardiographic examination evaluating epicardial adipose tissue may be used in the management of metabolic syndrome

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Praca recenzowana / peer-reviewed pape

Detection and Inspection of Steel Bars in Reinforced Concrete Structures Using Active Infrared Thermography with Microwave Excitation and Eddy Current Sensors

The purpose of this paper is to present a multi-sensor approach to the detection and inspection of steel bars in reinforced concrete structures. In connection with our past experience related to non-destructive testing of different materials, we propose using two potentially effective methods: active infrared thermography with microwave excitation and the eddy current technique. In this article active infrared thermography with microwave excitation is analyzed both by numerical modeling and experiments. This method, based on thermal imaging, due to its characteriatics should be considered as a preliminary method for the assessment of relatively shallowly located steel bar reinforcements. The eddy current technique, on the other hand, allows for more detailed evaluation and detection of deeply located rebars. In this paper a series of measurement results, together with the initial identification of certain features of steel reinforcement bars will be presented

An Evaluation of 3D-Printed Materials’ Structural Properties Using Active Infrared Thermography and Deep Neural Networks Trained on the Numerical Data

This article describes an approach to evaluating the structural properties of samples manufactured through 3D printing via active infrared thermography. The mentioned technique was used to test the PETG sample, using halogen lamps as an excitation source. First, a simplified, general numerical model of the phenomenon was prepared; then, the obtained data were used in a process of the deep neural network training. Finally, the network trained in this manner was used for the material evaluation on the basis of the original experimental data. The described methodology allows for the automated assessment of the structural state of 3D−printed materials. The usage of a generalized model is an innovative method that allows for greater product assessment flexibility

Resistance of thin disks and rings

In this paper the following, classic problem [1] is taken into consideration: calculate the resistance between two, perfectly conducting contacts on the rim of a thin disk (t > δ, where δ is the contacts’ size and d indicates the distance between them). Our purpose was to find more general solution, valid for contacts of finite size. Moreover, we propose the extension of above problem to thin rings. The exact analytical method of solving the Laplace equation to find the scalar potential was used. Afterwards, the Ohm law to obtain the formulas for disks and rings resistance was utilized. Using the dilogarithm function we obtained simplified, approximate formulas for the disks and rings resistance

Inspection of Reinforced Concrete Structures Using Active Infrared Thermography

Reinforced concrete is currently the most widely used construction material. The wide field of applications forces the usage of the advanced techniques for quality control and tests of these structures. Most frequently it is required, that such tests should be possible to perform after the reinforced concrete hardening, during its usage and without damaging the structure. Therefore, various non-destructive testing techniques are here the natural choice. There are several aspects of possible non-destructive evaluation of reinforced concrete structures. One of them is the detection and assessment of the rebars. The authors propose here selected active thermography techniques. In case of the active thermography, an external energy source has to be used to induce the thermal response of the tested specimen. For concrete structures heating source based on the radiation phenomena (like halogen lamps, flash lamps, infrared radiators and similar) may be not effective due to, usually, large size of the examined structures. Therefore, authors propose two different heating techniques: a microwave heating and an induction heating. The microwave heating has volumetric character and its ratio depends not only on thermal properties of the material, but also on electrical properties. In case of metals (rebars made of a steel) microwave heating is not effective, thus the colder spots observed on the specimens’ surface will indicate presence of the rebars. On the contrary, the induction heating, generates the heat by eddy currents only in the metal objects. The hot spots will indicate the rebars’ positions. In this article authors will present selected experimental results, which will allow to evaluate and compare the proposed two techniques of heating suitability of each one to assess the reinforced concrete by using the active thermography will be discussed.</p

Detection and Identification of Defects in 3D-Printed Dielectric Structures via Thermographic Inspection and Deep Neural Networks

In this paper, we propose a new method based on active infrared thermography (IRT) applied to assess the state of 3D-printed structures. The technique utilized here—active IRT—assumes the use of an external energy source to heat the tested material and to create a temperature difference between undamaged and defective areas, and this temperature difference is possible to observe with a thermal imaging camera. In the case of materials with a low value of thermal conductivity, such as the acrylonitrile butadiene styrene (ABS) plastic printout tested in the presented work, the obtained temperature differences are hardly measurable. Hence, the proposed novel IRT method is complemented by a dedicated algorithm for signal analysis and a multi-label classifier based on a deep convolutional neural network (DCNN). For the initial testing of the presented methodology, a 3D printout made in the shape of a cuboid was prepared. One type of defect was tested—surface breaking holes of various depths and diameters that were produced artificially by inclusion in the printout. As a result of examining the sample via the IRT method, a sequence of thermograms was obtained, which enabled the examination of the temporal representation of temperature variation over the examined region of the material. First, the obtained signals were analysed using a new algorithm to enhance the contrast between the background and the defect areas in the 3D print. In the second step, the DCNN was utilised to identify the chosen defect parameters. The experimental results show the high effectiveness of the proposed hybrid signal analysis method to visualise the inner structure of the sample and to determine the defect and size, including the depth and diameter