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Sample records for ir thermography methods

  1. The development of in-situ calibration method for divertor IR thermography in ITER

    SciTech Connect

    Takeuchi, M.; Sugie, T.; Ogawa, H.; Takeyama, S.; Itami, K.

    2014-08-21

    For the development of the calibration method of the emissivity in IR light on the divertor plate in ITER divertor IR thermography system, the laboratory experiments have been performed by using IR instruments. The calibration of the IR camera was performed by the plane black body in the temperature of 100–600 degC. The radiances of the tungsten heated by 280 degC were measured by the IR camera without filter (2.5–5.1 μm) and with filter (2.95 μm, 4.67 μm). The preliminary data of the scattered light of the laser of 3.34 μm that injected into the tungsten were acquired.

  2. The development of in-situ calibration method for divertor IR thermography in ITER

    NASA Astrophysics Data System (ADS)

    Takeuchi, M.; Sugie, T.; Ogawa, H.; Takeyama, S.; Itami, K.

    2014-08-01

    For the development of the calibration method of the emissivity in IR light on the divertor plate in ITER divertor IR thermography system, the laboratory experiments have been performed by using IR instruments. The calibration of the IR camera was performed by the plane black body in the temperature of 100-600 degC. The radiances of the tungsten heated by 280 degC were measured by the IR camera without filter (2.5-5.1 μm) and with filter (2.95 μm, 4.67 μm). The preliminary data of the scattered light of the laser of 3.34 μm that injected into the tungsten were acquired.

  3. IR Thermography NDE of ISS Radiator Panels

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay; Winfree, William; Morton, Richard; Wilson, Walter; Reynolds, Gary

    2010-01-01

    The presentation covers an active and a passive infrared (IR) thermography for detection of delaminations in the radiator panels used for the International Space Station (ISS) program. The passive radiator IR data was taken by a NASA astronaut in an extravehicular activity (EVA) using a modified FLIR EVA hand-held camera. The IR data could be successfully analyzed to detect gross facesheet disbonds. The technique used the internal hot fluid tube as the heat source in analyzing the IR data. Some non-flight ISS radiators were inspected using an active technique of IR flash thermography to detect disbond of face sheet with honeycomb core, and debonds in facesheet overlap areas. The surface temperature and radiated heat emission from flight radiators is stable during acquisition of the IR video data. This data was analyzed to detect locations of unexpected surface temperature gradients. The flash thermography data was analyzed using derivative analysis and contrast evolutions. Results of the inspection are provided.

  4. Corrosion detection on pipelines by IR thermography

    NASA Astrophysics Data System (ADS)

    Bison, P.; Marinetti, S.; Cuogo, G.; Molinas, B.; Zonta, P.; Grinzato, E.

    2011-05-01

    IR thermography is applied to detect hidden corrosion on carbon steel pipelines for oil transportation. The research is oriented to set up a robust technique to carry out in situ the early detection of corroded zones that may evolve either towards leakage or failure. The use of thermography associated with a transient thermal technique is investigated on 12.2 mm thick samples, machined to artificially create a reduction of wall thickness that simulates the effect of real corrosion in pipes. The extension and depth of the artificial defects is controlled by ultrasounds which represents the reference for the results obtained by thermography. Two approaches are proposed: the first is based on the processing of a single thermogram taken at the optimum time after a finite pulse heating of a large area of the external surface; the second technique is carried out by scanning the pipeline by means of a device composed of a linear lamp and a thermographic camera which move jointly over the surface to test. A suitable reconstruction provides a map of the tested surface with possible hot spots in correspondence with the corroded areas. The analysis of the thermal problem by Finite Element Method is used to optimize the experimental parameters. The experimental results demonstrate a detection capability starting from 15 % of wall thickness reduction.

  5. Air tightness monitoring by IR thermography

    NASA Astrophysics Data System (ADS)

    Grinzato, Ermanno G.; Marinetti, Sergio; Bison, Paolo G.

    2004-04-01

    The standard air tightness test of containers is based on measurement of global parameters as the outlet of a specific gas, detected by specialised mass spectrometers. The identification and location of air leakages is extremely important especially for the container manufacturer. At the same time, the measure of the mass flux is of importance. IR Thermography has been successfully applied for leakages detection on buildings, but unfortunately, the noise due to The standard air tightness test of containers is based on measurement of global parameters as the outlet of a specific gas, detected by specialised mass spectrometers. The identification and location of air leakages is extremely important especially for the container manufacturer. At the same time, the measure of the mass flux is of importance. IR Thermography has been successfully applied for leakage detection on buildings, but unfortunately, the noise due to environment limits its applicability, particularly in case of a small flux. A new thermal procedure has been developed for the leakage detection. The technique is based on the stimulation of the envelope with a low oscillating heat flux and lock-in analysis. An airflow is injected, with a harmonically varying flowrate and a slightly higher temperature than the ambient. Then, the thermograms sequence is analyzed in the frequency domain. A review of quantitative techniques for the convective heat exchange measurement is reported. The procedure has been utilized for special containers used for both transport and exhibition of pictures inside museums. Tests performed before and after gaskets improvements show the capability of the technique to estimate qualitatively the airflow.

  6. Heat transfer investigation in pipe by IR thermography

    NASA Astrophysics Data System (ADS)

    Koppel, Tiit; Ainola, Leo; Ekholm, Ari; Lahdeniemi, Matti

    2000-03-01

    The IR-thermography has proved to be a useful contactless instrument in fluid flow research, especially for investigation of heat transfer processes. Series of experimental measurements of suddenly accelerated and pulsating pipe flow were made at Satakunta Polytechnic, Technology in Pori, Finland, with this aim.

  7. IR Thermography of International Space Station Radiator Panels

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay; Winfree, WIlliam; Morton, Richard; Howell, Patricia

    2010-01-01

    Several non-flight qualification test radiators were inspected using flash thermography. Flash thermography data analysis used raw and second derivative images to detect anomalies (Echotherm and Mosaic). Simple contrast evolutions were plotted for the detected anomalies to help in anomaly characterization. Many out-of-family indications were noted. Some out-of-family indications were classified as cold spot indications and are due to additional adhesive or adhesive layer behind the facesheet. Some out-of-family indications were classified as hot spot indications and are due to void, unbond or lack of adhesive behind the facesheet. The IR inspection helped in assessing expected manufacturing quality of the radiators.

  8. Divertor IR thermography on Alcator C-Mod.

    PubMed

    Terry, J L; LaBombard, B; Brunner, D; Payne, J; Wurden, G A

    2010-10-01

    Alcator C-Mod is a particularly challenging environment for thermography. It presents issues that will similarly face ITER, including low-emissivity metal targets, low-Z surface films, and closed divertor geometry. In order to make measurements of the incident divertor heat flux using IR thermography, the C-Mod divertor has been modified and instrumented. A 6° toroidal sector has been given a 2° toroidal ramp in order to eliminate magnetic field-line shadowing by imperfectly aligned divertor tiles. This sector is viewed from above by a toroidally displaced IR camera and is instrumented with thermocouples and calorimeters. The camera provides time histories of surface temperatures that are used to compute incident heat-flux profiles. The camera sensitivity is calibrated in situ using the embedded thermocouples, thus correcting for changes and nonuniformities in surface emissivity due to surface coatings. PMID:21034041

  9. Divertor IR thermography on Alcator C-Mod

    SciTech Connect

    Terry, J. L.; LaBombard, B.; Brunner, D.; Payne, J.; Wurden, G. A.

    2010-10-15

    Alcator C-Mod is a particularly challenging environment for thermography. It presents issues that will similarly face ITER, including low-emissivity metal targets, low-Z surface films, and closed divertor geometry. In order to make measurements of the incident divertor heat flux using IR thermography, the C-Mod divertor has been modified and instrumented. A 6 deg. toroidal sector has been given a 2 deg. toroidal ramp in order to eliminate magnetic field-line shadowing by imperfectly aligned divertor tiles. This sector is viewed from above by a toroidally displaced IR camera and is instrumented with thermocouples and calorimeters. The camera provides time histories of surface temperatures that are used to compute incident heat-flux profiles. The camera sensitivity is calibrated in situ using the embedded thermocouples, thus correcting for changes and nonuniformities in surface emissivity due to surface coatings.

  10. Divertor IR thermography on Alcator C-Moda)

    NASA Astrophysics Data System (ADS)

    Terry, J. L.; LaBombard, B.; Brunner, D.; Payne, J.; Wurden, G. A.

    2010-10-01

    Alcator C-Mod is a particularly challenging environment for thermography. It presents issues that will similarly face ITER, including low-emissivity metal targets, low-Z surface films, and closed divertor geometry. In order to make measurements of the incident divertor heat flux using IR thermography, the C-Mod divertor has been modified and instrumented. A 6° toroidal sector has been given a 2° toroidal ramp in order to eliminate magnetic field-line shadowing by imperfectly aligned divertor tiles. This sector is viewed from above by a toroidally displaced IR camera and is instrumented with thermocouples and calorimeters. The camera provides time histories of surface temperatures that are used to compute incident heat-flux profiles. The camera sensitivity is calibrated in situ using the embedded thermocouples, thus correcting for changes and nonuniformities in surface emissivity due to surface coatings.

  11. Application of IR thermography for unsteady fluid-flow research

    NASA Astrophysics Data System (ADS)

    Koppel, Tiit; Lahdeniemi, Matti; Ekholm, Ari

    1998-03-01

    In the recent years the IR thermography technique has been sued successfully as a new contactless instrument for gas and fluid flow research in pipes and on the surface of a flat plate. It is well known that most energy changes in the flow take place in the boundary layer. This is in turn important for the intensity of convective heat transfer in pipe flows and enables to measure processes connected with energy changes in the flow from outside the pipe. Series of measurements of suddenly accelerated and pulsating pipe flow were made at Satakunta Polytechnic, Technology Pori, Finland. The theoretical criterion describing the transition from laminar to turbulent regime is found depending on the critical thickness of the boundary layer of suddenly accelerated flow. At the moment of transition of the 'plug' type flow into turbulent flow, the velocities in the wall region diminish and this can be detected using the IR thermography from the wall temperature changes. the experimental results of the mean velocity development and transition criteria correspond to the theoretical calculations. The changes of the internal structure of the flow affect the convective heat transfer and this in turn influences the pipe wall temperature. IR thermography measures pipe wall temperature changes and consequently we can detect flow structure changes in the boundary layer in the accelerated and decelerated phase of the pulsating pipe flow.

  12. Inspecting thermal barrier coatings by IR thermography

    NASA Astrophysics Data System (ADS)

    Bison, Paolo G.; Marinetti, Sergio; Grinzato, Ermanno G.; Vavilov, Vladimir P.; Cernuschi, Federico; Robba, Daniele

    2003-04-01

    As far as power generation is concerned, coating technologies find the main and more advanced applications. Nowadays, superalloys available for manufacturing hot path components in gas turbine like combustion liners, blades and vanes can not sustain temperatures up to 1100°C. In order to guarantee a significative temperature drop ceramic thermal barrier coatings are deposited onto the metallic core. The thickness of thermal barrier coatings (TBC) ranges from a few hundreds microns up to 1 millimetre or more, depending on component and deposition technique (mainly Air Plasma Spray or Electron Beam Physical Vapour Deposition). The structural integrity of both the substrate and the coating and their mutual adhesion is a key point because any loss of the protective layer exposes the bulk material to an extremely aggressive environment in terms of oxidation and temperature. Therefore, TBC must be tested for detecting of defects during both quality control and periodic in-service inspections. Because of the key role played by thickness and low thermal diffusivity of TBC in the decreasing of the substrate material temperature, both delaminations and thickness variation must be detected and classified. Pulsed Thermography has been successfully applied to this application field. Nevertheless, the procedure gives ambiguous results when thickness or thermal properties change in a continuous way within the thermal barrier. In this paper, a specific study on the detection performances of NDE techniques is presented, even when a non-uniform TBC thickness is superimposed to the disbonding defect. Tests performed at workshop on real and specifically manufactured components are reported. Dedicated processing algorithms improving the test reliability and effectiveness are presented as well. Tests on real components on the field are also reported.

  13. IR thermography for dynamic detection of laminar-turbulent transition

    NASA Astrophysics Data System (ADS)

    Simon, Bernhard; Filius, Adrian; Tropea, Cameron; Grundmann, Sven

    2016-05-01

    This work investigates the potential of infrared (IR) thermography for the dynamic detection of laminar-turbulent transition. The experiments are conducted on a flat plate at velocities of 8-14 m/s, and the transition of the laminar boundary layer to turbulence is forced by a disturbance source which is turned on and off with frequencies up to 10 Hz. Three different heating techniques are used to apply the required difference between fluid and structure temperature: a heated aluminum structure is used as an internal structure heating technique, a conductive paint acts as a surface bounded heater, while an IR heater serves as an example for an external heating technique. For comparison of all heating techniques, a normalization is introduced and the frequency response of the measured IR camera signal is analyzed. Finally, the different heating techniques are compared and consequences for the design of experiments on laminar-turbulent transition are discussed.

  14. Thermography.

    ERIC Educational Resources Information Center

    Cage, Bob N.

    1984-01-01

    Thermography, a diagnostic tool that combines photography and infrared sensing, permits direct measurement of apparent surface temperatures. Building energy losses can be detected and correction measures planned. Criteria for the use of thermography are provided. (MLF)

  15. High-resolution survey of buildings by lock-in IR thermography

    NASA Astrophysics Data System (ADS)

    Bortolin, A.; Cadelano, G.; Ferrarini, G.; Bison, P.; Peron, F.; Maldague, X.

    2013-05-01

    Applications of Infrared Thermography in buildings surveys are not limited to the identification of the temperature distribution and heat losses on building envelopes. As it is well known from NDT testing in industrial applications, active IR thermographic methods such as heating-up/cooling-down or lock-in thermography improve the results in many investigations. In civil engineering these techniques have not been used widely. Mostly, thermography is used in a quasistatic manner. This paper illustrates a new approach to achieve, by the lock-in technique, an in depth view of the structure of the wall evidencing the presence of buried elements, interfaces and cracks. The idea is to take advantage of the periodic heating and cooling of earth surface due to the alternating of day and night. The corresponding thermal wave has a period equal to 24 hours that can probe the walls of buildings with a penetration depth of the order of some centimeters. The periodic temperature signal is analysed to extract amplitude and phase. It is expected that the phase image gives the indication of inhomogeneity buried in the wall structure. As a case study, the exterior surface of Palazzo Ducale in Venice is analysed and illustrated. In addition to IR images, visible electromagnetic band is considered to evaluate the strength of the solar radiation and the geometrical distortion. Indeed, the periodicity due to the Earth rotation is only approximately of 24 hours. The passing clouds or the possibility of rainy days can superimpose other heating or cooling frequencies to the main one. The Fourier analysis of the impinging radiation on the wall is performed. The façade of Palazzo Ducale is tiled with stone of two different colours and types. A final attempt to automatically classify the stone tiles in the visible and infrared images is conducted.

  16. IR thermography for the assessment of the thermal conductivity of thermoelectric modules at intermediate temperature

    NASA Astrophysics Data System (ADS)

    Boldrini, S.; Ferrario, A.; Bison, P.; Miozzo, A.; Montagner, F.; Fabrizio, M.

    2016-05-01

    The correct measurement of the performances of thermoelectric (TE) modules for energy conversion is a mandatory task both for laboratory research and for industries engaged in TE modules development or in their integration into thermoelectric generators. A testing device oriented to the maximum flexibility, based on the heat flow meter method at the cold side of the module has been developed. The system is conceived to test TE modules (single or in cascade) with a footprint up to 60x60 mm2, from room temperature up to intermediate temperature. Modules can be tested under vacuum or inert atmosphere. Specifically, the flow meter is made of a block of material, with known thermal conductivity, in contact with the cold side of the thermoelectric module. The heat flow is finally determined by measuring the temperature profile along the heat flow path and that is obtained by IR thermography. IR thermography is also utilized to evaluate the contact resistance between the active thermoelectric elements made of ceramic materials and the ceramic layer working as heat diffuser and mechanical support. Some finite element thermal analyses of the system performed for its design are presented.

  17. CURVATURE EFFECT QUANTIFICATION FOR IN-VIVO IR THERMOGRAPHY.

    PubMed

    Cheng, Tze-Yuan; Deng, Daxiang; Herman, Cila

    2012-01-01

    Medical Infrared (IR) Imaging has become an important diagnostic tool over recent years. However, one underlying problem in medical diagnostics is associated with accurate quantification of body surface temperatures. This problem is caused by the artifacts induced by the curvature of objects, which leads to inaccurate temperature mapping and biased diagnostic results. Therefore, in our study, an experiment-based analysis is conducted to address the curvature effects toward the 3D temperature reconstruction of the IR thermography image. For quantification purposes, an isothermal copper plate with flat surface, and a cylindrical metal container filled with water are imaged. For the flat surface, the tilting angle measured from camera axis was varied incrementally from 0° to 60 °, such that the effects of surface viewing angle and travel distance on the measured temperature can be explored. On the cylindrical curved surface, the points viewed from 0° to 90° with respect to the camera axis are simultaneously imaged at different temperature levels. The experimental data obtained for the flat surface indicate that both viewing angle and distance effects become noticeable for angles over 40 °. The travel distance contributes a minor change when compared with viewing angle. The experimental results from the curved surface indicate that the curvature effect becomes pronounced when the viewing angle is larger than 60 °. The measurement error on the curved surface is compared with the simulation using the non-dielectric model, and the normalized temperature difference relative to 0° viewing angle was analyzed at six temperature levels. These results indicate that the linear formula associated with directional emissivity is a reasonable approximation for the measurement error, and the normalized error curves change consistently with viewing angle at various temperatures. Therefore, the analysis in this study implies that the directional emissivity based on the non

  18. Fuel Cell Manufacturing Diagnostic Techniques: IR Thermography with Reactive Flow through Excitation

    SciTech Connect

    Manak, A. J.; Ulsh, M.; Bender, G.

    2012-01-01

    While design and material considerations for PEMFCs have a large impact on cost, it is also necessary to consider a transition to high volume production of fuel cell systems, including MEA components, to enable economies of scale and reduce per unit cost. One of the critical manufacturing tasks is developing and deploying techniques to provide in‐process measurement of fuel cell components for quality control. This effort requires a subsidiary task: The study of the effect of manufacturing defects on performance and durability with the objective to establish validated manufacturing tolerances for fuel cell components. This work focuses on the development of a potential quality control method for gas diffusion electrodes (GDEs). The method consists of infrared (IR) thermography combined with reactive flow through (RFT) excitation. Detection of catalyst loading reduction defects in GDE catalyst layers will be presented.

  19. Evaluation of the sensitivity and response of IR thermography from a transparent heater under liquid jet impingement

    NASA Astrophysics Data System (ADS)

    Haustein, H. D.; Rohlfs, W.; Al-Sibai, F.; Kneer, R.

    2012-11-01

    The feasibility of a visible/IR transparent heater and its suitability for IR thermography is experimentally examined. The most common transparent conductive coating, Indium Tin Oxide (ITO), is quite reflective and its optical properties depend on thickness and manufacturing process. Therefore, the optical properties of several thicknesses and types of ITO, coated on an IR window (BaF2), are examined. A highly transparent Cadmium Oxide (CdO) coating on a ZnS window, also examined, is found to be unusable. Transmissivity is found to increase with a decrease in coating thickness, and total emittance is relatively low. A thick ITO coating was examined for IR thermography in the challenging test case of submerged water jet impingement, where temperature differences were characteristically small and distributed. The measurements under steady state conditions were found to agree well with the literature, and the method was validated. Comparison of two IR cameras did not show the LWIR low-temperature advantage, up to the maximal acquisition rate examined, 1.3KHz. Rather the MWIR camera had a stronger signal to noise ratio, due to the higher emissivity of the heater in this range. The transient response of the transparent heater showed no time-delay, though the substrate dampens the thermal response significantly. Therefore, only qualitative transient measurements are shown for the case of pulsating free-surface jet impingement, showing that the motion of the hydraulic jump coincides with thermal measurements. From these results, recommendations are made for coating/window combination in IR thermography.

  20. Validation of quantitative IR thermography for estimating the U-value by a hot box apparatus

    NASA Astrophysics Data System (ADS)

    Nardi, I.; Paoletti, D.; Ambrosini, D.; de Rubeis, T.; Sfarra, S.

    2015-11-01

    Energy saving plays a key role in the reduction of energy consumption and carbon emission, and therefore it is essential for reaching the goal of the 20-20-2020 policy. In particular, buildings are responsible of about 30% of the total amount of Europe energy consumption; the increase of their energy efficiency with the reduction of the thermal transmittance of the envelope is a point of strength with the actions and strategies of the policy makers. Currently, the study of energy performance of buildings is based on international standards, in particular the Italian one allows to calculate the U-value according the ISO 6946 or by in-situ measurements, using a heat flow meter (HFM), following recommendations provided in ISO 9869. In the last few years, a new technique, based on Infrared Thermography (IRT) (also referred to as Infrared Thermovision Technique - ITT), has been proposed for in situ determination of the thermal transmittance of opaque building elements. Some case studies have been reported. This method has already been applied on existing buildings, providing reliable results, but also revealing some weaknesses. In order to overcome such weak points and to assess a systematic procedure for the application of IRT, a validation of the method has been performed in a monitored environment. Infrared camera, the heat flow meter sensors and a nearby meteorological station have been used for thermal transmittance measurement. Comparison between the U-values measured in a hot box with IRT as well as values calculated following international standards and HFM results has been effected. Results give a good description of the advantages, as well as of the open problems, of IR Thermography for estimating the U-value. Further studies will help to refine the technique, and to identify the best operative conditions.

  1. Non-Destructive Evaluation of Slot-Die-Coated Lithium Secondary Battery Electrodes by In-Line Laser Caliper and IR Thermography Methods-Journal Cover Page

    SciTech Connect

    Mohanty, Debasish; Li, Jianlin; Born, Rachael; Maxey, L Curt; Dinwiddie, Ralph Barton; Daniel, Claus; Wood III, David L

    2014-01-01

    Note: This is a cover page for the 'Analytical Methods' journal, which was requested by the journal editor for consideration. The article has already been published and the PTS publication ID is 44000. The acknowledgements are same as mentioned in the PTS publication ID 44000.

  2. Treated-skin temperature regularities revealed by IR thermography

    NASA Astrophysics Data System (ADS)

    Vainer, Boris G.

    2001-03-01

    Experimental results disclosing temperature change of human skin affected by various unnatural factors are presented in detail. Thermograms are obtained with the IR thermograph containing high performance InAs CID FPA-based photosensitive unit. Using logarithmic scale of time, evolution of skin temperature after moistening, spirit sponging, and olive oil lubrication is investigated. A comparative analysis of the resulting effects of treatments including alpha-hydroxy acid, cosmetic regenerating cream, spirit, and water, is made. Quantitative distinctions between skin regions characterized by ordinary, and depleted blood supply, including areas located directly above surface main vessels, are revealed. Strongly logarithmic time- dependence of a skin temperature is discovered when the skin is cooled down after its preliminary heating with a hot wax. Non-monotonic change of a local temperature during electrically active procedure is described. Low level light therapy equipment is also applied. A special role of the temperature of nose is discussed.

  3. Control of CFRP strengthening applied to civil structures by IR thermography

    NASA Astrophysics Data System (ADS)

    Grinzato, E.; Trentin, R.; Bison, P. G.; Marinetti, S.

    2007-04-01

    NdT methods are highly promoted by an increasing demand of checking the effectiveness of strengthening and repair intervention on structural components, both in buildings and bridges. IR thermography exhibits excellent performances, particularly when innovative materials as CFRP (Carbon Fiber Reinforced Polymer) are used. Non destructive control by the use of thermographic analysis is used to detect adhesion defects or imperfections, which can lead the component to become brittle and collapsing unexpectedly. This paper shows as the geometrical evaluation of delaminated areas is carried out. Laboratory tests both on reduced or full scale are illustrated in order to set up and validate the proposed procedure. An experimental study on samples bonded with FRP and containing defects appropriately applied at the interface, will be presented. A series of beams (10 m long) have been tested under bending loads and strengthened conditions, by placing a pre-impregnated thin carbon (CFRP) laminate at the intrados. Different reinforcement configurations have been adopted in the beams (ordinary steel reinforcement and with addition of pre-stressed strands), using mechanical devices for the anchorage of the supplementary pre-tension of the strips. At local level, the simulation of possible lack of bonding during loading or intrinsic defects and imperfections has been contextually analysed on specifically dimensioned specimens. Different algorithms have been applied at the evaluation stage in order to estimate the defect size and location. Particularly, the extension of the delamination is estimate with a simple and robust algorithm. In facts, standards set the limit for acceptable defects, both in terms of number and size.

  4. Gamma-irradiation tests of IR optical fibres for ITER thermography--a case study

    SciTech Connect

    Reichle, R.; Pocheau, C.; Jouve, M.

    2008-03-12

    In the course of the development of a concept for a spectrally resolving infrared thermography diagnostic for the ITER divertor we have tested 3 types of infrared (IR) fibres in Co{sup 60} irradiation facilities under {gamma} irradiation. The fibres were ZrF{sub 4} (and HfF{sub 4}) fibres from different manufacturers, hollow fibres (silica capillaries with internal Ag/AgJ coating) and a sapphire fibre. For the IR range, only the latter fibre type encourages to go further for neutron tests in a reactor. If one restricted the interest onto the near infrared range, high purity core silica fibres could be used. This study might be seen as a typical example of the relation between diagnostic development for a nuclear environment and irradiation experiments.

  5. Flame attenuation effects on surface temperature measurements using IR thermography

    NASA Astrophysics Data System (ADS)

    de Vries, Jaap; Tabinowski, Robert

    2016-05-01

    Long-wave infrared (LWIR) cameras provide the unique ability to see through smoke and condensed water vapor. However, soot generated inside the flame does attenuate the LWIR signal. This work focuses on gas flame attenuation effects of LWIR signals originating from a blackbody. The experimental setup consists of time averaged, laboratory-scale turbulent diffusion flames with heat release rates set at 5 kW, 10 kW, and 15 kW. Propylene and ethylene were used as fuel, providing two different soot yields. A 30 cm by 30 cm blackbody was used with maximum surface temperatures set to 600°C. Both instantaneous and time-averaged blackbody temperature profiles through the flame were measured using a LWIR microbolometer camera (7.5-14 μm). Flame intermittency was quantified by color segmenting visible images. The experiments showed that low blackbody temperatures were significantly affected by the presence of the flame. At 600°C, the effect of flame absorption matches the emitted radiation from the flame itself. Using data obtained at various blackbody temperatures, the flame transmittance was obtained using a Generalized Reduced Gradient optimization method. The transmittance was lower for propylene flames compared to ethylene flames. Ethylene flames were shown to have higher temperatures. Using the values for flame radiance and transmissivity, the total averaged radiance of the flame plus the blackbody could be reproduced with 1% accuracy.

  6. Investigation of honeycomb structure using pulse infrared thermography method

    NASA Astrophysics Data System (ADS)

    Li, Huijuan

    2010-11-01

    To reduce weight and improve strength in the aerospace industry, composite structure has gained popularity as a replacement for conventional materials and structures, such as adhesive bonding and honeycomb structure. Honeycomb structures composed by a honeycomb core between two facesheets are very common on aerospace parts. However, the adhesive bonding process is more susceptible to quality variations during manufacturing than traditional joining methods. With the large increase in the use of composite materials and honeycomb structures, the need for high speed, large area inspection for fracture critical, sub-surface defects in aircraft, missiles and marine composites led to broad acceptance of infrared based NDT methods. Infrared thermography is one of several non-destructive testing techniques which can be used for defect detection in aircraft materials. Infrared thermography can be potentially useful, as it is quick, real time, non-contact and can examine over a relatively large area in one inspection procedure. In this paper, two kinds of defects which are of various size, shape and location below the test surface are planted in the honeycomb structure, they are all tested by pulsed thermography, analyze the thermal sequence and intensity graph got by this methods, it shows that pulsed thermography is an effective nondestructive technique for inspecting disbonding defect, can distinguish the location and the dimension of the defect exactly.

  7. Thermography as a quantitative imaging method for assessing postoperative inflammation

    PubMed Central

    Christensen, J; Matzen, LH; Vaeth, M; Schou, S; Wenzel, A

    2012-01-01

    Objective To assess differences in skin temperature between the operated and control side of the face after mandibular third molar surgery using thermography. Methods 127 patients had 1 mandibular third molar removed. Before the surgery, standardized thermograms were taken of both sides of the patient's face using a Flir ThermaCam™ E320 (Precisions Teknik AB, Halmstad, Sweden). The imaging procedure was repeated 2 days and 7 days after surgery. A region of interest including the third molar region was marked on each image. The mean temperature within each region of interest was calculated. The difference between sides and over time were assessed using paired t-tests. Results No significant difference was found between the operated side and the control side either before or 7 days after surgery (p > 0.3). The temperature of the operated side (mean: 32.39 °C, range: 28.9–35.3 °C) was higher than that of the control side (mean: 32.06 °C, range: 28.5–35.0 °C) 2 days after surgery [0.33 °C, 95% confidence interval (CI): 0.22–0.44 °C, p < 0.001]. No significant difference was found between the pre-operative and the 7-day post-operative temperature (p > 0.1). After 2 days, the operated side was not significantly different from the temperature pre-operatively (p = 0.12), whereas the control side had a lower temperature (0.57 °C, 95% CI: 0.29–0.86 °C, p < 0.001). Conclusions Thermography seems useful for quantitative assessment of inflammation between the intervention side and the control side after surgical removal of mandibular third molars. However, thermography cannot be used to assess absolute temperature changes due to normal variations in skin temperature over time. PMID:22752326

  8. Infrared contrast data analysis method for quantitative measurement and monitoring in flash infrared thermography

    NASA Astrophysics Data System (ADS)

    Koshti, Ajay M.

    2015-04-01

    The paper provides information on a new infrared (IR) image contrast data post-processing method that involves converting raw data to normalized contrast versus time evolutions from the flash infrared thermography inspection video data. Thermal measurement features such as peak contrast, peak contrast time, persistence time, and persistence energy are calculated from the contrast evolutions. In addition, simulation of the contrast evolution is achieved through calibration on measured contrast evolutions from many flat bottom holes in a test plate of the subject material. The measurement features are used to monitor growth of anomalies and to characterize the void-like anomalies. The method was developed to monitor and analyze void-like anomalies in reinforced carbon-carbon (RCC) materials used on the wing leading edge of the NASA Space Shuttle Orbiters, but the method is equally applicable to other materials. The thermal measurement features relate to the anomaly characteristics such as depth and size. Calibration of the contrast is used to provide an assessment of the anomaly depth and width which correspond to the depth and diameter of the equivalent flat bottom hole (EFBH) from the calibration data. An edge detection technique called the half-max is used to measure width and length of the anomaly. Results of the half-max width and the EFBH diameter are compared with actual widths to evaluate utility of IR Contrast method. Some thermal measurements relate to gap thickness of the delaminations. Results of IR Contrast method on RCC hardware are provided. Keywords: normalized contrast, flash infrared thermography.

  9. Study Methods to Standardize Thermography NDE

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Workman, Gary L.

    1998-01-01

    The purpose of this work is to develop thermographic inspection methods and standards for use in evaluating structural composites and aerospace hardware. Qualification techniques and calibration methods are investigated to standardize the thermographic method for use in the field. Along with the inspections of test standards structural hardware, support hardware is designed and fabricated to aid in the thermographic process. Also, a standard operating procedure is developed for performing inspections with the Bales Thermal Image Processor (TIP). Inspections are performed on a broad range of structural composites. These materials include various graphite/epoxies, graphite/cyanide-ester, graphite/silicon-carbide, graphite phenolic and Keviar/epoxy. Also metal honeycomb (titanium and aluminum faceplates over an aluminum honeycomb core) structures are investigated. Various structural shapes are investigated and the thickness of the structures vary from as few as 3 plies to as many as 80 plies. Special emphasis is placed on characterizing defects in attachment holes and bondlines, in addition to those resulting from impact damage and the inclusion of foreign matter. Image processing through statistical analysis and digital filtering is investigated to enhance the quality and quantify the NDE thermal images when necessary.

  10. Study Methods to Standardize Thermography NDE

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Workman, Gary L.

    1998-01-01

    The purpose of this work is to develop thermographic inspection methods and standards for use in evaluating structural composites and aerospace hardware. Qualification techniques and calibration methods are investigated to standardize the thermographic method for use in the field. Along with the inspections of test standards structural hardware, support hardware is designed and fabricated to aid in the thermographic process. Also, a standard operating procedure is developed for performing inspections with the Bales Thermal Image Processor (TIP). Inspections are performed on a broad range of structural composites. These materials include graphite/epoxies, graphite/cyanide-ester, graphite/silicon-carbide, graphite phenolic and Kevlar/epoxy. Also metal honeycomb (titanium and aluminum faceplates over an aluminum honeycomb core) structures are investigated. Various structural shapes are investigated and the thickness of the structures vary from as few as 3 plies to as many as 80 plies. Special emphasis is placed on characterizing defects in attachment holes and bondlines, in addition to those resulting from impact damage and the inclusion of foreign matter. Image processing through statistical analysis and digital filtering is investigated to enhance the quality and quantify the NDE thermal images when necessary.

  11. A comparative study of in-situ measurement methods of a building wall thermal resistance using infrared thermography

    NASA Astrophysics Data System (ADS)

    Ibos, Laurent; Monchau, Jean-Pierre; Feuillet, Vincent; Candau, Yves

    2015-04-01

    This study concerns the in-situ determination of the thermal resistance of a building wall. Measurements were performed in the PANISSE platform, which is a residential building with two floors located in the town of Villemomble, at about ten kilometers in the east of Paris. During a renovation, a 6cm-thick external insulating layer was fixed onto the cellular concrete walls of the house. Three methods using IR thermography were used to estimate the thermal resistance of the insulated walls. Results are compared to a standardized method (ISO 9869-1) that uses contact sensors. The comparison is made considering estimated thermal resistance values, measurement uncertainties and measurement duration.

  12. Endoscopic Shearography and Thermography Methods for Nondestructive Evaluation of Lined Pressure Vessels

    NASA Technical Reports Server (NTRS)

    Lansing, Matthew D.; Bullock, Michael W.

    1996-01-01

    The goal of this research effort was the development of methods for shearography and thermography inspection of coatings, bonds, or laminates inside rocket fuel or oxidizer tanks, fuel lines, and other closed structures. The endoscopic methods allow imaging and inspection inside cavities which are traditionally inaccessible with shearography or thermography cameras. The techniques are demonstrated and suggestions for practical application are made in this report. Drawings of the experimental setups, detailed procedures, and experimental data are included.

  13. Coupling IR Thermography and BIA to analyse body reaction after one acupuncture session

    NASA Astrophysics Data System (ADS)

    Piquemal, M.

    2013-04-01

    Coupling both thermography and bio-Impedance, some biophysical acupuncture mechanisms are statically studied on a small population of 18 subjects. Results show that a possible way of understanding acupuncture, in an electrical way, should be to consider ionic flux redistribution between vascular and extra cell compartments. This is a two steps mechanism. The first one is starting with needles insertion and the second one is lasting with more intensity after removing them from skin.

  14. Implementing recommendations of the Columbia accident investigation board: development of on-orbit IR thermography

    NASA Astrophysics Data System (ADS)

    Ottens, Brian P.; Parker, Bradford; Stephan, Ryan A.

    2005-03-01

    One of NASA"s Space Shuttle Return-to-Flight (RTF) efforts has been to develop thermography for the on-orbit inspection of the Reinforced Carbon Carbon (RCC) portion of the Orbiter Wing Leading Edge (WLE). This paper addresses the capability of thermography to detect cracks in RCC by using in-plane thermal gradients that naturally occur on-orbit. Crack damage, which can result from launch debris impact, is a detection challenge for other on-orbit sensors under consideration for RTF, such as the Intensified Television Camera and Laser Dynamic Range Imager. We studied various cracks in RCC, both natural and simulated, along with material characteristics, such as emissivity uniformity, in steady-state thermography. Severity of crack, such as those likely and unlikely to cause burn through were tested, both in-air and in-vacuum, and the goal of this procedure was to assure crew and vehicle safety during re-entry by identification and quantification of a damage condition while on-orbit. Expected thermal conditions are presented in typical shuttle orbits, and the expected damage signatures for each scenario are presented. Finally, through statistical signal detection, our results show that even at very low in-plane thermal gradients, we are able to detect damage at or below the threshold for fatality in the most critical sections of the WLE, with a confidence exceeding 1 in 10,000 probability of false negative.

  15. Implementing Recommendations of the Columbia Accident Investigation Board: Development of On-Orbit IR Thermography

    NASA Technical Reports Server (NTRS)

    Ottens, Brian P.; Parker, Bradford; Stephan, Ryan

    2005-01-01

    One of NASA's Space Shuttle Return-to-Flight (RTF) efforts has been to develop thermography for the on-orbit inspection of the Reinforced Carbon Carbon (RCC) portion of the Orbiter Wing Leading Edge (WLE). This paper addresses the capability of thermography to detect cracks in RCC by using in-plane thermal gradients that naturally occur on-orbit. Crack damage, which can result from launch debris impact, is a detection challenge for other on-orbit sensors under consideration for RTF, such as the Intensified Television Camera and Laser Dynamic Range Imager. We studied various cracks in RCC, both natural and simulated, along with material characteristics, such as emissivity uniformity, in steady-state thermography. Severity of crack, such as those likely and unlikely to cause burn through were tested, both in-air and in-vacuum, and the goal of this procedure was to assure crew and vehicle safety during reentry by identification and quantification of a damage condition while on-orbit. Expected thermal conditions are presented in typical shuttle orbits, and the expected damage signatures for each scenario are presented. Finally, through statistical signal detection, our results show that even at very low in-plane thermal gradients, we are able to detect damage at or below the threshold for fatality in the most critical sections of the WLE, with a confidence exceeding 1 in 10,000 probability of false negative.

  16. Study Methods to Characterize and Implement Thermography Nondestructive Evaluation (NDE)

    NASA Technical Reports Server (NTRS)

    Walker, James L.

    1998-01-01

    The limits and conditions under which an infrared thermographic nondestructive evaluation can be utilized to assess the quality of aerospace hardware is demonstrated in this research effort. The primary focus of this work is on applying thermography to the inspection of advanced composite structures such as would be found in the International Space Station Instrumentation Racks, Space Shuttle Cargo Bay Doors, Bantam RP-1 tank or RSRM Nose Cone. Here, the detection of delamination, disbond, inclusion and porosity type defects are of primary interest. In addition to composites, an extensive research effort has been initiated to determine how well a thermographic evaluation can detect leaks and disbonds in pressurized metallic systems "i.e. the Space Shuttle Main Engine Nozzles". In either case, research into developing practical inspection procedures was conducted and thermographic inspections were performed on a myriad of test samples, subscale demonstration articles and "simulated" flight hardware. All test samples were fabricated as close to their respective structural counterparts as possible except with intentional defects for NDE qualification. As an added benefit of this effort to create simulated defects, methods were devised for defect fabrication that may be useful in future NDE qualification ventures.

  17. Defect detection of wall paintings in the Château de Versailles using TV-holography and IR thermography

    NASA Astrophysics Data System (ADS)

    Chambard, Jean-Pierre; Roche, Alain

    2007-07-01

    Monuments are continuously submitted to external events like water infiltration or condensation, temperature variation, soil instability, that lead to internal damage of the structure itself as well as of its surfaces. Wall paintings are then submitted to stresses that may cause cracks, internal de-lamination of the plaster or de-bonding between canvas and plaster. In the frame of the restoration of the "galerie des glaces" in the "château de Versailles", TV-Holography and IR Thermography have been used to investigate the wall paintings of the vault. The surfaces to control were either direct paintings on the plaster or paintings on canvas backed on the plaster. IR Thermography for art work and in particular for wall paintings has only recently been used. The technique allows to record transient temperature maps, when slightly heating the surface during a short time. Then, nonhomogeneities in the conductive heat transfer are related to de-bonding or de-lamination. The time parameter gives information on the depth of the defect. A calibration procedure has to be carried out to ensure reliable defect detection. Speckle interferometry is a Non Destructive Testing technique that is currently used in industry. For the wall paintings, we have used TV-Holography associated with a continuous wave laser. The technique allows, 13 metres away from the surface, to detect parts of the paintings that were vibrating due to an acoustic excitation. The control processes based on these two technologies is detailed as well as the results obtained and a comparison with manual investigation is done.

  18. From photothermal radiometry to lock-in thermography methods

    NASA Astrophysics Data System (ADS)

    Busse, Gerd

    2010-03-01

    This thermal wave conference dates back to 1979 when it was held for the first time in Ames/Iowa. All participants have this area still in mind, maybe not only due to the landscape but also to the cheerleader courses held parallel to our sessions on the same campus. So after 30 years time has come to review some thermal wave developments that started back in 1979 and to see how they affected other fields, e.g. NDE. This paper traces the origin of lock-in thermography back to the roots which is essentially to show how initially two different areas (thermal waves and thermography) merged partially together to become a powerful tool for modern NDE.

  19. Heat flux determination at the AWJ cutting zone using IR thermography and inverse heat conduction problem

    SciTech Connect

    Mohan, R.S.; Kovacevic, R.; Beardsley, H.E.

    1996-12-31

    In abrasive waterjet (AWJ) cutting, the cutting tool is a thin stream of high velocity abrasive waterjet slurry which can be considered as a moving line heat source that increases the temperature of the narrow zone along the cut kerf wall. A suitably defined inverse heat conduction problem which uses the experimentally determined temperature histories at various points in the workpiece, is adopted to determine the heat flux at the cutting zone. Temperature distribution in the workpiece and the cutting nozzle during AWJ cutting is monitored using infrared thermography. A suitable strategy for on-line monitoring of the radial and axial wear of the AWJ nozzle based on the nozzle temperature distribution is also proposed.

  20. C/C composite brake disk nondestructive evaluation by IR thermography

    NASA Astrophysics Data System (ADS)

    Chu, Tsuchin P.; Poudel, Anish; Filip, Peter

    2012-06-01

    This paper discusses the non-destructive evaluation of thick Carbon/Carbon (C/C) composite aircraft brake disks by using transient infrared thermography (IRT) approach. Thermal diffusivity measurement technique was applied to identify the subsurface anomalies in thick C/C brake disks. In addition, finite element analysis (FEA) modeling tool was used to determine the transient thermal response of the C/C disks that were subjected to flash heating. For this, series of finite element models were built and thermal responses with various thermal diffusivities subjected to different heating conditions were investigated. Experiments were conducted to verify the models by using custom built in-house IRT system and commercial turnkey system. The analysis and experimental results showed good correlation between thermal diffusivity value and anomalies within the disk. It was demonstrated that the step-heating transient thermal approach could be effectively applied to obtain the whole field thermal diffusivity value of C/C composites.

  1. Experimental Heat Transfer Study of Endwall in a Linear Cascade with IR Thermography

    NASA Astrophysics Data System (ADS)

    Rojo, Borja; Jimenez, Carlos; Chernoray, Valery

    2014-03-01

    This abstract presents an endwall heat transfer experimental data of air flow going through outlet guide vanes (OGVs) situated in a low speed linear cascade. The measurement technique for this experiment was infrared thermography. In order to calculate the heat transfer coefficient (HTC) on the endwall, it has been used an instrumented window with a controlled constant temperature in one side of a 5 millimeter Plexiglass in order to generate high temperature gradients and, therefore, by measuring the surface temperature one the other side of the Plexiglass, it is calculated the HTC. Due to the fact that Plexiglass material has not good optical properties at infrared spectrum, it has been used a thin layer of black paint (10-12 μm) which has high emissivity (0.973) in the range of temperature that we are working. The Reynolds number for this experiment is 300000 in on and off-design configuration of the OGVs (on-design 25° and off-design cases are 40° and -25° incident angle). Furthermore, the on-design case is run at two different Reynolds number, 300000 and 450000. During this experiments it can be seen how changing the inlet angle to the OGVs produces significant differences on the heat transfer along the endwall. The main objective for this investigation is to study the heat transfer along the endwall of a linear cascade so that it would be a well-defined test case for CFD validation.

  2. Cloud2IR: Infrared thermography and environmental sensors integrated in an autonomoussystem for long term monitoring of structures

    NASA Astrophysics Data System (ADS)

    Crinière, Antoine; Dumoulin, Jean; Mevel, Laurent; Andrade-Barroso, Guillermo

    2016-04-01

    acquisition scenario the local storage management and the network management through SFTP or SOAP for the OGC frame. The data side only need an XML configuration file and if a configuration change occurs in time the system is automatically restarted with the new value. Cloud2IR has been deployed on field since several Monthat the SenseCity outdoor test bed in Marne La Vallée (France)[4]. The next step will be the full standardisation of the system and possibly the full separation between the sensor side and the data side which can be seen at term as an external framework. References: [1] A Crinière, J Dumoulin, L Mevel, G Andrade-Barosso, M Simonin. The Cloud2SM Project.European Geosciences Union General Assembly (EGU2015), Apr 2015, Vienne, Austria. 2015. [2] J Dumoulin, A Criniere, and R Averty. The detection and thermal characterization of the inner structure of the 'musmeci' bridge deck by infrared thermography monitoring. Journal Of Geophysics And Engineering doi:10.1088/1742-2132/10/6/064003, Vol 10, 2013. [3] J Dumoulin, R Averty. Development of an infrared system coupled with a weather station for real time atmospheric corrections using GPU computing: Application to bridge monitoring, in Proc of 11 th International Conference on Quantitative InfraRed Thermography, Naples Italy, 2012. [4] F Derkx, B Lebental, T Bourouina, Frédéric B, C Cojocaru, and al..The Sense-City project.XVIIIth Symposium on Vibrations, Shocks and Noise, Jul 2012, France. 9p, 2012.

  3. A new measurement method of coatings thickness based on lock-in thermography

    NASA Astrophysics Data System (ADS)

    Zhang, Jin-Yu; Meng, Xiang-bin; Ma, Yong-chao

    2016-05-01

    Coatings have been widely used in modern industry and it plays an important role. Coatings thickness is directly related to the performance of the functional coatings, therefore, rapid and accurate coatings thickness inspection has great significance. Existing coatings thickness measurement method is difficult to achieve fast and accurate on-site non-destructive coatings inspection due to cost, accuracy, destruction during inspection and other reasons. This paper starts from the introduction of the principle of lock-in thermography, and then performs an in-depth study on the application of lock-in thermography in coatings inspection through numerical modeling and analysis. The numerical analysis helps explore the relationship between coatings thickness and phase, and the relationship lays the foundation for accurate calculation of coatings thickness. The author sets up a lock-in thermography inspection system and uses thermal barrier coatings specimens to conduct an experiment. The specimen coatings thickness is measured and calibrated to verify the quantitative inspection. Experiment results show that the lock-in thermography method can perform fast coatings inspection and the inspection accuracy is about 95%. Therefore, the method can meet the field testing requirements for engineering projects.

  4. Temperature measurements on solid surfaces in rack-storage fires using IR thermography

    NASA Astrophysics Data System (ADS)

    de Vries, J.; Ren, N.; Chaos, M.

    2015-05-01

    The development of fire modeling tools capable of predicting large-scale fire phenomena is of great value to the fire science community. To this end, FM Global has developed an open-source CFD fire simulation code, FireFOAM. The accuracy of this code relies fundamentally on high-quality experimental validation data. However, at larger scales, detailed measurements of local quantities (e.g., surface temperatures) needed for model validation are difficult to obtain. Often, the information obtained from large-scale fire tests is limited to the global heat release rates (HRR) or point temperature or heat flux measurements from embedded thermocouples or heat flux gauges, respectively. The present study addresses this limitation by introducing IR thermographic measurements in a three- and a five-tier-high rack storage scenario. IR temperatures are compared against modeled results. The tested and modeled cases represent realistic industrial warehouse fire scenarios. The rack-stored commodity consisted of corrugated paperboard boxes wrapped around a steel cubic liners, placed on top of a hardwood pallet. The global heat release rate was measured using a 20- MW fire products collector located inside FM Global's Fire Technology Laboratory. An in-house calibrated microbolometer IR camera was used to obtain two-dimensional temperature measurements on the fuel surfaces and on the surfaces inside the flue spaces. Maximum temperatures up to 1200 K were observed on the external surfaces of the test array. Inside the flue spaces between pallet loads, temperatures up to 1400 K were measured. The modeled fire spread results match well fire spread shown in the IR thermographic images. The peak modeled surface temperatures obtained inside some of the horizontal flue spaces were ~1400K, which agreed well with the peak temperatures seen by the IR camera. The effect of the flames present between the surfaces of interest and the IR camera only contribute to about 50 K increase in measured

  5. Endoscopic Shearography and Thermography Methods for Nondestructive Evaluation of Lined Pressure Vessels

    NASA Technical Reports Server (NTRS)

    Russell, S. S.; Lansing, M. D.

    1997-01-01

    The goal of this research effort was the development of methods for shearographic and thermographic inspection of coatings, bonds, or laminates inside rocket fuel or oxidizer tanks, fuel lines, and other closed structures. The endoscopic methods allow imaging and inspection inside cavities that are traditionally inaccessible with shearography or thermography cameras. The techniques are demonstrated and suggestions for practical application are made in this report. Drawings of the experimental setups, detailed procedures, and experimental data are included.

  6. A novel and simple method for identifying the lung intersegmental plane using thermography.

    PubMed

    Sakamoto, Kei; Kanzaki, Masato; Mitsuboshi, Shota; Maeda, Hideyuki; Kikkawa, Takuma; Isaka, Tamami; Murasugi, Masahide; Onuki, Takamasa

    2016-07-01

    Identifying the intersegmental plane is very important for successful lung segmentectomy. Although several methods are available, they require specialized skills and pose a potential risk of losing sight of the correct intersegmental planes. Therefore, easier and more reliable methods are required. In this study, we hypothesized that surface temperatures of resecting segments or lobes decrease because of blood flow suppression after the ligation of target arteries and veins, and intersegmental planes can be visualized using a thermography. To test this hypothesis, we performed six lung resections (two lobectomies and four segmentectomies) on three pigs and, using a handheld thermography, we monitored the lung surface temperatures to identify intersegmental planes. We demonstrated that thermal imaging sharply demarcated intersegmental planes soon after the ligation of vessels in all procedures. Compared with other methods, thermography requires no special technical skills, drug injection and lung inflation. Therefore, we believe that the thermographic method described in this study will be a powerful option to identify intersegmental planes during anatomical lung segmentectomy. PMID:27030684

  7. Broadband Sub-terahertz Camera Based on Photothermal Conversion and IR Thermography

    NASA Astrophysics Data System (ADS)

    Romano, M.; Chulkov, A.; Sommier, A.; Balageas, D.; Vavilov, V.; Batsale, J. C.; Pradere, C.

    2016-05-01

    This paper describes a fast sub-terahertz (THz) camera that is based on the use of a quantum infrared camera coupled with a photothermal converter, called a THz-to-Thermal Converter (TTC), thus allowing fast image acquisition. The performance of the experimental setup is presented and discussed, with an emphasis on the advantages of the proposed method for decreasing noise in raw data and increasing the image acquisition rate. A detectivity of 160 pW Hz-0.5 per pixel has been achieved, and some examples of the practical implementation of sub-THz imaging are given.

  8. Clinical study on thermography, as modern investigation method for Candida-associated denture stomatitis.

    PubMed

    Iosif, Laura; Preoteasa, Cristina Teodora; Murariu-Măgureanu, Cătălina; Preoteasa, Elena

    2016-01-01

    Candida-associated denture stomatitis is an infectious inflammatory condition of the oral mucosa, with frequent recurrences. The aim of this study was to assess the use of infrared thermography as investigation method for Candida-associated denture stomatitis (as inflammatory disorder of the maxillary denture bearing area), by comparing disease and non-disease groups. An observational study was conducted on maxillary edentulous patients treated by acrylic dentures, with and without Candida-associated denture stomatitis. Diagnostic test methods used were clinical examination for denture stomatitis and conventional microbiological culture method for oral candidiasis. Thermography analysis of the maxillary denture bearing area was made using the ThermaCAM PM350 infrared camera (Inframetrics, Flir Systems) and ThermaGram Pro 95 software, data being acquired by usage of standard protocol of thermographic registrations. The sample included 52 patients, 21 with and 31 without Candida-associated denture stomatitis. The temperature of the maxillary mucosa corresponding to the denture bearing area was found to be statistically significantly higher in Candida-associated denture stomatitis (mean 36.20°C), compared to healthy oral mucosa (mean 34.85°C). The thermal threshold value of 35.44°C was identified as best differentiating a pathological from normal state of the maxillary mucosa corresponding to the denture bearing area. In conclusion, infrared thermography, a rapid non-invasive investigation method, has the premises to bring valuable data in inflammatory disorders of the maxillary denture bearing area, as Candida-associated denture stomatitis that may be used for screening, diagnostic or monitoring purposes. PMID:27151707

  9. Bridge deck surface temperature monitoring by infrared thermography and inner structure identification using PPT and PCT analysis methods

    NASA Astrophysics Data System (ADS)

    Dumoulin, Jean

    2013-04-01

    One of the objectives of ISTIMES project was to evaluate the potentialities offered by the integration of different electromagnetic techniques able to perform non-invasive diagnostics for surveillance and monitoring of transport infrastructures. Among the EM methods investigated, we focused our research and development efforts on uncooled infrared camera techniques due to their promising potential level of dissemination linked to their relative low cost on the market. On the other hand, works were also carried out to identify well adapted implementation protocols and key limits of Pulse Phase Thermography (PPT) and Principal Component Thermography (PCT) processing methods to analyse thermal image sequence and retrieve information about the inner structure. So the first part of this research works addresses infrared thermography measurement when it is used in quantitative mode (not in laboratory conditions) and not in qualitative mode (vision applied to survey). In such context, it requires to process in real time thermal radiative corrections on raw data acquired to take into account influences of natural environment evolution with time, thanks to additional measurements. But, camera sensor has to be enough smart to apply in real time calibration law and radiometric corrections in a varying atmosphere. So, a complete measurement system was studied and developed [1] with low cost infrared cameras available on the market. In the system developed, infrared camera is coupled with other sensors to feed simplified radiative models running, in real time, on GPU available on small PC. The whole measurement system was implemented on the "Musmeci" bridge located in Potenza (Italy). No traffic interruption was required during the mounting of our measurement system. The infrared camera was fixed on top of a mast at 6 m elevation from the surface of the bridge deck. A small weather station was added on the same mast at 1 m under the camera. A GPS antenna was also fixed at the

  10. Handy method to estimate uncertainty of temperature measurement by infrared thermography

    NASA Astrophysics Data System (ADS)

    Muniz, Pablo Rodrigues; de Araújo Kalid, Ricardo; Cani, Shirley P. N.; da Silva Magalhães, Robson

    2014-07-01

    Temperature measurement by infrared thermography is a technique that is widely used in predictive maintenance to detect faults. The uncertainty involved in measuring temperature by thermography is not only due to the imager, but also due to the measurements and estimates made by the user: emissivity of the inspected object, distance, temperature, and relative humidity of the propagation medium, temperature of objects located in the ambient, and the imager itself. This measurement uncertainty should be available for the thermographer to be able to make a more accurate diagnosis. The methods available in the literature to estimate the uncertainty of measured temperature usually require information nonaccessible to the regular thermographer. This paper proposes a method for calculating the uncertainty of temperature that requires only data available to the thermographer. This method is useful under usual conditions in predictive maintenance-short distance (7.5 to 14 μm) thermal imagers, no fog or rain, among others. It provides results similar to methods that use models that are not available or reserved by the manufacturers of imagers. The results indicate that not all sources of uncertainty are relevant in measurement uncertainty. However, the total uncertainty can be so high that it may lead to misdiagnosis.

  11. Buying Thermography

    NASA Astrophysics Data System (ADS)

    Madding, Robert P.

    1981-01-01

    The cost of thermographic information obtained by contracting for a service is compared to that of buying equipment and doing the work in-house. A breakeven analysis method is used to find the number of days per year an instrument must be used to justify buying it. Life-cycle costing techniques are used to find the equivalent annual cost of various classes of thermographic instruments. Results indicate that a full-time person earning 20,000 annually must use a 30,000 instrument at least 73 days per year if thermography can otherwise be contracted for $675 per day. By devoting a person to thermography part-time, the number of inspection days for this case can be reduced to about 28. Further in-house advantage can be gained by considering investment tax credits, salvage value and, to some extent, accelerated depreciation. Techniques for finding the breakeven number of inspection days for other costs are developed. A nomogram is included for rapid comparisons.

  12. Active IR-applications in civil engineering

    NASA Astrophysics Data System (ADS)

    Wiggenhauser, H.

    2002-06-01

    Applications of IR-thermography in civil engineering are not limited to the identification of heat losses in building envelopes. As it is well known from other areas of non-destructive testing, active IR-thermographic methods such as cooling down or lock-in thermography improves the results in many investigations. In civil engineering these techniques have not been used widely. Mostly thermography is used in a quasi-static manner. The interpretation of moisture measurements with thermography on surfaces can be very difficult due to several overlapping effects: emissivity changes due to composition, heat transfer through wet sections of the specimen, cooling through air flow or reflected spurious radiation sources. These effects can be reduced by selectively measuring the reflection in two wavelength windows, one on an absorption band of water and another in a reference band and then combining the results in a moisture index image. Cooling down thermography can be used to identify subsurface structural deficiencies. For building materials like concrete these measurements are performed on a much longer time scale than in flash lamp experiments. A quantitative analysis of the full cooling down process over several minutes can reliably identify defects at different depths. Experiments at BAM have shown, that active thermography is capabale of identifying structural deficiencies or moist areas in building materials much more reliable than quasi-static thermography.

  13. IrLaW an OGC compliant infrared thermography measurement system developed on mini PC with real time computing capabilities for long term monitoring of transport infrastructures

    NASA Astrophysics Data System (ADS)

    Dumoulin, J.; Averty, R.

    2012-04-01

    One of the objectives of ISTIMES project is to evaluate the potentialities offered by the integration of different electromagnetic techniques able to perform non-invasive diagnostics for surveillance and monitoring of transport infrastructures. Among the EM methods investigated, uncooled infrared camera is a promising technique due to its dissemination potential according to its relative low cost on the market. Infrared thermography, when it is used in quantitative mode (not in laboratory conditions) and not in qualitative mode (vision applied to survey), requires to process in real time thermal radiative corrections on raw data acquired to take into account influences of natural environment evolution with time. But, camera sensor has to be enough smart to apply in real time calibration law and radiometric corrections in a varying atmosphere. So, a complete measurement system was studied and developed with low cost infrared cameras available on the market. In the system developed, infrared camera is coupled with other sensors to feed simplified radiative models running, in real time, on GPU available on small PC. The system studied and developed uses a fast Ethernet camera FLIR A320 [1] coupled with a VAISALA WXT520 [2] weather station and a light GPS unit [3] for positioning and dating. It can be used with other Ethernet infrared cameras (i.e. visible ones) but requires to be able to access measured data at raw level. In the present study, it has been made possible thanks to a specific agreement signed with FLIR Company. The prototype system studied and developed is implemented on low cost small computer that integrates a GPU card to allow real time parallel computing [4] of simplified radiometric [5] heat balance using information measured with the weather station. An HMI was developed under Linux using OpenSource and complementary pieces of software developed at IFSTTAR. This new HMI called "IrLaW" has various functionalities that let it compliant to be use in

  14. Use of infra-red thermography for automotive climate control analysis

    SciTech Connect

    Burch, S.D.; Hassani, V.; Penney, T.R.

    1994-03-01

    In this paper, several automotive climate control applications for IR thermography are described. Some of these applications can be performed using conventional IR techniques. Others, such as visualizing the air temperature distribution within the cabin, at duct exits, and at heater and evaporator faces, require new experimental methods. In order to capture the temperature distribution within an airstream, a 0.25-mm-thick (0.01 inch) fiberglass screen is used. This screen can be positioned perpendicular or parallel to the flow to obtain three-dimensional spatial measurements. In many cases, the air flow pattern can be inferred from the resulting temperature distribution, allowing improved air distribution designs. In all cases, significant improvement in the speed, ease, and quantity of temperature distribution information can be realized with thermography as compared to conventional thermocouple array techniques. Comparisons are presented between IR thermography images and both thermocouple measurements and computational fluid dynamics (CFD) predictions.

  15. Thermography Applied to Interfacial Phenomena, Potentials and Pitfalls

    NASA Astrophysics Data System (ADS)

    Antoni, M.; Sefiane, K.

    Infrared (IR) thermography is a non-intrusive method for temperature measurement. Its ability to produce two-dimensional temperature images makes it a powerful tool for investigating systems exhibiting spatial variation of temperature. IR temperature measurements are almost always surface measurements; the technique has therefore found use in obtaining interfacial temperatures, primarily in heat and mass transfer investigations. The reasons for the technique's limited uptake likely stems from the requirement of accurate material emissivity data and the large number of potential sources of error. This chapter provides an overview of the underlying theory of radiative heat transfer. Key considerations and problems in the application of IR thermography are discussed with reference to some examples of recent successful applications.

  16. Thermography in undescended testes

    NASA Astrophysics Data System (ADS)

    Berghoff, Ruben; Sarti, Fernando; Urrutia, Azucena; Renee, Marcela; Lluesma, Eliseo G.

    2001-03-01

    Are one of the pathologies more frequent in infant surgery - intra-abdominal, inguinal or ectopic. With actual methods of diagnosis some inguinal and none of the abdominal are detectable. Change of temperature is one of the elements to explain the detection in the maturity and development of the testes. Hormonal stimuli are used to obtain the increase in the development and descent of the testis. In this research we will test if thermography can be an effective technology for the diagnosis in the localization and morphology testicular. Another important feature will be to test if thermography may detect some of the stimulus testis with induction hormonal.

  17. A novel intelligent fault diagnosis method for electrical equipment using infrared thermography

    NASA Astrophysics Data System (ADS)

    Zou, Hui; Huang, Fuzhen

    2015-11-01

    Infrared thermography (IRT) has taken a very important role in monitoring and inspecting thermal defects of electrical equipment without shutting down, which has important significance for the stability of power systems. It has many advantages such as non-contact detection, freedom from electromagnetic interference, safety, reliability and providing large inspection coverage. Manual analysis of infrared images for detecting defects and classifying the status of equipment may take a lot of time and efforts, and may also lead to incorrect diagnosis results. To avoid the lack of manual analysis of infrared images, many intelligent fault diagnosis methods for electrical equipment are proposed, but there are two difficulties when using these methods: one is to find the region of interest, another is to extract features which can represent the condition of electrical equipment, as it is difficult to segment infrared images due to their over-centralized distributions and low intensity contrasts, which are quite different from those in visual light images. In this paper, a new intelligent diagnosis method for classification different conditions of electrical equipment using data obtained from infrared images is presented. In the first stage of our method, an infrared image of electrical equipment is clustered using K-means algorithm, then statistical characteristics containing temperature and area information are extracted in each region. In the second stage, in order to select the salient features which can better represent the condition of electrical equipment, some or all statistical characteristics from each region are combined as input data for support vector machine (SVM) classifier. To improve the classification performance of SVM, a coarse-to-fine parameter optimization approach is adopted. The performance of SVM is compared with that of back propagation neural network. The comparison results show that our method can achieve a better performance with accuracy 97.8495%.

  18. Airborne infrared thermography

    NASA Astrophysics Data System (ADS)

    Miller, Geoffrey M.

    2003-01-01

    To explore the feasibility of utilizing an IR imaging system to support flow visualization studies, an initial series of tests were conducted using an AN/AAS-38, NITE Hawk targeting pod. The targeting pod, installed on the left side of an F/A-18 aircraft provides a stabilized infrared imaging capability in the 8-12 micron spectral band. Initial data acquired with system indicated that IR thermography was a very promising tool for flow visualization. For the next phase of the investigation, an advanced version of the NITE Hawk targeting pod equipped with a staring 3-5 micron sensor was utilized. Experimental results obtained with this sensor indicated improved sensitivity and resolution. This method was limited to position the experiment and chase aircraft sufficiently close to each other and with the sightline angle required to acquire the region of interest. For the current phase of the investigation, the proven 3-5 micron staring sensor was deployed in an externally mounted podlet, located on the experimental aircraft with a fixed line of sight, centered on the region of interest. Based on initial data collection efforts, this approach appears to provide consistent high quality data for a wide range of flight conditions. To minimize the size of the podlet and resultant drag, the sensor was oriented parallel to the air flow. This also placed the line of sight parallel to the experiment. A fold mirror was incorporated in the design to fold the line of sight inboard and down to center on the region of interest. The experimental results obtained during the current test phase have provided consistently high quality images clearly mapping regions of laminar and turbulent flow. Several examples of these images and further details of the experimental approach are presented.

  19. Aerodynamic applications of infrared thermography

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran; Alderfer, David W.

    1989-01-01

    A series of wind tunnel experiments were conducted as part of a systematic study for evaluation of infrared thermography as a viable non-intrusive thermal measurement technique for aerodynamic applications. The experiments consisted of obtaining steady-state surface temperature and convective heat transfer rates for a uniformly heated cylinder in transverse flow with a Reynolds number range of 46,000 to 250,000. The calculated convective heat transfer rates were in general agreement with classical data. Furthermore, IR thermography provided valuable real-time fluid dynamic information such as visualization of flow separation, transition and vortices.

  20. Nondestructive test of brazed cooling tubes of prototype bolometer camera housing using active infrared thermography.

    PubMed

    Tahiliani, Kumudni; Pandya, Santosh P; Pandya, Shwetang; Jha, Ratneshwar; Govindarajan, J

    2011-01-01

    The active infrared thermography technique is used for assessing the brazing quality of an actively cooled bolometer camera housing developed for steady state superconducting tokamak. The housing is a circular pipe, which has circular tubes vacuum brazed on the periphery. A unique method was adopted to monitor the temperature distribution on the internal surface of the pipe. A stainless steel mirror was placed inside the pipe and the reflected IR radiations were viewed using an IR camera. The heat stimulus was given by passing hot water through the tubes and the temperature distribution was monitored during the transient phase. The thermographs showed a significant nonuniformity in the brazing with a contact area of around 51%. The thermography results were compared with the x-ray radiographs and a good match between the two was observed. Benefits of thermography over x-ray radiography testing are emphasized. PMID:21280850

  1. Integration of infrared thermography and high-frequency electromagnetic methods in archaeological surveys

    NASA Astrophysics Data System (ADS)

    di Maio, Rosa; Meola, Carosena; Fedi, Maurizio; Carlomagno, Giovanni Maria

    2010-05-01

    An integration of high-resolution non-destructive techniques is presented for the inspection and evaluation of ancient architectonic structures. Infrared thermography (IRT) represents a valuable tool for nondestructive evaluation of architectonic structures and artworks because it is capable of giving indications about most of the degradation sources of artworks and buildings of both historical interest and civil use. In particular, it is possible to detect cracks, disbondings, alteration of material consistency, etc. Indeed, by choosing the most adequate thermographic technique, it is possible to monitor the conservation state of artworks in time and to detect the presence of many types of defects (e.g., voids, cracks, disbondings, etc.) in different types of materials (e.g., concrete, masonry structures, bronze, etc.). The main advantages of infrared thermography when dealing with precious artworks may be summarized with three words: non-contact, non-invasive, and two-dimensionality. It is possible to inspect either a large surface such as the facade of a palace, or a very small surface of only few square millimetres. Conversely, the inspection depth is quite small; generally, of the order of centimetres. However, as demonstrated in previous work, IRT well matches with electric-and electromagnetic-type geophysical methods to characterize the overlapping zone from low-to-high depth in masonry structures. In particular, the use of high-frequency electromagnetic techniques, such as the ground penetrating radar (GPR), permits to reach investigation depths of some ten of centimetres by choosing appropriate frequencies of the transmitted electromagnetic signal. In the last decade a large utilisation of the GPR methodology to non-destructive analysis of engineering and architectural materials and structures has been experienced. This includes diverse features, such as definition of layer thickness, characterisation of different constructive materials, identification of

  2. [The instrument for thermography].

    PubMed

    Hamaguchi, Shinsuke

    2014-07-01

    Thermography is an imaging method using the instrument to detect infrared rays emitted from the body surface, and to plot them as a distribution diagram of the temperature information. Therefore, a thermographic instrument can be assumed to measure the skin temperature of the diseased region. Such an instrument is a useful device for noninvasive and objective assessment of various diseases. Examination using a thermographic instrument can assess the autonomic dysfunction by measuring the skin blood flow involved with the sympathetic innervation. Thermography is useful in assisting the determination of the therapeutic effect. However, autonomic dysfunction should be confirmed correctly with the assessment of thermatome that shows abnormal thermal distribution in the region of the disease. Thermography should make noticeable the difference between the body temperature of abnormal and normal sites, and show the alteration of temperature. Monitoring using thermography is useful to determine the effect of sympathetic nerve block. If a thermographic instrument is used, it is important that examiners should understand the function of the instrument, as well as its advantages and disadvantages. PMID:25098130

  3. CFRP sandwiched facesheets inspected by pulsed thermography

    NASA Astrophysics Data System (ADS)

    Li, Huijuan; Huo, Yan; Cai, Liangxu; Huang, Zhenhua

    2010-10-01

    Carbon fiber reinforced polymer (CFRP) has been always used in aerospace, Sandwiched structures composed by a honeycomb core between two multi-layer CFRP facesheets are very common on aerospace parts. As to the application of the CFRP sandwiched facesheets is extended, The demand for quality control of CFRP sandwiched composites is increasing, Infrared thermography is one of several non-destructive testing techniques which can be used for defect detection in aircraft materials such as carbon-fibre-reinforced composites. Infrared thermography can be potentially useful, as it is quick, real time, non-contact and can examine over a relatively large area in one inspection procedure. The technique is based on heating the sample surface with different heat sources and monitoring the surface temperature of the sample with an IR camera, any abnormal behavior of the surface temperature distribution indicates the subsurface defect. This kind of structure is normally affected by anomalies such as delaminations, disbonding, water ingressing to the core. in this paper, several different kinds of defects which are of various size and depth below the test surface are planted in the CFRP composites, the Teflon inserts between the plies in the facesheet represents the delaminations, the Teflon inserts between the inner facesheet and adhensive or between adhensive and core are simulated disbonding in the composites, they are all tested by pulsed thermography, meanwhile, these samples are also inspected by ultrasonic testing, compare with each characteristic and the results got by these two different methods, it shows that pulsed thermography is an effective nondestructive technique for inspecting CFRP composites.

  4. Study on the heat flux reconstruction with the infrared thermography for the divertor target plates in the KSTAR tokamak.

    PubMed

    Kang, C S; Lee, H H; Oh, S; Lee, S G; Wi, H M; Kim, Y S; Kim, H S

    2016-08-01

    An infrared (IR) thermography is the preferred diagnostic that can quantify heat flux by measuring the surface temperature distributions of the divertor plates. The IR thermography is successfully instrumented on Korea Superconducting Tokamak Advanced Research (KSTAR). In this study, finite volume method is considered to solve the heat conduction equations. 1D-, 2D-, and 3D models are developed and compared with various calculation algorithms, such as Duhamel's theorem and THEODOR. These comparisons show good agreement. In order to acquire more efficient and reliable calculation results, we consider two numerical analysis schemes, influence of temperature on thermal properties and image stabilization. Recently, this reconstruction code is successfully applied to the KSTAR IR thermography. PMID:27587124

  5. Exit Presentation: Infrared Thermography on Graphite/Epoxy

    NASA Technical Reports Server (NTRS)

    Comeaux, Kayla

    2010-01-01

    This slide presentation reports on the internship project that was accomplished during the summer of 2010. The objectives of the project were to: (1) Simulate Flash Thermography on Graphite/Epoxy Flat Bottom hole Specimen and thin void specimens, (2) Obtain Flash Thermography data on Graphite/Epoxy flat bottom hole specimens, (3) Compare experimental results with simulation results, Compare Flat Bottom Hole Simulation with Thin Void Simulation to create a graph to determine size of IR Thermography detected defects

  6. Evaluation Method of Gas Turbine Blades Covering Integrity by IR Camera

    NASA Astrophysics Data System (ADS)

    Yang, Dong-Jo; Choi, Choul-Jun; Kim, Jae-Yeol

    Key parts of the main equipment in a gas turbine may likely be damaged due to operation under high temperature, high pressure, high-speed rotation, etc. Accordingly, the cost for maintenance increases and the damaged parts may cause generation to stop. The surface of a blade is thermal-sprayed, using powder with main compositions such as Ni, Cr, Al, etc, in order to inhibit hot oxidation. Conventional regular maintenance of the coating layer of a blade is made by FPI (Fluorescent Penetrant Inspection) and MTP (Magnetic Particle Testing). Such methods, however, are complicated and take a long time and also require high cost. In this study, defect diagnostics were tested on the coating layer of an industrial gas turbine blade, using an infrared thermography camera. Since the infrared thermography method can check a temperature distribution by means of non-contact on a wide range of areas, it can advantageously save expense and time as compared to conventional test methods. For the infrared thermography method, however, thermo-load must be applied onto a tested specimen and it is difficult to quantify the measured data. To solve the problems, this paper includes description about producing a specimen of a gas turbine blade (bucket), applying thermo-load onto the produced specimen, photographing thermography images by an infrared thermography camera, analyzing the thermography images, and pre-testing to analyze defects on the coating layer of the gas turbine blade.

  7. Infrared thermography

    SciTech Connect

    Roberts, C.C. Jr.

    1982-12-01

    Infrared thermography is a useful tool for the diagnosis of problems in building systems. In instances where a building owner has several large buildings, an investment in a typical $30,000 infrared system may be cost effective. In most instances, however, the rental of an infrared system or the hiring of an infrared consulting service is a cost effective alternative. As can be seen from the several applications presented here, any mechanical problem manifesting itself in an atypical temperature pattern can usually be detected. The two primary savings generated from infrared analysis of building systems are maintenance and energy.

  8. Thermal characterization of ZnBeMnSe mixed compounds by means of photopyroelectric and lock-in thermography methods

    NASA Astrophysics Data System (ADS)

    Strzałkowski, K.; Dadarlat, D.; Streza, M.; Zakrzewski, J.

    2015-06-01

    In this work, a thermal characterization (measurement of dynamic thermal parameters) of quaternary Zn1-x-yBexMnySe mixed crystals was carried out. The crystals under investigation were grown from the melt by the modified high-pressure Bridgman method with different Be and Mn contents. The effect of Be and Mn contents on thermal properties of Zn1-x-yBexMnySe compounds was analyzed, by using the photopyroelectric (PPE) method in the back configuration (BPPE) for thermal diffusivity measurements and the PPE technique in the front configuration for thermal effusivity investigations. Infrared lock-in thermography was used in order to validate the BPPE results. The measured thermal effusivity and diffusivity allowed the calculation of thermal conductivity of the investigated materials.

  9. Surface thermography

    SciTech Connect

    Ulrickson, M.

    1986-05-01

    The temperature sensitivity of many plasma materials interactions in both fusion plasmas and process plasmas requires the determination of the surface temperature of the material in contact with the plasma. The determination of the surface temperature is made difficult by the presence of the plasma, the large electrical potentials that may be present, and the need to not contaminate the surface. Radiation thermography permits determination of the surface temperature while overcoming the difficulties listed above. This paper briefly discusses thermal radiation, Planck's Law, and the selection of the best wavelength band for a given temperature range. Both one and two color pyrometry are discussed. Several considerations that are necessary for practical applications are discussed. Some examples of the use of radiation thermometry in fusion applications between 350 and 3000 /sup 0/C are presented. Surface heat flux has also been determined from the time variation of the surface temperature.

  10. High speed heterodyne infrared thermography applied to thermal diffusivity identification

    NASA Astrophysics Data System (ADS)

    Pradere, C.; Clerjaud, L.; Batsale, J. C.; Dilhaire, S.

    2011-05-01

    We have combined InfraRed thermography and thermal wave techniques to perform microscale, ultrafast (microsecond) temperature field measurements. The method is based on an IR camera coupled to a microscope and synchronized to the heat source by means of phase locked function generators. The principle is based on electronic stroboscopic sampling where the low IR camera acquisition frequency facq (25 Hz) undersamples a high frequency thermal wave. This technique permits the measurement of the emissive thermal response at a (microsecond) short time scale (microsecond) with the full frame mode of the IR camera with a spatial thermal resolution of 7 μm. Then it becomes possible to study 3D transient heat transfer in heterogeneous and high thermal conductive thin layers. Thus it is possible for the first time in our knowledge to achieve temperature field measurements in heterogeneous media within a wide range of time domains. The IR camera is now a suitable instrument for multiscale thermal analysis.

  11. Thermography pattern analysis and separation

    NASA Astrophysics Data System (ADS)

    Gao, Bin; Bai, Libing; Woo, W. L.; Tian, Guiyun

    2014-06-01

    Analysis of thermography spatial-transient patterns has considerable potential to enable automatic identification and quantification of defects in non-destructive testing and evaluation. This Letter proposes a non-negative pattern separation model for eddy current pulsed thermography to automatically extract important spatial and time patterns according to the transient thermal sequences without any pre-training or prior knowledge. In particular, the method is scale-invariant, such that large differences in surface emissivity, hot spots, and cool areas with dynamic range of thermal contrast can be extracted. Finally, an artificial slot in a steel sample with shining, black strip on the surface is tested to validate the proposed method.

  12. INFRARED THERMOGRAPHY OF CUTANEOUS MELANOMA METASTASES

    PubMed Central

    Shada, Amber L.; Dengel, Lynn T.; Petroni, Gina R.; Smolkin, Mark E.; Acton, Scott; Slingluff, Craig L.

    2014-01-01

    Background Differentiating melanoma metastasis from benign cutaneous lesions currently requires biopsy or costly imaging, such as positron emission tomography scans. Melanoma metastases have been observed to be subjectively warmer than similarly appearing benign lesions. We hypothesized that infrared (IR) thermography would be sensitive and specific in differentiating palpable melanoma metastases from benign lesions. Materials and methods Seventy-four patients (36 females and 38 males) had 251 palpable lesions imaged for this pilot study. Diagnosis was determined using pathologic confirmation or clinical diagnosis. Lesions were divided into size strata for analysis: 0–5, >5–15, >15–30, and >30 mm. Images were scored on a scale from −1 (colder than the surrounding tissue) to +3 (significantly hotter than the surrounding tissue). Sensitivity and specificity were calculated for each stratum. Logistical challenges were scored. Results IR imaging was able to determine the malignancy of small (0–5 mm) lesions with a sensitivity of 39% and specificity of 100%. For lesions >5–15 mm, sensitivity was 58% and specificity 98%. For lesions >15–30 mm, sensitivity was 95% and specificity 100%, and for lesions >30 mm, sensitivity was 78% and specificity 89%. The positive predictive value was 88%–100% across all strata, and the negative predictive value was 95% for >15–30 mm lesions and 80% for >30 mm lesions. Conclusions Malignant lesions >15 mm were differentiated from benign lesions with excellent sensitivity and specificity. IR imaging was well tolerated and feasible in a clinic setting. This pilot study shows promise in the use of thermography for the diagnosis of malignant melanoma with further potential as a noninvasive tool to follow tumor responses to systemic therapies. PMID:23043862

  13. Thermography analyses of the hole-drilling residual stress measuring technique

    NASA Astrophysics Data System (ADS)

    Honner, Milan; Litoš, Pavel; Švantner, Michal

    2004-03-01

    The paper deals with methods and results of thermography analyses of the hole-drilling residual stress measuring technique. Surface IR properties of the drilling mill and sample with strain gauge rosette of millimeter dimensions are determined by the emissivity and reflectivity measurements. Dynamic surface temperature field measurement is accompanied by the strain measurement during step-by-step drilling. Possible sources of errors in relation to the residual stress determination are discussed.

  14. Crack detection by stimulated infrared thermography

    NASA Astrophysics Data System (ADS)

    Bodnar, Jean-Luc

    2014-03-01

    In this paper, the potential of stimulated infrared thermography is studied for the detection of cracks located in metallic materials. To start with, the feasibility of the method is shown with the use of numerical simulations. Stimulated infrared thermography allows detecting emerging cracks in samples whether reflective or not as well as non-emerging cracks. In addition, crack detection is due to the radiative effects and/or the thermal effects induced by the defects. Then, the experimental device implemented for the study is detailed. Finally, experiments confirm that stimulated infrared thermography enables to detect microscopic cracks, whether emerging or non-emerging, in metal samples.

  15. Applied methods of testing and evaluation for IR imaging system

    NASA Astrophysics Data System (ADS)

    Liao, Xiao-yue; Lu, Jin

    2009-07-01

    Different methods of testing and evaluation for IR imaging system are used with the application of the 2nd and the 3rd generation infrared detectors. The performance of IR imaging system can be reflected by many specifications, such as Noise Equivalent Temperature Difference (NETD), Nonuniformity, system Modulation Transfer Function (MTF), Minimum Resolvable Temperature Difference (MRTD), and Minimum Detectable Temperature Difference (MRTD) etc. The sensitivity of IR sensors is estimated by NETD. The sensitivity of thermal imaging sensors and space resolution are evaluated by MRTD, which is the chief specification of system. In this paper, the theoretical analysis of different testing methods is introduced. The characteristics of them are analyzed and compared. Based on discussing the factors that affect measurement results, an applied method of testing NETD and MRTD for IR system is proposed.

  16. IR Spot Weld Inspect

    SciTech Connect

    Chen, Jian; Feng, Zhili

    2014-01-01

    In automotive industry, destructive inspection of spot welds is still the mandatory quality assurance method due to the lack of efficient non-destructive evaluation (NDE) tools. However, it is costly and time-consuming. Recently at ORNL, a new NDE prototype system for spot weld inspection using infrared (IR) thermography has been developed to address this problem. This software contains all the key functions that ensure the NDE system to work properly: system input/output control, image acquisition, data analysis, weld quality database generation and weld quality prediction, etc.

  17. IR Spot Weld Inspect

    Energy Science and Technology Software Center (ESTSC)

    2014-01-01

    In automotive industry, destructive inspection of spot welds is still the mandatory quality assurance method due to the lack of efficient non-destructive evaluation (NDE) tools. However, it is costly and time-consuming. Recently at ORNL, a new NDE prototype system for spot weld inspection using infrared (IR) thermography has been developed to address this problem. This software contains all the key functions that ensure the NDE system to work properly: system input/output control, image acquisition, datamore » analysis, weld quality database generation and weld quality prediction, etc.« less

  18. Using infrared thermography for the creation of a window surface temperature database to validate computer heat transfer models

    SciTech Connect

    Beck, F.A.; Griffith, B.T.; Tuerler, D.; Arasteh, D.

    1995-04-01

    IR thermography is well suited for resolving small differences in the thermal performance of highly insulating window systems. Infrared thermographic measurements made in conjunction with reference emitter techniques in a controlled and characterized laboratory setting can have an absolute accuracy of {plus_minus}0.5{degree}C. Quantitative infrared thermography requires that a number of sources of error related to measurement accuracy and test environmental conditions be quantified and minimized to the extent possible. Laboratory-based infrared thermography can be used to generate window surface temperature profile databases which can be used to direct the development of 2-D and 3-D finite element and finite difference method fenestration heat transfer simulation codes, identify their strengths and weaknesses, set research priorities, and validate finished modeling tools. Development of such a database is under way at Lawrence Berkeley Laboratory, and will be made available for public use.

  19. Comparison of TLD calibration methods for 192Ir dosimetry.

    PubMed

    Haworth, Annette; Butler, Duncan J; Wilfert, Lisa; Ebert, Martin A; Todd, Stephen P; Hayton, Anna J M; Kron, Tomas

    2013-01-01

    For the purpose of dose measurement using a high-dose rate (192)Ir source, four methods of thermoluminescent dosimeter (TLD) calibration were investigated. Three of the four calibration methods used the (192)Ir source. Dwell times were calculated to deliver 1 Gy to the TLDs irradiated either in air or water. Dwell time calculations were confirmed by direct measurement using an ionization chamber. The fourth method of calibration used 6 MV photons from a medical linear accelerator, and an energy correction factor was applied to account for the difference in sensitivity of the TLDs in (192)Ir and 6 MV. The results of the four TLD calibration methods are presented in terms of the results of a brachytherapy audit where seven Australian centers irradiated three sets of TLDs in a water phantom. The results were in agreement within estimated uncertainties when the TLDs were calibrated with the (192)Ir source. Calibrating TLDs in a phantom similar to that used for the audit proved to be the most practical method and provided the greatest confidence in measured dose. When calibrated using 6 MV photons, the TLD results were consistently higher than the (192)Ir-calibrated TLDs, suggesting this method does not fully correct for the response of the TLDs when irradiated in the audit phantom. PMID:23318392

  20. Reliable aerial thermography for energy conservation

    NASA Technical Reports Server (NTRS)

    Jack, J. R.; Bowman, R. L.

    1981-01-01

    A method for energy conservation, the aerial thermography survey, is discussed. It locates sources of energy losses and wasteful energy management practices. An operational map is presented for clear sky conditions. The map outlines the key environmental conditions conductive to obtaining reliable aerial thermography. The map is developed from defined visual and heat loss discrimination criteria which are quantized based on flat roof heat transfer calculations.

  1. Dynamic thermography in diagnostics of onychomycosis

    NASA Astrophysics Data System (ADS)

    Fryca, Jaroslaw; Nowakowski, Antoni; Urbanowski, Slawomir

    2004-07-01

    The paper shows the results of the research on the active dynamic thermography used for diagnostics of onychomycosis and progress of the healing process. It seems that the most essential factor affecting the development of mycosis in nails is the microcirculation in the tissue close to the nail. Active dynamic thermography may prove to be a new diagnostic method and a sufficient tool for measurements of this parameter.

  2. Techniques of infrared thermography.

    PubMed

    Jatteau, M

    1975-01-01

    Considering the main objectives of thermographic techniques and the particular characteristics of passive infrared detection, the essential arguments in favor of single detector scanners have been pointed out after a brief discussion of the detection and image pickup methods when quantitative and precise (0.1 degrees C) information on the temperature distribution near ambient temperature must be obtained. Single detector scanners can have sufficiently good performance to reach the objectives of precise thermography, but their real technical limits must be well-known in practice; consequently, the thermograph performance must be clearly defined by means of the modulation transfer function, the intrinsic thermal resolution and the response uniformity, as we indicate in the second part of this paper. PMID:1180865

  3. Temperature maps measurements on 3D surfaces with infrared thermography

    NASA Astrophysics Data System (ADS)

    Cardone, Gennaro; Ianiro, Andrea; Dello Ioio, Gennaro; Passaro, Andrea

    2012-02-01

    The use of the infrared camera as a temperature transducer in wind tunnel applications is convenient and widespread. Nevertheless, the infrared data are available in the form of 2D images while the observed surfaces are often not planar and the reconstruction of temperature maps over them is a critical task. In this work, after recalling the principles of IR thermography, a methodology to rebuild temperature maps on the surfaces of 3D object is proposed. In particular, an optical calibration is applied to the IR camera by means of a novel target plate with control points. The proposed procedure takes also into account the directional emissivity by estimating the viewing angle. All the needed steps are described and analyzed. The advantages given by the proposed method are shown with an experiment in a hypersonic wind tunnel.

  4. Quantitative Evaluation of Pulsed Thermography, Lock-in Thermography and Vibrothermography on Foreign Object Defect (FOD) in CFRP.

    PubMed

    Liu, Bin; Zhang, Hai; Fernandes, Henrique; Maldague, Xavier

    2016-01-01

    In this article, optical excitation thermographic techniques, including pulsed thermography and lock-in thermography, were used to detect foreign object defect (FOD) and delamination in CFRP. Then, vibrothermography as an ultrasonic excitation technique was used to detect these defects for the comparative purposes. Different image processing methods, including cold image subtraction (CIS), principal component thermography (PCT), thermographic signal reconstruction (TSR) and Fourier transform (FT), were performed. Finally, a comparison of optical excitation thermography and vibrothermography was conducted, and a thermographic probability of detection was given. PMID:27213403

  5. Quantitative Evaluation of Pulsed Thermography, Lock-in Thermography and Vibrothermography on Foreign Object Defect (FOD) in CFRP

    PubMed Central

    Liu, Bin; Zhang, Hai; Fernandes, Henrique; Maldague, Xavier

    2016-01-01

    In this article, optical excitation thermographic techniques, including pulsed thermography and lock-in thermography, were used to detect foreign object defect (FOD) and delamination in CFRP. Then, vibrothermography as an ultrasonic excitation technique was used to detect these defects for the comparative purposes. Different image processing methods, including cold image subtraction (CIS), principal component thermography (PCT), thermographic signal reconstruction (TSR) and Fourier transform (FT), were performed. Finally, a comparison of optical excitation thermography and vibrothermography was conducted, and a thermographic probability of detection was given. PMID:27213403

  6. Dynamic and static thermal study of micromachined heaters: the advantages of visible and near-infrared thermography compared to classical methods

    NASA Astrophysics Data System (ADS)

    Teyssieux, D.; Briand, D.; Charnay, J.; de Rooij, N. F.; Cretin, B.

    2008-06-01

    We report on the dynamic and static thermal characterization of microsystems using a visible and near-infrared (NIR) thermography system based on a low-cost standard CCD sensor. The interest of this method is that it is possible to obtain a true spatial resolution better than 500 nm, which is necessary in high spatial resolution applications (microsystem applications). Another interesting point of this optical method is that the temperature error versus the emissivity error is always very low (compared to infrared thermography). We show, in this study, that this behavior originates in the high sensitivity of Planck's law in this wavelength range (compared to infrared range). Thus, we demonstrate the principal advantages of this method for micromachined heater application. Thermal measurements (in dynamic and static modes) were performed on micro-heaters commonly used in microsystems, platinum- and silicon-based micromachined heaters. The results show the capability of the method in terms of the thermal resolution and spatial resolution as well as the capacity to quickly obtain static and dynamic thermal images of the studied sample.

  7. Methods and Systems for Measurement and Estimation of Normalized Contrast in Infrared Thermography

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay M. (Inventor)

    2015-01-01

    Methods and systems for converting an image contrast evolution of an object to a temperature contrast evolution and vice versa are disclosed, including methods for assessing an emissivity of the object; calculating an afterglow heat flux evolution; calculating a measurement region of interest temperature change; calculating a reference region of interest temperature change; calculating a reflection temperature change; calculating the image contrast evolution or the temperature contrast evolution; and converting the image contrast evolution to the temperature contrast evolution or vice versa, respectively.

  8. IR-based method for copper electrolysis short circuit detection

    NASA Astrophysics Data System (ADS)

    Makipaa, Esa; Tanttu, Juha T.; Virtanen, Henri

    1997-04-01

    In the copper electrorefining process short-circuits between the anodes and cathodes are harmful. They cause decreasing production rate and poor cathode copper quality. Short- circuits should be detected and eliminated as soon as possible. Manual inspection methods often take a lot of time and excessive walking on the electrodes can not be avoided. For these reasons there is a lot of interest to develop short-circuit detection and quality control. In this paper an IR based method for short circuit detection is presented. In the case of the short-circuited anode and cathode pair especially cathode bar becomes significantly warmer than bar in the normal condition. Using IR camera mounted on a moving crane these hot spots among the electrodes were easily detected. IR imaging was tested in the harsh conditions of the refinery hall with various crane speeds. Image processing is a tool to interpret the obtained IR images. In this paper an algorithm for searching the locations of the short-circuits in the electrolytic cell using imaging results as test material is proposed. The basic idea of the developed algorithm is first to search and calculate necessary edges and initial lines of the electrolytic cell. The second step is to determine the exact position of each cathode plate in the cell so that using thresholding the location of the short-circuited cathode can be determined. IR imaging combined with image processing has proven to be a superior method for predictive maintenance and process control compared to manual ones in the copper electrorefining process. It also makes it possible to collect valuable information for the quality control purposes.

  9. Effects of moisture in infrared thermography of resin matrix composites

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; Kantsios, A. G.; Mcerlean, E. A.; Babcock, R. A.; Buckingham, R. D.

    1978-01-01

    Several multiply graphite polyimide composite specimens were examined by real-time infrared thermography in order to study the effects of moisture on their thermograms. Heat was injected from one side and IR emission detected on the opposite side using AGA Thermovision System-680. No differences between the thermograms of dry and water containing specimens were detected for defect-free specimens. However, the presence of trapped water in defective specimens modified the thermographic contrast significantly. It is concluded that: (1) IR thermography can be used to detect moisture in defective composites, and (2) because of the possibility of moisture camouflaging defects, IR thermography for subsurface defect detection should be supplemented by other techniques - such as acoustical imaging and X-radiography.

  10. Infrared thermography for laser-based powder bed fusion additive manufacturing processes

    SciTech Connect

    Moylan, Shawn; Whitenton, Eric; Lane, Brandon; Slotwinski, John

    2014-02-18

    Additive manufacturing (AM) has the potential to revolutionize discrete part manufacturing, but improvements in processing of metallic materials are necessary before AM will see widespread adoption. A better understanding of AM processes, resulting from physics-based modeling as well as direct process metrology, will form the basis for these improvements. Infrared (IR) thermography of AM processes can provide direct process metrology, as well as data necessary for the verification of physics-based models. We review selected works examining how IR thermography was implemented and used in various powder-bed AM processes. This previous work, as well as significant experience at the National Institute of Standards and Technology in temperature measurement and IR thermography for machining processes, shapes our own research in AM process metrology with IR thermography. We discuss our experimental design, as well as plans for future IR measurements of a laser-based powder bed fusion AM process.

  11. Infrared thermography for laser-based powder bed fusion additive manufacturing processes

    NASA Astrophysics Data System (ADS)

    Moylan, Shawn; Whitenton, Eric; Lane, Brandon; Slotwinski, John

    2014-02-01

    Additive manufacturing (AM) has the potential to revolutionize discrete part manufacturing, but improvements in processing of metallic materials are necessary before AM will see widespread adoption. A better understanding of AM processes, resulting from physics-based modeling as well as direct process metrology, will form the basis for these improvements. Infrared (IR) thermography of AM processes can provide direct process metrology, as well as data necessary for the verification of physics-based models. We review selected works examining how IR thermography was implemented and used in various powder-bed AM processes. This previous work, as well as significant experience at the National Institute of Standards and Technology in temperature measurement and IR thermography for machining processes, shapes our own research in AM process metrology with IR thermography. We discuss our experimental design, as well as plans for future IR measurements of a laser-based powder bed fusion AM process.

  12. A nondestructive method for diagnostic of insulated building walls using infrared thermography

    NASA Astrophysics Data System (ADS)

    Larbi Youcef, Mohamed H. A.; Mazioud, Atef; Bremond, Pierre; Ibos, Laurent; Candau, Yves; Piro, Michel; Filloux, Alain

    2007-04-01

    This work deals with the development of an experimental protocol for the diagnostic of multi-layered insulated building walls. First, a test bench is set up in order to measure front and back sides temperatures of standard panels. The panels considered have insulation thicknesses of 2, 6 and 10cm. The front side is heated by two halogen lamps of 500W. A CEDIP Jade Long wave infrared camera and thermocouples are used to carry out temperature measurements. In a second time, a one dimensional model based on thermal quadruples and Laplace transforms was developped under Matlab environment. Also, we developped a three dimensional model based on finite volumes using Fluent computational code. Finally, a method of identification of physical parameters is implemented by performing least square minimization based on Levenberg-Marquardt method. The experimental measurements are compared to theoretical results and by minimization we obtain thermal conductivity and diffusivity as well as thickness of the two layers.

  13. Methods and Systems for Characterization of an Anomaly Using Infrared Flash Thermography

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay M. (Inventor)

    2013-01-01

    A method for characterizing an anomaly in a material comprises (a) extracting contrast data; (b) measuring a contrast evolution; (c) filtering the contrast evolution; (d) measuring a peak amplitude of the contrast evolution; (d) determining a diameter and a depth of the anomaly, and (e) repeating the step of determining the diameter and the depth of the anomaly until a change in the estimate of the depth is less than a set value. The step of determining the diameter and the depth of the anomaly comprises estimating the depth using a diameter constant C.sub.D equal to one for the first iteration of determining the diameter and the depth; estimating the diameter; and comparing the estimate of the depth of the anomaly after each iteration of estimating to the prior estimate of the depth to calculate the change in the estimate of the depth of the anomaly.

  14. Heat flux sensors for infrared thermography in convective heat transfer.

    PubMed

    Carlomagno, Giovanni Maria; de Luca, Luigi; Cardone, Gennaro; Astarita, Tommaso

    2014-01-01

    This paper reviews the most dependable heat flux sensors, which can be used with InfraRed (IR) thermography to measure convective heat transfer coefficient distributions, and some of their applications performed by the authors' research group at the University of Naples Federico II. After recalling the basic principles that make IR thermography work, the various heat flux sensors to be used with it are presented and discussed, describing their capability to investigate complex thermo-fluid-dynamic flows. Several applications to streams, which range from natural convection to hypersonic flows, are also described. PMID:25386758

  15. Heat Flux Sensors for Infrared Thermography in Convective Heat Transfer

    PubMed Central

    Carlomagno, Giovanni Maria; de Luca, Luigi; Cardone, Gennaro; Astarita, Tommaso

    2014-01-01

    This paper reviews the most dependable heat flux sensors, which can be used with InfraRed (IR) thermography to measure convective heat transfer coefficient distributions, and some of their applications performed by the authors' research group at the University of Naples Federico II. After recalling the basic principles that make IR thermography work, the various heat flux sensors to be used with it are presented and discussed, describing their capability to investigate complex thermo-fluid-dynamic flows. Several applications to streams, which range from natural convection to hypersonic flows, are also described. PMID:25386758

  16. Electro-thermography technique for nondestructive testing (NDT) applications

    NASA Astrophysics Data System (ADS)

    Chen, Y. S.; Hung, Y. Y.; Liu, L.

    2008-11-01

    In this paper, Electro-Thermography is introduced in nondestructive testing applications. Electro-Thermography is one of the novel active thermography techniques for nondestructive testing. It gains the advantages from the optical and electromagnetic properties in full-field, non-contact, high inspection speed, and sensitivity in geometry variation. It is mostly applicable to all kind of ferrous-metal, some composites materials. A fundamental difference among electro-thermography and other active thermography techniques are the excitation mechanism. Electro-Thermography is a combination of the electromagnetic induction and surface thermal radiation measuring technique; it used the induction method to excite the object, and then it used the radiation properties to measure the distribution of surface temperature of the object. It detects flaws by the flaw's anomalous heating and heat transfer response. The method of excitation is also different from others irradiation excitation. Electro-Thermography needs an electromagnetic coil to generate eddy current through induction to change the surface and subsurface temperature. Electro-Thermography can detect surface and sub-surface flaws, unless the flaw is too remote and tiny from the surface. Some experiments in flaw detections and other types of inspections are demonstrated.

  17. Thermography and k-means clustering methods for anti-reflective coating film inspection: scratch and bubble defects

    NASA Astrophysics Data System (ADS)

    Zhou, Xunfei; Wang, Hongjin; Hsieh, Sheng-Jen (Tony)

    2016-05-01

    Anti-reflective coating is widely used on telescopes, eyeglasses and screens to effectively enhance the transmission of light. However, the presence of defects such as bubbles or scratches lowers the usability and functionality of optical film. Optical cameras are often used for coating inspection, but their accuracy relies heavily on the illumination source, camera viewing angles and defect location. This paper describes an active thermography approach that can potentially overcome this issue. Eighteen scratch and bubble defects were located on AR film with dimensions ranging from 0.03mm to 4.4 mm. An infrared camera was used to capture thermal images of those defects over 65 seconds of heating. After the thermal images were acquired, time-domain analysis and space-domain analysis were conducted and k-means clustering methodology was used to highlight the defective area. Results suggest active thermography can be used to detect scratch defects with widths of 0.03mm to 4.40 mm and bubble defects with diameters ranging from 0.08 to 4 mm. For defects with dimensions larger than 0.4 mm, our algorithm can estimate the dimension with less than 15% bias. However, for defects with dimensions less than 0.4mm, the algorithm estimation error ranged from 68% to 900% due to camera resolution limitations. It should be noted that our algorithm can still distinguish a scratch defect with a width of less than one pixel. This study also suggests active thermography can detect scratch and bubble defects regardless of the location of the illumination source.

  18. First investigations to refine video-based IR thermography as a non-invasive tool to monitor the body temperature of calves.

    PubMed

    Hoffmann, G; Schmidt, M; Ammon, C

    2016-09-01

    In this study, a video-based infrared camera (IRC) was investigated as a tool to monitor the body temperature of calves. Body surface temperatures were measured contactless using videos from an IRC fixed at a certain location in the calf feeder. The body surface temperatures were analysed retrospectively at three larger areas: the head area (in front of the forehead), the body area (behind forehead) and the area of the entire animal. The rectal temperature served as a reference temperature and was measured with a digital thermometer at the corresponding time point. A total of nine calves (Holstein-Friesians, 8 to 35 weeks old) were examined. The average maximum temperatures of the area of the entire animal (mean±SD: 37.66±0.90°C) and the head area (37.64±0.86°C) were always higher than that of the body area (36.75±1.06°C). The temperatures of the head area and of the entire animal were very similar. However, the maximum temperatures as measured using IRC increased with an increase in calf rectal temperature. The maximum temperatures of each video picture for the entire visible body area of the calves appeared to be sufficient to measure the superficial body temperature. The advantage of the video-based IRC over conventional IR single-picture cameras is that more than one picture per animal can be analysed in a short period of time. This technique provides more data for analysis. Thus, this system shows potential as an indicator for continuous temperature measurements in calves. PMID:26190139

  19. Automated Induction Thermography of Generator Components

    NASA Astrophysics Data System (ADS)

    Goldammer, M.; Mooshofer, H.; Rothenfusser, M.; Bass, J.; Vrana, J.

    2010-02-01

    Using Active Thermography defects such as cracks can be detected fast and reliably. Choosing from a wide range of excitation techniques the method can be adapted to a number of tasks in non-destructive evaluation. Induction thermography is ideally suited for testing metallic components for cracks at or close to the surface. In power generation a number of components are subjected to high loads and stresses—therefore defect detection is crucial for a safe operation of the engines. Apart from combustion turbines this also applies to generators: At regular inspection intervals even small cracks have to be detected to avoid crack growth and consequently failure of the component. As an imaging technique thermography allows for a fast 100% testing of the complete surface of all relevant parts. An automated setup increases the cost effectiveness of induction thermography significantly. Time needed to test a single part is reduced, the number of tested parts per shift is increased, and cost for testing is reduced significantly. In addition, automation guarantees a reliable testing procedure which detects all critical defects. We present how non-destructive testing can be automated using as an example an industrial application at the Siemens sector Energy, and a new induction thermography setup for generator components.

  20. Induction and Conduction Thermography: Optimizing the Electromagnetic Excitation Towards Application

    NASA Astrophysics Data System (ADS)

    Vrana, J.; Goldammer, M.; Bailey, K.; Rothenfusser, M.; Arnold, W.

    2009-03-01

    Active thermography, using electromagnetic excitation, allows detecting defects like cracks which distort the flow of current in the component under examination. Like other thermography techniques it is rapid and reliably utilizing infrared imaging. Electric current can be used in two ways for thermography: In induction thermography a current is coupled to the component by passing an AC current through a coil which is in close proximity to the component inspected, while in conduction thermography the current is coupled directly into the component. In this paper, the specific advantages of both coupling methods are discussed, including the efficiency of the coupling and optimization strategies for testing and also the necessary algorithms required to analyze the data. Taking these considerations into account a number of different systems for laboratory and practical application were developed.

  1. Measuring and Estimating Normalized Contrast in Infrared Flash Thermography

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay M.

    2013-01-01

    Infrared flash thermography (IRFT) is used to detect void-like flaws in a test object. The IRFT technique involves heating up the part surface using a flash of flash lamps. The post-flash evolution of the part surface temperature is sensed by an IR camera in terms of pixel intensity of image pixels. The IR technique involves recording of the IR video image data and analysis of the data using the normalized pixel intensity and temperature contrast analysis method for characterization of void-like flaws for depth and width. This work introduces a new definition of the normalized IR pixel intensity contrast and normalized surface temperature contrast. A procedure is provided to compute the pixel intensity contrast from the camera pixel intensity evolution data. The pixel intensity contrast and the corresponding surface temperature contrast differ but are related. This work provides a method to estimate the temperature evolution and the normalized temperature contrast from the measured pixel intensity evolution data and some additional measurements during data acquisition.

  2. Thermography in ocular inflammation

    PubMed Central

    Kawali, Ankush A

    2013-01-01

    Background and Objectives: The purpose of this study was to evaluate ocular inflammatory and non-inflammatory conditions using commercially available thermal camera. Materials and Methods: A non-contact thermographic camera (FLIR P 620) was used to take thermal pictures of seven cases of ocular inflammation, two cases of non-inflammatory ocular pathology, and one healthy subject with mild refractive error only. Ocular inflammatory cases included five cases of scleritis, one case of postoperative anterior uveitis, and a case of meibomian gland dysfunction with keratitis (MGD-keratitis). Non-inflammatory conditions included a case of conjunctival benign reactive lymphoid hyperplasia (BRLH) and a case of central serous chorio-retinopathy. Thermal and non-thermal photographs were taken, and using analyzing software, the ocular surface temperature was calculated. Results: Patient with fresh episode of scleritis revealed high temperature. Eyes with MGD-keratitis depicted lower temperature in clinically more affected eye. Conjunctival BRLH showed a cold lesion on thermography at the site of involvement, in contrast to cases of scleritis with similar clinical presentation. Conclusion: Ocular thermal imaging is an underutilized diagnostic tool which can be used to distinguish inflammatory ocular conditions from non-inflammatory conditions. It can also be utilized in the evaluation of tear film in dry eye syndrome. Its applications should be further explored in uveitis and other ocular disorders. Dedicated “ocular thermographic” camera is today's need of the hour. PMID:24347863

  3. Clinical applications of computerized thermography

    NASA Technical Reports Server (NTRS)

    Anbar, Michael

    1988-01-01

    Computerized or digital, thermography is a rapidly growing diagnostic imaging modality. It has superseded contact thermography and analog imaging thermography which do not allow effective quantization. Medical applications of digital thermography can be classified in two groups: static and dynamic imaging. They can also be classified into macro thermography (resolution greater than 1 mm) and micro thermography (resolution less than 100 microns). Both modalities allow a thermal resolution of 0.1 C. The diagnostic power of images produced by any of these modalities can be augmented by the use of digital image enhancement and image recognition procedures. Computerized thermography has been applied in neurology, cardiovascular and plastic surgery, rehabilitation and sports medicine, psychiatry, dermatology and ophthalmology. Examples of these applications are shown and their scope and limitations are discussed.

  4. Nondestructive testing with thermography

    NASA Astrophysics Data System (ADS)

    Ibarra-Castanedo, Clemente; Tarpani, José Ricardo; Maldague, Xavier P. V.

    2013-11-01

    Thermography is a nondestructive testing (NDT) technique based on the principle that two dissimilar materials, i.e., possessing different thermo-physical properties, would produce two distinctive thermal signatures that can be revealed by an infrared sensor, such as a thermal camera. The fields of NDT applications are expanding from classical building or electronic components monitoring to more recent ones such as inspection of artworks or composite materials. Furthermore, thermography can be conveniently used as a didactic tool for physics education in universities given that it provides the possibility of visualizing fundamental principles, such as thermal physics and mechanics among others.

  5. Crack depth determination with inductive thermography

    NASA Astrophysics Data System (ADS)

    Oswald-Tranta, B.; Schmidt, R.

    2015-05-01

    Castings, forgings and other steel products are nowadays usually tested with magnetic particle inspection, in order to detect surface cracks. An alternative method is active thermography with inductive heating, which is quicker, it can be well automated and as in this paper presented, even the depth of a crack can be estimated. The induced eddy current, due to its very small penetration depth in ferro-magnetic materials, flows around a surface crack, heating this selectively. The surface temperature is recorded during and after the short inductive heating pulse with an infrared camera. Using Fourier transformation the whole IR image sequence is evaluated and the phase image is processed to detect surface cracks. The level and the local distribution of the phase around a crack correspond to its depth. Analytical calculations were used to model the signal distribution around cracks with different depth and a relationship has been derived between the depth of a crack and its phase value. Additionally, also the influence of the heating pulse duration has been investigated. Samples with artificial and with natural cracks have been tested. Results are presented comparing the calculated and measured phase values depending on the crack depth. Keywords: inductive heating, eddy current, infrared

  6. Thermography in Neurologic Practice

    PubMed Central

    Neves, Eduardo Borba; Vilaça-Alves, José; Rosa, Claudio; Reis, Victor Machado

    2015-01-01

    One kind of medical images that has been developed in the last decades is thermal images. These images are assessed by infrared cameras and have shown an exponential development in recent years. In this sense, the aim of this study was to describe possibilities of thermography usage in the neurologic practice. It was performed a systematic review in Web of Knowledge (Thompson Reuters), set in all databases which used two combination of keywords as “topic”: “thermography” and “neurology”; and “thermography” and “neurologic”. The chronological period was defined from 2000 to 2014 (the least 15 years). Among the studies included in this review, only seven were with experimental design. It is few to bring thermography as a daily tool in clinical practice. However, these studies have suggested good results. The studies of review and an analyzed patent showed that the authors consider the thermography as a diagnostic tool and they recommend its usage. It can be concluded that thermography is already used as a diagnostic and monitoring tool of patients with neuropathies, particularly in complex regional pain syndrome, and stroke. And yet, this tool has great potential for future research about its application in diagnosis of other diseases of neurological origin. PMID:26191090

  7. A synchronized particle image velocimetry and infrared thermography technique applied to an acoustic streaming flow

    PubMed Central

    Sou, In Mei; Layman, Christopher N.; Ray, Chittaranjan

    2013-01-01

    Subsurface coherent structures and surface temperatures are investigated using simultaneous measurements of particle image velocimetry (PIV) and infrared (IR) thermography. Results for coherent structures from acoustic streaming and associated heating transfer in a rectangular tank with an acoustic horn mounted horizontally at the sidewall are presented. An observed vortex pair develops and propagates in the direction along the centerline of the horn. From the PIV velocity field data, distinct kinematic regions are found with the Lagrangian coherent structure (LCS) method. The implications of this analysis with respect to heat transfer and related sonochemical applications are discussed. PMID:24347810

  8. A synchronized particle image velocimetry and infrared thermography technique applied to an acoustic streaming flow.

    PubMed

    Sou, In Mei; Allen, John S; Layman, Christopher N; Ray, Chittaranjan

    2011-11-01

    Subsurface coherent structures and surface temperatures are investigated using simultaneous measurements of particle image velocimetry (PIV) and infrared (IR) thermography. Results for coherent structures from acoustic streaming and associated heating transfer in a rectangular tank with an acoustic horn mounted horizontally at the sidewall are presented. An observed vortex pair develops and propagates in the direction along the centerline of the horn. From the PIV velocity field data, distinct kinematic regions are found with the Lagrangian coherent structure (LCS) method. The implications of this analysis with respect to heat transfer and related sonochemical applications are discussed. PMID:24347810

  9. Thermal diffusivity estimation with quantitative pulsed phase thermography

    NASA Astrophysics Data System (ADS)

    Ospina-Borras, J. E.; Florez-Ospina, Juan F.; Benitez-Restrepo, H. D.; Maldague, X.

    2015-05-01

    Quantitative Pulsed Phase Thermography (PPT) has been only used to estimate defect parameters such as depth and thermal resistance. Here, we propose a thermal quadrupole based method that extends quantitative pulsed phase thermography. This approach estimates thermal diffusivity by solving a inversion problem based on non-linear squares estimation. This approach is tested with pulsed thermography data acquired from a composite sample. We compare our results with another technique established in time domain. The proposed quantitative analysis with PPT provides estimates of thermal diffusivity close to those obtained with the time domain approach. This estimation requires only the a priori knowledge of sample thickness.

  10. Active Thermography for the Detection of Defects in Powder Metallurgy Compacts

    NASA Astrophysics Data System (ADS)

    Benzerrouk, Souheil; Ludwig, Reinhold; Apelian, Diran

    2007-03-01

    Active thermography is an established NDE technique that has become the method of choice in many industrial applications which require non-contact access to the parts under test. Unfortunately, when conducting on-line infrared (IR) inspection of powder metallic compacts, complications can arise due the generally low emissivity of metals and the thermally noisy environment typically encountered in manufacturing plants. In this paper we present results of an investigation that explores the suitability of active IR imaging of powder metallurgy compacts for the detection of surface and sub-surface defects in the pre-sinter state and in an on-line manufacturing setting to ensure complete quality assurance. Additional off-line tests can be carried out for statistical quality analyses. In this research, the IR imaging of sub-surface defects is based on a transient instrumentation approach that relies on an electric control system which synchronizes and monitors the thermal response due to an electrically generated heat source. Preliminary testing reveals that this newly developed pulsed thermography system can be employed for the detection of subsurface defects in green-state parts. Practical measurements agree well with theoretical predictions. The inspection approach being developed can be used for the testing of green-state compacts as they exit the compaction press at speeds of up to 1,000 parts per hour.

  11. Active Thermography for the Detection of Defects in Powder Metallurgy Compacts

    SciTech Connect

    Benzerrouk, Souheil; Ludwig, Reinhold; Apelian, Diran

    2007-03-21

    Active thermography is an established NDE technique that has become the method of choice in many industrial applications which require non-contact access to the parts under test. Unfortunately, when conducting on-line infrared (IR) inspection of powder metallic compacts, complications can arise due the generally low emissivity of metals and the thermally noisy environment typically encountered in manufacturing plants. In this paper we present results of an investigation that explores the suitability of active IR imaging of powder metallurgy compacts for the detection of surface and sub-surface defects in the pre-sinter state and in an on-line manufacturing setting to ensure complete quality assurance. Additional off-line tests can be carried out for statistical quality analyses. In this research, the IR imaging of sub-surface defects is based on a transient instrumentation approach that relies on an electric control system which synchronizes and monitors the thermal response due to an electrically generated heat source. Preliminary testing reveals that this newly developed pulsed thermography system can be employed for the detection of subsurface defects in green-state parts. Practical measurements agree well with theoretical predictions. The inspection approach being developed can be used for the testing of green-state compacts as they exit the compaction press at speeds of up to 1,000 parts per hour.

  12. Advanced multispectral dynamic thermography as a new tool for inspection of gas-fired furnaces

    NASA Astrophysics Data System (ADS)

    Pregowski, Piotr; Goleniewski, Grzegorz; Komosa, Wojciech; Korytkowski, Waldemar

    2004-04-01

    The main special feature of elaborated method is that the dynamic IR thermography (DIRT) bases on forming of single image consisting of pixels of chosen minimum (IMAX) or maximum (IMAX) value, noted during adequately long sequence of thermograms with total independence to the moment of its (image's) capture. In this way, additive or suppressed interferences of fluctuating character become bypassed. Due to this method thereafter elaborated in classic way such "artificial thermogram" offers the quality impossible to achieve with a classic "one shot" method. Although preliminary, results obtained clearly show great potential of the method. and confirmed the validity in decreasing errors caused by fluctuating disturbances. In the case of process furnaces of gas-fired type and especially of coal-fired, application of presented solutions should result in significant increasing the reliability of IR thermography application. By use of properly chosen optical filters and algorithm, elaborated method offers a new potential attractive to test temperature problems other than in tubes , as for example symmetry and efficiency of the furnace heaters.

  13. Department of National Defence's use of thermography for facilities maintenance

    NASA Astrophysics Data System (ADS)

    Kittson, John E.

    1990-03-01

    Since the late seventies DND through the Director General Works has been actively encouraging the use of thermography as an efficient and effective technique for supporting preventive maintenance quality assurance and energy conservation programs at Canadian Forces Bases (CFBs). This paper will provide an overview of DND''s experiences in the utilization of thermography for facilities maintenance applications. 1. HISTORICAL MILESTONES The following are milestones of DND''s use of thermography: a. Purchase of Infrared Equipment In 1976/77 DND purchased five AGA 750 Infrared Thermovision Systems which were distributed to commands. In 1980/81/82 six AGA liOs five AGA TPT8Os two AGA 782s and one AGA 720 were acquired. Finally DND also purchased seven AGEMA 870 systems during 1987/88. b. First and Second Interdepartaental Building Thermography Courses In 1978 and 1980 DND hosted two building thermography courses that were conducted by Public Works Canada. c. CE Thermographer Specialist Training Courses DND developed a training standard in 1983 for Construction Engineering (CE) Thermographer qualification which included all CE applications of thermography. The first annual inhouse training course was conducted at CFB Borden Ontario in 1984. These are now being conducted at the CFB Chilliwack Detachment in Vernon British Columbia. 2 . MARKETING FACILITIES MAINTENANCE IR Of paramount importance for successfully developing DND appreciation for thermography was providing familiarization training to CE staff at commands and bases. These threeday presentations emphasized motivational factors conducting thermographic surveys and utilizing infrared data of roofs electrical/mechanical systems heating plants steam distribution and building enclosures. These factors consisted mainly of the following objectives: a. preventive maintenance by locating deficiencies to be repaired b. quality assurance by verification of workmanship materials and design c. energy conservation by locating

  14. Airborne thermography of temperature patterns in sugar beet piles

    NASA Technical Reports Server (NTRS)

    Moore, D. G.; Bichsel, S.

    1975-01-01

    An investigation was conducted to evaluate the use of thermography for locating spoilage areas (chimneys) within storage piles and to subsequently use the information for the scheduling of their processing. Thermal-infrared quantitative scanner data were acquired initially on January 16, 1975, over the storage piles at Moorhead, Minnesota, both during the day and predawn. Photographic data were acquired during the day mission to evaluate the effect of uneven snow cover on the thermal emittance, and the predawn thermography was used to locate potential chimneys. The piles were examined the day prior for indications of spoilage areas, and the ground crew indicated that no spoilage areas were located using their existing methods. Nine spoilage areas were interpreted from the thermography. The piles were rechecked by ground methods three days following the flights. Six of the nine areas delineated by thermography were actual spoilage areas.

  15. Determination of effective resonance energy for the 193Ir(n,γ)194Ir reaction by the cadmium ratio method

    NASA Astrophysics Data System (ADS)

    Budak, Mustafa Guray; Karadag, Mustafa; Yücel, Haluk

    2016-04-01

    In this work, the effective resonance energy, Ebarr -value for the 193Ir(n,γ)194Ir reaction was measured using cadmium ratio method. A dual monitor (197Au-98Mo), which has convenient resonance properties, was employed for characterization of the irradiation sites. Then analytical grade iridium oxide samples diluted with CaCO3 to lower neutron self-shielding effect stacked in small cylindrical Teflon boxes were irradiated once with a 1 mm thick Cd cylindrical box placed in a thermalized neutron field of an 241Am-Be neutron source then without it. The activities produced in samples during 193Ir(n,γ)194Ir reaction were measured using a p-type HPGe detector γ-ray spectrometer with a 44.8% relative efficiency. The correction factors for thermal, epithermal neutron self-shielding (Gth, Gepi), true coincidence summing (Fcoi) and gamma-ray self-absorption (Fs) effects were determined with appropriate approaches and programs. Thus, the experimental Ebarr -value was determined to be 2.65 ± 0.61 eV for 193Ir target nuclide. The recent data for Q0 and FCd values for Ebarr determination were based on k0-NAA online database. The present experimental Ebarr value was calculated and compared with more recent values for Q0 and FCd for 193Ir. Additionally, the Ebarr -values was theoretically calculated from the up-to-date resonance data obtained from ENDF/B VII library using two different approaches. Since there is no experimentally determined Ebarr -value for the 193Ir isotope, the results are compared with the calculated ones given in the literature.

  16. Theoretical framework for quantitatively estimating ultrasound beam intensities using infrared thermography.

    PubMed

    Myers, Matthew R; Giridhar, Dushyanth

    2011-06-01

    In the characterization of high-intensity focused ultrasound (HIFU) systems, it is desirable to know the intensity field within a tissue phantom. Infrared (IR) thermography is a potentially useful method for inferring this intensity field from the heating pattern within the phantom. However, IR measurements require an air layer between the phantom and the camera, making inferences about the thermal field in the absence of the air complicated. For example, convection currents can arise in the air layer and distort the measurements relative to the phantom-only situation. Quantitative predictions of intensity fields based upon IR temperature data are also complicated by axial and radial diffusion of heat. In this paper, mathematical expressions are derived for use with IR temperature data acquired at times long enough that noise is a relatively small fraction of the temperature trace, but small enough that convection currents have not yet developed. The relations were applied to simulated IR data sets derived from computed pressure and temperature fields. The simulation was performed in a finite-element geometry involving a HIFU transducer sonicating upward in a phantom toward an air interface, with an IR camera mounted atop an air layer, looking down at the heated interface. It was found that, when compared to the intensity field determined directly from acoustic propagation simulations, intensity profiles could be obtained from the simulated IR temperature data with an accuracy of better than 10%, at pre-focal, focal, and post-focal locations. PMID:21682428

  17. Simple laboratory methods for quantitative IR measurements of CW agents

    NASA Astrophysics Data System (ADS)

    Puckrin, Eldon; Thériault, Jean-Marc; Lavoie, Hugo; Dubé, Denis; Lepage, Carmela J.; Petryk, Michael

    2005-11-01

    A simple method is presented for quantitatively measuring the absorbance of chemical warfare (CW) agents and their simulants in the vapour phase. The technique is based on a standard lab-bench FTIR spectrometer, 10-cm gas cell, a high accuracy Baratron pressure manometer, vacuum pump and simple stainless-steel hardware components. The results of this measurement technique are demonstrated for sarin (GB) and soman (GD). A second technique is also introduced for the passive IR detection of CW agents in an open- air path located in a fumehood. Using a modified open-cell with a pathlength of 45 cm, open-air passive infrared measurements have been obtained for simulants and several classical CW agents. Detection, identification and quantification results based on passive infrared measurements are presented for GB and the CW agent simulant, DMMP, using the CATSI sensor which has been developed by DRDC Valcartier. The open-cell technique represents a relatively simple and feasible method for examining the detection capability of passive sensors, such as CATSI, for CW agents.

  18. An active thermography approach for thermal and electrical characterization of thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Streza, M.; Longuemart, S.; Guilmeau, E.; Strzalkowski, K.; Touati, K.; Depriester, M.; Maignan, A.; Sahraoui, A. Hadj

    2016-07-01

    The enhancement of figure of merit (ZT) of thermoelectrics is becoming extremely important for an efficient conversion of thermal energy into electrical energy. In this respect, reliable measurements of thermal and electrical parameters are of paramount importance in order to characterize thermoelectric materials in terms of their efficiency. In this work, a combined theoretical-experimental active thermography approach is presented. The method consists of selecting the right sequential interdependence between the excitation frequency and the sampling rate of the infrared camera, by computing a temporal Fourier analysis of each pixel of the recorded IR image. The method is validated by using a reference sample which is then applied to a recent synthesized titanium trisulphide thermoelectric material (TiS3). By combining AC and steady-state experiments, one can obtain information on both thermal and electrical parameters of TE materials (namely thermal diffusivity, Seebeck coefficient). The thermal diffusivity and thermal conductivity of TiS3 are also measured using photothermal radiometry technique (PTR) and the resulting values of these parameters are α  =  9.7*10‑7 m2 s‑1 and k  =  2.2 W m‑1 K, respectively. The results obtained with the two techniques are in good agreement. In the case of TE materials, the main benefit of the proposed method is related to its non-contact nature and the possibility of obtaining the electric potential and temperature at the same probes. The Seebeck coefficient obtained by active IR thermography (S  =  ‑554 μV K‑1) is consistent with the one obtained using an ULVAC-ZEM3 system (S  =  ‑570 μV K‑1). For a large number of users of thermographic cameras, which are not equipped with a lock-in thermography module, the present approach provides an affordable and cheaper solution.

  19. Development of IR Contrast Data Analysis Application for Characterizing Delaminations in Graphite-Epoxy Structures

    NASA Technical Reports Server (NTRS)

    Havican, Marie

    2012-01-01

    Objective: Develop infrared (IR) flash thermography application based on use of a calibration standard for inspecting graphite-epoxy laminated/honeycomb structures. Background: Graphite/Epoxy composites (laminated and honeycomb) are widely used on NASA programs. Composite materials are susceptible for impact damage that is not readily detected by visual inspection. IR inspection can provide required sensitivity to detect surface damage in composites during manufacturing and during service. IR contrast analysis can provide characterization of depth, size and gap thickness of impact damage. Benefits/Payoffs: The research provides an empirical method of calibrating the flash thermography response in nondestructive evaluation. A physical calibration standard with artificial flaws such as flat bottom holes with desired diameter and depth values in a desired material is used in calibration. The research devises several probability of detection (POD) analysis approaches to enable cost effective POD study to meet program requirements.

  20. Surface temperature measurement of insulating glass units using infrared thermography

    SciTech Connect

    Elmahdy, H.

    1996-12-31

    Infrared (IR) thermography is a process to produce, by means of an infrared scanner, thermal images of surfaces by detecting the radiation emitted from the surfaces. The application of IR thermography as a diagnostic tool in building science assists in determining existing anomalies in the building envelope and other building components. In this paper, IR thermography is used to compare the glass surface temperatures of insulating glass (IG) units made with two types of spacer bar (metal and silicone foam) and different gap widths. The results from this research are compared with data obtained from another research laboratory using a different IR scanner and also with data from finite-element computer modeling. All the tests and simulations were performed on identical IG units. Tests performed on seven IG units indicated that IR thermography could be used to assess the edge-of-glass temperature of IG units for the prediction of condensation resistance of the units. The image processing and analysis depend on the knowledge of accurate emissivity of the surfaces under investigation as well as other variables that affect the final thermal image (e.g., ambient temperature, relative humidity of air in the optical path, and the optical path length). The IR scanner records all the radiation (both direct and reflected) it sees either from the intended target or from any other radiative surfaces in its field of view (FOV). The vertical temperature profiles of all the tested units showed considerable reduction of temperature at the bottom section of the IG unit. The degree of temperature reduction is affected by the type of spacer bar material and the gap thickness.

  1. T.S.A. and Thermography

    NASA Astrophysics Data System (ADS)

    Reynolds, W. N.

    1987-04-01

    The SIRA SPATE equipment for thermal stress analysis is a successful example of the application of modern instrumentation technology to the development and application of classical concepts in physics. The use of Infra Red Optics to monitor small temperature changes over the surface of a solid material has great advantages in many applications as it is rapid, non contacting and non-invasive, and produces signals which can be recorded and analysed in many ways. These advantages have already been exploited to some extent in other applications such as conventional thermography, in which the distribution of heat in a structure is monitored by an I.R. imager using a rotating scanning system, or an I.R. pyroelectric vidicon tube. Such systems are widely employed in monitoring electrical power supplies or chemical plant, but have proved of less relevance to problems of nondestructive testing. In recent years this idea has been combined with that of introducing an alternating or on-off source of heat by means of a chopped laser beam for example, and using recording equipment such as SPATE to monitor the flow heat through a solid. It can be shown that such a source produces a train of critically damped waves of length A where 1/2 A = 2{1T4 where a is the thermal diffusivity of the solid and v is the frequency of chopping and the wave amplitude falls to l/e of its initial value in one wavelength. For waves of frequency 1Hz in copper, A is about 20mm, but normally it is necessary to work at frequencies of 100Hz or more in materials of much lower diffusivity. Consequently this method is chiefly of interest in the examination of thin sheets or coatings up to 1-2mm in thickness. In another development which is more specifically adaptable 'to many problems of NDT, heat is introduced over a chosen area at a high rate for a predetermined time of between lms and about 10s. The subsequent flow through the solid is then monitored by means of an I.R. imager compatible with current TV

  2. Flash Infrared Thermography Contrast Data Analysis Technique

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay

    2014-01-01

    This paper provides information on an IR Contrast technique that involves extracting normalized contrast versus time evolutions from the flash thermography inspection infrared video data. The analysis calculates thermal measurement features from the contrast evolution. In addition, simulation of the contrast evolution is achieved through calibration on measured contrast evolutions from many flat-bottom holes in the subject material. The measurement features and the contrast simulation are used to evaluate flash thermography data in order to characterize delamination-like anomalies. The thermal measurement features relate to the anomaly characteristics. The contrast evolution simulation is matched to the measured contrast evolution over an anomaly to provide an assessment of the anomaly depth and width which correspond to the depth and diameter of the equivalent flat-bottom hole (EFBH) similar to that used as input to the simulation. A similar analysis, in terms of diameter and depth of an equivalent uniform gap (EUG) providing a best match with the measured contrast evolution, is also provided. An edge detection technique called the half-max is used to measure width and length of the anomaly. Results of the half-max width and the EFBH/EUG diameter are compared to evaluate the anomaly. The information provided here is geared towards explaining the IR Contrast technique. Results from a limited amount of validation data on reinforced carbon-carbon (RCC) hardware are included in this paper.

  3. Thermography evaluation of metal bonding materials

    NASA Astrophysics Data System (ADS)

    Safai, Morteza

    The thermographic technique used for the nondestructive evaluation of bondline integrity in metal and silicone rubber bonded material is described. An AGEMA model 880 IR thermographic scanner combined with a 20-deg lens was used to detect the IR radiation from the test panel. A video tape recorder was used to record the live temperature distribution at 25 picture frames per second. A personal computer with an AGEMA TIC-8000 digital image processor was used to record and plot the temperature vs time. The technique was found to be capable of detecting subsurface disbonds as small as 0.0625 sq in. in 0.187-in.-thick thermal protection system bonded materials. The thermography technique meets all the requirements of other approved NDT techniques, and it works well with complex structures and is noncontaminating, noncontact, real-time, and portable.

  4. Thermography evaluation of metal bonding materials

    NASA Astrophysics Data System (ADS)

    Safai, Morteza

    1992-04-01

    The thermographic technique used for the nondestructive evaluation of bondline integrity in metal and silicone rubber bonded material is described. An AGEMA model 880 IR thermographic scanner combined with a 20-deg lens was used to detect the IR radiation from the test panel. A video tape recorder was used to record the live temperature distribution at 25 picture frames per second. A personal computer with an AGEMA TIC-8000 digital image processor was used to record and plot the temperature vs time. The technique was found to be capable of detecting subsurface disbonds as small as 0.0625 sq in. in 0.187-in.-thick thermal protection system bonded materials. The thermography technique meets all the requirements of other approved NDT techniques, and it works well with complex structures and is noncontaminating, noncontact, real-time, and portable.

  5. Trends in quantitative aerial thermography

    SciTech Connect

    Schott, J.R.; Wilkinson, E.P.

    1983-06-01

    Recent improvements in aerial thermographic techniques, particularly in achievable spatial resolution and noise equivalent temperature variation, have enabled the use of thermography in a more objective fashion. Interpretation of the information contained in thermograms has also been improved through the use of certain techniques accounting for roof material type (emissivity), background effects, and atmospheric variables. With current methods, roof surface temperature from aerial imagery can be measured to within 1.8/sup 0/F (1.0/sup 0/C) of the actual temperature. These advances in thermogram analysis have opened the door for potential direct measurement of rooftop heat-loss levels from thermogram data. Ultimately, it is felt that this type of information would make it feasible to direct intensive energy-conservation efforts toward a smaller population, where the need and cost benefits will be the greatest.

  6. Recognition of wall materials through active thermography coupled with numerical simulations.

    PubMed

    Pietrarca, Francesca; Mameli, Mauro; Filippeschi, Sauro; Fantozzi, Fabio

    2016-09-01

    In the framework of historical buildings, wall thickness as well as wall constituents are not often known a priori, and active IR thermography can be exploited as a nonintrusive method for detecting what kind of material lies beneath the external plaster layer. In the present work, the wall of a historical building is subjected to a heating stimulus, and the surface temperature temporal trend is recorded by an IR camera. A hybrid numerical model is developed in order to simulate the transient thermal response of a wall made of different known materials underneath the plaster layer. When the numerical thermal contrast and the appearance time match with the experimental thermal images, the material underneath the plaster can be qualitatively identified. PMID:27607254

  7. IR imaging simulation and analysis for aeroengine exhaust system based on reverse Monte Carlo method

    NASA Astrophysics Data System (ADS)

    Chen, Shiguo; Chen, Lihai; Mo, Dongla; Shi, Jingcheng

    2014-11-01

    The IR radiation characteristics of aeroengine are the important basis for IR stealth design and anti-stealth detection of aircraft. With the development of IR imaging sensor technology, the importance of aircraft IR stealth increases. An effort is presented to explore target IR radiation imaging simulation based on Reverse Monte Carlo Method (RMCM), which combined with the commercial CFD software. Flow and IR radiation characteristics of an aeroengine exhaust system are investigated, which developing a full size geometry model based on the actual parameters, using a flow-IR integration structured mesh, obtaining the engine performance parameters as the inlet boundary conditions of mixer section, and constructing a numerical simulation model of engine exhaust system of IR radiation characteristics based on RMCM. With the above models, IR radiation characteristics of aeroengine exhaust system is given, and focuses on the typical detecting band of IR spectral radiance imaging at azimuth 20°. The result shows that: (1) in small azimuth angle, the IR radiation is mainly from the center cone of all hot parts; near the azimuth 15°, mixer has the biggest radiation contribution, while center cone, turbine and flame stabilizer equivalent; (2) the main radiation components and space distribution in different spectrum is different, CO2 at 4.18, 4.33 and 4.45 micron absorption and emission obviously, H2O at 3.0 and 5.0 micron absorption and emission obviously.

  8. Aerial thermography for energy conservation

    NASA Technical Reports Server (NTRS)

    Jack, J. R.

    1978-01-01

    Thermal infrared scanning from an aircraft is a convenient and commercially available means for determining relative rates of energy loss from building roofs. The need to conserve energy as fuel costs makes the mass survey capability of aerial thermography an attractive adjunct to community energy awareness programs. Background information on principles of aerial thermography is presented. Thermal infrared scanning systems, flight and environmental requirements for data acquisition, preparation of thermographs for display, major users and suppliers of thermography, and suggested specifications for obtaining aerial scanning services were reviewed.

  9. Automatized segmentation of photovoltaic modules in IR-images with extreme noise

    NASA Astrophysics Data System (ADS)

    Vetter, Andreas; Hepp, Johannes; Brabec, Christoph J.

    2016-05-01

    Local electric defects may result in considerable performance losses in solar cells. Infrared thermography is an essential tool to detect these defects on photovoltaic modules. Accordingly, IR-thermography is frequently used in R&D labs of PV manufactures and, furthermore, outdoors in order to identify faulty modules in PV-power plants. Massive amount of data is acquired which needs to be analyzed. An automatized method for detecting solar modules in IR-images would enable a faster and automatized analysis of the data. However, IR-images tend to suffer from rather large noise, which makes an automatized segmentation challenging. The aim of this study was to establish a reliable segmentation algorithm for R&D labs. We propose an algorithm, which detects a solar cell or module within an IR-image with large noise. We tested the algorithm on images of 10 PV-samples characterized by highly sensitive dark lock-in thermography (DLIT). The algorithm proved to be very reliable in detecting correctly the solar module. In our study, we focused on thin film solar cells, however, a transfer of the algorithm to other cell types is straight forward.

  10. Infrared Contrast Analysis Technique for Flash Thermography Nondestructive Evaluation

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay

    2014-01-01

    The paper deals with the infrared flash thermography inspection to detect and analyze delamination-like anomalies in nonmetallic materials. It provides information on an IR Contrast technique that involves extracting normalized contrast verses time evolutions from the flash thermography infrared video data. The paper provides the analytical model used in the simulation of infrared image contrast. The contrast evolution simulation is achieved through calibration on measured contrast evolutions from many flat bottom holes in the subject material. The paper also provides formulas to calculate values of the thermal measurement features from the measured contrast evolution curve. Many thermal measurement features of the contrast evolution that relate to the anomaly characteristics are calculated. The measurement features and the contrast simulation are used to evaluate flash thermography inspection data in order to characterize the delamination-like anomalies. In addition, the contrast evolution prediction is matched to the measured anomaly contrast evolution to provide an assessment of the anomaly depth and width in terms of depth and diameter of the corresponding equivalent flat-bottom hole (EFBH) or equivalent uniform gap (EUG). The paper provides anomaly edge detection technique called the half-max technique which is also used to estimate width of an indication. The EFBH/EUG and half-max width estimations are used to assess anomaly size. The paper also provides some information on the "IR Contrast" software application, half-max technique and IR Contrast feature imaging application, which are based on models provided in this paper.

  11. Active and passive infrared thermography applied to the detection and characterization of hidden defects in structure

    NASA Astrophysics Data System (ADS)

    Dumoulin, Jean

    2013-04-01

    Infrared thermography for Non Destructive Testing (NDT) has encountered a wide spreading this last 2 decades, in particular thanks to emergence on the market of low cost uncooled infrared camera. So, infrared thermography is not anymore a measurement technique limited to laboratory application. It has been more and more involved in civil engineering and cultural heritage applications, but also in many other domains, as indicated by numerous papers in the literature. Nevertheless, laboratory, measurements are done as much as possible in quite ideal conditions (good atmosphere conditions, known properties of materials, etc.), while measurement on real site requires to consider the influence of not controlled environmental parameters and additional unknown thermal properties. So, dedicated protocol and additional sensors are required for measurement data correction. Furthermore, thermal excitation is required to enhance the signature of defects in materials. Post-processing of data requires to take into account the protocol used for the thermal excitation and sometimes its nature to avoid false detection. This analysis step is based on signal and image processing tool and allows to carry out the detection. Characterization of anomalies detected at the previous step can be done by additional signal processing in particular for manufactured objects. The use of thermal modelling and inverse method allows to determine properties of the defective area. The present paper will first address a review of some protocols currently in use for field measurement with passive and/or active infrared measurements. Illustrations in various experiments carried out on civil engineering structure will be shown and discussed. In a second part, different post-processing approaches will be presented and discussed. In particular, a review of the most standard processing methods like Fast Fourier Analysis, Principal Components Analysis, Polynomial Decomposition, defect characterization using

  12. Track-before-declare methods in IR image sequences

    NASA Astrophysics Data System (ADS)

    Bolen, Steven M.

    1992-09-01

    The development of low observable (LO) targets, such as cruise missiles and cruise-missile-carrying aircraft, can severely stress the detection and tracking capabilities of infrared (IR) surveillance systems. Long-range surveillance requires the detection and tracking of targets that are spatially unresolved and often maneuvering in a low signal-to-clutter ratio (SCR) environment. These characteristics make the LO target difficult to detect in single-frame processing techniques. However, by combining intensity information from each pixel over many frames of data it is possible to improve target detection capability. A class of long-term integration techniques for weak target detection, known as track-before-declare (TBD), will be discussed in this paper.

  13. Shuttle Entry Imaging Using Infrared Thermography

    NASA Technical Reports Server (NTRS)

    Horvath, Thomas; Berry, Scott; Alter, Stephen; Blanchard, Robert; Schwartz, Richard; Ross, Martin; Tack, Steve

    2007-01-01

    During the Columbia Accident Investigation, imaging teams supporting debris shedding analysis were hampered by poor entry image quality and the general lack of information on optical signatures associated with a nominal Shuttle entry. After the accident, recommendations were made to NASA management to develop and maintain a state-of-the-art imagery database for Shuttle engineering performance assessments and to improve entry imaging capability to support anomaly and contingency analysis during a mission. As a result, the Space Shuttle Program sponsored an observation campaign to qualitatively characterize a nominal Shuttle entry over the widest possible Mach number range. The initial objectives focused on an assessment of capability to identify/resolve debris liberated from the Shuttle during entry, characterization of potential anomalous events associated with RCS jet firings and unusual phenomenon associated with the plasma trail. The aeroheating technical community viewed the Space Shuttle Program sponsored activity as an opportunity to influence the observation objectives and incrementally demonstrate key elements of a quantitative spatially resolved temperature measurement capability over a series of flights. One long-term desire of the Shuttle engineering community is to calibrate boundary layer transition prediction methodologies that are presently part of the Shuttle damage assessment process using flight data provided by a controlled Shuttle flight experiment. Quantitative global imaging may offer a complementary method of data collection to more traditional methods such as surface thermocouples. This paper reviews the process used by the engineering community to influence data collection methods and analysis of global infrared images of the Shuttle obtained during hypersonic entry. Emphasis is placed upon airborne imaging assets sponsored by the Shuttle program during Return to Flight. Visual and IR entry imagery were obtained with available airborne

  14. Influence of the acquisition parameters on the performance of laser-thermography for crack detection in metallic components

    NASA Astrophysics Data System (ADS)

    Myrach, Philipp; Ziegler, Mathias; Maierhofer, Christiane; Kreutzbruck, Marc

    2014-02-01

    We present a systematic study on the performance of laser-thermography for the detection of surface cracks in metallic components. Scanning a metallic surface with laser causes local heating that is mapped simultaneously by an IR-camera and allows identifying cracks with sub-μm openings. The detectability, however, depends on a number of acquisition parameters (e.g. scanning speed, laser power, IR-camera resolution) that typically relate on each other. Most importantly, the detection-sensitivity of surface breaking cracks is given by a particular combination for the acquisition parameter values. As a result, this sensitivity is adaptable within wide ranges allowing the detection of cracks with openings ranging from 200 to 0.1 μm at testing speeds of 100 to 0.05 cm2/s. By examining artificial as well as fatigue cracks, we demonstrate that the method can be even applied to shiny surfaces with no need of pretreatments, which makes it an entirely contactless, remote and automatable NDT technique. A comparison with magnetic particle testing shows that laser-thermography has the potential to become a strong competitor to conventional surface inspection methods in the future.

  15. Defect characterisation based on heat diffusion using induction thermography testing

    NASA Astrophysics Data System (ADS)

    He, Yunze; Pan, Mengchun; Luo, Feilu

    2012-10-01

    Pulsed eddy current (PEC) thermography (a.k.a. induction thermography) has been successfully applied to detect defects (corrosion, cracks, impact, and delamination) in metal alloy and carbon fiber reinforced plastic. During these applications, the defect detection mechanism is mainly investigated based on the eddy current interaction with defect. In this paper, defect characterisation for wall thinning defect and inner defect in steel is investigated based on heat diffusion. The paper presents the PEC thermography testing, which integrates the reflection mode and transmission mode by means of configuring two cameras on both sides of sample. The defect characterisation methods under transmission mode and reflection mode are investigated and compared through 1D analytical analysis, 3D numerical studies, and experimental studies. The suitable detection mode for wall thinning and inner defects quantification is concluded.

  16. Defect characterisation based on heat diffusion using induction thermography testing.

    PubMed

    He, Yunze; Pan, Mengchun; Luo, Feilu

    2012-10-01

    Pulsed eddy current (PEC) thermography (a.k.a. induction thermography) has been successfully applied to detect defects (corrosion, cracks, impact, and delamination) in metal alloy and carbon fiber reinforced plastic. During these applications, the defect detection mechanism is mainly investigated based on the eddy current interaction with defect. In this paper, defect characterisation for wall thinning defect and inner defect in steel is investigated based on heat diffusion. The paper presents the PEC thermography testing, which integrates the reflection mode and transmission mode by means of configuring two cameras on both sides of sample. The defect characterisation methods under transmission mode and reflection mode are investigated and compared through 1D analytical analysis, 3D numerical studies, and experimental studies. The suitable detection mode for wall thinning and inner defects quantification is concluded. PMID:23126785

  17. Detection of foreign substances in food using thermography

    NASA Astrophysics Data System (ADS)

    Meinlschmidt, Peter; Maergner, Volker

    2002-03-01

    This paper gives a short introduction into the possibility of detecting foreign bodies in food by using IR thermography. The first results shown for combinations of cherries and chocolate and berries contaminated with leaves, stalks, pedicel and thorns could be easily evaluated manually. Therefore the differing emissivity coefficients or the different heat conductivities and/or capacities are used for differentiation. Applying pulse thermography, first heat conductivity measurements of different food materials are performed. Calculating the contrast of possible food / contaminant combinations shows the difficulty of differentiating certain materials. A possible automatic evaluation for raisins contaminated with wooden sticks and almonds blended with stones could be shown. The power of special adapted algorithms using statistical or morphological analysis is shown to distinguish the foreign bodies from the foodstuff.

  18. Thermography in Occlusive Cerebrovascular Diseases

    PubMed Central

    Mawdsley, C.; Samuel, E.; Sumerling, M. D.; Young, G. B.

    1968-01-01

    Cooling of the skin over the medial supraorbital region in 80% of patients who have an occlusion or severe stenosis of a carotid artery can be demonstrated by facial thermography. Minor stenotic lesions in the carotid arteries do not produce characteristic thermographic changes, while thermography is of no help in the diagnosis of vertebrobasilar arterial disease. Thermographic changes suggestive of carotid arterial lesions are found occasionally in patients whose angiograms are normal, owing to variations in the size of the frontal sinuses, or factors such as fever or inflammatory lesions. It is suggested that facial thermography is of value in the preliminary investigation of patients with occlusive cerebrovascular disease. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6 PMID:5676953

  19. Real time capable infrared thermography for ASDEX Upgrade

    SciTech Connect

    Sieglin, B. Faitsch, M.; Herrmann, A.; Brucker, B.; Eich, T.; Kammerloher, L.; Martinov, S.

    2015-11-15

    Infrared (IR) thermography is widely used in fusion research to study power exhaust and incident heat load onto the plasma facing components. Due to the short pulse duration of today’s fusion experiments, IR systems have mostly been designed for off-line data analysis. For future long pulse devices (e.g., Wendelstein 7-X, ITER), a real time evaluation of the target temperature and heat flux is mandatory. This paper shows the development of a real time capable IR system for ASDEX Upgrade. A compact IR camera has been designed incorporating the necessary magnetic and electric shielding for the detector, cooler assembly. The camera communication is based on the Camera Link industry standard. The data acquisition hardware is based on National Instruments hardware, consisting of a PXIe chassis inside and a fibre optical connected industry computer outside the torus hall. Image processing and data evaluation are performed using real time LabVIEW.

  20. Real time capable infrared thermography for ASDEX Upgrade.

    PubMed

    Sieglin, B; Faitsch, M; Herrmann, A; Brucker, B; Eich, T; Kammerloher, L; Martinov, S

    2015-11-01

    Infrared (IR) thermography is widely used in fusion research to study power exhaust and incident heat load onto the plasma facing components. Due to the short pulse duration of today's fusion experiments, IR systems have mostly been designed for off-line data analysis. For future long pulse devices (e.g., Wendelstein 7-X, ITER), a real time evaluation of the target temperature and heat flux is mandatory. This paper shows the development of a real time capable IR system for ASDEX Upgrade. A compact IR camera has been designed incorporating the necessary magnetic and electric shielding for the detector, cooler assembly. The camera communication is based on the Camera Link industry standard. The data acquisition hardware is based on National Instruments hardware, consisting of a PXIe chassis inside and a fibre optical connected industry computer outside the torus hall. Image processing and data evaluation are performed using real time LabVIEW. PMID:26628130

  1. Real time capable infrared thermography for ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Sieglin, B.; Faitsch, M.; Herrmann, A.; Brucker, B.; Eich, T.; Kammerloher, L.; Martinov, S.

    2015-11-01

    Infrared (IR) thermography is widely used in fusion research to study power exhaust and incident heat load onto the plasma facing components. Due to the short pulse duration of today's fusion experiments, IR systems have mostly been designed for off-line data analysis. For future long pulse devices (e.g., Wendelstein 7-X, ITER), a real time evaluation of the target temperature and heat flux is mandatory. This paper shows the development of a real time capable IR system for ASDEX Upgrade. A compact IR camera has been designed incorporating the necessary magnetic and electric shielding for the detector, cooler assembly. The camera communication is based on the Camera Link industry standard. The data acquisition hardware is based on National Instruments hardware, consisting of a PXIe chassis inside and a fibre optical connected industry computer outside the torus hall. Image processing and data evaluation are performed using real time LabVIEW.

  2. Veterinary applications of infrared thermography.

    PubMed

    Rekant, Steven I; Lyons, Mark A; Pacheco, Juan M; Arzt, Jonathan; Rodriguez, Luis L

    2016-01-01

    Abnormal body temperature is a major indicator of disease; infrared thermography (IRT) can assess changes in body surface temperature quickly and remotely. This technology can be applied to a myriad of diseases of various etiologies across a wide range of host species in veterinary medicine. It is used to monitor the physiologic status of individual animals, such as measuring feed efficiency or diagnosing pregnancy. Infrared thermography has applications in the assessment of animal welfare, and has been used to detect soring in horses and monitor stress responses. This review addresses the variety of uses for IRT in veterinary medicine, including disease detection, physiologic monitoring, welfare assessment, and potential future applications. PMID:26709943

  3. Computerized tomography technique for reconstruction of obstructed temperature field in infrared thermography

    NASA Astrophysics Data System (ADS)

    Sham, F. C.; Huang, Y. H.; Liu, L.; Chen, Y. S.; Hung, Y. Y.; Lo, T. Y.

    2010-01-01

    Infrared thermography is a rapid, non-invasive and full-field technique for non-destructive testing and evaluation (NDT&E). With all the achievements on IR instrumentation and image processing techniques attained, it has been extended far beyond simple hot-spot detection and becomes one of the most promising NDT&E techniques in the last decades. It has achieved increasing acceptance in different sectors include medical imaging, manufacturing component fault detection and buildings diagnostic. However, one limitation of IR thermography is that the testing results are greatly affected by object surface emissivity. Surface with various emissivities may lead to difficult discrimination between area of defect and area with different emissivity. Therefore, many studies have been carried out on eliminating emissivity, for example, the time derivative approach, lock-in processing and differential contrast measurements. In these methods, sequence of themo-data/images are recorded and being processed in order to eliminate differences of emissivity. Another problem of IR thermography is that any obstruction may limit stimulations and imaging which leads to the observation of unclear defect image. To solve this problem, this paper proposes an algorithm based on the principle of computerized tomography which permits the reconstruction of unavailable/partially available temperature distribution of the affected area using the measured surrounding temperature field. In the process, a set of imaginary rays are projected from many different directions across the area. For each ray, integration of the temperature derivatives along the ray is equals to the temperature difference between the boundary points intercepted by the ray. Therefore, a set of linear equations can be established by considering the multiple rays. Each equation expresses the unknown temperature derivatives in the affected area in terms of the measured boundary temperature data. Solution of the set of simultaneous

  4. Infrared Thermography Flight Experimentation

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Carter, Matthew L.; Kirsch, Michael

    2003-01-01

    Analysis was done on IR data collected by DFRC on May 8, 2002. This includes the generation of a movie to initially examine the IR flight data. The production of the movie was challenged by the volume of data that needed to be processed, namely 40,500 images with each image (256 x 252) containing over 264 million points (pixel depth 4096). It was also observed during the initial analysis that the RTD surface coating has a different emissivity than the surroundings. This fact added unexpected complexity in obtaining a correlation between RTD data and IR data. A scheme was devised to generate IR data near the RTD location which is not affected by the surface coating This scheme is valid as long as the surface temperature as measured does not change too much over a few pixel distances from the RTD location. After obtaining IR data near the RTD location, it is possible to make a direct comparison with the temperature as measured during the flight after adjusting for the camera s auto scaling. The IR data seems to correlate well to the flight temperature data at three of the four RID locations. The maximum count intensity occurs closely to the maximum temperature as measured during flight. At one location (RTD #3), there is poor correlation and this must be investigated before any further progress is possible. However, with successful comparisons at three locations, it seems there is great potential to be able to find a calibration curve for the data. Moreover, as such it will be possible to measure temperature directly from the IR data in the near future.

  5. The effect of instrument attachment on the surface temperature of juvenile grey seals ( Halichoerus grypus) as measured by infrared thermography

    NASA Astrophysics Data System (ADS)

    McCafferty, Dominic J.; Currie, John; Sparling, Carol E.

    2007-02-01

    Previous research has highlighted the importance of minimising hydrodynamic drag from biologging instruments fitted to marine mammals. However, there is a need to investigate other possible impacts of instruments on animals. The aim of this study was to examine the effect of deploying instruments on the surface temperature distribution of grey seals ( Halichoerus grypus). Infrared (IR) thermography was used to record the surface temperature of two juveniles that had been fitted with heart rate recorders and mounting straps for the attachment of a time depth recorder. When animals were fully wet and inactive, the surface temperature pattern was unaffected by instruments. However, as animals dried out regions of high temperature were recorded around the edges of attachment sites compared to surrounding fur. This appeared to be due to heat leakage around the sides of instruments and mounting straps that provided an additional layer of insulation. There were no obvious changes in the surface temperature distribution around instruments associated with duration of deployment. This work shows that attachment of relatively small biologging instruments will produce localised effects on heat transfer in air but will not significantly change the total heat exchange of grey seals on land or at sea. IR thermography was also shown to be a useful method of detecting surface temperature patterns associated with epidural anaesthesia and blubber biopsy.

  6. Study of heating capacity of focused IR light soldering systems.

    PubMed

    Anguiano, C; Félix, M; Medel, A; Bravo, M; Salazar, D; Márquez, H

    2013-10-01

    An experimental study about four optical setups used for developing a Focused IR Light Soldering System (FILSS) for Surface Mount Technology (SMT) lead-free electronic devices specifically for Ball Grid Arrays (BGA) is presented. An analysis of irradiance and infrared thermography at BGA surface is presented, as well as heat transfer by radiation and conduction process from the surface of the BGA to the solder balls. The results of this work show that the heating provided by our proposed optical setups, measured at the BGA under soldering process, meets the high temperature and uniform thermal distribution requirements, which are defined by the reflow solder method for SMT devices. PMID:24104296

  7. A self-method for resolving the problem of apparent LWIR emissivity for quantitative thermography up to 130 °C

    NASA Astrophysics Data System (ADS)

    Riou, Olivier; Logerais, Pierre-Olivier; Delaleux, Fabien; Durastanti, Jean-Félix

    2014-11-01

    In a previous work, we succeeded in connecting normal LWIR apparent emissivity to the spectral one of an aluminum nitride ceramic plate. The key problem was the knowledge of the effective spectral bandwidth in use in the system. Hence we have developed an analyzer which permits to identify the spectral bandwidth of IR system using only its raw data. It proceeds by minimizing the dispersion from linearity of the characteristic thermosignals/integrated radiance over a temperature range of the IR system. The capacities of the analyzer are tested for five commercial cameras. Each of these systems exhibits a similar formatting process implemented during the thermogram recording. The effective spectral bandwidth shows plausible values. It varies significantly from one model to the other and the residual non-linearity is connected to the NETD of the IR system. The robustness of the apparent emissivity measurements is also tested with the aid of emissivity reference of 0.5. The overall accuracy of the method is less than 1%, depending on the specular or diffuse part of the reflected irradiation. Applied in field situation, the method is suitable to detect absolute variation of emissivity of less than 6 ṡ 10-3. We use the analyzer to determine the spectral bandwidth of a commercial 320 × 240 microbolometer uncooled IRFPA camera which had already served to characterize the normal LWIR apparent emissivity of the aluminum nitride ceramic plate. By using the spectral response of the two major microbolometer sensor technologies, the general formulation of apparent emissivity matches our apparent emissivity measurements. An agreement better than 0.6% in absolute value and a less than 6 ṡ 10-3%/°C dispersion are found over the entire temperature range [40-130 °C].

  8. Using infrared thermography to study freezing in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Factors that determine when and to what extent a plant will freeze are complex. While thermocouples have served as the main method of monitoring the freezing process in plants, infrared thermography offers distinct advantages, and the use of this latter technology has provided new insights on the p...

  9. Comparative defect evaluation of aircraft components by active thermography

    NASA Astrophysics Data System (ADS)

    Zauner, G.; Mayr, G.; Hendorfer, G.

    2009-02-01

    Active Thermography has become a powerful tool in the field of non-destructive testing (NDT) in recent years. This infrared thermal imaging technique is used for non-contact inspection of materials and components by visualizing thermal surface contrasts after a thermal excitation. The imaging modality combined with the possibility of detecting and characterizing flaws as well as determining material properties makes Active Thermography a fast and robust testing method even in industrial-/production environments. Nevertheless, depending on the kind of defect (thermal properties, size, depth) and sample material (CFRP carbon fiber reinforced plastics, metal, glass fiber) or sample structure (honeycomb, composite layers, foam), active thermography can sometimes produce equivocal results or completely fails in certain test situations. The aim of this paper is to present examples of results of Active Thermography methods conducted on aircraft components compared to various other (imaging) NDT techniques, namely digital shearography, industrial x-ray imaging and 3D-computed tomography. In particular we focus on detection limits of thermal methods compared to the above-mentioned NDT methods with regard to: porosity characterization in CFRP, detection of delamination, detection of inclusions and characterization of glass fiber distributions.

  10. Concept And Development Of Instruments For ITER Thermography

    SciTech Connect

    Reichle, R.; Balorin, C.; Carpentier, S.; Corre, Y.; Davi, M.; Delchambre, E.; Desgrange, C.; Escourbiac, F.; Fougerolle, S.; Gardarein, J. L.; Gauthier, E.; Guilhem, D.; Jouve, M.; Loarer, Th.; Martins, J. P.; Patterlini, J. C.; Pocheau, C.; Roche, H.; Salasca, S.; Travere, J. M.

    2008-03-12

    We give here a short overview of the status of the development for ITER thermography as performed by the CEA-Cadarache and some of its collaboration partners. The topics that have been included in this synthesis are the status of the optical design, the role of multi-wavelength mesurements, multicolour pyroreflectometry, photothermal methods, and reflection simulations and measurements.

  11. Infrared thermography to evaluate lameness in pregnant sows

    PubMed Central

    Amezcua, Rocio; Walsh, Shannon; Luimes, Paul H.; Friendship, Robert M.

    2014-01-01

    Early detection of lameness in sows is important to reduce losses and improve animal welfare. Mild-to-moderate lameness is difficult to diagnose in sows. Infrared thermography (IRT) was evaluated as a method of detecting signs of inflammation in the lower limbs as an aid in lameness detection. PMID:24587511

  12. Veterinary applications of infrared thermography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abnormal temperature is a major indicator of disease; infrared thermography (IRT) can assess changes in surface temperature quickly and remotely. This technology can be applied to myriad diseases in veterinary medicine, ranging across host species and disease etiologies. It can also be used to deter...

  13. Focal plane array based infrared thermography in fine physical experiment

    NASA Astrophysics Data System (ADS)

    Vainer, Boris G.

    2008-03-01

    By two examples of dissimilar physical phenomena causing thermophysical effects, the unique capabilities of one of the up-to-date methods of experimental physics—focal plane array (FPA) based infrared (IR) thermography (IRT), are demonstrated distinctly. Experimenters inexperienced in IRT can grasp how this method provides a means for combining real-time visualization with quantitative analysis. A narrow-band short-wavelength IR camera was used in the experiments. It is discussed and stated that IRT is best matched and suited to the next two test conditions—when a heated specimen is thin and when heat is generated in the immediate region of a surface of a solid. The first prerequisite is realized in the search for directional patterns of combined low-power radiation sources with the use of the IRT-aided method. The second one is realized in studies of water vapour adsorption on uneven (irregular) surfaces of solid materials. With multiple swatches taken from a set of different fabrics and used as experimental samples, a sharp distinction between adsorptivities of their surfaces is strikingly illustrated by IRT time-domain measurements exhibiting the associated thermal effect ranging within an order of magnitude. It is justified that the described IRT-aided test can find practical implementation at least in the light industry. Emissivities of different fabrics are evaluated experimentally with the described reflection method based on the narrow spectral range of IRT. On the basis of direct IR observations, attention is paid to the need for close control over the surface temperature increase while the adsorption isotherms are being measured. Sensitivity of the FPA-based IRT method, as applied to examine the kinetics of initial stages of adsorption of gaseous molecules on the solid surface, is evaluated analytically and quantitatively. The relationship between the amount of adsorbate and the measurable excess of adsorbent temperature is found. It is discovered

  14. Procedure to estimate thermophysical and geometrical parameters of embedded cancerous lesions using thermography.

    PubMed

    Manuel Luna, Jose; Romero-Mendez, Ricardo; Hernandez-Guerrero, Abel; Elizalde-Blancas, Francisco

    2012-03-01

    Based on the fact that malignant cancerous lesions (neoplasms) develop high metabolism and use more blood supply than normal tissue, infrared thermography (IR) has become a reliable clinical technique used to indicate noninvasively the presence of cancerous diseases, e.g., skin and breast cancer. However, to diagnose cancerous diseases by IR, the technique requires procedures that explore the relationship between the neoplasm characteristics (size, blood perfusion rate and heat generated) and the resulting temperature distribution on the skin surface. In this research work the dual reciprocity boundary element method (DRBEM) has been coupled with the simulated annealing technique (SA) in a new inverse procedure, which coupled to the IR technique, is capable of estimating simultaneously geometrical and thermophysical parameters of the neoplasm. The method is of an evolutionary type, requiring random initial values for the unknown parameters and no calculations of sensitivities or search directions. In addition, the DRBEM does not require any re-meshing at each proposed solution to solve the bioheat model. The inverse procedure has been tested considering input data for simulated neoplasms of different sizes and positions in relation to the skin surface. The successful estimation of unknown neoplasm parameters validates the idea of using the SA technique and the DRBEM in the estimation of parameters. Other estimation techniques, based on genetic algorithms or sensitivity coefficients, have not been capable of obtaining a solution because the skin surface temperature difference is very small. PMID:22482688

  15. Experimental developments towards an ITER thermography diagnostic

    NASA Astrophysics Data System (ADS)

    Reichle, R.; Brichard, B.; Escourbiac, F.; Gardarein, J. L.; Hernandez, D.; Le Niliot, C.; Rigollet, F.; Serra, J. J.; Badie, J. M.; van Ierschot, S.; Jouve, M.; Martinez, S.; Ooms, H.; Pocheau, C.; Rauber, X.; Sans, J. L.; Scheer, E.; Berghmans, F.; Decréton, M.

    2007-06-01

    In the course of the development of a concept for a spectrally resolving thermography diagnostic for the ITER divertor using optical fibres experimental development work has been carried out in three different areas. Firstly ZrF4 fibres and hollow fibres (silica capillaries with internal AG/AgJ coating) were tested in a Co60 irradiation facility under γ irradiation up to doses of 5 kGy and 27 kGy, respectively. The ZrF4 fibres suffered more radiation induced degradation (>1 db/m) then the hollow fibres (0-0.4 db/m). Secondly multi-colour pyroreflectometry is being developed towards tokamak applicability. The emissivity and temperature of tungsten samples were measured in the range of 700-1500 °C. The angular working range for off normal observation of the method was 20-30°. The working distance of the method has been be increased from cm to the m range. Finally, encouraging preliminary results have been obtained concerning the application of pulsed and modulated active thermography.

  16. Investigation on choosing technical parameters for pulse thermography

    NASA Astrophysics Data System (ADS)

    Li, Huijuan

    2015-04-01

    Composite material connected by glue has gained popularity as a replacement for conventional materials and structures to reduce weight and improve strength in the aerospace industry, with the development of material science and structural mechanics. However, the adhesive bonding process is more susceptible to quality variations during manufacturing than traditional joining methods. The integrality, strength and rigidity of product would be broken by disbonding. Infrared thermography is one of several non-destructive testing techniques which can be used for defect detection in aircraft materials. Pulsed infrared thermography has been widely used in aerospace and mechanical manufacture industry because it can offer noncontact, quickly and visual examinations of disbonding defects. However the parameter choosing method is difficult to decide. Investigate the choosing technical parameters for pulse thermograpghy is more important to ensure the product quality and testing efficiency. In this paper, two kinds of defects which are of various size, shape and location below the test surface are planted in the honeycomb structure, they are all tested by pulsed thermography. This paper presents a study of single factor experimental research on damage sample in simulation was carried out. The impact of the power of light source, detection distance, and the wave band of thermography camera on detecting effect is studied. The select principle of technique is made, the principle supplied basis for selection of detecting parameters in real part testing.

  17. Lock-in thermography, penetrant inspection, and scanning electron microscopy for quantitative evaluation of open micro-cracks at the tooth-restoration interface

    NASA Astrophysics Data System (ADS)

    Streza, M.; Hodisan, I.; Prejmerean, C.; Boue, C.; Tessier, Gilles

    2015-03-01

    The evaluation of a dental restoration in a non-invasive way is of paramount importance in clinical practice. The aim of this study was to assess the minimum detectable open crack at the cavity-restorative material interface by the lock-in thermography technique, at laser intensities which are safe for living teeth. For the analysis of the interface, 18 box-type class V standardized cavities were prepared on the facial and oral surfaces of each tooth, with coronal margins in enamel and apical margins in dentine. The preparations were restored with the Giomer Beautifil (Shofu) in combination with three different adhesive systems. Three specimens were randomly selected from each experimental group and each slice has been analysed by visible, infrared (IR), and scanning electron microscopy (SEM). Lock-in thermography showed the most promising results in detecting both marginal and internal defects. The proposed procedure leads to a diagnosis of micro-leakages having openings of 1 µm, which is close to the diffraction limit of the IR camera. Clinical use of a thermographic camera in assessing the marginal integrity of a restoration becomes possible. The method overcomes some drawbacks of standard SEM or dye penetration testing. The results support the use of an IR camera in dentistry, for the diagnosis of micro-gaps at bio-interfaces.

  18. Amplitude-sensitive modulation thermography to measure moisture in building materials

    NASA Astrophysics Data System (ADS)

    Wild, Walter; Buescher, Konstantin A.; Wiggenhauser, Herbert

    1998-03-01

    There have been reports about moisture detection in building walls by reflective IR-thermography. Typically, only limited results could be obtained because of the emission coefficient variations, leaking radiation or inhomogeneous illumination of the object. In addition, the quantitative relation between remission spectra and the moisture has often been unclear. Reflectometry uses constant excitation illumination which is recorded by the IR camera. With the use of the 'lock-in-technology' a low frequency modulated signal of an IR radiation source is coupled with the thermo camera and a frequency and phase sensitive signal from the thermal images can be derived. The advantage is, that emission coefficient dependencies are eliminated and that leaking radiation does not have any influence on the measured signal. The selective water measurement is possible, because there is an interference filter mounted in front of the radiator which has its transmission maximum at the wavelength of an absorption band of water. The area investigated is therefore illuminated under well defined circumstances and quantitative moisture measurement on the surface of building materials becomes a possibility. The illumination modulation is done with a sine wave to facilitate the calculation of the temporal intensity behavior of the amplitude signal. Subsequently, the amplitude image is used to determine the distribution and the level of moisture quantitatively. Point measurements in the laboratory were carried out on several building materials with changing moisture levels. It could be shown that this method successfully eliminates disturbing contributions to the measured signal like surface effects or leaking radiation.

  19. Prospects and limitations of digital Shearography and Active Thermography in finding and rating flaws in CFRP sandwich parts with honeycomb core

    NASA Astrophysics Data System (ADS)

    Gruber, J.; Mayr, G.; Hendorfer, G.

    2012-05-01

    This work shows the prospects and limitations of the non-destructive testing methods Digital Shearography and Active Thermography when applied to CFRP sandwich parts with honeycomb cores. Two specimens with different core materials (aluminum, NOMEX) and artificial flaws such as delaminations, disbonds and inclusions of foreign material, are tested with Digital Shearography and Pulse Thermography including Pulse Phase Thermography. Both methods provide a good ability for finding and rating the flaws.

  20. Modeling of the ITER-like wide-angle infrared thermography view of JET.

    PubMed

    Aumeunier, M-H; Firdaouss, M; Travère, J-M; Loarer, T; Gauthier, E; Martin, V; Chabaud, D; Humbert, E

    2012-10-01

    Infrared (IR) thermography systems are mandatory to ensure safe plasma operation in fusion devices. However, IR measurements are made much more complicated in metallic environment because of the spurious contributions of the reflected fluxes. This paper presents a full predictive photonic simulation able to assess accurately the surface temperature measurement with classical IR thermography from a given plasma scenario and by taking into account the optical properties of PFCs materials. This simulation has been carried out the ITER-like wide angle infrared camera view of JET in comparing with experimental data. The consequences and the effects of the low emissivity and the bidirectional reflectivity distribution function used in the model for the metallic PFCs on the contribution of the reflected flux in the analysis are discussed. PMID:23130792

  1. Modeling of the ITER-like wide-angle infrared thermography view of JET

    SciTech Connect

    Aumeunier, M.-H.; Firdaouss, M.; Travere, J.-M.; Loarer, T.; Gauthier, E.; Martin, V.; Chabaud, D.; Humbert, E.; Collaboration: JET-EFDA Contributors

    2012-10-15

    Infrared (IR) thermography systems are mandatory to ensure safe plasma operation in fusion devices. However, IR measurements are made much more complicated in metallic environment because of the spurious contributions of the reflected fluxes. This paper presents a full predictive photonic simulation able to assess accurately the surface temperature measurement with classical IR thermography from a given plasma scenario and by taking into account the optical properties of PFCs materials. This simulation has been carried out the ITER-like wide angle infrared camera view of JET in comparing with experimental data. The consequences and the effects of the low emissivity and the bidirectional reflectivity distribution function used in the model for the metallic PFCs on the contribution of the reflected flux in the analysis are discussed.

  2. Modeling of the ITER-like wide-angle infrared thermography view of JETa)

    NASA Astrophysics Data System (ADS)

    Aumeunier, M.-H.; Firdaouss, M.; Travère, J.-M.; Loarer, T.; Gauthier, E.; Martin, V.; Chabaud, D.; Humbert, E.; JET-EFDA Contributors

    2012-10-01

    Infrared (IR) thermography systems are mandatory to ensure safe plasma operation in fusion devices. However, IR measurements are made much more complicated in metallic environment because of the spurious contributions of the reflected fluxes. This paper presents a full predictive photonic simulation able to assess accurately the surface temperature measurement with classical IR thermography from a given plasma scenario and by taking into account the optical properties of PFCs materials. This simulation has been carried out the ITER-like wide angle infrared camera view of JET in comparing with experimental data. The consequences and the effects of the low emissivity and the bidirectional reflectivity distribution function used in the model for the metallic PFCs on the contribution of the reflected flux in the analysis are discussed.

  3. Membrane fouling characterization by infrared thermography

    NASA Astrophysics Data System (ADS)

    Ndukaife, Kennethrex O.; Ndukaife, Justus C.; Agwu Nnanna, A. G.

    2015-01-01

    An infrared thermography (IRT) technique for characterization of fouling on flat sheet membrane surface has been developed. In this work, an IR camera was used to measure surface temperature and emissivity of foulant on a membrane surface. Different fouling experiments were performed using different feed concentrations of aluminum oxide nanoparticle mixed with deionized water so as to investigate the effect of feed concentration on the degree of fouling and on the emissivity values measured on the membrane surfaces. Our findings revealed that the emissivity of the fouled membrane surface is contingent on the surface roughness as well as the material composition of the foulant. The technique was utilized to distinguish between foulants made of metallic materials from those that are non-metallic. This approach, which is simple to use and nondestructive represents an important addition to the toolset of fouling analysis techniques and would benefit a wide range of applications from observation of foulant structure to qualitative assessment of composition of foulant material.

  4. Aerial thermography in archaeological prospection: Applications & processing

    NASA Astrophysics Data System (ADS)

    Cool, Autumn Chrysantha

    Aerial thermography is one of the least utilized archaeological prospection methods, yet it has great potential for detecting anthropogenic anomalies. Thermal infrared radiation is absorbed and reemitted at varying rates by all objects on and within the ground depending upon their density, composition, and moisture content. If an area containing archaeological features is recorded at the moment when their thermal signatures most strongly contrast with that of the surrounding matrix, they can be visually identified in thermal images. Research conducted in the 1960s and 1970s established a few basic rules for conducting thermal survey, but the expense associated with the method deterred most archaeologists from using this technology. Subsequent research was infrequent and almost exclusively appeared in the form of case studies. However, as the current proliferation of unmanned aerial vehicles (UAVs) and compact thermal cameras draws renewed attention to aerial thermography as an attractive and exciting form of survey, it is appropriate and necessary to reevaluate our approach. In this thesis I have taken a two-pronged approach. First, I built upon the groundwork of earlier researchers and created an experiment to explore the impact that different environmental and climatic conditions have on the success or failure of thermal imaging. I constructed a test site designed to mimic a range of archaeological features and imaged it under a variety of conditions to compare and contrast the results. Second, I explored a new method for processing thermal data that I hope will lead to a means of reducing noise and increasing the clarity of thermal images. This step was done as part of a case study so that the effectiveness of the processing method could be evaluated by comparison with the results of other geophysical surveys.

  5. IR spectrum simulation of molecular structure model of Shendong coal vitrinite by using quantum chemistry method.

    PubMed

    Jia, Jian-Bo; Wang, Ying; Li, Feng-Hai; Yi, Gui-Yun; Zeng, Fan-Gui; Guo, Hong-Yu

    2014-01-01

    The structure of coal needs to be understood from a molecular point of view for clean, effective and high value-added utilization of coal. In the literature, molecular structure model of Shendong coal vitrinite (SV) was established by the authors on the basis of experimental results of ultimate analysis and 13C NMR, and the calculated 13C NMR spectrum of SV model was consistent with the experimental spectrum. In order to further verify the accuracy of SV structure model established by the authors, the infrared spectrum of SV structure model was calculated using quantum chemistry semi-empirical VAMP in this thesis. The results showed that the peak shape of calculated IR spectrum of SV structure model was similar to the experiment's, but the wave number of calculated IR spectrum was obviously higher than that of experimental spectrum. According to the calculated results for model compounds by using the same method, calculated vibrational frequency was higher than that of experiment for the same functional groups. Hence, the calculated IR spectrum should be corrected. After correction the calculated IR spectrum of SV structure model matched well with the experimental spectrum. In other words, the SV structure model can truly reflect the structure characteristics of SV. PMID:24783531

  6. Identification of age degradation in EPROM chips using infrared thermography

    NASA Astrophysics Data System (ADS)

    Allred, Lloyd G.

    1998-03-01

    In a recent upgrade of the digital flight control computer for the F-16, there was serious consternation expressed about the quality of the soldering repair process. Dozens of circuit cards failed to function after the upgrade, even though all of these cards operated correctly before the modifications. The shop called for the use of the IR camera to assist in diagnosing and repairing these cards. What the Neural Radiant Energy Detection found was faulty and marginal chips.Of particular interest was the presence of degraded EPROM chips on the Program Memory cards. While it is known that EPROMs have a limited life cycle, the failure has been further characterized. Thermography provides a quantification of the degradation in thermal performance as the EPROMs are reused. Pristine EPROM chips have a rise rate of about 0.008 degrees C/sec. When the heat rates exceed 0.021 degrees C/sec, the EPROM chips will not accept a program. Some of the chips exhibited heat rates exceeding 0.1 degrees C/sec. Some chips with degradation of 0.018 degrees C/sec would accept a program, but fail other functional tests. What is clear from these results is that IR thermography can be used to identify degrading EPROM chips for replacement before failures become immanent.

  7. Mirnov Coil Analysis by Singular Value Decomposition Method in IR-T1 Tokamak

    NASA Astrophysics Data System (ADS)

    Salemi, Mohammad K.; Saadat, Shervin; Ghoranneviss, Mahmoud; Tabadar, Alireza

    2010-10-01

    The spatial and temporal structures of magnetic signal in the tokamak is analyzed using recently developed singular value decomposition (SVD) technique to determine the structure of current perturbation as the discharge progresses. In this work we use SVD technique for that purpose in IR-T1 tokamak.ootnotetextC. Nardonet, ``Multichannel Fluctuation Data Analysis By The Singular Value Decomposition Method Application To MHD Modes In Jet,'' Plasma Physics & Controlled Fusion, V. 34, No. 9, 1992, 1447-1465

  8. Objective methods for achieving an early prediction of the effectiveness of regional block anesthesia using thermography and hyper-spectral imaging

    NASA Astrophysics Data System (ADS)

    Klaessens, John H. G. M.; Landman, Mattijs; de Roode, Rowland; Noordmans, Herke J.; Verdaasdonk, Rudolf M.

    2011-03-01

    An objective method to measure the effectiveness of regional anesthesia can reduce time and unintended pain inflicted to the patient. A prospective observational study was performed on 22 patients during a local anesthesia before undergoing hand surgery. Two non-invasive techniques thermal and oxygenation imaging were applied to observe the region affected by the peripheral block and the results were compared to the standard cold sensation test. The supraclavicular block was placed under ultrasound guidance around the brachial plexus by injecting 20 cc Ropivacaine. The sedation causes a relaxation of the muscles around the blood vessels resulting in dilatation and hence an increase of blood perfusion, skin temperature and skin oxygenation in the lower arm and hand. Temperatures were acquired with an IR thermal camera (FLIR ThermoCam SC640). The data were recorded and analyzed with the ThermaCamTMResearcher and Matlab software. Narrow band spectral images were acquired at selected wavelengths with a CCD camera either combined with a Liquid Crystal Tunable Filter (420-730 nm) or a tunable hyper-wavelength LED light source (450-880nm). Concentration changes of oxygenated and deoxygenated hemoglobin in the dermis of the skin were calculated using the modified Lambert Beer equation. Both imaging methods showed distinct oxygenation and temperature differences at the surface of the skin of the hand with a good correlation to the anesthetized areas. A temperature response was visible within 5 minutes compared to the standard of 30 minutes. Both non-contact methods show to be more objective and can have an earlier prediction for the effectiveness of the anesthetic block.

  9. Potentialities of steady-state and transient thermography in breast tumour depth detection: A numerical study.

    PubMed

    Amri, Amina; Pulko, Susan Helen; Wilkinson, Anthony James

    2016-01-01

    Breast thermography still has inherent limitations that prevent it from being fully accepted as a breast screening modality in medicine. The main challenges of breast thermography are to reduce false positive results and to increase the sensitivity of a thermogram. Further, it is still difficult to obtain information about tumour parameters such as metabolic heat, tumour depth and diameter from a thermogram. However, infrared technology and image processing have advanced significantly and recent clinical studies have shown increased sensitivity of thermography in cancer diagnosis. The aim of this paper is to study numerically the possibilities of extracting information about the tumour depth from steady state thermography and transient thermography after cold stress with no need to use any specific inversion technique. Both methods are based on the numerical solution of Pennes bioheat equation for a simple three-dimensional breast model. The effectiveness of two approaches used for depth detection from steady state thermography is assessed. The effect of breast density on the steady state thermal contrast has also been studied. The use of a cold stress test and the recording of transient contrasts during rewarming were found to be potentially suitable for tumour depth detection during the rewarming process. Sensitivity to parameters such as cold stress temperature and cooling time is investigated using the numerical model and simulation results reveal two prominent depth-related characteristic times which do not strongly depend on the temperature of the cold stress or on the cooling period. PMID:26522612

  10. Eddy current pulsed phase thermography and feature extraction

    NASA Astrophysics Data System (ADS)

    He, Yunze; Tian, GuiYun; Pan, Mengchun; Chen, Dixiang

    2013-08-01

    This letter proposed an eddy current pulsed phase thermography technique combing eddy current excitation, infrared imaging, and phase analysis. One steel sample is selected as the material under test to avoid the influence of skin depth, which provides subsurface defects with different depths. The experimental results show that this proposed method can eliminate non-uniform heating and improve defect detectability. Several features are extracted from differential phase spectra and the preliminary linear relationships are built to measure these subsurface defects' depth.

  11. IR-Sensography™—expanding the scope of contact-free sensing methods

    NASA Astrophysics Data System (ADS)

    Klein, Jens; Schunk, Stephan A.

    2005-01-01

    Capturing the response of one or more sensor materials is conventionally performed by the direct transformation of a chemical or physico-chemical signal into an electrical one. With an increasing number of sensor materials within an arrangement of sensor elements or a sensor array, problems such as contacting each single sensor, signal processing and resistance against cross-talk, harsh conditions such as corrosive atmospheres, etc are limiting factors for the further development of so-called 'chemical noses'. State-of-the-art and commercially available are arrays of eight different sensor materials, literature known in another context are sensor arrays with 256 materials on a silicon wafer, which are contacted via electrical conduits. We present here the concept of the IR-Sensography™, the use of an IR-camera as an external detector system for sensor libraries. Acting like an optical detection method, the IR-camera detects small temperature changes due to physisorption, chemisorption or other forms of interaction or reaction as an output signal in the form of radiation emitted by the multiplicity of sensor materials simultaneously. The temperature resolution of commercially available IR-camera systems can be tuned to the range below 0.1 K. Due to the separation of sensors and the detector device, reaction conditions at the sensor locus can be adapted to the analytical problem and do not need to take care of other boundary conditions which come into play with the analytical device, e.g. the IR-camera. Calibration or regeneration steps can as well be performed over the multiplicity of all sensor materials. Any given chemical compound that comes into contact with the sensor through the passing fluids will result in a specific activity pattern on a spatially fixed library of sensor materials that is unique for the given compound. While the pattern therefore serves as an identifier, the intensity of the pattern represents the quantitative amount of this compound in

  12. Using thermography for an obstruction of the lower lacrimal system.

    PubMed

    Machado, Marco Antonio de Campos; Silva, João Amaro Ferrari; Brioschi, Marcos Leal; Allemann, Norma

    2016-02-01

    Obstructions in the lacrimal pathways quite often require accurate and reliable image scanning for confirmation and documentation. Infrared thermal imaging, known as thermography, is a resource that complements diagnosis; it does not require touching the patient or applying contrast materials and has been used in various medical procedures for decades. However, there have been few studies in the literature about its use in ophthalmology. In this paper, the authors have presented a case of dacryocystitis where the obstruction of the lacrimal punctum was so acute that conventional dacryocystography could not be used. The authors have successfully reported the use of thermography as a complementary propaedeutic and will discuss the method they used. PMID:26840168

  13. The use of infrared thermography for nondestructive evaluation of joints

    NASA Astrophysics Data System (ADS)

    Meola, Carosena; Carlomagno, Giovanni M.; Squillace, Antonino; Giorleo, Giuseppe

    2004-12-01

    A junction between two similar, or dissimilar, materials represents generally a weak structural point and so it requires accurate choice of the most adequate joining technique and nondestructive evaluation of joined parts whatever the joining technique. The attention of the present paper is focused on the aid provided by infrared thermography for nondestructive evaluation of three types of joints: aluminum adhesively bonded joints, stainless steel laser welded joints and Glare ® mechanical fastened joints. Both techniques, pulse and modulated thermography with optical stimulation, are used. The attention is particularly focused on the second method because phase images are practically not affected by local nonuniform heating and/or local variation of the emissivity coefficient as thermal images.

  14. IR spectroscopic methods for the investigation of the CO release from CORMs.

    PubMed

    Klein, Moritz; Neugebauer, Ute; Gheisari, Ali; Malassa, Astrid; Jazzazi, Taghreed M A; Froehlich, Frank; Westerhausen, Matthias; Schmitt, Michael; Popp, Jürgen

    2014-07-24

    Carbon monoxide (CO) is a toxic gas for mammals, and despite this fact, it is naturally produced in these organisms and has been proven to be beneficial in medical treatments, too. Therefore, CO-releasing molecules (CORMs) are intensively developed to administer and dose CO for physiological applications. Nearly all of these compounds are metal carbonyl complexes, which have been synthesized and investigated. However, for most of these CORMs, the exact reaction mechanisms of CO release is not completely elucidated, although it is of utmost importance. The widely used myoglobin assay for testing the CO release has several disadvantages, and therefore, different methods have to be applied to characterize CORMs. In this work, different setups of IR absorption spectroscopy are used to analyze and quantify the CO release during the decay of various CORMs: IR spectroscopy of the gas phase is applied to follow the CO liberation, and attenuated total reflection (ATR) IR spectroscopy is used to record the decay of the metal carbonyl. IR spectroscopy supported by DFT calculations yields valuable insights in the CO release reaction mechanism. The focus is set on two different CORMs: CORM-2 (Ru2(CO)(6)Cl(4)) and on the photoactive CORM-S1 (photoCORM [Fe(CO)2(SCH2CH2NH2)2]). Our results indicate that the CO liberation from CORM-2 strongly depends on sodium dithionite, which is required for the commonly applied myoglobin assay and that CORM-S1 loses all its bound CO molecules upon irradiation with blue light. PMID:24978105

  15. Spatially resolved determination of the short-circuit current density of silicon solar cells via lock-in thermography

    SciTech Connect

    Fertig, Fabian Greulich, Johannes; Rein, Stefan

    2014-05-19

    We present a spatially resolved method to determine the short-circuit current density of crystalline silicon solar cells by means of lock-in thermography. The method utilizes the property of crystalline silicon solar cells that the short-circuit current does not differ significantly from the illuminated current under moderate reverse bias. Since lock-in thermography images locally dissipated power density, this information is exploited to extract values of spatially resolved current density under short-circuit conditions. In order to obtain an accurate result, one or two illuminated lock-in thermography images and one dark lock-in thermography image need to be recorded. The method can be simplified in a way that only one image is required to generate a meaningful short-circuit current density map. The proposed method is theoretically motivated, and experimentally validated for monochromatic illumination in comparison to the reference method of light-beam induced current.

  16. Non-destructive Testing of Forged Metallic Materials by Active Infrared Thermography

    NASA Astrophysics Data System (ADS)

    Maillard, S.; Cadith, J.; Bouteille, P.; Legros, G.; Bodnar, J. L.; Detalle, V.

    2012-11-01

    Nowadays, infrared thermography is considered as the reference method in many applications such as safety, the inspection of electric installations, or the inspection of buildings' heat insulation. In recent years, the evolution of both material and data-processing tools also allows the development of thermography as a real non-destructive testing method. Thus, by subjecting the element to be inspected to an external excitation and by analyzing the propagation of heat in the examined zone, it is possible to highlight surface or subsurface defects such as cracks, delaminations, or corrosion. One speaks then about active infrared thermography. In this study, some results obtained during the collective studies carried out by CETIM and the University of Reims for the forging industry are presented. Various experimental possibilities offered by active thermography are presented and the interest in this method in comparison with the traditional non-destructive testing methods (penetrant testing and magnetic particle inspection) is discussed. For example, comparative results on a forged cracked hub, a steering joint, and a threaded rod are presented. They highlight the interest of infrared thermography stimulated by induction for forged parts.

  17. Inspection of composite structures using line scanning thermography

    NASA Astrophysics Data System (ADS)

    Ley, Obdulia; Butera, Manny; Godinez, Valery

    2012-06-01

    This work deals with the non destructive analysis of different composite parts and structures using Line Scanning Thermography (LST), a non-contact inspection method based in dynamic thermography. The LST technique provides a quick and efficient methodology to scan wide areas rapidly; the technique has been used on the inspection of composite propellers, sandwich panels, motor case tubes and wind turbine blades, among others. In LST a line heat source is used to thermally excite the surface under study while an infrared detector records the transient surface temperature variation of the heated region. Line Scanning Thermography (LST), has successfully been applied to determine the thickness of metallic plates and to assess boiler tube thinning. In this paper the LST protocols developed for the detection of sub-surface defects in different composite materials commonly used in aerospace applications, plates will be presented. In most cases the thermal images acquired using LST will be compared with ultrasonic c-scans. The fundamentals of LST will be discussed, as well as the limitations of this technique for NDT inspection.

  18. The effective image denoising method for MEMS based IR image arrays

    NASA Astrophysics Data System (ADS)

    Dong, Liquan; Liu, Xiaohua; Zhao, Yuejin; Liu, Ming; Hui, Mei; Zhou, Xiaoxiao

    2008-12-01

    MEMS have become viable systems to utilize for uncooled infrared imaging in recent years. They offer advantages due to their simplicity, low cost and scalability to high-resolution FPAs without prohibitive increase in cost. An uncooled thermal detector array with low NETD is designed and fabricated using MEMS bimaterial microcantilever structures that bend in response to thermal change. The IR images of objects obtained by these FPAs are readout by an optical method. For the IR images, processed by a sparse representation-based image denoising and inpainting algorithm, which generalizing the K-Means clustering process, for adapting dictionaries in order to achieve sparse signal representations. The processed image quality is improved obviously. Great compute and analysis have been realized by using the discussed algorithm to the simulated data and in applications on real data. The experimental results demonstrate, better RMSE and highest Peak Signal-to-Noise Ratio (PSNR) compared with traditional methods can be obtained. At last we discuss the factors that determine the ultimate performance of the FPA. And we indicated that one of the unique advantages of the present approach is the scalability to larger imaging arrays.

  19. Finite element modeling of haptic thermography: A novel approach for brain tumor detection during minimally invasive neurosurgery.

    PubMed

    Sadeghi-Goughari, Moslem; Mojra, Afsaneh

    2015-10-01

    Intraoperative Thermal Imaging (ITI) is a novel neuroimaging method that can potentially locate tissue abnormalities and hence improves surgeon's diagnostic ability. In the present study, thermography technique coupled with artificial tactile sensing method called "haptic thermography" is utilized to investigate the presence of an abnormal object as a tumor with an elevated temperature relative to the normal tissue in the brain. The brain tissue is characterized as a hyper-viscoelastic material to be descriptive of mechanical behavior of the brain tissue during tactile palpation. Based on a finite element approach, Magnetic Resonance Imaging (MRI) data of a patient diagnosed to have a brain tumor is utilized to simulate and analyze the capability of haptic thermography in detection and localization of brain tumor. Steady-state thermal results prove that temperature distribution is an appropriate outcome of haptic thermography for the superficial tumors while heat flux distribution can be used as an extra thermal result for deeply located tumors. PMID:26590456

  20. Tracking composite material damage evolution using Bayesian filtering and flash thermography data

    NASA Astrophysics Data System (ADS)

    Gregory, Elizabeth D.; Holland, Steve D.

    2016-05-01

    We propose a method for tracking the condition of a composite part using Bayesian filtering of ash thermography data over the lifetime of the part. In this demonstration, composite panels were fabricated; impacted to induce subsurface delaminations; and loaded in compression over multiple time steps, causing the delaminations to grow in size. Flash thermography data was collected between each damage event to serve as a time history of the part. The ash thermography indicated some areas of damage but provided little additional information as to the exact nature or depth of the damage. Computed tomography (CT) data was also collected after each damage event and provided a high resolution volume model of damage that acted as truth. After each cycle, the condition estimate, from the ash thermography data and the Bayesian filter, was compared to 'ground truth'. The Bayesian process builds on the lifetime history of ash thermography scans and can give better estimates of material condition as compared to the most recent scan alone, which is common practice in the aerospace industry. Bayesian inference provides probabilistic estimates of damage condition that are updated as each new set of data becomes available. The method was tested on simulated data and then on an experimental data set.

  1. Non-destructive Testing by Infrared Thermography Under Random Excitation and ARMA Analysis

    NASA Astrophysics Data System (ADS)

    Bodnar, J. L.; Nicolas, J. L.; Candoré, J. C.; Detalle, V.

    2012-11-01

    Photothermal thermography is a non-destructive testing (NDT) method, which has many applications in the field of control and characterization of thin materials. This technique is usually implemented under CW or flash excitation. Such excitations are not adapted for control of fragile materials or for multi-frequency analysis. To allow these analyses, in this article, the use of a new control mode is proposed: infrared thermography under random excitation and auto regressive moving average analysis. First, the principle of this NDT method is presented. Then, the method is shown to permit detection, with low energy constraints, of detachments situated in mural paintings.

  2. Differential identification of mushrooms sclerotia by IR macro-fingerprint method

    NASA Astrophysics Data System (ADS)

    Choong, Yew Keong; Lan, Jin; Lee, Han Lim; Chen, Xiang-dong; Wang, Xiao-guang; Yang, Yu-ping

    2016-01-01

    Many macrofungus sclerotia are well-known medicinal herbs, health food and nutritional supplements. However, the prevalent adulterant commercial products are major hindrances to their incorporation into mainstream medical use in many countries. The mushroom sclerotia of Lignosus rhinocerotis, Poria cocos, Polyporus umbellatus, Pleurotus tuber-regium and Omphalia lapidescens are commonly used in traditional Chinese medicine. In this study, IR macro-fingerprint method was used in the identification of these sclerotia. The results showed that the spectrum of L. rhinocerotis (LR) was comparable with P. cocos with 94.4% correlation, except that the peak at 1543 cm-1 of LR appeared in lower intensity. The spectrum of P. umbellatus and P. tuber-regium was also correlated (91.5%), as both spectra could be clearly discriminated in that P. umbellatus spectrum has small base peaks located at the range of 1680-1500 cm-1. O. lapidescens was not comparable with all the other sclerotia as its spectrum was totally different. Its base peak was broad and derivated equally along the range. The first IR has revealed the dissimilarity among five mushrooms sclerotia. The second derivative and 2DIR further enhanced the identification in detail.

  3. X-shooter near-IR spectrograph arm: design and manufacturing methods

    NASA Astrophysics Data System (ADS)

    Navarro, Ramon; Elswijk, Eddy; de Haan, Menno; Hanenburg, Hiddo; ter Horst, Rik; Kleszcz, Pawel; Kragt, Jan; Pragt, Johan; Rigal, Florence; Roelfsema, Ronald; Schoenmaker, Ton; Tromp, Niels; Venema, Lars; Groot, Paul; Kaper, Lex

    2006-06-01

    X-shooter, the first 2nd generation VLT instrument, is a new high-efficiency echelle spectrograph. X-shooter operates at the Cassegrain focus and covers an exceptionally wide spectral range from 300 to 2500 nm in a single exposure, with an intermediate spectral resolving power R~5000. The instrument consists of a central structure and three prism cross-dispersed echelle spectrographs optimized for the UV-blue, visible and near-IR wavelength ranges. The design of the near-IR arm of the X-shooter instrument employs advanced design methods and manufacturing techniques. Integrated system design is done at cryogenic working temperatures, aiming for an almost alignment-free integration. ASTRON Extreme Light Weighting is used for high stiffness at low mass. Bare aluminium is post-polished to optical quality mirrors, preserving high shape accuracy at cryogenic conditions. Cryogenic optical mounts compensate for CTE differences of various materials, while ensuring high thermal contact. This paper addresses the general design and the application of these specialized techniques.

  4. Differential identification of mushrooms sclerotia by IR macro-fingerprint method.

    PubMed

    Choong, Yew Keong; Lan, Jin; Lee, Han Lim; Chen, Xiang-Dong; Wang, Xiao-Guang; Yang, Yu-Ping

    2016-01-01

    Many macrofungus sclerotia are well-known medicinal herbs, health food and nutritional supplements. However, the prevalent adulterant commercial products are major hindrances to their incorporation into mainstream medical use in many countries. The mushroom sclerotia of Lignosus rhinocerotis, Poria cocos, Polyporus umbellatus, Pleurotus tuber-regium and Omphalia lapidescens are commonly used in traditional Chinese medicine. In this study, IR macro-fingerprint method was used in the identification of these sclerotia. The results showed that the spectrum of L. rhinocerotis (LR) was comparable with P. cocos with 94.4% correlation, except that the peak at 1543cm(-1) of LR appeared in lower intensity. The spectrum of P. umbellatus and P. tuber-regium was also correlated (91.5%), as both spectra could be clearly discriminated in that P. umbellatus spectrum has small base peaks located at the range of 1680-1500cm(-1). O. lapidescens was not comparable with all the other sclerotia as its spectrum was totally different. Its base peak was broad and derivated equally along the range. The first IR has revealed the dissimilarity among five mushrooms sclerotia. The second derivative and 2DIR further enhanced the identification in detail. PMID:26186395

  5. Joint estimation of TOA and DOA in IR-UWB system using a successive propagator method

    NASA Astrophysics Data System (ADS)

    Wang, Fangqiu; Zhang, Xiaofei; Wang, Chenghua; Zhou, Shengkui

    2015-10-01

    Impulse radio ultra-wideband (IR-UWB) ranging and positioning require accurate estimation of time-of-arrival (TOA) and direction-of-arrival (DOA). With receiver of two antennas, both of the TOA and DOA parameters can be estimated via two-dimensional (2D) propagator method (PM), in which the 2D spectral peak searching, however, renders much higher computational complexity. This paper proposes a successive PM algorithm for joint TOA and DOA estimation in IR-UWB system to avoid 2D spectral peak searching. The proposed algorithm firstly gets the initial TOA estimates in the two antennas from the propagation matrix, then utilises successively one-dimensional (1D) local searches to achieve the estimation of TOAs in the two antennas, and finally obtains the DOA estimates via the difference in the TOAs between the two antennas. The proposed algorithm, which only requires 1D local searches, can avoid the high computational cost in 2D-PM algorithm. Furthermore, the proposed algorithm can obtain automatically paired parameters and has better joint TOA and DOA estimation performance than conventional PM algorithm, estimation of signal parameters via rotational invariance techniques algorithm and matrix pencil algorithm. Meanwhile, it has very close parameter estimation to that of 2D-PM algorithm. We have also derived the mean square error of TOA and DOA estimation of the proposed algorithm and the Cramer-Rao bound of TOA and DOA estimation in this paper. The simulation results verify the usefulness of the proposed algorithm.

  6. Exploring the solar system: the view of planetary surfaces with VIS/IR remote sensing methods

    NASA Astrophysics Data System (ADS)

    Arnold, Gabriele E.

    2011-09-01

    The structure of planetary surfaces unveils basic formation processes and evolution lines of different objects in the solar system, and often the view on the top of a planet is the only available information about it. Advanced remote sensing technologies on deep space missions are aimed at accessing a maximum of relevant data to characterize a planetary object holistically. This approach requires concert strategies in planetary and engineering science. In this framework VIS/IR spectroscopic remote sensing methods are key technologies for imaging planetary atmospheres and surfaces, for studying their composition, texture, structure and dynamics. Basing on these analyses it succeeds to observe the single objects in more global geo-scientific content. The paper focuses on main geo-scientific output coming from spectroscopic studies of planetary surfaces in conjunction with their interiors, atmospheres, and the interplanetary space. It summarizes selected results of spectral studies onboard of the ESA deep space missions BepiColombo, Venus Express, Mars Express, and Rosetta. The corresponding spectral instruments are introduced. The complex conflation of special knowledge of the disciplines planetology, optical and IR measuring techniques, and space flight engineering is demonstrated in several examples. Finally, the paper gives an outlook of current developments for spectral studies in planned missions, and sums up some of the driving questions in planetary science.

  7. Low-velocity impact damage characterization of carbon fiber reinforced polymer (CFRP) using infrared thermography

    NASA Astrophysics Data System (ADS)

    Li, Yin; Zhang, Wei; Yang, Zheng-wei; Zhang, Jin-yu; Tao, Sheng-jie

    2016-05-01

    Carbon fiber reinforced polymer (CFRP) after low-velocity impact is detected using infrared thermography, and different damages in the impacted composites are analyzed in the thermal maps. The thermal conductivity under pulse stimulation, frictional heating and thermal conductivity under ultrasonic stimulation of CFRP containing low-velocity impact damage are simulated using numerical simulation method. Then, the specimens successively exposed to the low-velocity impact are respectively detected using the pulse infrared thermography and ultrasonic infrared thermography. Through the numerical simulation and experimental investigation, the results obtained show that the combination of the above two detection methods can greatly improve the capability for detecting and evaluating the impact damage in CFRP. Different damages correspond to different infrared thermal images. The delamination damage, matrix cracking and fiber breakage are characterized as the block-shape hot spot, line-shape hot spot,

  8. Damage Detection in Rotorcraft Composite Structures Using Thermography and Laser-Based Ultrasound

    NASA Technical Reports Server (NTRS)

    Anastasi, Robert F.; Zalameda, Joseph N.; Madaras, Eric I.

    2004-01-01

    New rotorcraft structural composite designs incorporate lower structural weight, reduced manufacturing complexity, and improved threat protection. These new structural concepts require nondestructive evaluation inspection technologies that can potentially be field-portable and able to inspect complex geometries for damage or structural defects. Two candidate technologies were considered: Thermography and Laser-Based Ultrasound (Laser UT). Thermography and Laser UT have the advantage of being non-contact inspection methods, with Thermography being a full-field imaging method and Laser UT a point scanning technique. These techniques were used to inspect composite samples that contained both embedded flaws and impact damage of various size and shape. Results showed that the inspection techniques were able to detect both embedded and impact damage with varying degrees of success.

  9. Thermography to Inspect Insulation of Large Cryogenic Tanks

    NASA Technical Reports Server (NTRS)

    Arens, Ellen; Youngquist, Robert

    2011-01-01

    Thermography has been used in the past to monitor active, large, cryogenic storage tanks. This approach proposes to use thermography to monitor new or refurbished tanks, prior to filling with cryogenic liquid, to look for insulation voids. Thermography may provide significant cost and schedule savings if voids can be detected early before a tank is returned to service.

  10. Measurement of Crystallization Temperature Using Thermography for Thin Film Amorphous Alloy Samples

    NASA Astrophysics Data System (ADS)

    Hata, Seiichi; Aono, Yuko; Sakurai, Junpei; Shimokohbe, Akira

    2009-03-01

    This report describes a new non-contact measurement method for the crystallization temperature (Tx) of a thin film amorphous alloy. The thermal emissivity of the amorphous alloy sample is predicted to be modified when it crystallizes. It was attempted to relate this modification to changes in the apparent temperature by thermography. Thin film amorphous alloys of Pt67Si33 and Pt73Si27 were sputtered onto an Al2O3 substrate and then heated at 20 K/min in vacuum, and the film temperature was monitored by thermography. The Tx indicated by the proposed method coincided with the temperature measured by conventional differential scanning calorimeter within 8 K.

  11. Fusion of the Dhfr/Mtx and IR/MAR Gene Amplification Methods Produces a Rapid and Efficient Method for Stable Recombinant Protein Production

    PubMed Central

    Miki, Daisuke; Shimizu, Noriaki

    2012-01-01

    Amplification of the dihydrofolate reductase gene (Dhfr) by methotrexate (Mtx) exposure is commonly used for recombinant protein expression in Chinese hamster ovary (CHO) cells. However, this method is both time- and labor-intensive, and the high-producing cells that are generated are frequently unstable in culture. Another gene amplification method is based on using a plasmid bearing a mammalian replication initiation region (IR) and a matrix attachment region (MAR), which result in the spontaneous initiation of gene amplification in transfected cells. The IR/MAR and Dhfr/Mtx methods of gene amplification are based on entirely different principles. In this study, we combine these two methods to yield a novel method, termed the IR/MAR-Dhfr fusion method, which was used to express three proteins, the Fc receptor, GFP, and recombinant antibody. The fusion method resulted in a dramatic increase in expression of all three proteins in two CHO sub-lines, DXB-11, and DG44. The IR/MAR-Dhfr fusion amplified the genes rapidly and efficiently, and produced larger amounts of antibody than the Dhfr/Mtx or IR/MAR methods alone. While the amplified structure produced by the Dhfr/Mtx method was highly unstable, and the antibody production rate rapidly decreased with the culture time of the cells, the IR/MAR-Dhfr fusion method resulted in stable amplification and generated clonal cells that produced large amounts of antibody protein over a long period of time. In summary, the novel IR/MAR-Dhfr fusion method enables isolation of stable cells that produce larger amounts of a target recombinant protein more rapidly and easily than either the Dhfr/Mtx or IR/MAR methods alone. PMID:23300841

  12. Application of Infrared Thermography as a Diagnostic Tool of Knee Osteoarthritis

    NASA Astrophysics Data System (ADS)

    Arfaoui, Ahlem; Bouzid, Mohamed Amine; Pron, Hervé; Taiar, Redha; Polidori, Guillaume

    This paper aimed to study the feasibility of application of infrared thermography to detect osteoarthritis of the knee and to compare the distribution of skin temperature between participants with osteoarthritis and those without pathology. All tests were conducted at LACM (Laboratory of Mechanical Stresses Analysis) and the gymnasium of the University of Reims Champagne Ardennes. IR thermography was performed using an IR camera. Ten participants with knee osteoarthritis and 12 reference healthy participants without OA participated in this study. Questionnaires were also used. The participants with osteoarthritis of the knee were selected on clinical examination and a series of radiographs. The level of pain was recorded by using a simple verbal scale (0-4). Infrared thermography reveals relevant disease by highlighting asymmetrical behavior in thermal color maps of both knees. Moreover, a linear evolution of skin temperature in the knee area versus time has been found whatever the participant group is in the first stage following a given effort. Results clearly show that the temperature can be regarded as a key parameter for evaluating pain. Thermal images of the knee were taken with an infrared camera. The study shows that with the advantage of being noninvasive and easily repeatable, IRT appears to be a useful tool to detect quantifiable patterns of surface temperatures and predict the singular thermal behavior of this pathology. It also seems that this non-intrusive technique enables to detect the early clinical manifestations of knee OA.

  13. Calibration and Evaluation of Ultrasound Thermography Using Infrared Imaging.

    PubMed

    Hsiao, Yi-Sing; Deng, Cheri X

    2016-02-01

    Real-time monitoring of the spatiotemporal evolution of tissue temperature is important to ensure safe and effective treatment in thermal therapies including hyperthermia and thermal ablation. Ultrasound thermography has been proposed as a non-invasive technique for temperature measurement, and accurate calibration of the temperature-dependent ultrasound signal changes against temperature is required. Here we report a method that uses infrared thermography for calibration and validation of ultrasound thermography. Using phantoms and cardiac tissue specimens subjected to high-intensity focused ultrasound heating, we simultaneously acquired ultrasound and infrared imaging data from the same surface plane of a sample. The commonly used echo time shift-based method was chosen to compute ultrasound thermometry. We first correlated the ultrasound echo time shifts with infrared-measured temperatures for material-dependent calibration and found that the calibration coefficient was positive for fat-mimicking phantom (1.49 ± 0.27) but negative for tissue-mimicking phantom (-0.59 ± 0.08) and cardiac tissue (-0.69 ± 0.18°C-mm/ns). We then obtained the estimation error of the ultrasound thermometry by comparing against the infrared-measured temperature and revealed that the error increased with decreased size of the heated region. Consistent with previous findings, the echo time shifts were no longer linearly dependent on temperature beyond 45°C-50°C in cardiac tissues. Unlike previous studies in which thermocouples or water bath techniques were used to evaluate the performance of ultrasound thermography, our results indicate that high-resolution infrared thermography is a useful tool that can be applied to evaluate and understand the limitations of ultrasound thermography methods. PMID:26547634

  14. Nde of Advanced Automotive Composite Materials that Apply Ultrasound Infrared Thermography Technique

    NASA Astrophysics Data System (ADS)

    Choi, Seung-Hyun; Park, Soo-Keun; Kim, Jae-Yeol

    The infrared thermographic nondestructive inspection technique is a quality inspection and stability assessment method used to diagnose the physical characteristics and defects by detecting the infrared ray radiated from the object without destructing it. Recently, the nondestructive inspection and assessment that use the ultrasound-infrared thermography technique are widely adopted in diverse areas. The ultrasound-infrared thermography technique uses the phenomenon that the ultrasound wave incidence to an object with cracks or defects on its mating surface generates local heat on the surface. The car industry increasingly uses composite materials for their lightweight, strength, and environmental resistance. In this study, the car piston passed through the ultrasound-infrared thermography technique for nondestructive testing, among the composite material car parts. This study also examined the effects of the frequency and power to optimize the nondestructive inspection.

  15. Bridge concrete deteriorating diagnosis by infrared thermography

    NASA Astrophysics Data System (ADS)

    Shibata, Hiroki; Fukuyama, Nobuhiro; Sakuma, Joji; Mochizuki, Jun; Kimura, Yukinori

    2006-04-01

    Bridge is indispensable as social overhead capital. In the past, concrete construction was believed to be semi-permanent. Actually, however, concrete is deteriorated by various factors including seawater damage, annual temperature change, etc. Therefore, it is now obvious that maintenance and management are essential to keep performance of the bridge. In Japan, we had many reports of using infrared thermography for diagnosis of building, mainly for delamination of tile and mortar used for surface of the building for more than 10 years. In recent years, infrared thermogrephy is more actively used for delamination of surface of the bridge. Passive method is usually used for open-air concrete structure diagnosis, which utilizes intraday environmental temperature change and/or radiation energy emitted from the sun which create delta-T of delamination portion of the concrete structure. It is very important to take thermal image at right conditions. Otherwise, you may easily fall onto false diagnosis. In our presentation, many case examples and study of thermal data will be shown, which are taken at the right condition.

  16. 3D medical thermography device

    NASA Astrophysics Data System (ADS)

    Moghadam, Peyman

    2015-05-01

    In this paper, a novel handheld 3D medical thermography system is introduced. The proposed system consists of a thermal-infrared camera, a color camera and a depth camera rigidly attached in close proximity and mounted on an ergonomic handle. As a practitioner holding the device smoothly moves it around the human body parts, the proposed system generates and builds up a precise 3D thermogram model by incorporating information from each new measurement in real-time. The data is acquired in motion, thus it provides multiple points of view. When processed, these multiple points of view are adaptively combined by taking into account the reliability of each individual measurement which can vary due to a variety of factors such as angle of incidence, distance between the device and the subject and environmental sensor data or other factors influencing a confidence of the thermal-infrared data when captured. Finally, several case studies are presented to support the usability and performance of the proposed system.

  17. Study on detecting CFRP composites using pulsed infrared thermography

    NASA Astrophysics Data System (ADS)

    Huo, Yan; Li, Hui-Juan; Zhao, Yue-Jin; Zhang, Cun-Lin

    2011-08-01

    Composite sandwich structure has been widely used in aerospace due to its lightweight, high stiffness and strength. The quality of the structure is crucial to durability and structural integrity of the rehabilitated the structure, Delaminations, debonding and water ingressing to honeycomb are typical defects in the structure. Defects in the structure will influence the quality of product. Pulse thermography has been an effective NDE method in recent ten years. The technique uses pulse to excite the specimen, because the presence of subsurface defects reduce the diffusion rate, then temperature difference between defect area and sound area will be measured by an infrared camera. Subsurface defects become visible with time delays, it is a non-contact, quickly inspection method. Pulsed infrared thermography has been widely used in aerospace and mechanical manufacture industry because it can offer non-contact, quickly and visual examinations of defects. It is a meaningful research topic to study on quantitative testing with the structure rapidly and non-destructively. Sandwich composites with aluminum facesheet and aluminum honeycomb cores are chosen as study objectives. Some back-drilled holes with different sizes and depths in the specimen are used to simulate delaminations between plies in the strcuture .The paper presents a method for defining the boundaries, quantitatively estimating the sizes of the flaws in the CFRP using pulsed infrared thermography. Processing captured data using splinefitting, measuring the size of the defects by calculating the pixels numbers that exceed the detection threshold and computing areas of defects by binary image. Compared with the designed sizes and areas having defects, the results show that the method offers more than 90% accuracies with reference to the sizes of artificial flaws embedded in the CFRP sheet. The experimental results demonstrate the feasibility of using detection threshold to inspect the CFRP sheet. The curve of

  18. Open crack depth sizing by laser stimulated infrared lock-in thermography

    NASA Astrophysics Data System (ADS)

    Fedala, Y.; Streza, M.; Roger, J.-P.; Tessier, G.; Boué, C.

    2014-11-01

    Recent advances in infrared imaging have made active thermography an interesting non destructive technique for sub-surface defect detection. Here, we present a method for the estimation of the depth of open surface defects by infrared lock-in thermography, based on the relation between the crack depth and the Laplacian of the surface temperature distribution induced by a local heating using a laser. A comparison to numerical finite element modelling for different depths allows an accurate determination of fatigue crack depth in Inconel alloy test blocks.

  19. 29 CFR 2520.104-48 - Alternative method of compliance for model simplified employee pensions-IRS Form 5305-SEP.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 9 2013-07-01 2013-07-01 false Alternative method of compliance for model simplified... Provisions Applicable to Both Reporting and Disclosure Requirements § 2520.104-48 Alternative method of compliance for model simplified employee pensions—IRS Form 5305-SEP. Under the authority of section 110...

  20. 29 CFR 2520.104-48 - Alternative method of compliance for model simplified employee pensions-IRS Form 5305-SEP.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 9 2014-07-01 2014-07-01 false Alternative method of compliance for model simplified... Provisions Applicable to Both Reporting and Disclosure Requirements § 2520.104-48 Alternative method of compliance for model simplified employee pensions—IRS Form 5305-SEP. Under the authority of section 110...

  1. 29 CFR 2520.104-48 - Alternative method of compliance for model simplified employee pensions-IRS Form 5305-SEP.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 9 2011-07-01 2011-07-01 false Alternative method of compliance for model simplified... Provisions Applicable to Both Reporting and Disclosure Requirements § 2520.104-48 Alternative method of compliance for model simplified employee pensions—IRS Form 5305-SEP. Under the authority of section 110...

  2. 29 CFR 2520.104-48 - Alternative method of compliance for model simplified employee pensions-IRS Form 5305-SEP.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 9 2012-07-01 2012-07-01 false Alternative method of compliance for model simplified... Provisions Applicable to Both Reporting and Disclosure Requirements § 2520.104-48 Alternative method of compliance for model simplified employee pensions—IRS Form 5305-SEP. Under the authority of section 110...

  3. Molecular IR Spectroscopy: New Trends and Methods of Noninvasive Diagnostics of Tissue IN VIVO

    NASA Astrophysics Data System (ADS)

    Afanasyeva, Natalia; Bruch, Reinhard

    1998-05-01

    Fiberoptic evanescent wave Fourier transform infrared (FEW-FTIR) spectroscopy using fiberoptic sensors operated in the attenuated total reflection (ATR) regime in the middle infrared (IR) region of the spectrum (850-1850 cm-1) has recently been applied to the diagnostics of tissues. The method is suitable for noninvasive and rapid (seconds) direct measurements of the spectra of normal and pathological tissues in vitro, ex vivo and in vivo. The aim of our studies is the express testing of various tumor tissues at the early stages of their development. The method is expected to be further developed for endoscopic and biopsy applications. We measured the normal skin and malignant tissues in vivo on the surface (directly on patients) in various cases of basaloma, melanoma and nevus. The experiments were performed in the operating room to measure the skin in the depth (under/in the layers of epidermis) of human breast, stomach, lung, and kidney tissues. The breast and skin tissues at different stages of tumor or cancer were distinguished very clearly in spectra of amide, side cyclic and noncyclic hydrogen bonded fragments of aminoacid residuals, phosphate groups and sugars. Computer monitoring is being developed for diagnostics.

  4. Simple fully reflective method of scatter reduction in 2D-IR spectroscopy.

    PubMed

    Spector, Ivan C; Olson, Courtney M; Huber, Christopher J; Massari, Aaron M

    2015-04-15

    A fully reflective two-dimensional IR (2D-IR) setup is described that enables efficient cancellation of scattered light from multiple pulses in the phase-matched direction. The local oscillator pulse and the pulse that stimulates the vibrational echo signal are synchronously modulated (or fibrillated) in time maintaining their phase relationships with the echo wavepacket. The modification is cost-effective and can be easily implemented on existing 2D-IR instruments, and it avoids the addition of dispersive elements into the beam paths. The fibrillation results in a decrease of waiting-time resolution of only tens of femtoseconds and has no impact on the spectral lineshape, making it a general improvement for 2D-IR spectrometers even for weakly or non-scattering samples. PMID:25872090

  5. Fabrication of 0.0075-Scale Orbiter Phosphor Thermography Test Models for Shuttle RTF Aeroheating Studies

    NASA Technical Reports Server (NTRS)

    Buck, Gregory M.; Powers, Michael A.; Griffith, Mark S.; Hopins, John W.; Veneris, Pete H.; Kuykendoll, Kathryn

    2006-01-01

    This report details the techniques and fidelity associated with aeroheating models constructed in support of the return-to-flight boundary layer transition (BLT) activity for STS-114. This report provides technical descriptions of the methods, materials, and equipment used, as well as the surface quality results obtained with the cast ceramic phosphor thermography models.

  6. Tone Burst Eddy-Current Thermography (tbet)

    NASA Astrophysics Data System (ADS)

    Kumar, Ch. N. Kiran; Krishnamurthy, C. V.; Maxfield, Bruce W.; Balasubramaniam, Krishnan

    2008-02-01

    This paper reports on a Tone Burst Eddycurrent Thermography (TBET) technique that uses short-time bursts of eddy-currents induced in conducting media to generate local heating inside the material. The transient diffusion of the heat inside the material, induced by pulsed/short-time induction heating, is imaged by measuring the transient temperature profiles on the surface of the material. The presence and characteristics of the defects inside the materials changes the surface temperature transients and thus can be used for the nondestructive evaluation (NDE) of conducting materials. Axisymmetric numerical models of the conventional transient thermography technique are used to benchmark the TBET technique. From the temperature profile data, temperature contrast information is obtained for the different defect depths. Temperature contrast data obtained for TBET, in this process, was compared with that obtained from conventional transient thermography data. It was found that the frequency of the eddy-current and, consequently, the skin-depth of the induced field play an important role in the effective utilization of this technique. Simulation details and the experimental results are presented in the paper. Possible advantages of TBET over conventional flash thermography are also discussed and supported by experimental data.

  7. FPA-based infrared thermography as applied to the study of cutaneous perspiration and stimulated vascular response in humans.

    PubMed

    Vainer, Boris G

    2005-12-01

    This review gives an overview of focal plane array (FPA)-based infrared (IR) thermography as a powerful research method in the field of physiology and medicine. Comparison of the gained results with the data previously obtained by other authors with other research tools is given. Outer thermoregulatory manifestations displayed by the human organism subjected to whole-body heating (sauna bath) and physical loads (exercise bicycling) are quantitatively analysed. Some details of human body emotional sweating (psycho-physiological effect) are reported. Particular attention is paid to studying active sweat glands as individual objects. All experimental data were obtained with the help of a high-sensitivity (0.03 degrees C) fast 128 x 128 InAs IR detector-based thermal imaging system operating in the short-wave spectral region (2.5 to 3 microm) and perfectly suiting medical purposes. It is shown that IR thermography makes it possible to overcome limitations inherent to contact measuring means that were traditionally used before in thermal studies. It is also shown that heterogeneous thermograms displayed by organisms with disturbed inner equilibrium can be quantitatively analysed in terms of statistical parameters of related surface-temperature histograms, such as the mean temperature and the standard deviation of temperature (SDT). The increase and the decrease in SDT turned out to be typical of prolonged physical load and subsequent relaxation, and of external whole-body heating, respectively. Explanation of this result based on a hypothesis advanced within the context of the doctrine of human-organism evolution is given. Skin-temperature distribution function accompanying the relaxed organism in normality was found to closely resemble normal-distribution function. Symmetry break down and variation of the shape of this characteristic may serve as an indicator of homeostasis shift and can be used as a quantitative criterion for the latter. A new phenomenon, stable

  8. Spectral and angular responses of microbolometer IR FPA: a characterization method using a FTIR

    NASA Astrophysics Data System (ADS)

    Touvignon, Aurélie; Durand, Alain; Romanens, Fabien; Favreau, Julien; Gravrand, Olivier; Tisse, Christel-Loïc.

    2014-05-01

    In order to evaluate the impact of technological evolutions on the spectral responsivity of microbolometer FPAs (Focal Plane Arrays) as well as to find out a way to estimate the mechanical stability of microbolometric pixel membranes, ULIS is proposing a new method to measuring the spectral response of the detector array over a large region (area of pixels) simultaneously. This is done by tweaking the standard protocol of a commercial FTIR (Fourier Transform InfraRed) spectrometer where the IR detector is replaced by the array to be measured. All the calculations (i.e. interferogram processing) are taken care of externally. We use this new set up to measure the angular spectral response of the detector array and to analyse the relationship between spectral response and mechanical behaviour of the pixel. Firstly the setup of this measurement is presented and some preliminary technical issues are outlined. Then we focus on the results obtained from the measurements on 17μm pitch pixels over a wide range of angles of incidence (from normal to 45° incidence). Finally, we share some theoretical insights on both those results and the inherent limitations of this protocol using a simple optical cavity model.

  9. Application of infrared thermography in computer aided diagnosis

    NASA Astrophysics Data System (ADS)

    Faust, Oliver; Rajendra Acharya, U.; Ng, E. Y. K.; Hong, Tan Jen; Yu, Wenwei

    2014-09-01

    The invention of thermography, in the 1950s, posed a formidable problem to the research community: What is the relationship between disease and heat radiation captured with Infrared (IR) cameras? The research community responded with a continuous effort to find this crucial relationship. This effort was aided by advances in processing techniques, improved sensitivity and spatial resolution of thermal sensors. However, despite this progress fundamental issues with this imaging modality still remain. The main problem is that the link between disease and heat radiation is complex and in many cases even non-linear. Furthermore, the change in heat radiation as well as the change in radiation pattern, which indicate disease, is minute. On a technical level, this poses high requirements on image capturing and processing. On a more abstract level, these problems lead to inter-observer variability and on an even more abstract level they lead to a lack of trust in this imaging modality. In this review, we adopt the position that these problems can only be solved through a strict application of scientific principles and objective performance assessment. Computing machinery is inherently objective; this helps us to apply scientific principles in a transparent way and to assess the performance results. As a consequence, we aim to promote thermography based Computer-Aided Diagnosis (CAD) systems. Another benefit of CAD systems comes from the fact that the diagnostic accuracy is linked to the capability of the computing machinery and, in general, computers become ever more potent. We predict that a pervasive application of computers and networking technology in medicine will help us to overcome the shortcomings of any single imaging modality and this will pave the way for integrated health care systems which maximize the quality of patient care.

  10. 29 CFR 2520.104-48 - Alternative method of compliance for model simplified employee pensions-IRS Form 5305-SEP.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Alternative method of compliance for model simplified employee pensions-IRS Form 5305-SEP. 2520.104-48 Section 2520.104-48 Labor Regulations Relating to Labor (Continued) EMPLOYEE BENEFITS SECURITY ADMINISTRATION, DEPARTMENT OF LABOR REPORTING AND DISCLOSURE UNDER THE EMPLOYEE RETIREMENT INCOME SECURITY...

  11. A relative-intensity two-color phosphor thermography system

    NASA Technical Reports Server (NTRS)

    Merski, N. Ronald

    1991-01-01

    The NASA LaRC has developed a relative-intensity two-color phosphor thermography system. This system has become a standard technique for acquiring aerothermodynamic data in LaRC Hypersonic Facilities Complex (HFC). The relative intensity theory and its application to the LaRC phosphor thermography system is discussed along with the investment casting technique which is critical to the utilization of the phosphor method for aerothermodynamic studies. Various approaches to obtaining quantitative heat transfer data using thermographic phosphors are addressed and comparisons between thin-film data and thermographic phosphor data on an orbiter-like configuration are presented. In general, data from these two techniques are in good agreement. A discussion is given on the application of phosphors to integration heat transfer data reduction techniques (the thin film method) and preliminary heat transfer data obtained on a calibration sphere using thin-film equations are presented. Finally, plans for a new phosphor system which uses target recognition software are discussed.

  12. Robust remote monitoring of breathing function by using infrared thermography.

    PubMed

    Pereira, Carina B; Yu, Xinchi; Blazek, Vladimir; Leonhardt, Steffen

    2015-08-01

    An abnormal breathing rate (BR) is one of the strongest markers of physiological distress. Moreover, it plays an important role in early detection of sudden infant death syndrome, as well as in the diagnosis of respiratory disorders. However, the current measuring modalities can cause discomfort to the patient, since attachment to the patient's body is required. This paper proposes a new approach based on infrared thermography to remotely monitor BR. This method allows to (1) detect automatically the nose, (2) track the associate region of interest (ROI), and (3) extract BR. To evaluate the performance of this method, thermal recording of 5 healthy subjects were acquired. Results were compared with BR obtained by capnography. The introduced approach demonstrated an excellent performance. ROIs were precisely segmented and tracked. Furthermore, a Bland-Altman diagram showed a good agreement between estimated BR and gold standard. The mean correlation and mean absolute BR error are 0.92 ± 0.07 and 0.53 bpm, respectively. In summary, infrared thermography seems to be a great, clinically relevant alternative to attached sensors, due to its outstanding characteristics and performance. PMID:26737233

  13. Medical applications of model-based dynamic thermography

    NASA Astrophysics Data System (ADS)

    Nowakowski, Antoni; Kaczmarek, Mariusz; Ruminski, Jacek; Hryciuk, Marcin; Renkielska, Alicja; Grudzinski, Jacek; Siebert, Janusz; Jagielak, Dariusz; Rogowski, Jan; Roszak, Krzysztof; Stojek, Wojciech

    2001-03-01

    The proposal to use active thermography in medical diagnostics is promising in some applications concerning investigation of directly accessible parts of the human body. The combination of dynamic thermograms with thermal models of investigated structures gives attractive possibility to make internal structure reconstruction basing on different thermal properties of biological tissues. Measurements of temperature distribution synchronized with external light excitation allow registration of dynamic changes of local temperature dependent on heat exchange conditions. Preliminary results of active thermography applications in medicine are discussed. For skin and under- skin tissues an equivalent thermal model may be determined. For the assumed model its effective parameters may be reconstructed basing on the results of transient thermal processes. For known thermal diffusivity and conductivity of specific tissues the local thickness of a two or three layer structure may be calculated. Results of some medical cases as well as reference data of in vivo study on animals are presented. The method was also applied to evaluate the state of the human heart during the open chest cardio-surgical interventions. Reference studies of evoked heart infarct in pigs are referred, too. We see the proposed new in medical applications technique as a promising diagnostic tool. It is a fully non-invasive, clean, handy, fast and affordable method giving not only qualitative view of investigated surfaces but also an objective quantitative measurement result, accurate enough for many applications including fast screening of affected tissues.

  14. Scanning induction thermography (SIT) for imaging damages in carbon-fibre reinforced plastics (CFRP) components

    NASA Astrophysics Data System (ADS)

    Thomas, K. Renil; Balasubramaniam, Krishnan

    2015-03-01

    Scanning Induction Thermography (SIT) combines both Eddy Current Technique (ECT) and Thermographic Non-Destructive Techniques (TNDT) [1],[2]. This NDT technique has been earlier demonstrated for metallic components for the detection of cracks, corrosion, etc.[3]-[9] Even though Carbon-Fiber Reinforced Plastics (CFRP) has a relatively less electrical conductivity compared to metals, it was observed that sufficient heat could be generated using induction heating that can be used for nondestructive evaluation using the Induction Thermography technique. Also, measurable temperatures could be achieved using relatively less currents, when compared to metals. In Scanning Induction Thermography (SIT) technique, the induction coil moves over the sample at optimal speeds and the temperature developed in the sample due to Joule heating effects is captured as a function of time and distance using an IR camera in the form of video images. A new algorithm is also presented for the analysis of the video images for improved analysis of the data obtained. Several CFRP components were evaluated for detection of impact damage and delaminations using the SIT technique.

  15. Application of infrared thermography for online monitoring of wall temperatures in inductively coupled plasma torches with conventional and low-flow gas consumption

    NASA Astrophysics Data System (ADS)

    Engelhard, Carsten; Scheffer, Andy; Maue, Thomas; Hieftje, Gary M.; Buscher, Wolfgang

    2007-10-01

    Inductively coupled plasma (ICP) sources typically used for trace elemental determination and speciation were investigated with infrared (IR) thermography to obtain spatially resolved torch temperature distributions. Infrared thermographic imaging is an excellent tool for the monitoring of temperatures in a fast and non-destructive way. This paper presents the first application of IR thermography to inductively coupled plasma torches and the possibility to investigate temperatures and thermal patterns while the ICP is operating and despite background emission from the plasma itself. A fast and easy method is presented for the determination of temperature distributions and stress features within ICP torches. Two different ICP operating torches were studied: a commercially available Fassel-type ICP unit with 14 L min - 1 total Ar consumption and a SHIP torch with the unusually low Ar flow of 0.6 L min - 1 . Spatially resolved infrared images of both torches were obtained and laterally resolved temperature profiles were extracted. After temperature-resolved calibration of the emissivity (between 0.5 and 0.35 at 873-1323 K) and transmission (20% between 3.75 and 4.02 μm) of the fused quartz used in the torch construction, an image correction was applied. Inhomogeneous temperature distributions with locally defined stress areas in the conventional Fassel-type torch were revealed. As a general trend, it was found that the SHIP torch exhibited higher temperatures ( Tmax = 1580 K) than the conventional torch ( Tmax = 730 K). In the former case, torch sites with efficient and inefficient cooling were discovered and the external flow of cooling air (24-48 m s - 1 ) was identified as the limiting factor.

  16. The Use of Infrared Thermography as a Rapid, Quantitative, and Noninvasive Method for Evaluation of Inflammation Response in Different Anatomical Regions of Rats

    PubMed Central

    Całkosiński, Ireneusz; Dobrzyński, Maciej; Rosińczuk, Joanna; Dudek, Krzysztof; Chrószcz, Aleksander; Fita, Katarzyna

    2015-01-01

    Purpose. Thermographic assessment of temperature distribution within the examined tissues allows a quick, noncontact, noninvasive measurement of their temperature. The aim of the study was to evaluate the usefulness of digital infrared imaging in monitoring experimental inflammation of pleura (PL), lower lip (LL), and left paw (LP) and right paw (RP) of lower limbs in rats. Materials and Methods. The inflammatory reaction was induced by injection of 1% carrageenin solution into pleural cavity, lip, or paws. With the use of digital infrared imaging temperature measurement was conducted at 0 to 72 hours of the inflammatory reaction. Results. The temperature decrease was observed at the site of injection directly afterwards. Next, it was gradually increasing and it reached the maximum on the third day of the inflammatory reaction. Statistically significant changes were observed after 48-hour period in PL and LL regions, as well as after 72-hour period in LP and RP regions (P < 0.005). Conclusion. It was found that thermographic examination allows for indicating the presence of inflammatory reaction within examined tissues and determining the dynamics of this process. This method could be used as alternative procedure that allows using fewer animals for experiments. PMID:25834830

  17. Particular features of the application of IR reflection spectroscopy methods in studies in archeology and paleontology

    NASA Astrophysics Data System (ADS)

    Zolotarev, V. M.; Khlopachev, G. A.

    2013-06-01

    We have considered an optical model of a porous rough surface with optical properties of objects (bone, flint) that are typical of archeology and paleontology. We have formulated an approach that makes it possible to perform mathematical processing of the IR reflection spectra of objects of this kind using standard algorithms and determine criteria that ensure obtaining reliable information on objects with a rough surface in the course of interpretation of frequencies in their IR reflection spectra. The potential of the approach has been demonstrated using as an example an investigation by the IR Fourier-transform reflection spectroscopy of mineralization processes of mammoth tusks from two paleolithic sites (14000 and 16000 BCE) located by the town of Yudinovo, Bryansk oblast, Russia.

  18. Use of thermography in the differential diagnosis of phylloides tumour.

    PubMed

    Pierart, J; Burmeister, R; Steinberg, J; Schalper, J; Cid, L

    1990-07-01

    Thermography can be used as a method of diagnosing breast masses. We report our results of its use in the differential diagnosis of fibroadenoma from phylloides tumours (n = 47 and 20 respectively). Thermographic resolution (Th) and the difference in temperature between the tumour and a similar zone in the contralateral breast (delta 2) were compared. Thermograms were class Th1 (with a similar thermal pattern in both breasts without hypervascularization or hot points) and Th2 (with hypervascularization or a hot area with a thermal difference with the same area in the opposite breast (delta 2) of less than 2 degrees C) in most (95.7 per cent) of the patients with fibroadenoma and were class Th5 (having one or more pathological sign) in 85 per cent of the patients with phylloides tumours. Patients with phylloides tumours had a mean delta 2 of 2.99 degrees C whereas most of the patients with a fibroadenoma showed no difference in temperature. Their mean delta 2 was 0.2 degrees C (P less than 0.0005). We conclude that thermography helps in differential diagnosis between a fibroadenoma and a phylloides tumour. PMID:2166612

  19. The Effect of Penetration Depth on Thermal Contrast of NDT by Thermography

    NASA Technical Reports Server (NTRS)

    Chu, Tsuchin Philip; DiGregorio, Anthony; Russell, Samuel S.

    1999-01-01

    Nondestructive evaluation by Thermography (TNDE) is generally classified into two categories, the passive approach and the active approach. The passive approach is usually performed by measuring the natural temperature difference between the ambient and the material or structure to be tested. The active approach, on the other hand, requires the application of an external energy source to stimulate the material for inspection. A laser, a heater, a hot air blower, a high power thermal pulse, mechanical, or electromagnetic energy may provide the energy sources. For the external heating method to inspect materials for defects and imperfection at ambient temperature, a very short burst of heat can be introduced to one of the surfaces or slow heating of the side opposite to the side being observed. Due to the interruption of the heat flow through the defects, the thermal images will reveal the defective area by contrasting against the surrounding good materials. This technique is called transient Thermography, pulse video Thermography, or thermal wave imaging. As an empirical rule, the radius of the smallest defect should be at least one to two times larger than its depth under the surface. Thermography is being used to inspect void, debond, impact damage, and porosity in composite materials. It has been shown that most of the defects and imperfection can be detected. However, the current method of inspection using thermographic technique is more of an art than a practical scientific and engineering approach. The success rate of determining the defect location and defect type is largely depend on the experience of the person who operates thermography system and performs the inspection. The operator has to try different type of heat source, different duration of its application time, as well as experimenting with the thermal image acquisition time and interval during the inspection process. Further-more, the complexity of the lay-up and structure of composites makes it

  20. Short-circuit current density imaging of crystalline silicon solar cells via lock-in thermography: Robustness and simplifications

    SciTech Connect

    Fertig, Fabian Greulich, Johannes; Rein, Stefan

    2014-11-14

    Spatially resolved determination of solar cell parameters is beneficial for loss analysis and optimization of conversion efficiency. One key parameter that has been challenging to access by an imaging technique on solar cell level is short-circuit current density. This work discusses the robustness of a recently suggested approach to determine short-circuit current density spatially resolved based on a series of lock-in thermography images and options for a simplified image acquisition procedure. For an accurate result, one or two emissivity-corrected illuminated lock-in thermography images and one dark lock-in thermography image have to be recorded. The dark lock-in thermography image can be omitted if local shunts are negligible. Furthermore, it is shown that omitting the correction of lock-in thermography images for local emissivity variations only leads to minor distortions for standard silicon solar cells. Hence, adequate acquisition of one image only is sufficient to generate a meaningful map of short-circuit current density. Beyond that, this work illustrates the underlying physics of the recently proposed method and demonstrates its robustness concerning varying excitation conditions and locally increased series resistance. Experimentally gained short-circuit current density images are validated for monochromatic illumination in comparison to the reference method of light-beam induced current.

  1. Short-circuit current density imaging of crystalline silicon solar cells via lock-in thermography: Robustness and simplifications

    NASA Astrophysics Data System (ADS)

    Fertig, Fabian; Greulich, Johannes; Rein, Stefan

    2014-11-01

    Spatially resolved determination of solar cell parameters is beneficial for loss analysis and optimization of conversion efficiency. One key parameter that has been challenging to access by an imaging technique on solar cell level is short-circuit current density. This work discusses the robustness of a recently suggested approach to determine short-circuit current density spatially resolved based on a series of lock-in thermography images and options for a simplified image acquisition procedure. For an accurate result, one or two emissivity-corrected illuminated lock-in thermography images and one dark lock-in thermography image have to be recorded. The dark lock-in thermography image can be omitted if local shunts are negligible. Furthermore, it is shown that omitting the correction of lock-in thermography images for local emissivity variations only leads to minor distortions for standard silicon solar cells. Hence, adequate acquisition of one image only is sufficient to generate a meaningful map of short-circuit current density. Beyond that, this work illustrates the underlying physics of the recently proposed method and demonstrates its robustness concerning varying excitation conditions and locally increased series resistance. Experimentally gained short-circuit current density images are validated for monochromatic illumination in comparison to the reference method of light-beam induced current.

  2. Infrared Thermography And The Expert Witness

    NASA Astrophysics Data System (ADS)

    Roberts, Charles C.

    1985-03-01

    With the continued growth of legal activities involving litigation, lawsuits involving technical matters may be very complex. Expert witnesses are often hired by both plaintiffs and defendants to help clarify and simplify technical merits of a case in order for the jury to make an educated decision. The usage of infrared thermography in legal matters has also been growing. This paper reviews several areas where infrared thermography has been utilized in legal matters. These include analysis of building defects, fire analysis and equipment failures. Expert witness qualifications, test procedures and analyses are discussed. The role of industry and governmental standards is reviewed. Opinions from the infrared thermographic expert should be unbiased, factual and within the area of qualification of the expert.

  3. Infrared Thermography in the Architectural Field

    PubMed Central

    2013-01-01

    Infrared thermography is becoming ever more popular in civil engineering/architecture mainly due to its noncontact character which includes two great advantages. On one side, it prevents the object, under inspection, from any alteration and this is worthwhile especially in the presence of precious works of art. On the other side, the personnel operate in a remote manner far away from any hazard and this complies well with safety at work regulations. What is more, it offers the possibility to quickly inspect large surfaces such as the entire facade of a building. This paper would be an overview of the use of infrared thermography in the architectural and civil engineering field. First, some basic testing procedures are described, and then some key examples are presented owing to both laboratory tests and applications in situ spanning from civil habitations to works of art and archaeological sites. PMID:24319358

  4. Some fundamentals of handheld snow surface thermography

    NASA Astrophysics Data System (ADS)

    Shea, C.; Jamieson, B.

    2011-02-01

    This paper presents the concepts needed to perform snow surface thermography with a modern thermal imager. Snow-specific issues in the 7.5 to 13 μm spectrum such as ice emissivity, photographic angle, operator heating, and others receive detailed review and discussion. To illustrate the usefulness of this measurement technique, various applications are presented. These include detecting spatial temperature variation on snow pit walls and measuring the dependence of heat conduction on grain type.

  5. Some fundamentals of handheld snow surface thermography

    NASA Astrophysics Data System (ADS)

    Shea, C.; Jamieson, B.

    2010-08-01

    This paper presents the concepts needed to perform snow surface thermography with a modern thermal imager. Snow-specific issues in the 7.5 to 13 μm spectrum such as ice emissivity, photographic angle, operator heating, and others receive detailed review and discussion. To illustrate the usefulness of this measurement technique, various applications are presented. These include detecting spatial temperature variation on snow pit walls and measuring the dependence of heat conduction on grain type.

  6. Pulsed thermography in multiple infrared spectral bands

    NASA Astrophysics Data System (ADS)

    Netzelmann, U.; Abuhamad, M.

    2010-03-01

    Spectrally resolved active thermography by flash pulse excitation was performed in four sub-bands of a mid-wave infrared camera using spectral filtering and in the full long-wave band of a second infrared camera. On zirconia thermal barrier coatings on steel and PVC blocks, spectrally dependent decay rates of the thermal contrast were found. The observed behaviour can be explained by the infrared spectra of the specimens.

  7. NDT of railway components using induction thermography

    NASA Astrophysics Data System (ADS)

    Netzelmann, U.; Walle, G.; Ehlen, A.; Lugin, S.; Finckbohner, M.; Bessert, S.

    2016-02-01

    Induction or eddy current thermography is used to detect surface cracks in ferritic steel. The technique is applied to detect surface cracks in rails from a moving test car. Cracks were detected at a train speed between 2 and 15 km/h. An automated demonstrator system for testing railway wheels after production is described. While the wheel is rotated, a robot guides the detection unit consisting of inductor and infrared camera over the surface.

  8. Advances in the Use of Thermography to Inspect Composite Tanks for Liquid Fuel Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Lansing, Matthew D.; Russell, Samuel S.; Walker, James L.; Jones, Clyde S. (Technical Monitor)

    2001-01-01

    This viewgraph presentation gives an overview of advances in the use of thermography to inspect composite tanks for liquid fuel propulsion systems. Details are given on the thermographic inspection system, thermographic analysis method (includes scan and defect map, method of inspection, and inclusions, ply wrinkle, and delamination defects), graphite composite cryogenic feedline (including method, image map, and deep/shallow inclusions and resin rich area defects), and material degradation nondestructive evaluation.

  9. A new method for a quantitative determination of piroxicam in pharmaceutical formulations using FT-IR spectrometry.

    PubMed

    Bunaciu, Andrei A; Fleschin, Şerban; Aboul-Enein, Hassan Y

    2012-01-01

    A Fourier transform infrared (FT-IR) spectrometric method was developed for the rapid, and direct measurement of piroxicam (Pir) in pharmaceutical drugs. Pir is a well known and very effective antiinflammatory drug. Pir can be determined by various methods and now we are adding a new one that uses a Fourier transform infrared spectrophotometric technique. Conventional spectra were compared for best determination of active substance in pharmaceutical formulations. The Beer-Lambert law and two chemometric approaches, partial least squares (PLS) and principal component regression (PCR+) methods, were tried in data processing. PMID:23140406

  10. IR-based spot weld NDT in automotive applications

    NASA Astrophysics Data System (ADS)

    Chen, Jian; Feng, Zhili

    2015-05-01

    Today's auto industry primarily relies on destructive teardown evaluation to ensure the quality of the resistance spot welds (RSWs) due to their criticality in crash resistance and performance of vehicles. The destructive teardown evaluation is labor intensive and costly. The very nature of the destructive test means only a few selected welds will be sampled for quality. Most of the welds in a car are never checked. There are significant costs and risks associated with reworking and scrapping the defective welded parts made between the teardown tests. IR thermography as a non-destructive testing (NDT) tool has its distinct advantage — its non-intrusive and non-contact nature. This makes the IR based NDT especially attractive for the highly automated assembly lines. IR for weld quality inspection has been explored in the past, mostly limited to the offline post-processing manner in a laboratory environment. No online real-time RSW inspection using IR thermography has been reported. Typically for postprocessing inspection, a short-pulse heating via xenon flash lamp light (in a few milliseconds) is applied to the surface of a spot weld. However, applications in the auto industry have been unsuccessful, largely due to a critical drawback that cannot be implemented in the high-volume production line - the prerequisite of painting the weld surface to eliminate surface reflection and other environmental interference. This is due to the low signal-to-noise ratio resulting from the low/unknown surface emissivity and the very small temperature changes (typically on the order of 0.1°C) induced by the flash lamp method. An integrated approach consisting of innovations in both data analysis algorithms and hardware apparatus that effectively solved the key technical barriers for IR NDT. The system can be used for both real-time (during welding) and post-processing inspections (after welds have been made). First, we developed a special IR thermal image processing method that

  11. Classification of edible oils and modeling of their physico-chemical properties by chemometric methods using mid-IR spectroscopy

    NASA Astrophysics Data System (ADS)

    Luna, Aderval S.; da Silva, Arnaldo P.; Ferré, Joan; Boqué, Ricard

    This research work describes two studies for the classification and characterization of edible oils and its quality parameters through Fourier transform mid infrared spectroscopy (FT-mid-IR) together with chemometric methods. The discrimination of canola, sunflower, corn and soybean oils was investigated using SVM-DA, SIMCA and PLS-DA. Using FT-mid-IR, DPLS was able to classify 100% of the samples from the validation set, but SIMCA and SVM-DA were not. The quality parameters: refraction index and relative density of edible oils were obtained from reference methods. Prediction models for FT-mid-IR spectra were calculated for these quality parameters using partial least squares (PLS) and support vector machines (SVM). Several preprocessing alternatives (first derivative, multiplicative scatter correction, mean centering, and standard normal variate) were investigated. The best result for the refraction index was achieved with SVM as well as for the relative density except when the preprocessing combination of mean centering and first derivative was used. For both of quality parameters, the best results obtained for the figures of merit expressed by the root mean square error of cross validation (RMSECV) and prediction (RMSEP) were equal to 0.0001.

  12. Calculation of the TLD700:LiF energy response from Ir-192 using novel Monte Carlo and empirical methods.

    PubMed

    Rijken, J D; Harris-Phillips, W; Lawson, J M

    2015-03-01

    Lithium fluoride thermoluminescent dosimeters (TLDs) exhibit a dependence on the energy of the radiation beam of interest so need to be carefully calibrated for different energy spectra if used for clinical radiation oncology beam dosimetry and quality assurance. TLD energy response was investigated for a specific set of TLD700:LiF(Mg,Ti) chips for a high dose rate (192)Ir brachytherapy source. A novel method of energy response calculation for (192)Ir was developed where dose was determined through Monte Carlo modelling in Geant4. The TLD response was then measured experimentally. Results showed that TLD700 has a depth dependent response in water ranging from 1.170 ± 0.125 at 20 mm to 0.976 ± 0.043 at 50 mm (normalised to a nominal 6 MV beam response). The method of calibration and Monte Carlo data developed through this study could be easily applied by other Medical Physics departments seeking to use TLDs for (192)Ir patient dosimetry or treatment planning system experimental verification. PMID:25663432

  13. Self-gravitation interaction of IR deformed Hořava-Lifshitz gravity via new Hamilton-Jacobi method

    NASA Astrophysics Data System (ADS)

    Liu, Molin; Xu, Yin; Lu, Junwang; Yang, Yuling; Lu, Jianbo; Wu, Yabo

    2014-06-01

    The apparent discovery of logarithmic entropies has a significant impact on IR deformed Hořava-Lifshitz (IRDHL) gravity in which the original infrared (IR) property is improved by introducing three-geometry's Ricci scalar term "μ4 R" in action. Here, we reevaluate the Hawking radiation in IRDHL by using recent new Hamilton-Jacobi method (NHJM). In particular, a thorough analysis is considered both in asymptotically flat Kehagias-Sfetsos and asymptotically non-flat Park models in IRDHL. We find the NHJM offers simplifications on the technical side. The modification in the entropy expression is given by the physical interpretation of self-gravitation of the Hawking radiation in this new Hamilton-Jacobi (HJ) perspectives.

  14. Detection of pathogenic gram negative bacteria using infrared thermography

    NASA Astrophysics Data System (ADS)

    Lahiri, B. B.; Divya, M. P.; Bagavathiappan, S.; Thomas, Sabu; Philip, John

    2012-11-01

    Detection of viable bacteria is of prime importance in all fields of microbiology and biotechnology. Conventional methods of enumerating bacteria are often time consuming and labor-intensive. All living organisms generate heat due to metabolic activities and hence, measurement of heat energy is a viable tool for detection and quantification of bacteria. In this article, we employ a non-contact and real time method - infrared thermography (IRT) for measurement of temperature variations in four clinically significant gram negative pathogenic bacteria, viz. Vibrio cholerae, Vibrio mimicus, Proteus mirabilis and Pseudomonas aeruginosa. We observe that, the energy content, defined as the ratio of heat generated by bacterial metabolic activities to the heat lost from the liquid medium to the surrounding, vary linearly with the bacterial concentration in all the four pathogenic bacteria. The amount of energy content observed in different species is attributed to their metabolisms and morphologies that affect the convection velocity and hence heat transport in the medium.

  15. A combined approach for using thermography for the detection of diabetes mellitus

    NASA Astrophysics Data System (ADS)

    Berry, Bob

    2014-05-01

    This paper presents work done to develop an early diagnosis and monitoring method-encompassing thermography for the detection of Diabetes Mellitus. The early detection method involves fusion of images from infrared cameras, ultrasound devices, a 3D camera and a dermatascope. The project is to develop a novel system that could be easily used by physicians to allow for early intervention, and the paper highlights the approach taken by the Skindetector project.

  16. On-orbit Passive Thermography

    NASA Technical Reports Server (NTRS)

    Howell, Patricia A.; Winfree, William P.; Cramer, K. Elliott

    2008-01-01

    On July 12, 2006, British-born astronaut Piers Sellers became the first person to conduct thermal nondestructive evaluation experiments in space, demonstrating the feasibility of a new tool for detecting damage to the reinforced carbon-carbon (RCC) structures of the Shuttle. This new tool was an EVA (Extravehicular Activity, or spacewalk) compatible infrared camera developed by NASA engineers. Data was collected both on the wing leading edge of the Orbiter and on pre-damaged samples mounted in the Shuttle s cargo bay. A total of 10 infrared movies were collected during the EVA totaling over 250 megabytes of data. Images were downloaded from the orbiting Shuttle to Johnson Space Center for analysis and processing. Results are shown to be comparable to ground-based thermal inspections performed in the laboratory with the same type of camera and simulated solar heating. The EVA camera system detected flat-bottom holes as small as 2.54cm in diameter with 50% material loss from the back (hidden) surface in RCC during this first test of the EVA IR Camera. Data for the time history of the specimen temperature and the capability of the inspection system for imaging impact damage are presented.

  17. Ultraviolet excitation for thermography inspection of surface cracks in welded joints

    NASA Astrophysics Data System (ADS)

    Runnemalm, Anna; Broberg, Patrik; Henrikson, Per

    2014-10-01

    Infrared thermography is a non-contact and full field inspection method which has proven to be suitable for automatic surface crack detection. For automatic analysis of the inspection results, a high signal-to-noise ratio (SNR) is required. In this paper an alternative excitation method, using ultraviolet (UV) illumination, is presented and evaluated. Artificial surface defects, so-called notches, in a titanium plate are detected both in the weld seam and in the heat affected zone. Notches with a size from 80 μm in width and 250 μm in length are detected. The SNR using UV illumination is compared with that using flash lamp excitation. The results show that UV illumination using a mercury lamp is a good alternative as excitation source for thermography when detecting surface cracks. To validate the excitation method, results from real surface cracks are included.

  18. Advanced Image Processing for Defect Visualization in Infrared Thermography

    NASA Technical Reports Server (NTRS)

    Plotnikov, Yuri A.; Winfree, William P.

    1997-01-01

    Results of a defect visualization process based on pulse infrared thermography are presented. Algorithms have been developed to reduce the amount of operator participation required in the process of interpreting thermographic images. The algorithms determine the defect's depth and size from the temporal and spatial thermal distributions that exist on the surface of the investigated object following thermal excitation. A comparison of the results from thermal contrast, time derivative, and phase analysis methods for defect visualization are presented. These comparisons are based on three dimensional simulations of a test case representing a plate with multiple delaminations. Comparisons are also based on experimental data obtained from a specimen with flat bottom holes and a composite panel with delaminations.

  19. Eddy current pulsed thermography for fatigue evaluation of gear

    NASA Astrophysics Data System (ADS)

    Tian, Gui Yun; Yin, Aijun; Gao, Bin; Zhang, Jishan; Shaw, Brian

    2014-02-01

    The pulsed eddy current (PEC) technique generates responses over a wide range of frequencies, containing more spectral coverage than traditional eddy current inspection. Eddy current pulsed thermography (ECPT), a newly developed non-destructive testing (NDT) technique, has advantages such as rapid inspection of a large area within a short time, high spatial resolution, high sensitivity and stand-off measurement distance. This paper investigates ECPT for the evaluation of gear fatigue tests. The paper proposes a statistical method based on single channel blind source separation to extract details of gear fatigue. The discussion of transient thermal distribution and patterns of fatigue contact surfaces as well as the non-contact surfaces have been reported. In addition, the measurement for gears with different cycles of fatigue tests by ECPTand the comparison results between ECPT with magnetic Barkhausen noise (MBN) have been evaluated. The comparison shows the competitive capability of ECPT in fatigue evaluation.

  20. Thermography inspection for detection and tracking of composite cylinder damage during load testing

    SciTech Connect

    Zalameda, J. N.; Winfree, W. P.; Johnston, P. H.; Seebo, J. P.

    2011-06-23

    Two thermography techniques, passive and active, are used to detect damage initiation and progression in a cyclically loaded composite cylinder. The passive thermography tracks damage progression in real time during cyclic loading. Active flash thermography, using a flash tube enclosed within the cylinder, images delaminations. A differential thermography processing technique eliminates normal material variations and improves sensitivity to and sizing of delaminations. The thermography results were compared to non-immersion ultrasonic results.

  1. Thermography Inspection for Detection and Tracking of Composite Cylinder Damage During Load Testing

    NASA Technical Reports Server (NTRS)

    Zalameda, J. N.; Winfree, W. P.; Seebo, J. P.; Johnston, P. H.

    2010-01-01

    Two thermography techniques, passive and active, are used to detect damage initiation and progression in a cyclically loaded composite cylinder. The passive thermography tracks damage progression in real time during cyclic loading. Active flash thermography, using a flash tube enclosed within the cylinder, images delaminations in a cylinder under different loads. A differential thermography processing technique eliminates normal material variations and improves sensitivity to and sizing of delaminations. The thermography results were compared to nonimmersion ultrasonic results.

  2. IR Hiding: A Method to Prevent Video Re-shooting by Exploiting Differences between Human Perceptions and Recording Device Characteristics

    NASA Astrophysics Data System (ADS)

    Yamada, Takayuki; Gohshi, Seiichi; Echizen, Isao

    A method is described to prevent video images and videos displayed on screens from being re-shot by digital cameras and camcorders. Conventional methods using digital watermarking for re-shooting prevention embed content IDs into images and videos, and they help to identify the place and time where the actual content was shot. However, these methods do not actually prevent digital content from being re-shot by camcorders. We developed countermeasures to stop re-shooting by exploiting the differences between the sensory characteristics of humans and devices. The countermeasures require no additional functions to use-side devices. It uses infrared light (IR) to corrupt the content recorded by CCD or CMOS devices. In this way, re-shot content will be unusable. To validate the method, we developed a prototype system and implemented it on a 100-inch cinema screen. Experimental evaluations showed that the method effectively prevents re-shooting.

  3. Evaluation of angle dependence in spectral emissivity of ceramic tiles measured by FT-IR

    NASA Astrophysics Data System (ADS)

    Kobayashi, C.; Ogasawara, N.; Yamada, H.; Yamada, S.; Kikuchi, T.

    2015-05-01

    Ceramic tiles are widely used for building walls. False detections are caused in inspections by infrared thermography because of the infrared reflection and angle dependence of emissivity. As the first problem, ceramic tile walls are influenced from backgrounds reflection. As the second problem, in inspection for tall buildings, the camera angles are changed against the height. Thus, to reveal the relation between the emissivity and angles is needed. However, there is very little data about it. It is impossible to decrease the false detection on ceramic tile walls without resolving these problems; background reflection and angle dependence of emissivity. In this study, the angle problem was investigated. The purpose is to establish a revision method in the angle dependence of the emissivity for infrared thermography. To reveal the relation between the emissivity and angles, the spectral emissivity of a ceramic tile at various angles was measured by FT-IR and infrared thermographic instrument. These two experimental results were compared with the emissivity-angle curves from the theoretical formula. In short wavelength range, the two experimental results showed similar behavior, but they did not agree with the theoretical curve. This will be the subject of further study. In long wavelength range, the both experimental results almost obeyed the theoretical curve. This means that it is possible to revise the angle dependence of spectral emissivity, for long wavelength range.

  4. Value of Mammary Thermography in Differential Diagnosis

    PubMed Central

    Nathan, B. E.; Burn, J. Ian; MacErlean, D. P.

    1972-01-01

    Thermographic examinations of the breasts were carried out in 359 women, most of whom had mammary symptoms. Of the 195 patients with abnormal thermograms, 27 had cancer of the breast, 53 had benign lesions, and 115 had no confirmed organic disease. The incidence of false-positive thermograms was 59%. Of the 164 patients with normal thermograms, 116 had no confirmed organic disease, 41 had benign lesions, and 7 had cancer. The incidence of false-negative mammary thermograms was 29%. We conclude that mammary thermography is of no practical value in the differential diagnosis of symptomatic mammary disease. PMID:5022040

  5. Assessment of techniques of massage and pumping in the treatment of breast engorgement by thermography

    PubMed Central

    Heberle, Anita Batista dos Santos; de Moura, Marcos Antônio Muniz; de Souza, Mauren Abreu; Nohama, Percy

    2014-01-01

    Objective to evaluate techniques of massage and pumping in the treatment of postpartum breast engorgement through thermography. Method the study was conducted in the Human Milk Bank of a hospital in Curitiba, Brazil. We randomly selected 16 lactating women with engorgement with the classification lobar, ampullary and glandular, moderate and intense. We compared the differential patterns of temperature, before and after the treatment by means of massage and pumping. Results we found a negative gradient of 0.3°C of temperature between the pre- and post-treatment in the experimental group. Breasts with intense engorgement were 0.7°C warmer when compared with moderate engorgement. Conclusion massage and electromechanical pumping were superior to manual methods when evaluated by thermography. REBEC: U1111-1136-9027. PMID:26107836

  6. Near-infrared thermography using a charge-coupled device camera: Application to microsystems

    NASA Astrophysics Data System (ADS)

    Teyssieux, D.; Thiery, L.; Cretin, B.

    2007-03-01

    Using near-infrared thermography microscopy and a low-cost charge-coupled device (CCD) camera, we have designed a system which is able to deliver quantitative submicronic thermal images. Using a theoretical model based on Planck's law and CCD sensor properties allowed us to determine a minimal theoretical detection temperature and an optimal temperature sensitivity of our system. In order to validate this method, we show a good relationship between a theoretical study and a thermal measurement of a microsample.

  7. Infrared thermography for true temperature measurement of the main board in personal computer

    NASA Astrophysics Data System (ADS)

    Yang, Jing; Behnia, Masud; Morrison, Graham

    2002-11-01

    This paper presents a way to measure the true temperature of the electronic devices without disturbing their normal operating conditions, which involved with estimating target emissivity, background temperature correctly and choosing infrared transparent material and its transmission estimation. The temperature distributions of the main board in personal computer were measured by the method presented here with infrared thermography in several different running conditions. The measurement errors and their possible remedies are also discussed.

  8. HeatWave: the next generation of thermography devices

    NASA Astrophysics Data System (ADS)

    Moghadam, Peyman; Vidas, Stephen

    2014-05-01

    Energy sustainability is a major challenge of the 21st century. To reduce environmental impact, changes are required not only on the supply side of the energy chain by introducing renewable energy sources, but also on the demand side by reducing energy usage and improving energy efficiency. Currently, 2D thermal imaging is used for energy auditing, which measures the thermal radiation from the surfaces of objects and represents it as a set of color-mapped images that can be analysed for the purpose of energy efficiency monitoring. A limitation of such a method for energy auditing is that it lacks information on the geometry and location of objects with reference to each other, particularly across separate images. Such a limitation prevents any quantitative analysis to be done, for example, detecting any energy performance changes before and after retrofitting. To address these limitations, we have developed a next generation thermography device called Heat Wave. Heat Wave is a hand-held 3D thermography device that consists of a thermal camera, a range sensor and color camera, and can be used to generate precise 3D model of objects with augmented temperature and visible information. As an operator holding the device smoothly waves it around the objects of interest, Heat Wave can continuously track its own pose in space and integrate new information from the range and thermal and color cameras into a single, and precise 3D multi-modal model. Information from multiple viewpoints can be incorporated together to improve the accuracy, reliability and robustness of the global model. The approach also makes it possible to reduce any systematic errors associated with the estimation of surface temperature from the thermal images.

  9. Detection of seal contamination in heat-sealed food packaging based on active infrared thermography

    NASA Astrophysics Data System (ADS)

    D'huys, Karlien; Saeys, Wouter; De Ketelaere, Bart

    2015-05-01

    In the food industry packaging is often applied to protect the product from the environment, assuring quality and safety throughout shelf life if properly performed. Packaging quality depends on the material used and the closure (seal). The material is selected based on the specific needs of the food product to be wrapped. However, proper closure of the package is often harder to achieve. One problem possibly jeopardizing seal quality is the presence of food particles between the seal. Seal contamination can cause a decreased seal strength and thus an increased packaging failure risk. It can also trigger the formation of microchannels through which air and microorganisms can enter and spoil the enclosed food. Therefore, early detection and removal of seal-contaminated packages from the production chain is essential. In this work, a pulsed-type active thermography method using the heat of the sealing bars as an excitation source was studied for detecting seal contamination. The cooling profile of contaminated seals was recorded. The detection performance of four processing methods (based on a single frame, a fit of the cooling profile, pulsed phase thermography and a matched filter) was compared. High resolution digital images served as a reference to quantify contamination. The lowest detection limit (equivalent diameter of 0.63 mm) and the lowest processing time (0.42 s per sample) were obtained for the method based on a single frame. Presumably, practical limitations in the recording stage prevented the added value of active thermography to be fully reflected in this application.

  10. Application of infrared lock-in thermography for the quantitative evaluation of bruises on pears

    NASA Astrophysics Data System (ADS)

    Kim, Ghiseok; Kim, Geon-Hee; Park, Jongmin; Kim, Dae-Yong; Cho, Byoung-Kwan

    2014-03-01

    An infrared lock-in thermography technique was adjusted for the detection of early bruises on pears. This mechanical damage is usually difficult to detect in the early stage after harvested using conventional visual sorting or CCD sensor-based imaging processing methods. We measured the thermal emission signals from pears using a highly sensitive mid-infrared thermal camera. These images were post-processed using a lock-in method that utilized the periodic thermal energy input to the pear. By applying the lock-in method to infrared thermography, the detection sensitivity and signal to noise ratio were enhanced because of the phase-sensitive narrow-band filtering effect. It was also found that the phase information of thermal emission from pears provides good metrics with which to identify quantitative information about both damage size and damage depth for pears. Additionally, a photothermal model was implemented to investigate the behavior of thermal waves on pears under convective conditions. Theoretical results were compared to experimental results. These results suggested that the proposed lock-in thermography technique and resultant phase information can be used to detect mechanical damage to fruit, especially in the early stage of bruising.

  11. Neonatal infrared thermography imaging: Analysis of heat flux during different clinical scenarios

    NASA Astrophysics Data System (ADS)

    Abbas, Abbas K.; Heimann, Konrad; Blazek, Vladimir; Orlikowsky, Thorsten; Leonhardt, Steffen

    2012-11-01

    IntroductionAn accurate skin temperature measurement of Neonatal Infrared Thermography (NIRT) imaging requires an appropriate calibration process for compensation of external effects (e.g. variation of environmental temperature, variable air velocity or humidity). Although modern infrared cameras can perform such calibration, an additional compensation is required for highly accurate thermography. This compensation which corrects any temperature drift should occur during the NIRT imaging process. We introduce a compensation technique which is based on modeling the physical interactions within the measurement scene and derived the detected temperature signal of the object. Materials and methodsIn this work such compensation was performed for different NIRT imaging application in neonatology (e.g. convective incubators, kangaroo mother care (KMC), and an open radiant warmer). The spatially distributed temperatures of 12 preterm infants (average gestation age 31 weeks) were measured under these different infant care arrangements (i.e. closed care system like a convective incubator, and open care system like kangaroo mother care, and open radiant warmer). ResultsAs errors in measurement of temperature were anticipated, a novel compensation method derived from infrared thermography of the neonate's skin was developed. Moreover, the differences in temperature recording for the 12 preterm infants varied from subject to subject. This variation could be arising from individual experimental setting applied to the same region of interest over the neonate's body. The experimental results for the model-based corrections is verified over the selected patient group. ConclusionThe proposed technique relies on applying model-based correction to the measured temperature and reducing extraneous errors during NIRT. This application specific method is based on different heat flux compartments present in neonatal thermography scene. Furthermore, these results are considered to be

  12. A novel evaluating method for the MEMS-based uncooled IR system

    NASA Astrophysics Data System (ADS)

    Fan, Bingqing; Zhao, Yuejin; Dong, Liquan

    2009-11-01

    An experiment using 4f system model is designed to test the consistency of the units on the FPA , which is made based on MEMS technology. An optical stop as a filter is set at the back focal plane of the first lens. We get each image where the light source locates when it is rotated round FPA. The size of the stop and the rotating angle can be deduced according to the parameters of two lens. Meanwhile reflectance spectrum of each unit on the FPA can be drawn with the gray level of the image presented by CCD. Contourgraph is used to test the displacement deflection value caused by thermal deformation of FPA. According to the displacement deflection value and the unit size of FPA, we get the average deflection angle of FPA's units when temperature changes per centigrade degree. We can define a gray level difference of two adjacent images at the same position as M. When we let the value of M larger than a number N, we can say that the system has met the requirement of temperature sensitivity-T. With the help of M, light rotating angle and FPA's deflection angle, we can get the temperature sensitivity of the IR system. The actual value of temperature sensitivity approximates the NETD of the system. The calculating process proves that it can estimate the NETD, if we don't want to get the accurate value of NETD. The expression of T is much easier and more feasible than that of NETD.

  13. Switching to Infrared! A New Method for Non-professional Imaging in the mid-IR

    NASA Astrophysics Data System (ADS)

    Kaye, T. G.

    2006-05-01

    With the continuing expansion of amateur astronomy, some work has been done in the near infrared where CCD's are still sensitive in the 1 micron range. In order to advance into the mid-infrared out to 12 microns, expensive CCD arrays are required that use exotic sensor materials such as Mercury-Cadmium- Telluride (MCT). With the advent of eBay, used MCT detectors cooled by liquid nitrogen are now obtainable at reasonable cost. They are functionally limited to a single pixel, which would generally make them unsuitable for imaging. Raster scanning of the image field in conjunction with a single pixel sensor to rapidly assemble an infrared image is described as a solution to this problem. The image presented here is believed to be the first mid-IR telescopic image of Mars taken by a non-professional. The use of MCT sensors in conjunction with products such as the AO-7 and advanced scripting will be discussed as further roads for development.

  14. TOPICAL REVIEW: FPA-based infrared thermography as applied to the study of cutaneous perspiration and stimulated vascular response in humans

    NASA Astrophysics Data System (ADS)

    Vainer, Boris G.

    2005-12-01

    This review gives an overview of focal plane array (FPA)-based infrared (IR) thermography as a powerful research method in the field of physiology and medicine. Comparison of the gained results with the data previously obtained by other authors with other research tools is given. Outer thermoregulatory manifestations displayed by the human organism subjected to whole-body heating (sauna bath) and physical loads (exercise bicycling) are quantitatively analysed. Some details of human body emotional sweating (psycho-physiological effect) are reported. Particular attention is paid to studying active sweat glands as individual objects. All experimental data were obtained with the help of a high-sensitivity (0.03 °C) fast 128 × 128 InAs IR detector-based thermal imaging system operating in the short-wave spectral region (2.5 to 3 µm) and perfectly suiting medical purposes. It is shown that IR thermography makes it possible to overcome limitations inherent to contact measuring means that were traditionally used before in thermal studies. It is also shown that heterogeneous thermograms displayed by organisms with disturbed inner equilibrium can be quantitatively analysed in terms of statistical parameters of related surface-temperature histograms, such as the mean temperature and the standard deviation of temperature (SDT). The increase and the decrease in SDT turned out to be typical of prolonged physical load and subsequent relaxation, and of external whole-body heating, respectively. Explanation of this result based on a hypothesis advanced within the context of the doctrine of human-organism evolution is given. Skin-temperature distribution function accompanying the relaxed organism in normality was found to closely resemble normal-distribution function. Symmetry break down and variation of the shape of this characteristic may serve as an indicator of homeostasis shift and can be used as a quantitative criterion for the latter. A new phenomenon, stable punctate

  15. Wide-band IR imaging in the NIR-MIR-FIR regions for in situ analysis of frescoes

    NASA Astrophysics Data System (ADS)

    Daffara, C.; Pezzati, L.; Ambrosini, D.; Paoletti, D.; Di Biase, R.; Mariotti, P. I.; Frosinini, C.

    2011-06-01

    Imaging methods offer several advantages in the field of conservation allowing to perform non-invasive inspection of works of art. In particular, non-invasive techniques based on imaging in different infrared (IR) regions are widely used for the investigation of paintings. Using radiation beyond the visible range, different characteristics of the inspected artwork may be revealed according to the bandwidth acquired. In this paper we present the recent results of a joint project among the two research institutes DIMEG and CNR-INO, and the restoration facility Opificio delle Pietre Dure, concerning the wide-band integration of IR imaging techniques, in the spectral ranges NIR 0.8-2.5 μm, MIR 3-5 μm, and FIR 8-12 μm, for in situ analysis of artworks. A joint, multi-mode use of reflection and thermal bands is proposed for the diagnostics of mural paintings, and it is demonstrated to be an effective tool in inspecting the layered structure. High resolution IR reflectography and, to a greater extent, IR imaging in the 3-5 μm band, are effectively used to characterize the superficial layer of the fresco and to analyze the stratigraphy of different pictorial layers. IR thermography in the 8-12 μm band is used to characterize the support deep structure. The integration of all the data provides a multi- layered and multi-spectral representation of the fresco that yields a comprehensive analysis.

  16. Method of spectral subtraction of gas-phase Fourier transform infrared (FT-IR) spectra by minimizing the spectrum length.

    PubMed

    Kozlov, Denis; Besov, Alexey

    2011-08-01

    A new method of spectral subtraction for gas-phase Fourier transform infrared (FT-IR) spectra was developed for long-path gas measurements. The method is based on minimization of the length of the spectrum that results from subtracting the spectrum of an individual component of a gas mixture (water, CO(2), etc.) from the experimental spectrum of the mixture. For this purpose a subtraction coefficient (k(min)) is found for which the length of the resulting spectrum is minimized. A mathematical simulation with two Lorentzian absorption bands was conducted and the limits of application for the proposed method were determined. Two experimental examples demonstrate that a successful result could be achieved in the case when the subtrahend spectrum contains a number of narrow absorption bands (such as the spectrum of water vapor). PMID:21819781

  17. Evaluation of the diagnostic power of thermography in breast cancer using Bayesian network classifiers.

    PubMed

    Nicandro, Cruz-Ramírez; Efrén, Mezura-Montes; María Yaneli, Ameca-Alducin; Enrique, Martín-Del-Campo-Mena; Héctor Gabriel, Acosta-Mesa; Nancy, Pérez-Castro; Alejandro, Guerra-Hernández; Guillermo de Jesús, Hoyos-Rivera; Rocío Erandi, Barrientos-Martínez

    2013-01-01

    Breast cancer is one of the leading causes of death among women worldwide. There are a number of techniques used for diagnosing this disease: mammography, ultrasound, and biopsy, among others. Each of these has well-known advantages and disadvantages. A relatively new method, based on the temperature a tumor may produce, has recently been explored: thermography. In this paper, we will evaluate the diagnostic power of thermography in breast cancer using Bayesian network classifiers. We will show how the information provided by the thermal image can be used in order to characterize patients suspected of having cancer. Our main contribution is the proposal of a score, based on the aforementioned information, that could help distinguish sick patients from healthy ones. Our main results suggest the potential of this technique in such a goal but also show its main limitations that have to be overcome to consider it as an effective diagnosis complementary tool. PMID:23762182

  18. Evaluation of the Diagnostic Power of Thermography in Breast Cancer Using Bayesian Network Classifiers

    PubMed Central

    Nicandro, Cruz-Ramírez; Efrén, Mezura-Montes; María Yaneli, Ameca-Alducin; Enrique, Martín-Del-Campo-Mena; Héctor Gabriel, Acosta-Mesa; Nancy, Pérez-Castro; Alejandro, Guerra-Hernández; Guillermo de Jesús, Hoyos-Rivera; Rocío Erandi, Barrientos-Martínez

    2013-01-01

    Breast cancer is one of the leading causes of death among women worldwide. There are a number of techniques used for diagnosing this disease: mammography, ultrasound, and biopsy, among others. Each of these has well-known advantages and disadvantages. A relatively new method, based on the temperature a tumor may produce, has recently been explored: thermography. In this paper, we will evaluate the diagnostic power of thermography in breast cancer using Bayesian network classifiers. We will show how the information provided by the thermal image can be used in order to characterize patients suspected of having cancer. Our main contribution is the proposal of a score, based on the aforementioned information, that could help distinguish sick patients from healthy ones. Our main results suggest the potential of this technique in such a goal but also show its main limitations that have to be overcome to consider it as an effective diagnosis complementary tool. PMID:23762182

  19. Field test of infrared thermography applied to biogas controlling in landfill sites

    NASA Astrophysics Data System (ADS)

    Madruga, Francisco J.; Muñoz, Jaime M.; González, Daniel A.; Tejero, Juan I.; Cobo, Adolfo; Gil, José L.; Conde, Olga M.; López-Higuera, Jose M.

    2007-04-01

    The gases accumulated inside the landfill as result of the fermentation of Municipal Solid Waste (MSW) known as biogas, are taking into consideration all possible uses as direct transformation into electricity. The system for collecting, regulating and controlling the biogas must include all the necessary safety features where the biogas leakage presents a high impact. Infrared thermography can be use to detect gas leakages due to the differences in temperature between the gas and the immediate surroundings. This method is able to monitor a wide area of landfill sites, quickly. This technology will not be effective if the differences in temperature are not better than five degrees. This paper describes a field test conducted to study the limitations of the infrared thermography caused by weather conditions and the moment of day or/and season when the thermal images was captured. Pipelines, borders, cells, covers, slopes and leakage (hot spots) are studied and optimum conditions are defined.

  20. Inspection of Impact Damage in Honeycomb Composite by Espi, Thermography and Ultrasonic Testing

    NASA Astrophysics Data System (ADS)

    Choi, Manyong; Park, Jeonghak; Kim, Wontae; Kang, Kisoo

    Honeycomb composites are now fairly widely used in civilian and military aircraft structures. Common defects found in these materials are delaminations by impact damage and their presence will lead to structural weaknesses which could lead failure of the airframe structures. It is important to develop effective non-destructive testing procedures to identify these defects and increase the safety of aircraft travel. This paper describes the detection technique of impact damage defect using thermography and ESPI. The results obtained with the two techniques are compared with ultrasonic C-scan testing. The investigation shows that both imaging NDT methods are able to identify the presence of artificial defect and impact damage. The adoption of the thermography allowed significant advantages in inspection condition, and gives smaller error in quantitative estimation of defects.

  1. Quantitative analysis of pulse thermography data for degradation assessment of historical buildings

    NASA Astrophysics Data System (ADS)

    Di Maio, Rosa; Piegari, Ester; Mancini, Cecilia; Chiapparino, Antonella

    2015-06-01

    In the last decades, infrared thermography has been successfully applied to various materials and structures for the assessment of their state of conservation and planning suitable restoration works. To this aim, mathematical models are required to characterize thermal anomaly sources, such as detachments, water infiltration and material decomposition processes. In this paper, an algorithm based on the conservative finite difference method is used to analyse pulse thermography data acquired on an ancient building in the Pompeii archaeological site (Naples, Italy). The numerical study is applied to both broad and narrow elongated thermal anomalies. In particular, from the comparison between simulated and experimental thermal decays, the plaster thickness was characterized in terms of thermal properties and areas of possible future detachments, and moisture infiltration depths were identified.

  2. Quantitative detection of defects based on Markov-PCA-BP algorithm using pulsed infrared thermography technology

    NASA Astrophysics Data System (ADS)

    Tang, Qingju; Dai, Jingmin; Liu, Junyan; Liu, Chunsheng; Liu, Yuanlin; Ren, Chunping

    2016-07-01

    Quantitative detection of debonding defects' diameter and depth in TBCs has been carried out using pulsed infrared thermography technology. By combining principal component analysis with neural network theory, the Markov-PCA-BP algorithm was proposed. The principle and realization process of the proposed algorithm was described. In the prediction model, the principal components which can reflect most characteristics of the thermal wave signal were set as the input, and the defect depth and diameter was set as the output. The experimental data from pulsed infrared thermography tests of TBCs with flat bottom hole defects was selected as the training and testing sample. Markov-PCA-BP predictive system was arrived, based on which both the defect depth and diameter were identified accurately, which proved the effectiveness of the proposed method for quantitative detection of debonding defects in TBCs.

  3. Transmission thermography for inspecting the busbar insulation layer in thermonuclear experimental reactor

    NASA Astrophysics Data System (ADS)

    Chen, Dapeng; Zhang, Guang; Zhang, Xiaolong; Zeng, Zhi

    2014-11-01

    In Thermonuclear Experimental Reactor, Superconducting Busbar is used for current transmission between magnet coils and current leads. The work temperature of the Busbar is about 4K because of liquid helium via inside. The large temperature grad from 300K to 4K could lead to the defects and damages occur on the insulation layer, which is made of glass fiber and polyimide and has a big different thermal expansion coefficient compared with the metal inner cylinder. This paper aims at developing an infrared transmission non-destructive evaluation (NDE) method for inspecting the insulation layer of Superconducting Busbar; theoretical model of transient heat conduction under a continuous inner heat source for cylindrical structure is described in the paper; a Busbar specimen which is designed with three delamination defects of different depths is heated inside by pouring hot water and monitored by an infrared detector located outside. Results demonstrate excellent detection performance for delamination defects in the insulation layer by using transmission thermography, all of the three defects of different depths can be visualized clearly in the thermal images, and the deeper defect has a better signal contrast, which is also shown in the temperature difference between defects and sound area vs. time curves. The results of light pulse thermography is also shown as a comparison, and it is found that the thermal images obtained by the transmission thermography has a much better signal contrast than that of the pulse thermography. In order to verify the experiments, finite element method is applied to simulate the heat conduction in the Busbar under the continuous inside heating, and it is found that the simulated temperature vs. time and simulated temperature difference vs. time curves are basically coincident with the experimental results. In addition, the possibility of in-service inspection for Busbar insulation layer in ITER item is discussed.

  4. Line scanning thermography for rapid nondestructive inspection of large scale composites

    SciTech Connect

    Chung, S.; Ley, O.; Godinez, V.; Bandos, B.

    2011-06-23

    As next generation structures are utilizing larger amounts of composite materials, a rigorous and reliable method is needed to inspect these structures in order to prevent catastrophic failure and extend service life. Current inspection methods, such as ultrasonic, generally require extended down time and man hours as they are typically carried out via point-by-point measurements. A novel Line Scanning Thermography (LST) System has been developed for the non-contact, large-scale field inspection of composite structures with faster scanning times than conventional thermography systems. LST is a patented dynamic thermography technique where the heat source and thermal camera move in tandem, which allows the continuous scan of long surfaces without the loss of resolution. The current system can inspect an area of 10 in{sup 2} per 1 second, and has a resolution of 0.05x0.03 in{sup 2}. Advanced data gathering protocols have been implemented for near-real time damage visualization and post-analysis algorithms for damage interpretation. The system has been used to successfully detect defects (delamination, dry areas) in fiber-reinforced composite sandwich panels for Navy applications, as well as impact damage in composite missile cases and armor ceramic panels.

  5. Active thermography for potato characterization

    NASA Astrophysics Data System (ADS)

    Hsieh, Sheng-Jen; Sun, Chih-Chen

    2008-03-01

    This paper describes the design of a semi-automated heating and scanning system and analytic method for potato characterization. Potatoes are heated using lamps in a heating chamber and then transferred on a movable fixture to an imaging chamber. A non-linear model was designed to predict which potatoes have excessive sugar defects and the model was evaluated with good results. Results from this research will benefit potato growers and manufacturers/producers of potato-based products such as chips and fries.

  6. Infrared Thermography for Temperature Measurement and Non-Destructive Testing

    PubMed Central

    Usamentiaga, Rubèn; Venegas, Pablo; Guerediaga, Jon; Vega, Laura; Molleda, Julio; Bulnes, Francisco G.

    2014-01-01

    The intensity of the infrared radiation emitted by objects is mainly a function of their temperature. In infrared thermography, this feature is used for multiple purposes: as a health indicator in medical applications, as a sign of malfunction in mechanical and electrical maintenance or as an indicator of heat loss in buildings. This paper presents a review of infrared thermography especially focused on two applications: temperature measurement and non-destructive testing, two of the main fields where infrared thermography-based sensors are used. A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented. Furthermore, developments in these fields and recent advances are reviewed. PMID:25014096

  7. Induction thermography for non-destructive evaluation of adhesive bonds

    NASA Astrophysics Data System (ADS)

    Balaji, L.; Balasubramaniam, Krishnan; Krishnamurthy, C. V.

    2013-01-01

    Adhesive bonding is widely used in automotive industry in the recent times. One of the major problems with adhesive bonds is the lack of a suitable non-destructive evaluation technique for assessing bonding. In this paper, an experimental study was carried out to apply induction thermography technique to evaluate adhesively bonded steel plates. Samples were fabricated with artificial defects such as air gap, foreign material, and improper adhesive filling. Induction thermography technique was found to detect defects and foreign inclusions. The sample specimen was also inspected using standard techniques such as Ultrasonic testing and Radiography testing. Defect detecting capabilities of the three techniques are compared. Induction thermography heating was FE modelled in 3D using COMSOL 3.5a. The simulated Induction thermography model was compared and validated with experimental results.

  8. Building thermography and energy performance directive of buildings

    NASA Astrophysics Data System (ADS)

    Kauppinen, Timo; Siikanen, Sami

    2012-06-01

    Energy Performance of Buildings Directive came in to the force in Europe couple of years ago and it had an immediate effect on Building Codes in Europe. Finland have changed its building codes since 2007 - the insulation requirements have been tightened and the requirements have been specified. The biggest change is energy efficient calculations and determination of energy efficiency and energy label for buildings. This has caused a boom of new service providers (thermography services, air-tightness measurements and other services like new calculation tools). Thermography is used in verification in performance of buildings. In this presentation some examples of building thermography in walk-through energy audits combined with the results of energy efficiency calculations are presented - also some special problems in buildings of specific use (e.g. an art museum) and use of thermography to solve them.

  9. Low-temperature infiltration identified using infrared thermography in patients with subcutaneous edema revealed ultrasonographically: A case report.

    PubMed

    Oya, Maiko; Takahashi, Toshiaki; Tanabe, Hidenori; Oe, Makoto; Murayama, Ryoko; Yabunaka, Koichi; Matsui, Yuko; Sanada, Hiromi

    2016-01-01

    Infiltration is a frequent complication of infusion therapy. We previously demonstrated the usefulness of infrared thermography as an objective method of detecting infiltration in healthy people. However, whether thermography can detect infiltration in clinical settings remains unknown. Therefore, we report two cases where thermography was useful in detecting infiltration at puncture sites. In both cases, tissue changes were verified ultrasonographically. The patients were a 56-year-old male with cholangitis and a 76-year-old female with hepatoma. In both cases, infiltration symptoms such as swelling and erythema occurred one day after the insertion of a peripheral intravenous catheter. Thermographic images from both patients revealed low-temperature areas spreading from the puncture sites; however, these changes were not observed in other patients. The temperature difference between the low-temperature areas and their surrounding skin surface exceeded 1.0°C. Concurrently, ultrasound images revealed that tissues surrounding the vein had a cobblestone appearance, indicating edema. In both patients, subcutaneous tissue changes suggested infiltration and both had low-temperature areas spreading from the puncture sites. Thus, subcutaneous edema may indicate infusion leakage, resulting in a decrease in the temperature of the associated skin surface. These cases suggest that infrared thermography is an effective method of objectively and noninvasively detecting infiltration. PMID:27210893

  10. Thermography in mass screening investigations of industrial workers

    NASA Astrophysics Data System (ADS)

    Chehter, A. I.; Ginsburg, L. I.; Traktinsky, A. G.

    1993-11-01

    The role of thermography in screening, directed to diagnose breast diseases, chronic tonsillitis, neurocirculatory dystonia, gall bladder dyskinesia, sinusitis, and to detect the character of influence of harmful factors on workers organisms is studied. The investigations demonstrate a possibility of a successful utilization of thermography in mass prophylactive examinations in order to diagnose these diseases, but the problem of breast tumors diagnostics demands the following investigations.

  11. Wavelet-based subsurface defect characterization in pulsed phase thermography for non-destructive evaluation

    NASA Astrophysics Data System (ADS)

    Zauner, G.; Mayr, G.; Hendorfer, G.

    2009-02-01

    Active infrared thermography is a method for non-destructive testing (NDT) of materials and components. In pulsed thermography (PT), a brief and high intensity flash is used to heat the sample. The decay of the sample surface temperature is detected and recorded by an infrared camera. Any subsurface anomaly (e.g. inclusion, delamination, etc.) gives rise to a local temperature increase (thermal contrast) on the sample surface. Conventionally, in Pulsed Phase Thermography (PPT) the analysis of PT time series is done by means of Discrete Fourier Transform producing phase images which can suppress unwanted physical effects (due to surface emissivity variations or non-uniform heating). The drawback of the Fourier-based approach is the loss of temporal information, making quantitative inversion procedures tricky (e.g. defect depth measurements). In this paper the complex Morlet-Wavelet transform is used to preserve the time information of the signal and thus provides information about the depth of a subsurface defect. Additionally, we propose to use the according phase contrast value to derive supplementary information about the thermal reflection properties at the defect interface. This provides additional information (e.g. about the thermal mismatch factor between the specimen and the defect) making interpretation of PPT results easier and perhaps unequivocal.

  12. Angular effects on thermochromic liquid crystal thermography

    NASA Astrophysics Data System (ADS)

    Kodzwa, Paul M.; Eaton, John K.

    2007-12-01

    This paper directly discusses the effects of lighting and viewing angles on liquid crystal thermography. This is because although thermochromic liquid crystals (TLCs) are a widely-used and accepted tool in heat transfer research, little effort has been directed to analytically describing these effects. Such insight is invaluable for the development of effective mitigation strategies. Using analytical relationships that describe the perceived color shift, a systematic manner of improving the performance of a TLC system is presented. This is particularly relevant for applications where significant variations in lighting and/or viewing angles are expected (such as a highly curved surface). This discussion includes an examination of the importance of the definition of the hue angle used to calibrate the color of a TLC-painted surface. The theoretical basis of the validated high-accuracy calibration approach reported by Kodzwa et al. (Exp Fluids s00348-007-0310-6, 2007) is presented.

  13. Defect characterization by inductive heated thermography

    NASA Astrophysics Data System (ADS)

    Noethen, Matthias; Meyendorf, Norbert

    2012-05-01

    During inductive-thermographic inspection, an eddy current of high intensity is induced into the inspected material and the thermal response is detected by an infrared camera. Anomalies in the surface temperature during and after inductive heating correspond to inhomogeneities in the material. A finite element simulation of the surface crack detection process using active thermography with inductive heating has been developed. The simulation model is based on the finite element software ANSYS. The simulation tool was tested and used for investigations on steel components with different longitudinal orientated cracks, varying in shape, width and height. This paper focuses on surface connected longitudinal orientated cracks in austenitic steel. The results show that depending on the excitation frequency the temperature distribution of the material under test are different and a possible way to measure the depth of the crack will be discussed.

  14. Non Destructive Testing by active infrared thermography coupled with shearography under same optical heat excitation

    NASA Astrophysics Data System (ADS)

    Theroux, Louis-Daniel; Dumoulin, Jean; Maldague, Xavier

    2014-05-01

    As infrastructures are aging, the evaluation of their health is becoming crucial. To do so, numerous Non Destructive Testing (NDT) methods are available. Among them, thermal shearography and active infrared thermography represent two full field and contactless methods for surface inspection. The synchronized use of both methods presents multiples advantages. Most importantly, both NDT are based on different material properties. Thermography depend on the thermal properties and shearography on the mechanical properties. The cross-correlation of both methods result in a more accurate and exact detection of the defects. For real site application, the simultaneous use of both methods is simplified due to the fact that the excitation method (thermal) is the same. Active infrared thermography is the measure of the temperature by an infrared camera of a surface subjected to heat flux. Observation of the variation of temperature in function of time reveal the presence of defects. On the other hand, shearography is a measure of out-of-plane surface displacement. This displacement is caused by the application of a strain on the surface which (in our case) take the form of a temperature gradient inducing a thermal stress To measure the resulting out-of-plane displacement, shearography exploit the relation between the phase difference and the optical path length. The phase difference is measured by the observation of the interference between two coherent light beam projected on the surface. This interference is due to change in optical path length as the surface is deformed [1]. A series of experimentation have been conducted in laboratory with various sample of concrete reinforced with CFRP materials. Results obtained reveal that with both methods it was possible to detect defects in the gluing. An infrared lamp radiating was used as the active heat source. This is necessary if measurements with shearography are to be made during the heating process. A heating lamp in the

  15. Service and maintenance damage assessment of composite structures using various modes of infrared thermography

    NASA Astrophysics Data System (ADS)

    Grammatikos, S. A.; Kordatos, E. Z.; Matikas, T. E.; Paipetis, A. S.

    2015-02-01

    Carbon Fibre Reinforced Polymers (CFRPs) have been widely used recently in aerospace technology as primary materials. During aircraft operation the combination of thermo-mechanical loads, gradually degrades the material properties. Therefore, the development of reliable and cost effective damage inspection protocols throughout the service life of these structures is of primary importance for their safe function. Within the scope of this study, Infrared Thermography (IrT) was employed with the aim of assessing the structural integrity of composite aero-structures in both maintenance (off-line) and service (on-line) conditions. In the maintenance concept, IrT was employed in Lock-in mode to evaluate artificially induced damage in bonded repaired materials. For this purpose, various configurations of damage were investigated. In the service concept, IrT was employed for the continuous monitoring of loaded repaired structures in order to assess in real-time any progressive evolution of de-bonding which could lead to failure of the bonded patch repair. The experimental results provided evidence that IrT is capable of qualitative and quantitative field assessment of aero-structures.

  16. Quantitative estimation of ultrasound beam intensities using infrared thermography-Experimental validation.

    PubMed

    Giridhar, Dushyanth; Robinson, Ronald A; Liu, Yunbo; Sliwa, Jack; Zderic, Vesna; Myers, Matthew R

    2012-06-01

    Infrared (IR) thermography is a technique that has the potential to rapidly and noninvasively determine the intensity fields of ultrasound transducers. In the work described here, IR temperature measurements were made in a tissue phantom sonicated with a high-intensity focused ultrasound (HIFU) transducer, and the intensity fields were determined using a previously published mathematical formulation relating intensity to temperature rise at a tissue/air interface. Intensity fields determined from the IR technique were compared with those derived from hydrophone measurements. Focal intensities and beam widths determined via the IR approach agreed with values derived from hydrophone measurements to within a relative difference of less than 10%, for a transducer with a gain of 30, and about 13% for a transducer with a gain of 60. At axial locations roughly 1 cm in front (pre-focal) and behind (post-focal) the focus, the agreement with hydrophones for the lower-gain transducer remained comparable to that in the focal plane. For the higher-gain transducer, the agreement with hydrophones at the pre-focal and post-focal locations was around 40%. PMID:22712903

  17. Optically and non-optically excited thermography for composites: A review

    NASA Astrophysics Data System (ADS)

    Yang, Ruizhen; He, Yunze

    2016-03-01

    Composites, such as glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP), and adhesive bonding are being increasingly used in fields of aerospace, renewable energy, civil and architecture, and other industries. Flaws and damages are inevitable during either fabrication or lifetime of composites structures or components. Thus, nondestructive testing (NDT) are extremely required to prevent failures and to increase reliability of composite structures or components in both manufacture and in-service inspection. Infrared thermography techniques including pulsed thermography, pulsed phase thermography, and lock-in thermography have shown the great potential and advantages. Besides conventional optical thermography, other sources such as laser, eddy current, microwave, and ultrasound excited thermography are drawing increasingly attentions for composites. In this work, a fully, in-depth and comprehensive review of thermography NDT techniques for composites inspection was conducted based on an orderly and concise literature survey and detailed analysis. Firstly, basic concepts for thermography NDT were defined and introduced, such as volume heating thermography. Next, the developments of conventional optic, laser, eddy current, microwave, and ultrasound thermography for composite inspection were reviewed. Then, some case studies for scanning thermography were also reviewed. After that, the strengths and limitations of thermography techniques were concluded through comparison studies. At last, some research trends were predicted. This work containing critical overview, detailed comparison and extensive list of references will disseminates knowledge between users, manufacturers, designers and researchers involved in composite structures or components inspection by means of thermography NDT techniques.

  18. A New Method for Detecting Sea Fog Using COMS IR Channels along with OSTIA SST

    NASA Astrophysics Data System (ADS)

    Shin, D.; Park, H.; Kim, J. H.

    2013-12-01

    Sea fog detection with satellite at night time has been used the dual channel difference method based on Brightness Temperature Difference between 3.7μm and 11μm channel (BTD). However, this method cannot distinguish between fog and low cloud well, and sometimes misjudges high cloud as fog. This study suggests a new method by combining surface temperature difference between sea surface and cloud top surface (STD) threshold values in conjunction with BTD to overcome these problems. Based on the fact that the difference between sea surface and fog top temperature is relatively smaller than that between sea surface and any type of cloud top temperature, our proposed method is to discriminate between sea fog and clouds. In order to find the appropriate threshold values for STD and BTD, Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) SST was used for sea surface temperature under the clouds and Communication, Ocean and Meteorological Satellite (COMS) were used to determine surface brightness temperature for clear and cloudy conditions. The monthly varying BTD and STD threshold values are determined by analysing scatter density plot between them for May to July when the most fog occurs around the Korea Peninsula. The determined STD threshold values for nighttime fog are 5.03 K, 3.17 K, 4.10 K and BTD values are -1.38 K, -1.10 K, -0.54 K corresponding to May-July, respectively. To validate this method, CALIPSO Lidar profile data was used for various cases. Our suggested method that combines BTD with STD shows considerable improvement for detecting sea fog over BTD-only method.

  19. IR laser welding of thin polymer films as a fabrication method for polymer MEMS

    NASA Astrophysics Data System (ADS)

    Beck, William A.; Huang, Michelle; Ketterl, Joe; Hughes, Thayer

    2003-09-01

    MEMS (Micro Electro-Mechanical Systems) continue to be something of a solution looking for a problem. Even as the glamour has moved on to the smaller realm of nano technologies and devices, progress continues towards making micro-scale devices more useful and manufacturable. One avenue this work is taking is into the realm of polymer MEMS, shifting from the expensive, complicated methods of semiconductor processing to the much simpler methods of plastics processing. Polymeric materials are rugged, lightweight and low cost, and their use in manufacturing has a long history. While many bulk polymer manufacturing processes such as molding, machining and adhesive bonding are adaptable to the micro realm, their use in MEMS devices often requires development of specialized processing methods. Here we report on development of laser welding as a bonding method for thin polymer films, including automation of the welding process, steps towards standardization of that process, preparation of standardized test samples, and development of specialized test methods used to evaluate the strength of polymer welds. Our initial results show a direct correlation between welding parameters and weld strengths.

  20. Detection Method of Skin Region by Near-IR Spectrum Multi-Band

    NASA Astrophysics Data System (ADS)

    Suzuki, Yasuhiro; Yamamoto, Kazuhiko; Kato, Kunihito; Andoh, Michinori; Kojima, Shinichi

    Many active safety technologies for the driver support system are developing. Most of the traffic accidents are caused by driver's inattentive or drowsy. We are developing a driver support system that protects from traffic accidents by these causes. Our purpose is to detect the driver's face region by using a camera. A lot of face detection methods are proposed, but there is not a technique addressing every environment inside the car. For example, skin color segmentation can not detect the skin region in the night, because it has to light up the driver by bright light. In this paper, we propose a skin detection method by the unique reflection characteristics of the materials. Our method is very simple algorithm. We developed a skin detection system, and confirmed effectiveness by the evaluation experiment in indoor environment, and showed the effectiveness by a driving experiment in the night.

  1. Identification of thermal properties distribution in building wall using infrared thermography

    NASA Astrophysics Data System (ADS)

    Brouns, Jordan; Dumoulin, Jean

    2016-04-01

    In the construction sector, most of the measurements carried out from IR camera devices are exploited in a qualitative way (e.g. observation of thermal bridges). However, unless a quantitative analysis is realized, it is not possible to assess the impact of the observed phenomena. Most of research efforts and proposed solutions to identify quantified thermal properties (e.g. U-values) have to be completed, adapted to the built environment and validated in experimental and real conditions to allow quantified assessment of materials thermal properties thanks to IR camera devices [1]. We still need several steps in terms of scientific and technical developments for such technological progress. The H2020 European Built2Spec research project (http://built2spec-project.eu/) aims at giving highlights on that. Heat transfer through the walls are generally model by 1D heat equation in the wall depth. The built is composed by a multilayer domain representing the construction process. In this context, the thermal parameters of the wall are piecewise constant space functions. We propose a methodology to recover the vector of the wall thermal properties (conductivity and capacity) from boundary measurements obtained from an IR camera. It formulates as an inverse problem where the unknown are sought as minimizers of a cost function evaluating the gap between the measures and the model response. This optimization problem is non linear, and we solve it with the Levenberg-Marquardt algorithm coupled with the conjugate gradient method [2-3]. To shorten the time of the identification process, we use the adjoint method coming from the control theory [4]. This method fasten the gradient computation by solving an associated model, named the adjoint model. We study the ability of the procedure to reconstruct internal wall constitution from different environmental conditions. Furthermore, we propose a controlled experimental test to evaluate the method in laboratory conditions. References

  2. Modeling the IR Spectra of Acetaldehyde from a New Vibrational Configuration Interaction Method

    SciTech Connect

    Begue, Didier; Pouchan, Claude

    2007-12-26

    In this paper we present a new vibrational configuration interaction method known as a parallel vibrational multiple window configuration interaction P lowbar VMWCI which generates several VCI matrices and enables the variational treatment of medium size molecular systems. Application to acetaldehyde gives a new interpretation of the MIR experimental data.

  3. Improving spatial resolution in skin-contact thermography: comparison between a spline based and linear interpolation.

    PubMed

    Giansanti, Daniele

    2008-07-01

    A wearable device for skin-contact thermography [Giansanti D, Maccioni G. Development and testing of a wearable integrated thermometer sensor for skin contact thermography. Med Eng Phys 2006 [ahead of print

  4. Time-Resolved O3 Chemical Chain Reaction Kinetics Via High-Resolution IR Laser Absorption Methods

    NASA Technical Reports Server (NTRS)

    Kulcke, Axel; Blackmon, Brad; Chapman, William B.; Kim, In Koo; Nesbitt, David J.

    1998-01-01

    Excimer laser photolysis in combination with time-resolved IR laser absorption detection of OH radicals has been used to study O3/OH(v = 0)/HO2 chain reaction kinetics at 298 K, (i.e.,(k(sub 1) is OH + 03 yields H02 + 02 and (k(sub 2) is H02 + 03 yields OH + 202). From time-resolved detection of OH radicals with high-resolution near IR laser absorption methods, the chain induction kinetics have been measured at up to an order of magnitude higher ozone concentrations ([03] less than or equal to 10(exp 17) molecules/cu cm) than accessible in previous studies. This greater dynamic range permits the full evolution of the chain induction, propagation, and termination process to be temporally isolated and measured in real time. An exact solution for time-dependent OH evolution under pseudo- first-order chain reaction conditions is presented, which correctly predicts new kinetic signatures not included in previous OH + 03 kinetic analyses. Specifically, the solutions predict an initial exponential loss (chain "induction") of the OH radical to a steady-state level ([OH](sub ss)), with this fast initial decay determined by the sum of both chain rate constants, k(sub ind) = k(sub 1) + k(sub 2). By monitoring the chain induction feature, this sum of the rate constants is determined to be k(sub ind) = 8.4(8) x 10(exp -14) cu cm/molecule/s for room temperature reagents. This is significantly higher than the values currently recommended for use in atmospheric models, but in excellent agreement with previous results from Ravishankara et al.

  5. Glued structures inspection based on lock-in thermography

    NASA Astrophysics Data System (ADS)

    Perez, Laetitia; Autrique, Laurent

    2015-04-01

    Active thermography is a widely employed technique for parametric identification and non-destructive inspection. This attractive method is based on the observation of thermal waves propagation induced by a periodic heating. For nondestructive testing usual approaches are based on a global heating (a large surface of the inspected material is submitted to thermal excitation). In the following a local approach is investigated: the heated area is small (order of magnitude is one square centimeter) and lateral propagation is studied in order to reveal the defect in the sample. In fact, both modulus (heat wave amplitude) and phase lag (delay) of the measured periodic signal are modified by the defect neighborhood and the search for the most effective area leads to the defect localization. Several results are highlighted in this communication in order to investigate an automated procedure. Temperatures are measured by an infrared camera and analyses of modulus cartography are performed in order to estimate the defect location. In such an aim, the downhill simplex method is implemented in order to converge toward defect location. Illustrations are dedicated to glued structures (two plates separated by a thin glue interface) for which unknown defect is a lack of glue which can be considered as a bubble (air trapped between the lower and the upper plane surface). Automated method attractiveness is established in several configurations.

  6. Evaluation of allergic response using dynamic thermography

    NASA Astrophysics Data System (ADS)

    Rokita, E.; Rok, T.; Tatoń, G.

    2015-03-01

    Skin dynamic termography supplemented by a mathematical model is presented as an objective and sensitive indicator of the skin prick test result. Termographic measurements were performed simultaneously with routine skin prick tests. The IR images were acquired every 70 s up to 910 s after skin prick. In the model histamine is treated as the principal mediator of the allergic reaction. Histamine produces vasolidation and the engorged vessels are responsible for an increase in skin temperature. The model parameters were determined by fitting the analytical solutions to the spatio-temporal distributions of the differences between measured and baseline temperatures. The model reproduces experimental data very well (coefficient of determination = 0.805÷0.995). The method offers a set of parameters to describe separately skin allergic reaction and skin reactivity. The release of histamine after allergen injection is the best indicator of allergic response. The diagnostic parameter better correlates with the standard evaluation of a skin prick test (correlation coefficient = 0.98) than the result of the thermographic planimetric method based on temperature and heated area determination (0.81). The high sensitivity of the method allows for determination of the allergic response in patients with the reduced skin reactivity.

  7. Characterization of pores in high pressure die cast aluminum using active thermography and computed tomography

    NASA Astrophysics Data System (ADS)

    Maierhofer, Christiane; Myrach, Philipp; Röllig, Mathias; Jonietz, Florian; Illerhaus, Bernhard; Meinel, Dietmar; Richter, Uwe; Miksche, Ronald

    2016-02-01

    Larger high pressure die castings (HPDC) and decreasing wall thicknesses are raising the issue of casting defects like pores in aluminum structures. Properties of components are often strongly influenced by inner porosity. As these products are being established more and more in lightweight construction (e.g. automotive and other transport areas), non-destructive testing methods, which can be applied fast and on-site, are required for quality assurance. In this contribution, the application of active thermography for the direct detection of larger pores is demonstrated. The analysis of limits and accuracy of the method are completed by numerical simulation and the method is validated using computed tomography.

  8. Photothermal Thermography Applied to the Non-destructive Testing of Different Types of Works of Art

    NASA Astrophysics Data System (ADS)

    Bodnar, J. L.; Mouhoubi, K.; Szatanik-Perrier, G.; Vallet, J. M.; Detalle, V.

    2012-11-01

    In this article, various cases in helping to restore works of art by stimulated infrared thermography are presented. First, the method allows detecting old restorations found on a mural painting in the French senate. Then, it is demonstrated how the photothermal method enables determination of the underlying structure of the mural painting "The Apotheosis of Saint Bruno" in the Charterhouse of Villeneuve-lez-Avignon. Finally, the method allows locating separate canvas paintings on "Avenant de l'aurore" in the "Luxembourg" French Senate building.

  9. Correlation Study Of Diffenrential Skin Temperatures (DST) For Ovulation Detection Using Infra-Red Thermography

    NASA Astrophysics Data System (ADS)

    Rao, K. H. S.; Shah, A. v.; Ruedi, B.

    1982-11-01

    The importance of ovulation time detection in the Practice of Natural Birth Control (NBC) as a contraceptive tool, and for natural/artificial insemination among women having the problem of in-fertility, is well known. The simple Basal Body Temperature (BBT) method of ovulation detection is so far unreliable. A newly proposed Differential Skin Temperature (DST) method may help minimize disturbing physiological effects and improve reliability. This paper explains preliminary results of a detailed correlative study on the DST method, using Infra-Red Thermography (IRT) imaging, and computer analysis techniques. Results obtained with five healthy, normally menstruating women volunteers will be given.

  10. Using infrared thermography to evaluate the injuries of cold-stored guava.

    PubMed

    Gonçalves, Bárbara Jordana; Giarola, Tales Márcio de Oliveira; Pereira, Daniele Fernanda; Vilas Boas, Eduardo Valério de Barros; de Resende, Jaime Vilela

    2016-02-01

    This study aimed to identify using the infrared (IR) thermography data the injuries of guavas during cooling and storage at different temperatures. Three experiments were performed at three different temperatures with one storage time. The first experiment was done with static air in a refrigerator at 5 °C, the second experiment was conducted in a tunnel with forced air at 10 °C, and the third experiment was conducted in an air conditioned environment at 20 °C. Mechanical injuries caused by the impact of a pendulum were induced on guava surfaces. The surface temperatures were obtained for bruised and sound tissues during cooling and storage using an Infrared (IR) camera. With thermography, it was possible to distinguish the injured tissues of the fruits that were unaffected at temperatures of 5, 10 and 20 °C in first hours of cooling. The results suggest that the storage of guava fruits at 5 °C in static air resulted in cold-induced injury, while storage at 20 °C resulted in an altered activity pattern. The stored guava fruits were analyzed for mass loss, firmness, color, total sugars, total pectin and solubility. The parameters values were lower during the forced-air cooling and storage at 5 and 10 °C. When stored at 20 °C, there was fruit maturation that caused tissue softening, which makes the fruits more susceptible to deterioration and thermographic readings showed opposite trends. PMID:27162386

  11. Use of modern infrared thermography for wildlife population surveys

    NASA Astrophysics Data System (ADS)

    Garner, Dale L.; Underwood, H. Brian; Porter, William F.

    1995-03-01

    A commercially available thermal-infrared scanning system was used to survey populations of several wildlife species. The system's ability to detect species of different sizes in varying habitats relative to conventional survey methods, to differentiate between species in the same habitat, and the influence of environtmental factors on operational aspects of employing this technology in the field were evaluated. Total costs for the surveys were approximately 0.36/ha. There were marked discrepancies in the counts of untrained observers and those from trained analysis. Computer-assisted analysis of infrared imagery recorded 52% fewer deer than were estimated from drive counts, and densities of moose were five times those estimated from conventional aerial methods. By flying concentric circles and using telephoto, detailed counts of turkeys and deer were possible. With the aid of computer-assisted analysis, infrared thermography may become a useful wildlife population survey tool. More research is needed to verify the actual efficiency of detection by combining aerial scans with ground truthing for a variely of species and habitals.

  12. Automated diagnosis of dry eye using infrared thermography images

    NASA Astrophysics Data System (ADS)

    Acharya, U. Rajendra; Tan, Jen Hong; Koh, Joel E. W.; Sudarshan, Vidya K.; Yeo, Sharon; Too, Cheah Loon; Chua, Chua Kuang; Ng, E. Y. K.; Tong, Louis

    2015-07-01

    Dry Eye (DE) is a condition of either decreased tear production or increased tear film evaporation. Prolonged DE damages the cornea causing the corneal scarring, thinning and perforation. There is no single uniform diagnosis test available to date; combinations of diagnostic tests are to be performed to diagnose DE. The current diagnostic methods available are subjective, uncomfortable and invasive. Hence in this paper, we have developed an efficient, fast and non-invasive technique for the automated identification of normal and DE classes using infrared thermography images. The features are extracted from nonlinear method called Higher Order Spectra (HOS). Features are ranked using t-test ranking strategy. These ranked features are fed to various classifiers namely, K-Nearest Neighbor (KNN), Nave Bayesian Classifier (NBC), Decision Tree (DT), Probabilistic Neural Network (PNN), and Support Vector Machine (SVM) to select the best classifier using minimum number of features. Our proposed system is able to identify the DE and normal classes automatically with classification accuracy of 99.8%, sensitivity of 99.8%, and specificity if 99.8% for left eye using PNN and KNN classifiers. And we have reported classification accuracy of 99.8%, sensitivity of 99.9%, and specificity if 99.4% for right eye using SVM classifier with polynomial order 2 kernel.

  13. On Field Inspection of Composite Pipes Using Pulsed Phase Thermography

    NASA Astrophysics Data System (ADS)

    Souza, M. P. V.; Almeida, R. M.; Rebello, J. M. A.; Soares, S. D.

    2010-02-01

    The pulsed phase thermography (PPT) is becoming a valuable tool on the detection and dimensioning of defects on composite materials. However, the most of the works that adopt the PPT needs very sophisticated equipment to thermal excitation of the specimen and data acquisition. This work uses the concepts of the PPT to inspect sections of fiberglass reinforced epoxy pipes used on adhesively bonded joints applied on the oil industry on extraction and transportation of fluids, using low cost and simple equipment to thermal excitation. A MatLab routine to data processing was used intending to achieve a fast and reliable non-destructive method to be performed on field. Amplitude and phase images are generated from the infrared images without any pre-processing technique revealing simulated defects that were impossible to be detected on the original data. A study of how deep the thermal wave can reach along the thickness of this kind of material is also performed trying to estipulate the limits of the technique aiming on the detection of problems on adhesive layers using two heat sources: halogen lamp and industrial air blower. Results support the possibility of implementing a reliable and low cost method of inspection on field to various values of pipe thicknesses found on plants of the oil industry.

  14. Aerial Thermography - Cartographic Presentation Of Thermographic Data For Building Applications

    NASA Astrophysics Data System (ADS)

    Ljungberg, Sven-Ake

    1989-03-01

    When using aerial thermography to indicate energy-related conditions of buildings in a large investigation area the question arises how to store and present the final product of classified, energy-related data. A full scale study of 7000 buildings demonstrated the need fur computerbased systems and cartographic methods to store, to arrange and to illustrate thermograpic data. A data base was created including aerial thermograpic data, technical data on the buildings and information on energy consumption of each building. The data base consisted of 100 variables. The key-code for the data base was the real estate name and number. The position of each building was given in terms of coordinates of the real estate. The main purpose of the study was to create an energy-related data base to be used for assigning a priority to measurements within the local energy conservation program. The thermographic data was collected with a longwave airborne infrared line-scanner (3-14 um). The technical data on the buildings and their energy consumption were gathered from existing data bases and from field investigations. Thermograpic data, technical data of the buildings and information on energy consumption was classified and different symbols were used to identify the classes presented on thematic maps. Results from this study implies that computerbased cartography is a favorable method to present and illustrate thermographic information on buildings in large investigation areas. The paper deals mainly with the aspect of carthography for presentation of thermographic and energy-related data.

  15. Breast cancer detection in rotational thermography images using texture features

    NASA Astrophysics Data System (ADS)

    Francis, Sheeja V.; Sasikala, M.; Bhavani Bharathi, G.; Jaipurkar, Sandeep D.

    2014-11-01

    Breast cancer is a major cause of mortality in young women in the developing countries. Early diagnosis is the key to improve survival rate in cancer patients. Breast thermography is a diagnostic procedure that non-invasively images the infrared emissions from breast surface to aid in the early detection of breast cancer. Due to limitations in imaging protocol, abnormality detection by conventional breast thermography, is often a challenging task. Rotational thermography is a novel technique developed in order to overcome the limitations of conventional breast thermography. This paper evaluates this technique's potential for automatic detection of breast abnormality, from the perspective of cold challenge. Texture features are extracted in the spatial domain, from rotational thermogram series, prior to and post the application of cold challenge. These features are fed to a support vector machine for automatic classification of normal and malignant breasts, resulting in a classification accuracy of 83.3%. Feature reduction has been performed by principal component analysis. As a novel attempt, the ability of this technique to locate the abnormality has been studied. The results of the study indicate that rotational thermography holds great potential as a screening tool for breast cancer detection.

  16. Physical interpretation and separation of eddy current pulsed thermography

    NASA Astrophysics Data System (ADS)

    Yin, Aijun; Gao, Bin; Yun Tian, Gui; Woo, W. L.; Li, Kongjing

    2013-02-01

    Eddy current pulsed thermography (ECPT) applies induction heating and a thermal camera for non-destructive testing and evaluation (NDT&E). Because of the variation in resultant surface heat distribution, the physical mechanism that corresponds to the general behavior of ECPT can be divided into an accumulation of Joule heating via eddy current and heat diffusion. However, throughout the literature, the heating mechanisms of ECPT are not given in detail in the above two thermal phenomena and they are difficult to be separated. Nevertheless, once these two physical parameters are separated, they can be directly used to detect anomalies and predict the variation in material properties such as electrical conductivity, magnetic permeability and microstructure. This paper reports physical interpretation of these two physical phenomena that can be found in different time responses given the ECPT image sequences. Based on the phenomenon and their behaviors, the paper proposes a statistical method based on single channel blind source separation to decompose the two physical phenomena using different stages of eddy current and thermal propagation from the ECPT images. Links between mathematical models and physical models have been discussed and verified. This fundamental understanding of transient eddy current distribution and heating propagation can be applied to the development of feature extraction and pattern recognition for the quantitative analysis of ECPT measurement images and defect characterization.

  17. Mechanisms and Models for Crack Detection with Induction Thermography

    NASA Astrophysics Data System (ADS)

    Vrana, J.; Goldammer, M.; Baumann, J.; Rothenfusser, M.; Arnold, W.

    2008-02-01

    Induction thermography is a non-contacting, non-destructive evaluation method with a wide range of applications. A deeper understanding of the detectability of cracks requires fundamental knowledge about the induced current density distribution in the component under test. A calculation of the current distribution provides information how much current is flowing at which location of the component, how a crack disturbs the current density, how much heat is produced at which location of the component, and how the heat diffuses to the surface. The heating process depends on the type of crack. On the one hand there are cracks which can be detected mainly by direct observation of the heating process due to an increased current density, and on the other hand there are cracks which can be detected mainly because of a modification of the heat diffusion. This paper presents an analytical model for the calculation of the current distribution, including the back-flow current along with finite-element calculations. Furthermore, two new crack models are presented for a better description of real cracks.

  18. Medical applications of infrared thermography: A review

    NASA Astrophysics Data System (ADS)

    Lahiri, B. B.; Bagavathiappan, S.; Jayakumar, T.; Philip, John

    2012-07-01

    Abnormal body temperature is a natural indicator of illness. Infrared thermography (IRT) is a fast, passive, non-contact and non-invasive alternative to conventional clinical thermometers for monitoring body temperature. Besides, IRT can also map body surface temperature remotely. Last five decades witnessed a steady increase in the utility of thermal imaging cameras to obtain correlations between the thermal physiology and skin temperature. IRT has been successfully used in diagnosis of breast cancer, diabetes neuropathy and peripheral vascular disorders. It has also been used to detect problems associated with gynecology, kidney transplantation, dermatology, heart, neonatal physiology, fever screening and brain imaging. With the advent of modern infrared cameras, data acquisition and processing techniques, it is now possible to have real time high resolution thermographic images, which is likely to surge further research in this field. The present efforts are focused on automatic analysis of temperature distribution of regions of interest and their statistical analysis for detection of abnormalities. This critical review focuses on advances in the area of medical IRT. The basics of IRT, essential theoretical background, the procedures adopted for various measurements and applications of IRT in various medical fields are discussed in this review. Besides background information is provided for beginners for better understanding of the subject.

  19. Hidden heterogeneous materials recognition in pulsed thermography

    NASA Astrophysics Data System (ADS)

    Zeng, Zhi; Tao, Ning; Feng, Lichun; Li, Yue; Zhang, Cunlin

    2012-05-01

    Pulsed thermography has been proven to effectively identify fluid ingress in aerospace honeycomb parts while inspecting large areas in a fast manner. Water, hydraulic oil and excess glue between skin and core may have similar appearance in the infrared image sequences, it is useful to detect what kind of ingress it is. In this study, a simple structure was used to simulate the fluid ingress in a honeycomb part, a 20mm thick steel slab was machined four 1.1mm depth and four 2mm depth circular flat-bottom holes with 20mm diameter at the same side. All holes were filled with different materials: water, oil, air and wax to simulate fluid ingress and excess glue. An algorithm was proposed to first find each hole based on fundamental imaging processing technologies, and then it is based on temporal thermal diffusive properties to automatically recognize what kind of fluid ingress it is in each hole. It was verified with the experimental results of different quantities of fluid ingress and several different flash power levels.

  20. Infrared thermography for condition monitoring - A review

    NASA Astrophysics Data System (ADS)

    Bagavathiappan, S.; Lahiri, B. B.; Saravanan, T.; Philip, John; Jayakumar, T.

    2013-09-01

    Temperature is one of the most common indicators of the structural health of equipment and components. Faulty machineries, corroded electrical connections, damaged material components, etc., can cause abnormal temperature distribution. By now, infrared thermography (IRT) has become a matured and widely accepted condition monitoring tool where the temperature is measured in real time in a non-contact manner. IRT enables early detection of equipment flaws and faulty industrial processes under operating condition thereby, reducing system down time, catastrophic breakdown and maintenance cost. Last three decades witnessed a steady growth in the use of IRT as a condition monitoring technique in civil structures, electrical installations, machineries and equipment, material deformation under various loading conditions, corrosion damages and welding processes. IRT has also found its application in nuclear, aerospace, food, paper, wood and plastic industries. With the advent of newer generations of infrared camera, IRT is becoming a more accurate, reliable and cost effective technique. This review focuses on the advances of IRT as a non-contact and non-invasive condition monitoring tool for machineries, equipment and processes. Various conditions monitoring applications are discussed in details, along with some basics of IRT, experimental procedures and data analysis techniques. Sufficient background information is also provided for the beginners and non-experts for easy understanding of the subject.

  1. Transient infrared thermography for damage evaluation in aerospace composites

    NASA Astrophysics Data System (ADS)

    Pawar, S.; Peters, K.

    2010-04-01

    In this paper we investigate the performance of defect detection using long duration transient thermography for woven composite laminates subjected to low-velocity impacts. Two types of defects are studied: inclusions represented by foam tabs inserted into the laminate during fabrication and barely visible impact damage due to low-velocity impacts. These defects represent the expected damage states that are necessary for inspection during the service life of a woven composite aircraft component. The long duration transient thermography is demonstrated to successfully detect the embedded inclusions, with a dimension to depth ratio detection capability of approximately 3. It is also demonstrated that the detection of low velocity impact damage with the transient thermography is less successful due to uneven emissivity of the surface. Therefore, processing of the image using a self referencing algorithm is performed which improves the damage detection clarity.

  2. Evaluation of IR technology applied to cooling tower performance

    NASA Astrophysics Data System (ADS)

    MacNamara, Neal A.; Zayicek, Paul A.

    1999-03-01

    Infrared thermography (IR) is widely used by electric utilities as an integral part of their predictive maintenance program. IR is utilized for inspection of a variety of plant mechanical and electrical components. Additionally, IR can be used to provide thermal performance information for other key plant systems, including assessment of cooling towers. Cooling tower performance directly affects availability and heat rate in fossil and nuclear power plants. Optimal tower performance contributes to efficient turbine operation and maximum power output. It is estimated that up to half of the cooling towers installed have failed to meet their design performance specifications. As a result, any additional degradation of tower performance resulting from fouling, valve degradation, unbalanced flow, or a poor maintenance practice has a direct effect on generation output. We have collected infrared thermography images of mechanical draft cooling towers, as part of Evaluation of IR Technology Applied to Cooling Tower Performance. IR images have been analyzed to provide information regarding general performance conditions and identification of operational deficiencies related to thermal performance. Similarly, IR can be implemented for monitoring of tower flow balance activities and for post-maintenance surveillance. To date, IR images have been used to identify areas of general flow imbalance, flooding or limited flow in individual cells, missing or broken tower fill material, fan performance and other problems related to maintenance or operational issues. Additionally, an attempt is being made to use quantitative thermal data, provided by the IR image analysis software, in conjunction with condenser input/output site ambient information, to evaluate and compare individual tower cell performance.

  3. Studies of the degradation mechanisms in high-power diode lasers using multi-channel micro-thermography

    NASA Astrophysics Data System (ADS)

    Kozłowska, Anna; Tomm, Jens W.; Wawrzyniak, Piotr; Maląg, Andrzej; Weik, Fritz; Latoszek, Mateusz

    2005-09-01

    We demonstrate the applicability of imaging thermography for investigations of mechanisms associated with gradual degradation in diode lasers. The introduction of two spectral channels provides the means for separate observation of deep level luminescence and thermal radiation emitted according to Planck's law. In the near IR region we found the signal detected by the camera to be mainly affected by mid-gap deep-level luminescence. An intensity increase of the luminescence signal for an aged diode laser compared to an unaged device is noticed. It can be explained by an increase of deep level defect concentration during the aging. In the mid IR, we mainly encounter thermal radiation, which can be used for the analysis of the thermal properties of devices. In present work the thermal behavior of the device subjected to an aging of 3000 hours is analyzed. A significant increase of device temperature is noticed.

  4. Computer Assisted Thermography And Its Application In Ovulation Detection

    NASA Astrophysics Data System (ADS)

    Rao, K. H.; Shah, A. V.

    1984-08-01

    Hardware and software of a computer-assisted image analyzing system used for infrared images in medical applications are discussed. The application of computer-assisted thermography (CAT) as a complementary diagnostic tool in centralized diagnostic management is proposed. The authors adopted 'Computer Assisted Thermography' to study physiological changes in the breasts related to the hormones characterizing the menstrual cycle of a woman. Based on clinical experi-ments followed by thermal image analysis, they suggest that 'differential skin temperature (DST)1 be measured to detect the fertility interval in the menstrual cycle of a woman.

  5. Nondestructive evaluation technique using infrared thermography and terahertz imaging

    NASA Astrophysics Data System (ADS)

    Sakagami, Takahide; Shiozawa, Daiki; Tamaki, Yoshitaka; Iwama, Tatsuya

    2016-05-01

    Nondestructive testing (NDT) techniques using pulse heating infrared thermography and terahertz (THz) imaging were developed for detecting deterioration of oil tank floor, such as blister and delamination of corrosion protection coating, or corrosion of the bottom steel plate under coating. Experimental studies were conducted to demonstrate the practicability of developed techniques. It was found that the pulse heating infrared thermography was utilized for effective screening inspection and THz-TDS imaging technique performed well for the detailed inspection of coating deterioration and steel corrosion.

  6. Locating levels in tanks and silos using infrared thermography

    NASA Astrophysics Data System (ADS)

    Snell, John R., Jr.; Schwoegler, Matt

    2004-04-01

    Thermography is a powerful tool for locating or verifying levels in tanks and silos. But one could ask "Why bother?" All too often existing level indication instruments are simply not reliable or positive verification of instrumentation readings is required. When properly used, thermography can reveal not only the liquid/gas interface, but also sludge buildup and floating materials such as waxes and foams. Similar techniques can be used to locate levels and bridging problems in silos containing fluidized solids. This paper discusses the parameters and limitations that must be addressed, shows techniques that can be employed, and illustrates the discussions with numerous thermal images.

  7. Near-infrared thermography using a charge-coupled device camera: application to microsystems.

    PubMed

    Teyssieux, D; Thiery, L; Cretin, B

    2007-03-01

    Using near-infrared thermography microscopy and a low-cost charge-coupled device (CCD) camera, we have designed a system which is able to deliver quantitative submicronic thermal images. Using a theoretical model based on Planck's law and CCD sensor properties allowed us to determine a minimal theoretical detection temperature and an optimal temperature sensitivity of our system. In order to validate this method, we show a good relationship between a theoretical study and a thermal measurement of a microsample. PMID:17411208

  8. Thermophotonic radar imaging: An emissivity-normalized modality with advantages over phase lock-in thermography

    NASA Astrophysics Data System (ADS)

    Tabatabaei, Nima; Mandelis, Andreas; Amaechi, Bennett T.

    2011-04-01

    One major problem of frequency-domain photothermal radiometry, or alternatively in two-dimensional lock-in thermography, is the compromise one has to make between dynamic range (probing depth) and depth resolution. The thermal-wave radar incorporates chirped excitation through matched filtering to maintain good resolution and depth range inside a sample. This letter experimentally demonstrates the advantages of chirped modulation and introduces a thermophotonic modality of thermal-wave radar based on an emissivity-normalized, higher-dynamic-range contrast parameter known as cross-correlation phase. Finally, comparisons made on a biological (dental) sample show potential applications of the method.

  9. Discrimination of edible oils and fats by combination of multivariate pattern recognition and FT-IR spectroscopy: A comparative study between different modeling methods

    NASA Astrophysics Data System (ADS)

    Javidnia, Katayoun; Parish, Maryam; Karimi, Sadegh; Hemmateenejad, Bahram

    2013-03-01

    By using FT-IR spectroscopy, many researchers from different disciplines enrich the experimental complexity of their research for obtaining more precise information. Moreover chemometrics techniques have boosted the use of IR instruments. In the present study we aimed to emphasize on the power of FT-IR spectroscopy for discrimination between different oil samples (especially fat from vegetable oils). Also our data were used to compare the performance of different classification methods. FT-IR transmittance spectra of oil samples (Corn, Colona, Sunflower, Soya, Olive, and Butter) were measured in the wave-number interval of 450-4000 cm-1. Classification analysis was performed utilizing PLS-DA, interval PLS-DA, extended canonical variate analysis (ECVA) and interval ECVA methods. The effect of data preprocessing by extended multiplicative signal correction was investigated. Whilst all employed method could distinguish butter from vegetable oils, iECVA resulted in the best performances for calibration and external test set with 100% sensitivity and specificity.

  10. A comparative study of principal component analysis and independent component analysis in eddy current pulsed thermography data processing.

    PubMed

    Bai, Libing; Gao, Bin; Tian, Shulin; Cheng, Yuhua; Chen, Yifan; Tian, Gui Yun; Woo, W L

    2013-10-01

    Eddy Current Pulsed Thermography (ECPT), an emerging Non-Destructive Testing and Evaluation technique, has been applied for a wide range of materials. The lateral heat diffusion leads to decreasing of temperature contrast between defect and defect-free area. To enhance the flaw contrast, different statistical methods, such as Principal Component Analysis and Independent Component Analysis, have been proposed for thermography image sequences processing in recent years. However, there is lack of direct and detailed independent comparisons in both algorithm implementations. The aim of this article is to compare the two methods and to determine the optimized technique for flaw contrast enhancement in ECPT data. Verification experiments are conducted on artificial and thermal fatigue nature crack detection. PMID:24182145

  11. Predicting electronic component lifetime using thermography

    NASA Astrophysics Data System (ADS)

    Moy, Richard Q.; Vargas, Raymund; Eubanks, Charles

    1991-03-01

    The concept of using IR imaging technology in locating failures in populated and unpopulated printed circuit boards (PCB) has been around since the mid 70's. However, the use of IR imaging technology in predicting component failure has been almost nonexistent. An IR workstation was developed to identify components that had become degraded as a result of aging, stress, or 'wear and tear'. Unlike previous work in IR diagnostic which uses a 'gold' image for comparison, the image history is developed on an individual board basis. The boards were subjected to both thermal and voltage stress to induce component degradation and failure. Preliminary results indicate that some components show a consisted thermal profile that may be used in predicating the lifetime of some components; other components exhibit no consisted thermal pattern change. Due to the varying statistical nature of stress to PCB modules during use in the field and the complexity of designing thermal simulations for each type of PCB module, designing a low cost IR workstation to predict component lifetime is not practical. However, a related application of the effort offers the means to significantly enhance the reliability of PCB modules which have large populations.

  12. Facial thermography is a sensitive tool to determine antihistaminic activity: comparison of levocetirizine and fexofenadine

    PubMed Central

    Larbig, Michael; Burtin, Bernard; Martin, Laurent; Stamm, Holger; Luettig, Birgit; Hohlfeld, Jens M; Krug, Norbert

    2006-01-01

    Aims To assess the antihistaminic activity of levocetirizine and fexofenadine 2 h and 24 h after drug administration using facial thermography and to compare the results with those using well-established parameters of antihistaminic activity in the nose and skin. Methods This was a randomized, double-blind, three-treatment, three-period, single-dose, cross-over study in healthy males taking levocetirizine 5 mg, fexofenadine 120 mg or placebo. The primary endpoint was nasal skin temperature after nasal histamine challenge recorded for 20 min at 2 and 24 h after drug intake. The secondary endpoints were nasal symptoms and a histamine skin prick test. Results Thirty subjects were randomized. At 2 h after drug intake the inhibition of the nasal temperature increase from baseline was not significantly different between levocetirizine and fexofenadine. At 24 h it was significantly more pronounced after levocetirizine than fexofenadine (difference: least-squares mean: −0.13 °C; P ≤ 0.024, 95% CI −0.24, −0.02). Both drugs significantly reduced (P≤ 0.001) the mean temperature increase from baseline compared with placebo at 2 and 24 h (least-squares mean increase and (95% CI): levocetirizine, −0.28 °C (−0.42, −0.14) and −0.32 °C (−0.43, −0.21); fexofenadine −0.35 °C (−0.49, −0.21) and −0.19 °C (−0.30, −0.08), respectively). Results of nasal symptom score and wheal and flare were consistent with the thermography results. Conclusions Facial thermography is an objective, non-invasive and sensitive method to study antihistaminic activity at the nose level. Levocetirizine and fexofenadine demonstrate the same activity at 2 h after drug intake, but levocetirizine has a more sustained activity at 24 h. PMID:16842390

  13. The quantitative inspection of iron aluminide green sheet using transient thermography

    NASA Astrophysics Data System (ADS)

    Watkins, Michael L.; Hinders, Mark K.; Scorey, Clive; Winfree, William

    1999-12-01

    The recent development of manufacturing techniques for the fabrication of thin iron aluminide, FeAl, sheet requires advanced quantitative methods for on-line inspection. An understanding of the mechanisms responsible for flaws and the development of appropriate flaw detection methods are key elements in an effective quality management system. The first step in the fabrication of thin FeAl alloy sheet is the formation of a green sheet, either by cold rolling or tape casting FeAl powder mixed with organic binding agents. The finished sheet is obtained using a series of process steps involving binder elimination, densification, sintering, and annealing. Non-uniformities within the green sheet are the major contributor to material failure in subsequent sheet processing and the production of non-conforming finished sheet. Previous work has demonstrated the advantages of using active thermography to detect the flaws and heterogeneity within green powder composites (1)(2)(3). The production environment and physical characteristics of these composites provide for unique challenges in developing a rapid nondestructive inspection capability. Thermography is non-contact and minimizes the potential damage to the fragile green sheet. Limited access to the material also demands a one-sided inspection technique. In this paper, we will describe the application of thermography for 100% on-line inspection within an industrial process. This approach is cost competitive with alternative technologies, such as x-ray imaging systems, and provides the required sensitivity to the variations in material composition. The formation of green sheet flaws and their transformation into defects within intermediate and finished sheet products will be described. A green sheet conformance criterion will be presented which would significantly reduce the probability of processing poor quality green sheet which contributes to higher waste and inferior bulk alloy sheet.

  14. Thermal diffusivity measurements of thin plates and filaments using lock-in thermography.

    PubMed

    Mendioroz, Arantza; Fuente-Dacal, Raquel; Apiñaniz, Estibaliz; Salazar, Agustín

    2009-07-01

    Photothermal radiometry has been widely used to measure the thermal diffusivity of bulk materials. In the case of thin plates and filaments, a one-dimensional heat propagation model including heat losses has been developed, predicting that the thermal diffusivity can be obtained by recording both the surface temperature amplitude and phase profile slopes ("slope method"). However, this method has given highly overestimated values of the thermal diffusivity of poor-conducting films and filaments. In this paper we analyze the effect of the experimental factors affecting the thermal diffusivity measurements of thin plates and filaments using infrared thermography, in order to establish the experimental conditions needed to obtain accurate and reliable values of the diffusivity of any kind of material using the slope method. We present the calculations of the surface temperature of thin isotropic and anisotropic plates heated by a modulated and tightly focused laser beam, showing that the slope method is also valid for this kind of pointlike heating. Special attention is paid to the effect of surface heat losses (convective and radiative) on the diffusivity measurements of small-dimension and poor-conducting materials. Lock-in thermography measurements performed in the best experimental conditions on a wide set of samples of different thermal properties (thin isotropic and anisotropic plates and filaments) confirm the validity of the slope method to measure accurately the thermal diffusivity of samples of these shapes. PMID:19655974

  15. Technologies of high-performance thermography systems

    NASA Astrophysics Data System (ADS)

    Breiter, R.; Cabanski, Wolfgang A.; Mauk, K. H.; Kock, R.; Rode, W.

    1997-08-01

    A family of 2 dimensional detection modules based on 256 by 256 and 486 by 640 platinum silicide (PtSi) focal planes, or 128 by 128 and 256 by 256 mercury cadmium telluride (MCT) focal planes for applications in either the 3 - 5 micrometer (MWIR) or 8 - 10 micrometer (LWIR) range was recently developed by AIM. A wide variety of applications is covered by the specific features unique for these two material systems. The PtSi units provide state of the art correctability with long term stable gain and offset coefficients. The MCT units provide extremely fast frame rates like 400 Hz with snapshot integration times as short as 250 microseconds and with a thermal resolution NETD less than 20 mK for e.g. the 128 by 128 LWIR module. The unique design idea general for all of these modules is the exclusively digital interface, using 14 bit analog to digital conversion to provide state of the art correctability, access to highly dynamic scenes without any loss of information and simplified exchangeability of the units. Device specific features like bias voltages etc. are identified during the final test and stored in a memory on the driving electronics. This concept allows an easy exchange of IDCAs of the same type without any need for tuning or e.g. the possibility to upgrade a PtSi based unit to an MCT module by just loading the suitable software. Miniaturized digital signal processor (DSP) based image correction units were developed for testing and operating the units with output data rates of up to 16 Mpixels/s. These boards provide the ability for freely programmable realtime functions like two point correction and various data manipulations in thermography applications.

  16. Dosimetric modeling of the microselectron high-dose rate 192Ir source by the multigroup discrete ordinates method.

    PubMed

    Daskalov, G M; Baker, R S; Rogers, D W; Williamson, J F

    2000-10-01

    The DANTSYS multigroup discrete ordinates computer code is applied to quantitatively estimate the absorbed dose rate distributions in the vicinity of a microSelectron 192Ir high-dose-rate (HDR) source in two-dimensional cylindrical R-Z geometry. The source is modeled in a cylindrical water phantom of diameter 20 cm and height 20 cm. The results are also used for evaluation of the Task Group 43 (TG-43) dosimetric quantities. The DANTSYS accuracy is estimated by direct comparisons with corresponding Monte Carlo results. Our 210-group photon cross section library developed previously, together with angular quadratures consisting of 36 (S16) to 210 (S40) directions and associated weights per octant, are used in the DANTSYS simulations. Strong ray effects are observed but are significantly mitigated through the use of DANTSYS's stochastic ray-tracing first collision source algorithm. The DANTSYS simulations closely approximate Monte Carlo estimates of both direct dose calculations and TG-43 dosimetric quantities. The discrepancies with S20 angular quadrature (55 directions and weights per octant) or higher are shown to be less than +/- 5% (about 2.5 standard deviations of Monte Carlo calculations) everywhere except for limited regions along the Z axis of rotational symmetry, where technical limitations in the DANTSYS first collision source implementation makes adequate suppression of ray effects difficult to achieve. The efficiency of DANTSYS simulations is compared with that of the EGS4 Monte Carlo code. It is demonstrated that even with the 210-group cross section library, DANTSYS achieves two-fold efficiency gains using the the S20 quadrature set. The potential of discrete ordinates method for further efficiency improvements is also discussed. PMID:11099199

  17. IRS organigram

    NASA Technical Reports Server (NTRS)

    Messerschmid, Ernst

    1991-01-01

    Charts and graphs relative to magnetoplasmadynamic (MPD) thruster technology are given. The research activities at the Institute of Space Transportation, University of Stuttgart, are summarized. Information is given on the Institute's Electric Propulsion and Plasma Wind Tunnel; thermal arcjet research; the nozzle-type thruster, DT-IRS; nozzle-type MPD thrusters; a hot anode thruster; the DT6 thruster; the ZT-1 thruster; the cylindrical MPD thruster; and a comparison of continuous and quasi-steady MPD.

  18. Modeling and experimental implementation of infrared thermography on concrete masonry structures

    NASA Astrophysics Data System (ADS)

    Khan, Fuad; Bolhassani, Mohammad; Kontsos, Antonios; Hamid, Ahmad; Bartoli, Ivan

    2015-03-01

    This paper is a combined numerical and experimental study which aims to demonstrate the implementation of the infrared thermography (IRT) method for the non-destructive evaluation of concrete masonry structural components. Specifically, a three-dimensional finite element (FE) analysis is formulated and implemented to predict both steady state and transient heat transfer in masonry specimens. A micro-element approach is followed to build the FE model geometry of the masonry walls. The model provides surface temperature contours which are the prime interest of infrared thermography. Three different scaled masonry specimens with identical thermal properties are considered for this study. The FE simulation results of heat diffusion are initially compared with finite difference method predictions for one specimen. Subsequently, the FE results are validated by implementing experimentally the IRT method on the other two specimens. The numerically predicted temperature values agree well with the actual measured values which validate the use of the IRT method for the nondestructive evaluation of concrete masonry components.

  19. Infrared thermography as a diagnostic tool to indicate sick-house-syndrome: a case-study

    NASA Astrophysics Data System (ADS)

    Ljungberg, Sven-Ake

    1996-03-01

    Every third child and many adults in Sweden have allergic reactions caused by indoor environmental problems. A lot of buildings constructed during the building-boom period of 1950 - 1990 expose the sick-house-syndrome, due to built-in moisture problems and poor ventilation performance of the building. Leaky building construction, transport of humid air condensing on thermal bridges within the construction gives rise to a humid environment, and forms a base for a microbial deterioration process of organic materials, with emissions hazardous for human health. So far there are no universal and cost efficient techniques or methods developed which could be used to reveal the sick-house-syndrome. In this paper we present the results of a case-study of the sick-house-syndrome, and an investigation concept with a combination of different techniques and methods to detect and to map underlying factors that form the base for microbial activities. The concept includes mobile and indoor thermography, functional control of ventilation systems, tracer gas techniques for measurement of air flow exchange rate in different rooms, microbial investigation of emissions, field inspections within the building construction and the building envelope, and medical investigation of the health status of the people working in the building. Mobile thermography of the exterior facades has been performed with a longwave AGEMA THV 900, respectively THV 1000 infrared system, during the period December 1994 - June 1995, at different and similar weather and radiation conditions, and with the building pressurized at one accession. Indoor thermography has been performed with a shortwave AGEMA THV 470 system, for a selection of objects/surfaces with thermal deviations, indicated in thermograms from the different mobile thermographic surveys. Functional control was performed for the ventilation systems, and air flow rates were measured using tracer gas technique for a selection of rooms with different

  20. Nondestructive testing of rocket engine injector panel using ultrasonic burst phase thermography

    NASA Astrophysics Data System (ADS)

    Chen, Dapeng; Zhang, Cunlin; Wu, Naiming; Zeng, Zhi; Xing, Chunfei; Li, Yue; Zhao, Shibin; Ning, Tao

    2010-10-01

    As the key parts of the liquid rocket oxyhydrogen engine, the injector panel is a kind of transpiration material, which is braided and Sintered with stainless steel wire. If some hidden delaminition defects that are difficult to detect appear in the process of Sintering and rolling, a significant safety problem would occur. In this paper, we use the Ultrasonic Burst Phase Thermography (UBP) to detect the delamination defects in the injector panel, UBP is a rapid and reliable nondestructive technique derived from Ultrasonic Lock-in Thermography(ULT). It uses a controllable, adjustable ultrasonic burst as the heat source to stimulate the sample, the defects within the material are revealed through their heat generation caused by friction, clapping and thermoelastic effect, as the resulting surface temperature distribution is observed by an infrared camera. The original thermal images sequence is processed by Fast Fourier Transformation to obtain the phase information of the defects. In the experiments of the delamination sample, the UBP realized the selective heating of delamination defects in the injector panel, and the signal to noise of phase image is higher than the original thermal image because the phase information can not be disturbed by the initial conditions (such as the reflective surface of sample). However, the result of the detection of flat bottom hole transpiration panel sample reflects that UBP is not appropriate for the detection of this kind of defects, because it is difficult to induce frictional heating of flat bottom holes. As contrast, Flash Pulse Thermography is used to detect the flat bottom holes, all of the holes of different depth and sizes can be seen distinctly. The results show that PT is more appropriate for the detection of flat bottom holes defects than UBP, therefore, it is important to select the appropriate excitation method according to different defects.

  1. A protocol for analysing thermal stress in insects using infrared thermography.

    PubMed

    Gallego, Belén; Verdú, José R; Carrascal, Luis M; Lobo, Jorge M

    2016-02-01

    The study of insect responses to thermal stress has involved a variety of protocols and methodologies that hamper the ability to compare results between studies. For that reason, the development of a protocol to standardize thermal assays is necessary. In this sense, infrared thermography solves some of the problems allowing us to take continuous temperature measurements without handling the individuals, an important fact in cold-blooded organisms like insects. Here, we present a working protocol based on infrared thermography to estimate both cold and heat thermal stress in insects. We analyse both the change in the body temperature of individuals and their behavioural response. In addition, we used partial least squares regression for the statistical analysis of our data, a technique that solves the problem of having a large number of variables and few individuals, allowing us to work with rare or endemic species. To test our protocol, we chose two species of congeneric, narrowly distributed dung beetles that are endemic to the southeastern part of the Iberian Peninsula. With our protocol we have obtained five variables in the response to cold and twelve in the response to heat. With this methodology we discriminate between the two flightless species of Jekelius through their thermal response. In response to cold, Jekelius hernandezi showed a higher rate of cooling and reached higher temperatures of stupor and haemolymph freezing than Jekelius punctatolineatus. Both species displayed similar thermoregulation ranges before reaching lethal body temperature with heat stress. Overall, we have demonstrated that infrared thermography is a suitable method to assess insect thermal responses with a high degree of sensitivity, allowing for the discrimination between closely related species. PMID:26857985

  2. Use of aerial thermography in Canadian energy conservation programs

    NASA Technical Reports Server (NTRS)

    Cihlar, J.; Brown, R. J.; Lawrence, G.; Barry, J. N.; James, R. B.

    1977-01-01

    Recent developments in the use of aerial thermography in energy conservation programs within Canada were summarized. Following a brief review of studies conducted during the last three years, methodologies of data acquisition, processing, analysis and interpretation was discussed. Examples of results from an industrial oriented project were presented and recommendations for future basic work were outlined.

  3. Defect Detection in Composite Coatings by Computational Simulation Aided Thermography

    NASA Astrophysics Data System (ADS)

    Almeida, R. M.; Souza, M. P. V.; Rebello, J. M. A.

    2010-02-01

    Thermography is based on the measurement of superficial temperature distribution of an object inspected subjected to tension, normally thermal heat. This measurement is performed with a thermographic camera that detects the infrared radiation emitted by every object. In this work thermograph was simulated by COMSOL software for optimize experimental parameters in composite material coatings inspection.

  4. Infrared thermography to detect residual ceramic in gas turbine blades

    NASA Astrophysics Data System (ADS)

    Meola, C.; Carlomagno, G. M.; di Foggia, M.; Natale, O.

    2008-06-01

    A serious problem in the production of gas turbine blades is the detection of residual ceramic cores inside the cooling passages; in fact, the presence of even small ceramic pieces affects turbine performance and may cause difficulties in successive manufacturing. Therefore, it is important to have a non-destructive technique that must be capable of detecting tiny ceramic fragments in a fast and easy way. In this perspective, the suitability of infrared thermography was investigated within cooperation between the University of Naples and the Europea Microfusioni Aerospaziali S.p.A. (EMA). Several blades of three different types were inspected revealing that in many cases infrared thermography can discover small ceramic fragments which were missed by X-ray inspection. In addition, infrared thermography allows gaining of information about other types of anomalies (e.g., surface defects) during the same testing step (by eventually changing the test parameters) and then saving time and money. The obtained results look promising in view of introducing infrared thermography among industrial instrumentation as an alternative to, or integrated with, the most currently utilized non-destructive techniques.

  5. Infrared thermography for CFRP inspection: computational model and experimental results

    NASA Astrophysics Data System (ADS)

    Fernandes, Henrique C.; Zhang, Hai; Morioka, Karen; Ibarra-Castanedo, Clemente; López, Fernando; Maldague, Xavier P. V.; Tarpani, José R.

    2016-05-01

    Infrared Thermography (IRT) is a well-known Non-destructive Testing (NDT) technique. In the last decades, it has been widely applied in several fields including inspection of composite materials (CM), specially the fiber-reinforced polymer matrix ones. Consequently, it is important to develop and improve efficient NDT techniques to inspect and assess the quality of CM parts in order to warranty airworthiness and, at the same time, reduce costs of airline companies. In this paper, active IRT is used to inspect carbon fiber-reinforced polymer (CFRP) at laminate with artificial inserts (built-in sample) placed on different layers prior to the manufacture. Two optical active IRT are used. The first is pulsed thermography (PT) which is the most widely utilized IRT technique. The second is a line-scan thermography (LST) technique: a dynamic technique, which can be employed for the inspection of materials by heating a component, line-by-line, while acquiring a series of thermograms with an infrared camera. It is especially suitable for inspection of large parts as well as complex shaped parts. A computational model developed using COMSOL Multiphysics® was used in order to simulate the inspections. Sequences obtained from PT and LST were processed using principal component thermography (PCT) for comparison. Results showed that it is possible to detect insertions of different sizes at different depths using both PT and LST IRT techniques.

  6. NASA MUST Paper: Infrared Thermography of Graphite/Epoxy

    NASA Technical Reports Server (NTRS)

    Comeaux, Kayla; Koshti, Ajay

    2010-01-01

    The focus of this project is to use Infrared Thermography, a non-destructive test, to detect detrimental cracks and voids beneath the surface of materials used in the space program. This project will consist of developing a simulation model of the Infrared Thermography inspection of the Graphite/Epoxy specimen. The simulation entails finding the correct physical properties for this specimen as well as programming the model for thick voids or flat bottom holes. After the simulation is completed, an Infrared Thermography inspection of the actual specimen will be made. Upon acquiring the experimental test data, an analysis of the data for the actual experiment will occur, which includes analyzing images, graphical analysis, and analyzing numerical data received from the infrared camera. The simulation will then be corrected for any discrepancies between it and the actual experiment. The optimized simulation material property inputs can then be used for new simulation for thin voids. The comparison of the two simulations, the simulation for the thick void and the simulation for the thin void, provides a correlation between the peak contrast ratio and peak time ratio. This correlation is used in the evaluation of flash thermography data during the evaluation of delaminations.

  7. Investigation of defect characteristics and heat transfer in step heating thermography of metal plates repaired with composite patches

    NASA Astrophysics Data System (ADS)

    Daryabor, P.; Safizadeh, M. S.

    2016-05-01

    Nowadays, composite patches are widely used in different industries to repair damaged metal structures. Inspection of such repaired structures is always considered as a challenging task. Different thermography methods such as step heating are commonly used to inspect repaired structures. Some parameters such as defect features or heating procedure play major roles in defect detection. In this work, in order to investigate such effects, step heating thermography of an aluminum plate repaired with a composite patch is modeled and tested. The main goal of this study is to evaluate the effects of defect type (delamination and disbond), size and depth on the detection ability of the test. Moreover, regarding the heat transfer process obtained from the simulation, the appropriate heating procedure for inspecting the repaired metal structures is determined. To validate the simulation outputs, experimental results corresponding to the temperature variations are compared with those predicted from the simulation.

  8. Introduction of the use of thermography and thermometry in the diagnosis of uveitis in horses: a pilot project

    PubMed Central

    Rushton, J O; Tichy, A; Nell, B

    2015-01-01

    Aims and objectives To date assessment of changes in ocular temperature, as a hallmark of uveitis in horses has not been determined. Therefore the aim of the current study was to determine whether ocular temperature is increased in acute uveitic eyes compared with non-uveitic eyes, and to compare an affordable thermometry device with a thermography device. Material and methods Ocular temperatures of both eyes of five horses with acute unilateral uveitis and 10 normal horses were measured using thermometry and thermography. Presence and absence of acute uveitis were diagnosed through a complete ophthalmological examination. Ambient temperature and core body temperature were also recorded. Results The difference in temperatures between uveitic eyes and non-uveitic eyes was marked but not statistically significant (mean thermography temperature 34.0°C sd±1.6°C and 32.7°C sd±2.4°C, respectively v mean thermometry temperature 34.0°C sd±1.9°C and 31.6°C sd±3.1°C, respectively). No influence of core body temperature on either method was detected. Thermography was less influenced by ambient temperature than was thermometry. Conclusion In conclusion uveitic eyes are not significantly warmer than non-uveitic eyes. Despite the lack of significance, a tendency towards increased ocular temperature in uveitic eyes, compared with non-uveitic eyes was noted. Therefore more research on this topic is warranted. PMID:26392900

  9. Line laser lock-in thermography for instantaneous imaging of cracks in semiconductor chips

    NASA Astrophysics Data System (ADS)

    An, Yun-Kyu; Yang, Jinyeol; Hwang, Soonkyu; Sohn, Hoon

    2015-10-01

    This study proposes a new line laser lock-in thermography (LLT) technique for instantaneous inspection of surface cracks in semiconductor chips. First, a new line LLT system is developed by integrating a line scanning laser source, a high-speed infrared (IR) camera with a close-up lens, and a control computer. The proposed line LLT system scans a line laser beam onto a target semiconductor chip surface and measures the corresponding thermal wave propagation using an IR camera. A novel baseline-free crack visualization algorithm is then proposed so that heat blocking phenomena caused by crack formation can be automatically visualized and diagnosed without relying on the baseline data obtained from the pristine condition of a target semiconductor chip. The proposed inspection technique offers the following advantages over the existing semiconductor chip inspection techniques: (1) inspection is performed in a noncontact, nondestructive and nonintrusive manner; (2) the crack diagnosis can be accomplished using only current-state thermal images and thus past thermal images are unnecessary; and (3) crack detectability is significantly enhanced by achieving high spatial resolution for thermal images and removing undesired noise components from the measured thermal images. Validation tests are performed on two different types of semiconductor die chips with real micro-cracks produced during actual fabrication processes. The experiments demonstrate that the proposed line LLT technique can successfully visualize and detect semiconductor chip cracks with width of 28-54 μm.

  10. IR Asterisms

    NASA Astrophysics Data System (ADS)

    Riess, Adam

    2010-09-01

    Observing asterisms for photometric calibration provides a "happy medium" between observing single stars which areobservable from the ground but lack statistics, and star clusters which have excellent statistics but are too crowded to observe from the ground.Asterisms in the IR for calibration have been less available than in the optical, e.g., Landolt's standard fields.While ad-hoc asterisms for calibration could be formed from 2MASS calibration, the photometric precision of 2MASSis relatively low, 0.02-0.05, for the fainter stars, m=9-13, that can still be observed without saturation in WFC3-IR.However, IR monitoring of variable phenomena {e.g., AGN SNe, stellar variables} from the ground has produced calibration of stars in asterisms with m=9-13 with a relative uncertainty of 0.001 to 0.01 mag due to the high frequency of monitoring. We have selected 4 such asterisms to observe. Because the stars are bright we need to use subarrays of 64x64 or 128x128 to get read out short enough to avoid saturation. The observations are obtained in pairs of 3 close stars, i.e., 2x3=6 stars per orbit in F125W and F160W as well as a F555W full frame to verify astrometry. In all we expect to measure 24 stars with m=9 to 14. The goal is to provide 2 calibrations, an independent zeropoint and its uncertainty as well as a measure of count rate non linearity. For the latter, an expected CRNL over 2 dex {5 mag} is expected tobe 0.02 mag.

  11. Using aerial infrared thermography to detect utility theft of service

    NASA Astrophysics Data System (ADS)

    Stockton, Gregory R.; Lucas, R. Gillem

    2012-06-01

    Natural gas and electric utility companies, public utility commissions, consumer advocacy groups, city governments, state governments and the federal government United States continue to turn a blind eye towards utility energy theft of service which we conservatively estimate is in excess of 10 billion a year. Why? Many in the United States have exhausted their unemployment benefits. The amounts for federal funding for low income heating assistance programs (LIHEAP) funds were cut by nearly 40% for 2012 to 3.02 billion. "At peak funding ($5.1 billion in 2009), the program was national in scale but still only had enough resources to support roughly 1/4 of the eligible households.i" Contributions to charities are down and the number of families below the poverty line who are unable to pay to heat their houses continues to rise. Many of the less fortunate in our society now consider theft and fraud to be an attractive option for their supply of natural gas and/or electricity. A record high mild winter in 2011-2012 coupled with 10-year low natural gas prices temporarily obscured the need for low income heating assistance programs (LIHEAPs) from the news and federal budgets, but cold winters will return. The proliferation of smart meters and automated meter infrastructures across our nation can do little to detect energy theft because the thieves can simply by-pass the meters, jumper around the meters and/or steal meters from abandoned houses and use them. Many utility systems were never set-up to stop these types of theft. Even with low-cost per identified thief method using aerial infrared thermography, utilities continue to ignore theft detection.

  12. Numerical analysis of angular defects in bent plates using tone burst eddy-current thermography (TBET)

    NASA Astrophysics Data System (ADS)

    Libin, M. N.; Balasubramaniam, Krishnan; Maxfield, B. W.

    2013-01-01

    Tone Burst Eddy current Thermography (TBET) is a new hybrid, non-contacting, Non-Destructive Evaluation (NDT) method which employs a combination of Pulsed Eddy current Thermography (PEC) and Thermographic Non-Destructive Evaluation (TNDE). For understanding angular cracks, fundamental knowledge about the induced current density distribution in the component under test is required. Further, this information enables us to find the amount of heat produced at those locations and how it diffuses to the surface. This paper describes simulation work done for cracks set at an angle to the surface in flat and bent aluminum plates. The investigation is implemented by the simulating transient thermal distribution for 2D angular cracks via finite element package COMSOL multi-physics with AC/DC module and general heat transfer. At crack edges, induced current is seen concentrated thus indicating a localized high heating in those areas relative to other regions. A numerical study was also carried out by varying parameters like crack angle (0°, 22.5°, 45°, 67.5°) and crack length (0.6mm, 1.2mm, 1.8mm) the transient thermal distributions were compared for different plate bend angles (180°, 120°, 90°, 60°, 30°). TBET method was found well suited for the detection of service induced cracks, usually caused by either rolling contact fatigue or stress corrosion, with a high degree of sensitivity.

  13. Detection and characterisation of delamination in PV modules by active infrared thermography

    NASA Astrophysics Data System (ADS)

    Sinha, A.; Sastry, O. S.; Gupta, R.

    2016-01-01

    The paper presents a fast and efficient method for the detection and characterisation of delamination in photovoltaic (PV) modules by using active infrared thermography approach. A discrete part of PV module was irradiated by step heating and its thermal image sequence was used to detect and analyse delamination. Different types of heating source for thermal excitation for this application have been studied. An electro-thermal model was developed to simulate the active thermography approach for the characterisation of delamination in PV module by equivalent resistance-capacitance (RC) network using a circuit simulator. This simulation approach was used to estimate the extent of delamination in the module and to determine the optimum parameters for the characterisation of delamination. Different applications based on front and backsides of heating the module were also proposed in this paper. The proposed method has the potential to be employed for the quality check of PV modules during inline production as well as for the predictive maintenance of outdoor PV plants.

  14. Investigation of the use of thermography for research and clinical applications in pregnant women

    NASA Astrophysics Data System (ADS)

    Topalidou, Anastasia; Downe, Soo

    2016-03-01

    Background: The possibility of using thermal imaging, as a non-invasive method, in medicine may provide potential ability of advanced imaging. Objective: The conduction of a preliminary study in healthy non-pregnant females in order to investigate the imaging ability of thermography and its implementation; and to determine hot and cold areas in order to create a "map" of temperature distribution of the abdomen and the torso. Methods: Participants were 18-45 years old non-pregnant women (n = 10), who were measured at 4 different distances. Two thermal imaging cameras and their corresponding software were used to measure abdomen, low back, left and right side of the torso. Results: There were no statistically significant differences in the mean values of the exported temperatures according the distance and the angle between the camera and the subject. The inferior part of the rectus abdominis muscle recorded the coldest zone and the umbilicus appeared as the most prominent hot spot. Conclusions: Thermography shows to be a potential non-invasive technique offering new options in the evaluation of pregnant and laboring women.

  15. Pulse thermography for quantitative nondestructive evaluation of sound, de-mineralized and re-mineralized enamel

    NASA Astrophysics Data System (ADS)

    Ando, Masatoshi; Sharp, Nathan; Adams, Douglas

    2012-04-01

    Current limitations for diagnosing mineralization state of tooth enamel can lead to improper surgical treatments. A method is investigated by which the tooth health state is characterized according to its thermal response, which is hypothesized to be sensitive to increased porosity in enamel that is caused by demineralization. Several specimens consisting of previously extracted human teeth a re prepared by exposure to Streptococcus mutans A32-2 in trypticase-soy-borth supplemented with 5% sucrose at 37°C for 3 or 6 days to de-mineralize two 1×1mm2-windows on each tooth. One of these windows is then re-mineralized with 250 or 1,100ppm-F as NaF for 10 days by pH-cyclic-model. Pulse thermography is used to measure the thermal response of these sections as well as the sound (healthy) portions of the specimen. A spatial profile of the thermal parameters of the specimens is then extracted from the thermography data and are used to compare the sound, de-mineralized, and re-mineralized areas. Results show that the thermal parameters are sensitive to the mineralization state of the tooth and that this method has the potential to accurately and quickly characterize the mineralization state of teeth, thereby allowing future dentists to make informed decisions regarding the best treatment for teeth that have experienced demineralization.

  16. Mid-infrared thermal imaging for an effective mapping of surface materials and sub-surface detachments in mural paintings: integration of thermography and thermal quasi-reflectography

    NASA Astrophysics Data System (ADS)

    Daffara, C.; Parisotto, S.; Mariotti, P. I.

    2015-06-01

    Cultural Heritage is discovering how precious is thermal analysis as a tool to improve the restoration, thanks to its ability to inspect hidden details. In this work a novel dual mode imaging approach, based on the integration of thermography and thermal quasi-reflectography (TQR) in the mid-IR is demonstrated for an effective mapping of surface materials and of sub-surface detachments in mural painting. The tool was validated through a unique application: the "Monocromo" by Leonardo da Vinci in Italy. The dual mode acquisition provided two spatially aligned dataset: the TQR image and the thermal sequence. Main steps of the workflow included: 1) TQR analysis to map surface features and 2) to estimate the emissivity; 3) projection of the TQR frame on reference orthophoto and TQR mosaicking; 4) thermography analysis to map detachments; 5) use TQR to solve spatial referencing and mosaicking for the thermal-processed frames. Referencing of thermal images in the visible is a difficult aspect of the thermography technique that the dual mode approach allows to solve in effective way. We finally obtained the TQR and the thermal maps spatially referenced to the mural painting, thus providing the restorer a valuable tool for the restoration of the detachments.

  17. Measurement of Three-Dimensional Anisotropic Thermal Diffusivities for Carbon Fiber-Reinforced Plastics Using Lock-In Thermography

    NASA Astrophysics Data System (ADS)

    Ishizaki, Takuya; Nagano, Hosei

    2015-11-01

    A new measurement technique to measure the in-plane thermal diffusivity, the distribution of in-plane anisotropy, and the out-of-plane thermal diffusivity has been developed to evaluate the thermal conductivity of anisotropic materials such as carbon fiber-reinforced plastics (CFRPs). The measurements were conducted by using a laser-spot-periodic-heating method. The temperature of the sample is detected by using lock-in thermography. Thermography can analyze the phase difference between the periodic heat input and the temperature response of the sample. Two kinds of samples, unidirectional (UD) and cross-ply (CP) pitch-based CFRPs, were fabricated and tested in an atmospheric condition. All carbon fibers of the UD sample run in one direction [90°]. The carbon fibers of the CP sample run in two directions [0°/90°]. It is found that, by using lock-in thermography, it is able to visualize the thermal anisotropy and calculate the angular dependence of the in-plane thermal diffusivity of the CFRPs. The out-of-plane thermal diffusivity of CFRPs was also measured by analyzing the frequency dependence of the phase difference.

  18. Active thermography and post-processing image enhancement for recovering of abraded and paint-covered alphanumeric identification marks

    NASA Astrophysics Data System (ADS)

    Montanini, R.; Quattrocchi, A.; Piccolo, S. A.

    2016-09-01

    Alphanumeric marking is a common technique employed in industrial applications for identification of products. However, the realised mark can undergo deterioration, either by extensive use or voluntary deletion (e.g. removal of identification numbers of weapons or vehicles). For recovery of the lost data many destructive or non-destructive techniques have been endeavoured so far, which however present several restrictions. In this paper, active infrared thermography has been exploited for the first time in order to assess its effectiveness in restoring paint covered and abraded labels made by means of different manufacturing processes (laser, dot peen, impact, cold press and scribe). Optical excitation of the target surface has been achieved using pulse (PT), lock-in (LT) and step heating (SHT) thermography. Raw infrared images were analysed with a dedicated image processing software originally developed in Matlab™, exploiting several methods, which include thermographic signal reconstruction (TSR), guided filtering (GF), block guided filtering (BGF) and logarithmic transformation (LN). Proper image processing of the raw infrared images resulted in superior contrast and enhanced readability. In particular, for deeply abraded marks, good outcomes have been obtained by application of logarithmic transformation to raw PT images and block guided filtering to raw phase LT images. With PT and LT it was relatively easy to recover labels covered by paint, with the latter one providing better thermal contrast for all the examined targets. Step heating thermography never led to adequate label identification instead.

  19. Clinical applications of dynamic infrared thermography in plastic surgery: a systematic review

    PubMed Central

    John, Hannah Eliza; Niumsawatt, Vachara; Whitaker, Iain S.

    2016-01-01

    Background Infrared thermography (IRT) has become an increasingly utilized adjunct to more expensive and/or invasive investigations in a range of surgical fields, no more so than in plastic surgery. The combination of functional assessment, flow characteristics and anatomical localization has led to increasing applications of this technology. This article aims to perform a systematic review of the clinical applications of IRT in plastic surgery. Methods A systematic literature search using the keywords ‘IRT’ and ‘dynamic infrared thermography (DIRT)’ has been accomplished. A total of 147 papers were extracted from various medical databases, of which 34 articles were subjected to a full read by two independent reviewers, to ensure the papers satisfied the inclusion and exclusion criteria. Studies focusing on the use of IRT in breast cancer diagnosis were excluded. Results A systematic review of 29 publications demonstrated the clinical applications of IRT in plastic surgery today. They include preoperative planning of perforators for free flaps, post operative monitoring of free flaps, use of IRT as an adjunct in burns depth analysis, in assessment of response to treatment in hemangioma and as a diagnostic test for cutaneous melanoma and carpal tunnel syndrome (CTS). Conclusions Modern infrared imaging technology with improved standardization protocols is now a credible, useful non-invasive tool in clinical practice. PMID:27047781

  20. Toward understanding the complex mechanisms behind breast thermography: an overview for comprehensive numerical study

    NASA Astrophysics Data System (ADS)

    Jiang, Li; Zhan, Wang; Loew, Murray H.

    2011-03-01

    The abnormal thermogram has been shown to be a reliable indicator of a high risk of breast cancer. Nevertheless, a major weakness of current infrared breast thermography is its poor sensitivity for deeper tumors. Numerical modeling for breast thermography provides an effective tool to investigate the complex relationships between the breast thermal behaviors and the underlying patho-physiological conditions. We have developed a set of new modeling techniques to take into account some subtle factors usually ignored in previous studies, such as gravity-induced elastic deformations of the breast, nonlinear elasticity of soft tissues, and dynamic behavior of thermograms. Conventional "forward problem" modeling cannot be used directly to improve tumor detectability, however, because the underlying tissue thermal properties are generally unknown. Therefore, we propose an "inverse problem" modeling technique that aims to estimate the tissue thermal properties from the breast surface thermogram. Our data suggest that the estimation of the tumor-induced thermal contrast can be improved significantly by using the proposed inverse problem solving techniques to provide the individual-specific thermal background, especially for deeper tumors. We expect the proposed new methods, taken together, to provide a stronger foundation for, and greater specificity and precision in, thermographic diagnosis, and treatment, of breast cancer.

  1. Non-destructive testing of composite materials by means of active thermography-based tools

    NASA Astrophysics Data System (ADS)

    Lizaranzu, Miguel; Lario, Alberto; Chiminelli, Agustín; Amenabar, Ibán

    2015-07-01

    Infrared analysis tools are nowadays widely used for the non-destructive testing of components made up in composite materials, belonging to many different industrial sectors. Being a non-contact method, its capability for the inspection of large areas in short periods of time justifies the great number of works and technical studies that can be found in this field. The growing interest in the technique is also supported by the development, during recent years, of increasingly powerful equipment and data analysis tools. In order to establish a base of knowledge to assist defect identification in real components inspections, the design and manufacturing of inspection samples including controlled defects, is a frequently used strategy. This paper deals with the analysis, by means of transient active thermography, of a set of inspection patterns made out of different composite materials and configurations that can be found in the wind turbine blade manufacturing industry. The design and manufacturing of these patterns are described, including different types of representative defects, stack configurations and composite manufacturing techniques. Reference samples are then inspected by means of active thermography analysis tools and the results obtained are discussed.

  2. Dynamic Infrared Thermography Study of Blood Flow Relative to Lower Limp Position

    NASA Astrophysics Data System (ADS)

    Stathopoulos, I.; Skouroliakou, K.; Michail, C.; Valais, I.

    2015-09-01

    Thermography is an established method for studying skin temperature distribution. Temperature distribution on body surface is influenced by a variety of physiological mechanisms and has been proven a reliable indicator of various physiological disorders. Blood flow is an important factor that influences body heat diffusion and skin temperature. In an attempt to validate and further elucidate thermal models characterizing the human skin, dynamic thermography of the lower limp in horizontal and vertical position was performed, using a FLIR T460 thermographic camera. Temporal variation of temperature was recorded on five distinct points of the limp. Specific points were initially cooled by the means of an ice cube and measurements of the skin temperature were obtained every 30 seconds as the skin temperature was locally reduced and afterwards restored at its initial value. The return to thermal balance followed roughly the same pattern for all points of measurement, although the heating rate was faster when the foot was in horizontal position. Thermal balance was achieved faster at the spots that were positioned on a vein passage. Our results confirm the influence of blood flow on the thermal regulation of the skin. Spots located over veins exhibit different thermal behaviour due to thermal convection through blood flow. Changing the position of the foot from vertical to horizontal, effectively affects blood perfusion as in the vertical position blood circulation is opposed by gravity.

  3. Application of the Correlation Method to Vibrational Spectra of C60 and Other Fullerenes: Predicting the Number of IR- and Raman-Active Bands

    NASA Astrophysics Data System (ADS)

    Nakamoto, Kazuo; McKinney, Michael A.

    2000-06-01

    The C60 molecule (Buckyball/soccer ball) exhibits only 4 IR and 10 Raman bands although it possesses 174 (3 x 60 - 6) normal vibrations. This striking reduction in the number of observed bands is evidently due to the molecule's extremely high symmetry (Ih point group). First, the 120 symmetry elements of its truncated icosahedral structure are identified and the local (site) symmetry of the carbon atoms (Cc) is determined. Use of molecular models greatly facilitates the process in determining the local and molecular symmetries. Then the correlation method is used to derive a table that classifies the 174 normal vibrations into the respective symmetry species of the Ih point group. In this method, symmetry properties of atomic displacements in terms of the local point group (Cc) are correlated with those in terms of the molecular point group (Ih). After the normal vibrations are classified into respective symmetry species, the numbers of IR- and Raman-active vibrations can be determined by the symmetry selection rules for IR and Raman spectra. The vibrational spectra of C60 and C70 (rugby ball) are analyzed by the above procedure, and the results obtained for C28, C32, C50, and dodecahedrane are provided.

  4. Measurement of transient surface temperatures during rubbing using infrared thermography

    NASA Astrophysics Data System (ADS)

    You, Tau; Yu, Jianwei; Yu, Xiaofen

    2013-10-01

    Infrared thermometer could provide IR radiance information to get the corresponding temperature as the machine is working. But the emissivity coefficient, which converts IR radiance to temperature, would vary with change of surface properties during rubbing, and this would bring dynamic error in measurement. In this study, we introduced a special tester, in the side of which compact IR thermometer are mounted. The thermometer enables us to measure contact surface temperature directly during tests of a rotating ring and a flat block which had a laser diode fixed under its contact surface. Based on Kirchhoff theory, the calculate model of the spectral emissivity is constructed. The normal emissivity at target region are measured through trigonometric ray consisted of InGaAsP laser source, PbSe detector and objective surface. So the temperature value from the IR thermometer could be corrected dynamically according to the real-time emissivity. The structure and the principle of the apparatus are described. The key technologies and the corresponding solution methods are briefly discussed. The error due to the rapid variations of emissivity value with change in contact conditions was shown, and it must be taken into consideration in radiometric temperature measurement in rubbing and could be especially useful in the verification of friction surface temperature predictions.

  5. Involuntary motion tracking for medical dynamic infrared thermography using a template-based algorithm

    PubMed Central

    Herman, Cila

    2013-01-01

    In medical applications, Dynamic Infrared (IR) Thermography is used to detect the temporal variation of the skin temperature. Dynamic Infrared Imaging first introduces a thermal challenge such as cooling on the human skin, and then a sequence of hundreds of consecutive frames is acquired after the removal of the thermal challenge. As a result, by analyzing the temporal variation of the skin temperature over the image sequence, the thermal signature of skin abnormality can be examined. However, during the acquisition of dynamic IR imaging, the involuntary movements of patients are unavoidable, and such movements will undermine the accuracy of diagnosis. In this study, based on the template-based algorithm, a tracking approach is proposed to compensate the motion artifact. The affine warping model is adopted to estimate the motion parameter of the image template, and then the Lucas-Kanade algorithm is applied to search for the optimized parameters of the warping function. In addition, the weighting mask is also incorporated in the computation to ensure the robustness of the algorithm. To evaluate the performance of the approach, two sets of IR image sequences of a subject’s hand are analyzed: the steady-state image sequence, in which the skin temperature is in equilibrium with the environment, and the thermal recovery image sequence, which is acquired after cooling is applied on the skin for 60 seconds. By selecting the target region in the first frame as the template, satisfactory tracking results were obtained in both experimental trials, and the robustness of the approach can be effectively ensured in the recovery trial. PMID:24392205

  6. Evaluation of the Validity of Crystallization Temperature Measurements Using Thermography with Different Sample Configurations

    NASA Astrophysics Data System (ADS)

    Yuko Aono,; Junpei Sakurai,; Akira Shimokohbe,; Seiichi Hata,

    2010-07-01

    We describe further progress of a previously reported novel crystallization temperature (Tx) measurement method applicable for small sample sizes. The method uses thermography and detects Tx as a change in emissivity of thin film amorphous alloy samples. We applied this method to various sample configurations of Pd-Cu-Si thin film metallic glass (TFMG). The validity of the detected Tx was determined by electrical resistivity monitoring and differential scanning calorimetry (DSC). Crystallization temperature can be detected in all sample configurations; however, it was found that the magnitude of the detected change of emissivity at Tx depended on the sample configuration. This emissivity change was clear in the absence of a higher emissivity material. The results suggest that this method can achieve high-throughput characterization of Tx for integrated small samples such as in a thin film library.

  7. Developing written inspection procedures for thermal/infrared thermography

    SciTech Connect

    Snell, J.

    1996-12-31

    Written inspection procedures are essential to acquiring valid data on a repeatable basis. They are also vital to the safety of the thermographer, and may, for that reason alone, be required by a company. Many thermographers are working with no written procedures. To date only a few of the necessary procedures have been developed by recognized standards organizations. The lack of procedures is limiting the use of thermography. Where thermography is being used without them, results are often less than optimum. This paper will (1) survey existing procedures and standards; (2) discuss current efforts by standards organizations to develop standards and procedures; and (3) present a general methodology from which written inspection procedures can be developed for many thermographic inspections.

  8. Noninvasive express diagnostics of pulmonary diseases based on control of patient's gas emission using methods of IR and terahertz laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Starikova, M. K.; Bulanova, A. A.; Bukreeva, E. B.; Karapuzikov, A. A.; Karapuzikov, A. I.; Kistenev, Y. V.; Klementyev, V. M.; Kolker, D. B.; Kuzmin, D. A.; Nikiforova, O. Y.; Ponomarev, Yu. N.; Sherstov, I. V.; Boyko, A. A.

    2013-11-01

    Pulmonary diseases diagnostics always occupies one of the key positions in medicine practices. A large variety of high technology methods are used today, but none of them cannot be used for early screening of pulmonary diseases. We discuss abilities of methods of IR and terahertz laser spectroscopy for noninvasive express diagnostics of pulmonary diseases on a base of analysis of absorption spectra of patient's gas emission, in particular, exhaled air. Experience in the field of approaches to experimental data analysis and hard-ware realization of gas analyzers for medical applications is also discussed.

  9. Estimation of cellulose crystallinity of lignocelluloses using near-IR FT-Raman spectroscopy and comparison of the Raman and Segal-WAXS methods.

    PubMed

    Agarwal, Umesh P; Reiner, Richard R; Ralph, Sally A

    2013-01-01

    Of the recently developed univariate and multivariate near-IR FT-Raman methods for estimating cellulose crystallinity, the former method was applied to a variety of lignocelluloses: softwoods, hardwoods, wood pulps, and agricultural residues/fibers. The effect of autofluorescence on the crystallinity estimation was minimized by solvent extraction or chemical treatment or both. Additionally, when the roles of lignin and hemicellulose in the Raman crystallinity assessment were investigated, it was found that syringyl lignin containing lignocelluloses generated somewhat higher crystallinity, whereas the presence of hemicellulose reduced the crystallinity. Overall, when autofluorescence was minimized and corrections made for hemicellulose and syringyl lignin contributions, the univariate Raman method performed well and estimated cellulose crystallinity accurately. Moreover, when the Raman and Segal-WAXS methods were compared, we observed that in the absence of significant fluorescence, the Raman method was influenced mostly by hemicellulose and syringyl lignin, whereas the Segal-WAXS was affected by various types of lignin and hemicellulose. It was concluded that the near-IR FT-Raman method with corrections for influences of syringyl lignin and hemicellulose can be used to correctly estimate cellulose crystallinity. PMID:23241140

  10. On line sensing of weld penetration using infrared thermography

    SciTech Connect

    Wang, Y.; Chin, B.A.

    1986-01-01

    The objective of this research is to apply new sensing techniques, artificial intelligence, and robotics to improve the welding process through control of penetration depth and width parameters. By producing a constant depth and width of penetration through on line control, the quality and strength of welds may be improved to a new level of reliability previously unobtainable. Experimental data presented in this paper indicate that depth and width of penetration can be monitored by infrared thermography and hence controlled dynamically during the weld process. Infrared thermography is used to monitor surface temperature distributions in the vicinity of the molten metal pool. Characteristics of temperature distributions perpendicular to the direction of arc travel are analyzed and correlated with weld bead width and depth as measured by destructive examination after the weld production. The results show that there is a linear relationship between peak weld plate surface temperature and depth of penetration. Additionally, surface puddle width is found to be directly correlated to measured distance separating solidus temperatures of the molten metal as measured by infrared thermography.

  11. On Line Sensing Of Weld Penetration Using Infrared Thermography

    NASA Astrophysics Data System (ADS)

    Wang, Yuwen; Chin, B. A.

    1986-10-01

    The objective of this research is to apply new sensing techniques, artificial intelligence, and robotics to improve the welding process through control of penetration depth and width parameters. By producing a constant depth and width of penetration through on line control, the quality and strength of welds may be improved to a new level of reliability previously unobtainable. Experimental data presented in this paper indicate that depth and width of penetration can be monitored by infrared thermography and hence controlled dynamically during the weld process. Infrared thermography is used to monitor surface temperature distributions in the vicinity of the molten metal pool. Characteristics of temperature distributions perpendicular to the direction of arc travel are analyzed and correlated with weld bead width and depth as measured by destructive examination after the weld production. The results show that there is a linear relationship between peak weld plate surface temperature and depth of penetration. Additionally, surface puddle width is found to be directly correlated to measured distance separating solidus temperatures of the molten metal as measured by infrared thermography.

  12. Applications of the thermography in the animal production

    NASA Astrophysics Data System (ADS)

    Piñeiro, Carlos; Vizcaino, Elena; Morales, Joaquín.; Manso, Alberto; Díaz, Immaculada; Montalvo, Gema

    2015-04-01

    Infrared thermography is a working technology for over decades, which have been applied mainly in the buildings. We want to move this use to the animal production in order to help us to detect problems of energy efficiency in the facilities preventing, for example, the animal's welfare. In animal production it is necessary to provide a suitable microclimate according to age and production stage of the animals. This microclimate is achieved in the facilities through the environment modification artificially, providing an appropriate comfort for the animals. Many of the problems detected in farms are related to a poor environmental management and control. This is where infrared thermography becomes an essential diagnostic tool to detect failures in the facilities that will be related with health and performance of the animals. The use of this technology in energy audits for buildings, facilities, etc. is becoming more frequent, enabling the technician to easily detect and assess the temperature and energy losses, and it can be used as a support to draft reports and to transmit the situation to the owner in a visual format. In this way, both will be able to decide what improvements are required. Until now, there was not an appropriate technology with affordable prices and easy to manage enough in order to allow the use of the thermography like a routine tool for the diagnostic of these problems, but currently there are some solutions which are starting to appear on the market to meet the requirements needed by the industry.

  13. Medical thermography (digital infrared thermal imaging - DITI) in paediatric forearm fractures - A pilot study.

    PubMed

    Ćurković, S; Antabak, A; Halužan, D; Luetić, T; Prlić, I; Šiško, J

    2015-11-01

    Trauma is the most common cause of hospitalisation in children, and forearm fractures comprise 35% of all paediatric fractures. One-third of forearm fractures are distal forearm fractures, which are the most common fractures in the paediatric population. This type of fracture represents an everyday problem for the paediatric surgeon. The three phases of fracture healing in paediatric trauma are associated with skin temperature changes that can be measured and then compared with standard plain radiographs of visible callus formation, and eventually these methods can be used in everyday practice. Thermographic assessment of temperature distribution within the examined tissues enables a quick, non-contact, non-invasive measurement of their temperature. Medical thermography is used as a screening method in other parts of medicine, but the use of this method in traumatology has still not been researched. PMID:26603613

  14. Combined use of terrestrial laser scanning and IR thermography applied to a historical building.

    PubMed

    Costanzo, Antonio; Minasi, Mario; Casula, Giuseppe; Musacchio, Massimo; Buongiorno, Maria Fabrizia

    2015-01-01

    The conservation of architectural heritage usually requires a multidisciplinary approach involving a variety of specialist expertise and techniques. Nevertheless, destructive techniques should be avoided, wherever possible, in order to preserve the integrity of the historical buildings, therefore the development of non-destructive and non-contact techniques is extremely important. In this framework, a methodology for combining the terrestrial laser scanning and the infrared thermal images is proposed, in order to obtain a reconnaissance of the conservation state of a historical building. The proposed case study is represented by St. Augustine Monumental Compound, located in the historical centre of the town of Cosenza (Calabria, South Italy). Adopting the proposed methodology, the paper illustrates the main results obtained for the building test overlaying and comparing the collected data with both techniques, in order to outline the capabilities both to detect the anomalies and to improve the knowledge on health state of the masonry building. The 3D model, also, allows to provide a reference model, laying the groundwork for implementation of a monitoring multisensor system based on the use of non-destructive techniques. PMID:25609042

  15. Sportswear textiles emissivity measurement: comparison of IR thermography and emissometry techniques

    NASA Astrophysics Data System (ADS)

    Bison, P.; Grinzato, E.; Libbra, A.; Muscio, A.

    2012-06-01

    Three sportswear textiles are compared, one normal and two 'special' with Ag+ ions and Carbon powder added, with different colors. The emissivity of the textiles has been measured to determine if it is increased in the 'special' textiles with respect to the normal one. The test implied some non-standard procedure due to the semitransparent nature of the textiles, in comparison with the normal procedure that is commonly used on opaque surfaces. The test is also carried out by a standard emissometry technique, based on a comparative approach with reference samples having known thermal emissivity. The results are compared and discussed.

  16. Combined Use of Terrestrial Laser Scanning and IR Thermography Applied to a Historical Building

    PubMed Central

    Costanzo, Antonio; Minasi, Mario; Casula, Giuseppe; Musacchio, Massimo; Buongiorno, Maria Fabrizia

    2015-01-01

    The conservation of architectural heritage usually requires a multidisciplinary approach involving a variety of specialist expertise and techniques. Nevertheless, destructive techniques should be avoided, wherever possible, in order to preserve the integrity of the historical buildings, therefore the development of non-destructive and non-contact techniques is extremely important. In this framework, a methodology for combining the terrestrial laser scanning and the infrared thermal images is proposed, in order to obtain a reconnaissance of the conservation state of a historical building. The proposed case study is represented by St. Augustine Monumental Compound, located in the historical centre of the town of Cosenza (Calabria, South Italy). Adopting the proposed methodology, the paper illustrates the main results obtained for the building test overlaying and comparing the collected data with both techniques, in order to outline the capabilities both to detect the anomalies and to improve the knowledge on health state of the masonry building. The 3D model, also, allows to provide a reference model, laying the groundwork for implementation of a monitoring multisensor system based on the use of non-destructive techniques. PMID:25609042

  17. Infrared thermography system on DIII-D

    SciTech Connect

    Petrie, T.W. ); Hill, D.N.; Baptista, J.; Brown, M. )

    1990-10-01

    Six infrared cameras measure temperature changes on the protective graphite armor inside the DIII-D vacuum vessel. Simultaneous time dependent temperature measurements are made on armor tiles located on the centerpost and divertor regions, and on both outboard limiters. The nearly-complete poloidal coverage is useful in measuring both the plasma heat flux distributions inside the vessel and the plasma power balance. Spatial resolution of each camera system is {approx lt}1 cm, while the minimum resolvable time is 125 {mu}sec. Data from the IR TV systems is recorded on video tape, and is post-processed serially, using an image processor with an AT-compatible microcomputer. The processing system controls all VCRs, interprets DIII-D timing pulses, digitizes video data in the pre-determined regions of interest, averages digitized signals to reduce noise, and constructs data files which are then stored as part of the permanent shot record.

  18. IR Windstreaks

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Windstreaks are features caused by the interaction of wind and topographic landforms. The raised rims and bowls of impact craters causes a complex interaction such that the wind vortex in the lee of the crater can both scour away the surface dust and deposit it back in the center of the lee. If you look closely, you will see evidence of this in a darker 'rim' enclosing a brighter interior.

    This infrared image shows windstreaks in the region between Gordii Dorsum and Amazonis Mensa.

    Image information: IR instrument. Latitude -15.8, Longitude 215 East (145 West). 97 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. [The use of a method of solid-phase extraction for sample preparation in the identification of unknown substances by IR spectroscopy].

    PubMed

    Beliaev, A V; Sorokin, V I; Orlova, O S; Kimstach, T B

    1997-01-01

    Identification of synthetic narcotics is difficult because they do not possess any apparent individual signs and the specimens are contaminated with various fillers and additives, which rules out investigations by infrared spectroscopy, widely used in expert practice. Use of solid-phase extraction during preparation of samples helps prepare highly purified samples which can be further identified by IR spectroscopy. The authors present the protocol of identification of unknown substances and recognition of narcotics and describe methods for identification of some confiscated narcotics (methadone, MDA, phencyclidine, methaqualone, codeine, ethylmorphine, cocaine, etc.). PMID:9304249

  20. Automated Fast Screening Method for Cocaine Identification in Seized Drug Samples Using a Portable Fourier Transform Infrared (FT-IR) Instrument.

    PubMed

    Mainali, Dipak; Seelenbinder, John

    2016-05-01

    Quick and presumptive identification of seized drug samples without destroying evidence is necessary for law enforcement officials to control the trafficking and abuse of drugs. This work reports an automated screening method to detect the presence of cocaine in seized samples using portable Fourier transform infrared (FT-IR) spectrometers. The method is based on the identification of well-defined characteristic vibrational frequencies related to the functional group of the cocaine molecule and is fully automated through the use of an expert system. Traditionally, analysts look for key functional group bands in the infrared spectra and characterization of the molecules present is dependent on user interpretation. This implies the need for user expertise, especially in samples that likely are mixtures. As such, this approach is biased and also not suitable for non-experts. The method proposed in this work uses the well-established "center of gravity" peak picking mathematical algorithm and combines it with the conditional reporting feature in MicroLab software to provide an automated method that can be successfully employed by users with varied experience levels. The method reports the confidence level of cocaine present only when a certain number of cocaine related peaks are identified by the automated method. Unlike library search and chemometric methods that are dependent on the library database or the training set samples used to build the calibration model, the proposed method is relatively independent of adulterants and diluents present in the seized mixture. This automated method in combination with a portable FT-IR spectrometer provides law enforcement officials, criminal investigators, or forensic experts a quick field-based prescreening capability for the presence of cocaine in seized drug samples. PMID:27006022

  1. Inversion of tone burst eddy current thermography data for defect sizing - A simulation study

    NASA Astrophysics Data System (ADS)

    Biju, N.; Ganesan, N.; Krishnamurthy, C. V.; Balasubramaniam, Krishnan

    2013-01-01

    In this paper, the results of the simulation study to reconstruct the size of the defects from the data obtained using the active thermography technique based on transient induction heating, will be presented. The forward problem of electro-magnetic induction was solved with an axi-symmetric model using finite element method and from the temperature history profiles, an inverse analysis was performed using Genetic Algorithm (GA) to size the defect. Simulations were performed using the finite element model to obtain the temperature data which are then used to reconstruct the radius (rd) and depth (dd) of the wall thinning defects in aluminum plate using inversion method. Two cases, coil inner radius less than the defect radius (rcrd), were considered. The analysis of the sensitivity of coil dimensions to the calculated peak temperature at the observation point was carried out.

  2. Non-destructive testing of works of art by stimulated infrared thermography

    NASA Astrophysics Data System (ADS)

    Candoré, J. C.; Bodnar, J. L.; Detalle, V.; Grossel, P.

    2012-02-01

    In this work, we present various examples of assistance to the restoration of works of art by stimulated infrared thermography. We show initially that the method allows the detection of delamination located in mural paintings, such as in the "Saint Christophe" of the Campana collection of the Louvre French museum. We show then that it also makes it possible to detect delaminations or galleries of worms in marquetries. We show in a third stage that it provides for the detection of detachment of grayness in stained glasses. We show in a fourth stage that it allows the visualization of shards or metal inserts located in a Greek "panathénaque" amphora of the French National museum of the Ceramics of Sevres. We show finally, that the method permits the detection of a crack located in an ovoid vase of the same French National museum of the Ceramics of Sevres.

  3. Using lock-in infrared thermography for the visualization of the hand vascular tree

    NASA Astrophysics Data System (ADS)

    Bouzida, Nabila; Bendada, Abdel Hakim; Piau, Jean-Marc; Akhloufi, Moulay; Maldague, Xavier; Raymond, Mathieu

    2008-03-01

    An imaging technique of the hand vein tree is presented in this paper. Using the natural human circulatory system and a controlled armband pressure around the arm, a lock-in thermography technique with an internal excitation is carried out. Since the stimulation frequency is inversely proportional to the inspection depth, the subcutaneous layer requires the use of a very slow frequency. Thus, a sawtooth waveform is preferred to minimize the duration of the pressure applied to the armband during the experiment. A frequency of approximately 0.03 Hz and a pressure range between 100 and 140 mmHg, according to the diastolic and systolic blood pressure, are used as stimulation. Then, dorsal hand amplitude and phase images are obtained with IR_view (Klein, 1999), a tool specifically designed to analyze infrared images. The hand vein structure is thermally mapped by an infrared camera operating in the middle wavelength infrared range (MWIR) at room temperature. Parasitic frequencies are avoided by keeping the hand fixed. The resulting images show a gradient of temperature between surrounding tissues and the back-of-hand veins. The vascular signature segmentation is extracted from the amplitude and phase images by using a Fast Fourier Transform image processing technique. This work could be used for vein localization for perfusion or for the early diagnosis of vein diseases such as primitive varicose and deep vein thrombosis (DVT). A hand vein signature database for identification purposes is also possible.

  4. Infrared thermography of fan and compressor systems in a predictive maintenance program

    NASA Astrophysics Data System (ADS)

    Wurzbach, Richard N.

    1998-03-01

    Predictive Maintenance programs have been shown to be an effective and efficient approach to managing facilities maintenance. Cost savings through the reduction of time- based preventive tasks, and the reduction of unanticipated failures can be significant. Several inspection techniques have become standard, and are applicable to a broad range of equipment types and inspection scenarios. IR thermography of fan and compressor equipment presents a significant opportunity for cost saving applications in may facilities. Ventilation systems supply air to and remove air from working spaces, and mitigate environmental conditions for a number or purposes. Removal of hazardous pairs or gases, positive pressure atmosphere, or negative pressure atmosphere are a few examples. Vaneaxial fans are a common equipment type used to achieve this purpose. Both direct drive and belt driven fans are common for these systems. Belt drives present some unique imaging applications, where sheave and belt surface scan be observed. Compressor equipment has normally high operating temperatures, relative to other rotating equipment. The compression of gases is exothermic, and as a result, most compressors rely on an integral cooling process to function properly. Uniformity of temperature distribution on equipment surfaces, function of cooling systems, and verification of proper operation of loading and relief valves provide an overall illustration of equipment health.

  5. Characterization of atherosclerotic plaque by reflection spectroscopy and thermography: a comparison

    NASA Astrophysics Data System (ADS)

    Lilledahl, Magnus B.; Haugen, Olav A.; Randeberg, Lise L.; Svaasand, Lars O.

    2005-04-01

    Many methods for detecting and measuring vulnerable atherosclerotic plaques have been proposed. These include reflection spectroscopy, thermography, ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). This paper presents an analysis and a comparison of two of these methods, near-infrared reflection spectroscopy (NIRS) and thermography. Most of the published literature evaluate methods statistically. A more analytic approach will make it easier to compare the different methods and determine if the measured signal will be strong enough in a real measurement situation. This is the approach taken in this article. Eight samples of human aorta were examined by NIRS and subsequently prepared for histology. A total of 28 measurement points were selected. A measure of the lipid content based on reflection spectra is proposed. Comparisons of this lipid measure with histology show that the lipid content in the plaques yields relatively small changes in the value of this lipid-index. Reflectance spectra from models based on the diffusion approximation for total reflectance were simulated. Temperature measurements were performed on three Watanabe heritable hyperlipidemic (WHHL) rabbits and one New Zealand white (NZW) rabbit with a thermistor-type intravascular temperature sensor. The measurements gave no significant signals which correlated with the subsequent histology. A simple analytic model was developed which indicates that a temperature increase of more than 0.01-0.04 °C at the surface of a vessel wall, due to inflammation in a plaque, is unlikely. Such a small temperature difference will probably be obscured by normal variation in the vessel wall temperature.

  6. The effect of L mode filaments on divertor heat flux profiles as measured by infrared thermography on MAST

    NASA Astrophysics Data System (ADS)

    Thornton, A. J.; Fishpool, G.; Kirk, A.; the MAST Team; the EUROfusion MST1 Team

    2015-11-01

    Filamentary transport across the scrape off layer is a key issue for the design and operation of future devices, such as ITER, DEMO and MAST-U, as it sets the power loadings to the divertor and first wall of the machine. Analysis has been performed on L mode filaments in MAST in order to gain an understanding of the spatial structure and attempt to reconcile the different scales of the filament width and the power fall off length ({λq} ). The L mode filament heat flux arriving at the divertor has been measured using high spatial resolution (1.5 mm) infrared (IR) thermography. The filaments form discrete spiral patterns at the divertor which can be seen as bands of increased heat flux in the IR measurements. Analysis of the width and spacing of these bands at the divertor has allowed the toroidal mode number of the filaments to be determined (7≤slant n≤slant 22 ). The size of the filaments at the midplane has been determined using the target filament radial width and the magnetic field geometry. The filament width perpendicular to the magnetic field at the midplane has been found to be between 3 and 5 cm. Direct calculation of the filament width from midplane visible imaging gives a range of 4-6 cm which agrees well with the IR data.

  7. A calibration method for the measurement of IR detector spectral responses using a FTIR spectrometer equipped with a DTGS reference cell

    NASA Astrophysics Data System (ADS)

    Gravrand, Olivier; Wlassow, J.; Bonnefond, L.

    2014-07-01

    Various high performance IR detectors are today available on the market from QWIPs to narrow gap semiconductor photodiodes, which exhibit various spectral features. In the astrophysics community, the knowledge of the detector spectral shape is of first importance. This quantity (spectral QE or response) is usually measured by means of a monochromator followed by an integrating sphere and compared to a calibrated reference detector. This approach is usually very efficient in the visible range, where all optical elements are very well known, particularly the reference detector. This setup is also widely used in the near IR (up to 3μm) but as the wavelength increases, it becomes less efficient. For instance, the internal emittance of integrating spheres in the IR, and the bad knowledge of reference detectors for longer wavelengths tend to degrade the measurement reliability. Another approach may therefore be considered, using a Fourier transform IR spectrometer (FTIR). In this case, as opposed to the monochromator, the tested detector is not in low flux condition, the incident light containing a mix of different wavelengths. Therefore, the reference detector has to be to be sensitive (and known) in the whole spectral band of interest, because it will sense all those wavelengths at the same time. A popular detector used in this case is a Deuterated Triglycine Sulfate thermal detector (DTGS). Being a pyro detetector, the spectral response of such a detector is very flat, mainly limited by its window. However, the response of such a detector is very slow, highly depending on the temporal frequency of the input signal. Moreover, being a differential detector, it doesn't work in DC. In commercial FTIR spectrometers, the source luminance is usually continuously modulated by the moving interferometer, and the result is that the interferogram mixes optical spectral information (optical path difference) and temporal variations (temporal frequency) so that the temporal

  8. Use of thermography in testing skin creams

    NASA Astrophysics Data System (ADS)

    Anttonen, Hannu; Kauppinen, Timo T.; Lehmuskallio, Eero; Rintamaki, Hannu

    1994-03-01

    The aim of the study was to test the effect of skin creams and their components in windy (3 m/s) and cold (-15 degree(s)C) conditions on face temperature and heat flux. The tests were carried out in a climatic chamber with 18 persons sitting in front of the opening of the wind tunnel, the wind directed against the face. Skin temperatures were measured from 4 points on both sides of the face with thermistors and the heat fluxes were measured using heat flux sensors on both cheeks. Also the ambient temperature and wind were registered. In addition to these measurements an IR thermal scanner was also used to measure the spatial and temporal distribution of temperature variation on the face during the exposure. The results were continuously recorded on VHS-video tape. Using still pictures from recorded material the area temperature of the cheek was measured, which described the mean temperature of the cheek. Test periods were 30 minutes and the same test subjects were not used until 48 h after the previous cold exposure. The test persons were young (20 - 30 years) healthy male persons. The total number of tests was 38.

  9. Stability-indicating reversed-phase HPLC method development and characterization of impurities in vortioxetine utilizing LC-MS, IR and NMR.

    PubMed

    Liu, Lei; Cao, Na; Ma, Xingling; Xiong, Kaihe; Sun, Lili; Zou, Qiaogen; Yao, Lili

    2016-01-01

    The current study reports the development and validation of a stability-indicating reversed phase HPLC method for the separation and identification of potential impurities in vortioxetine, a recently developed antidepressant. The structures of a new compound and four process-related impurities formed during the synthesis were characterized and confirmed by NMR, MS, and IR spectroscopy analyses. The most probable formation mechanisms of the impurities identified were proposed. Based on the characterization data, the new compound was proposed to be 1-[4-[(2,4-dimethylphenyl)thio]phenyl]-piperazine. In addition, an efficient chromatographic method was optimized to separate and quantify the impurities, which were obtained in the 0.05-0.75 μg/mL range. The developed HPLC method was validated with respect to accuracy, precision, linearity, robustness, and limits of detection and quantitation. PMID:26412721

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

    PubMed Central

    Szymanik, Barbara; Frankowski, Paweł Karol; Chady, Tomasz; John Chelliah, Cyril Robinson Azariah

    2016-01-01

    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. PMID:26891305

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

    PubMed

    Szymanik, Barbara; Frankowski, Paweł Karol; Chady, Tomasz; John Chelliah, Cyril Robinson Azariah

    2016-01-01

    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. PMID:26891305

  12. Simplified method for the determination of Ru, Pd, Re, Os, Ir and Pt in chromitites and other geological materials by isotope dilution ICP-MS and acid digestion.

    PubMed

    Meisel, T; Moser, J; Fellner, N; Wegscheider, W; Schoenberg, R

    2001-03-01

    A method for the determination of low Ru, Pd, Re, Os, Ir and Pt abundances in geological reference materials by isotope dilution inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion in a high pressure asher (HPA-S) is presented. The digestion technique is similar to that using Carius tubes but easier to handle and reaches higher temperatures. Osmium can be determined as OsO4 with ICP-MS directly after digestion through a sparging technique. The remaining elements are preconcentrated by means of anion column chromatography. The resin is digested directly without elution leading to high yields but this causes problems if Zr is present at higher levels in the silicate rich materials. The analytical results for international platinum group element (PGE) reference materials, chromitite CHR-Bkg, basalt TDB-1 and gabbro WGB-1, are presented and compared with literature data, demonstrating the validity of the described method. Although higher in concentration, PGEs determined for reference material WGB-1 were worse than for TDB-1 indicating a more inhomogeneous distribution of the platinum group mineral phases. The low PGE abundance chromitite standard, CHR-Bkg, is likely to be homogeneous for Ru, Re, Os and Ir and is recommended as a reference material for the study of chromitites. Detection limits (3s x total procedure blank) range from 0.012 ng (Re and Os) to 0.77 ng (Pt), which could be further improved by applying higher quality acids. PMID:11284333

  13. Depth-Penetrating Luminescence Thermography of Thermal- Barrier Coatings

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey

    2005-01-01

    A thermographic method has been developed for measuring temperatures at predetermined depths within dielectric material layers . especially thermal-barrier coatings. This method will help satisfy a need for noncontact measurement of through-the-thickness temperature gradients for evaluating the effectiveness of thermal- barrier coatings designed to prevent overheating of turbine blades, combustor liners, and other engine parts. Heretofore, thermography has been limited to measurement of surface and near-surface temperatures. In the thermographic method that is the immediate predecessor of the present method, a thermographic phosphor is applied to the outer surface of a thermal barrier coating, luminescence in the phosphor is excited by illuminating the phosphor at a suitable wavelength, and either the time dependence of the intensity of luminescence or the intensities of luminescence spectral lines is measured. Then an emissivity-independent surface-temperature value is computed by use of either the known temperature dependence of the luminescence decay time or the known temperature dependence of ratios between intensities of selected luminescence spectral lines. Until now, depth-penetrating measurements have not been possible because light of the wavelengths needed to excite phosphors could not penetrate thermal-barrier coating materials to useful depths. In the present method as in the method described above, one exploits the temperature dependence of luminescence decay time. In this case, the phosphor is incorporated into the thermal-barrier coat at the depth at which temperature is to be measured. To be suitable for use in this method, a phosphor must (1) exhibit a temperature dependence of luminescence decay time in the desired range, (2) be thermochemically compatible with the thermal-barrier coating, and (3) exhibit at least a minor excitation spectral peak and an emission spectral peak, both peaks being at wavelengths at which the thermal-barrier coating is

  14. Real Time Fatigue Damage Growth Assessment of a Composite Three-Stringer Panel Using Passive Thermography

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N.; Burke, Eric R.; Horne, Michael R.; Bly, James B.

    2015-01-01

    Fatigue testing of advanced composite structures is critical to validate both structural designs and damage prediction models. In-situ inspection methods are necessary to track damage onset and growth as a function of load cycles. Passive thermography is a large area, noncontact inspection technique that is used to detect composite damage onset and growth in real time as a function of fatigue cycles. The thermal images are acquired in synchronicity to the applied compressive load using a dual infrared camera acquisition system for full (front and back) coverage. Image processing algorithms are investigated to increase defect contrast areas. The thermal results are compared to non-immersion ultrasound inspections and acoustic emission data.

  15. Evaluation of thermal load during laser corneal refractive surgery using infrared thermography

    NASA Astrophysics Data System (ADS)

    Brunsmann, U.; Sauer, U.; Arba-Mosquera, S.; Magnago, T.; Triefenbach, N.

    2010-09-01

    Infrared thermography is used for evaluation of the mean temperature as a measure of thermal load during corneal refractive surgery. An experimental method to determine emissivity and to calibrate the thermografic system is presented. In a case study on the porcine eye two dimensional temperature distributions with lateral resolution of 170 μm and line scans with temporal resolution of 13 μs are discussed with respect to the meaning of mean temperature. Using the newest generation of surgery equipment it is shown, that the mean temperature rise can be kept below 5 °C during myopic laser in situ keratomileusis (LASIK) treatments corresponding to an aberration-free correction of -2.75 diopter.

  16. Dimensionless heat transfer model to compress and analyze pulsed thermography data for NDT of materials

    NASA Astrophysics Data System (ADS)

    Ramirez-Granados, Juan C.; Paez, G.; Strojnik, M.

    2008-03-01

    We develop a dimensionless heat transfer model to analyze pulsed thermography data for non-destructive testing (NDT) of materials. Simulated thermographic sequences are used in order to evaluate the performance of the inspection technique. Also, we inspect organic and inorganic samples, including a layered plate and two dental pieces, in search of internal defects and structural inhomogeneities. We detect cavities and the inner structure of the samples by means of reconstructed thermograms and a modified version of the differential absolute contrast (DAC). Moreover, we develop an effective data compression method that reduces a thermographic video with m frames of p × q pixels to two matrices of p × q elements. In this data reconstruction process, precision and compression ratio are independent parameters. Finally, we find that partial translucency of dental enamel, in infrared, permits imaging of the internal structure of a tooth. This inspection technique does not require a priori knowledge about a reference defect-free area.

  17. Comparison of luminescence imaging and illuminated lock-in thermography on silicon solar cells

    NASA Astrophysics Data System (ADS)

    Kasemann, Martin; Schubert, Martin C.; The, Manuel; Köber, Mariana; Hermle, Martin; Warta, Wilhelm

    2006-11-01

    Spatially resolved electroluminescence (EL) and photoluminescence (PL) images of solar cells are compared to spatially resolved power loss images obtained by illuminated lock-in thermography (ILIT). A significant difference is shown for a solar cell with shunts, while series resistance and charge carrier recombination cause only minor differences in the images. The PL image of a solar cell with shunts appears highly blurred in the shunted region. The origin of this effect is discussed, and a circuit simulation with an appropriate solar cell model is performed. The authors conclude that the blurring of shunted regions is inherent in the method of EL/PL imaging and that ILIT is advantageous for localizing shunts.

  18. Logarithmic analysis of eddy current thermography based on longitudinal heat conduction for subsurface defect evaluation

    NASA Astrophysics Data System (ADS)

    Yang, Ruizhen; He, Yunze

    2014-11-01

    Longitudinal heat conduction from surface to inside of solid material could be used to evaluate the subsurface defects. Considering that the skin depth of high frequency eddy current in metal is quite small, this paper proposed logarithmic analysis of eddy current thermography (ECT) to quantify the depth of subsurface defects. The proposed method was verified through numerical and experimental studies. In numerical study, ferromagnetic material and non-ferromagnetic material were both considered. Results showed that the temperature-time curve in the logarithm domain could be used to detect subsurface defects. Separation time was defined as the characteristic feature to measure the defect's depth based on their linear relationships. The thermograms reconstructed by logarithm of temperature can improve defect detectability.

  19. The use of thermography in energy performance of buildings-directive (EPBD)-applications

    NASA Astrophysics Data System (ADS)

    Kauppinen, T.

    2009-05-01

    EPBD-directive has taken into the use in European Union Countries. In Finland, in connection with the directive and with harmonization of building codes, the building codes dealing with insulation and energy use has been renewed. At the first time there is a requirement of energy efficiency calculations. Energy efficiency is connected with energy labeling. Also first time there are now prerequisites for air tightness of buildings. These new challenges have created a boom of increased quality control needs in construction companies, including different verification methods. The use of thermography and air-tightness test (blower door tests) has been exploited by increasing speed. The interpretation of result will be a growing problem, even lot of work has been done e.g. in certification procedure of building thermographers. In this presentation some results of multi-storey apartment houses and other targets will be presented, and discussion about the problems which may occur in the future.

  20. Application of line scanning thermography for the detection of interlaminar disbonds in sandwich composite structures

    NASA Astrophysics Data System (ADS)

    Ley, Obdulia; Chung, Simon; Schutte, Jaco; Caiazzo, Anthony; Godinez, Valery; Bandos, Bruce

    2010-04-01

    An innovative Line Scanning Thermography (LST) inspection method is being developed as part of a Structural Damage Assessment System to access the health of in-service composite structures. The system utilizes a line heat source to thermally excite the surface inspected and an infrared detector to record the transient surface temperature variation and to detect regions of increased heat resistance associated to interlaminar disbonds, cracks and other imperfections found in composites structures. In this study our efforts towards the applications of LST for the analysis of carbon fiber sandwich composites will be discussed. The LST technique provides a quick and efficient methodology to scan wide areas rapidly. The scanning protocols developed for the detection of sub-surface disbonds (delamination) in composite sandwich parts will be presented. The results presented correspond to scans of test coupons with manufactured defects.

  1. Effect of Gold Nanoparticles on Prostate Dose Distribution under Ir-192 Internal and 18 MV External Radiotherapy Procedures Using Gel Dosimetry and Monte Carlo Method

    PubMed Central

    Khosravi, H.; Hashemi, B.; Mahdavi, S. R.; Hejazi, P.

    2015-01-01

    Background Gel polymers are considered as new dosimeters for determining radiotherapy dose distribution in three dimensions. Objective The ability of a new formulation of MAGIC-f polymer gel was assessed by experimental measurement and Monte Carlo (MC) method for studying the effect of gold nanoparticles (GNPs) in prostate dose distributions under the internal Ir-192 and external 18MV radiotherapy practices. Method A Plexiglas phantom was made representing human pelvis. The GNP shaving 15 nm in diameter and 0.1 mM concentration were synthesized using chemical reduction method. Then, a new formulation of MAGIC-f gel was synthesized. The fabricated gel was poured in the tubes located at the prostate (with and without the GNPs) and bladder locations of the phantom. The phantom was irradiated to an Ir-192 source and 18 MV beam of a Varian linac separately based on common radiotherapy procedures used for prostate cancer. After 24 hours, the irradiated gels were read using a Siemens 1.5 Tesla MRI scanner. The absolute doses at the reference points and isodose curves resulted from the experimental measurement of the gels and MC simulations following the internal and external radiotherapy practices were compared. Results The mean absorbed doses measured with the gel in the presence of the GNPs in prostate were 15% and 8 % higher than the corresponding values without the GNPs under the internal and external radiation therapies, respectively. MC simulations also indicated a dose increase of 14 % and 7 % due to presence of the GNPs, for the same experimental internal and external radiotherapy practices, respectively. Conclusion There was a good agreement between the dose enhancement factors (DEFs) estimated with MC simulations and experiment gel measurements due to the GNPs. The results indicated that the polymer gel dosimetry method as developed and used in this study, can be recommended as a reliable method for investigating the DEF of GNPs in internal and external

  2. Advanced IR System For Supersonic Boundary Layer Transition Flight Experiment

    NASA Technical Reports Server (NTRS)

    Banks, Daniel W.

    2008-01-01

    Infrared thermography is a preferred method investigating transition in flight: a) Global and non-intrusive; b) Can also be used to visualize and characterize other fluid mechanic phenomena such as shock impingement, separation etc. F-15 based system was updated with new camera and digital video recorder to support high Reynolds number transition tests. Digital Recording improves image quality and analysis capability and allows for accurate quantitative (temperature) measurements and greater enhancement through image processing allows analysis of smaller scale phenomena.

  3. [Methods of studying the microcirculation].

    PubMed

    Shagal, D I; Tsvik, A I; Razygrin, B A

    1980-01-01

    The article shows possibilities of thermography in the study of peripheral blood circulation. Data are presented on examining the patients with diverse pathology forms by means of conjunctival biomicroscopy and television capillaroscopy of the nail bed. Evaluation of these methods and analysis of the data obtained are presented. The authors believe in more extended possibilities of applying microcirculation study methods together with thermography for disclosure of some diseases. PMID:7402036

  4. Infrared thermography monitoring of the NaCl crystallisation process

    NASA Astrophysics Data System (ADS)

    Vázquez, Patricia; Thomachot-Schneider, Céline; Mouhoubi, Kamel; Fronteau, Gilles; Gommeaux, Maxime; Benavente, David; Barbin, Vincent; Bodnar, Jean-Luc

    2015-07-01

    In this work, we describe the growth of NaCl crystals by evaporating droplets of aqueous solution while monitoring them with infrared thermography. Over the course of the evaporation experiments, variations in the recorded signal were observed and interpreted as being the result of evaporation and crystallisation. In particular, we observed sharp and transient decreases in the thermosignal during the later stages of high-concentration drop evaporation. The number of such events per experiment, referred to as "pop-cold events", varied from 1 to over 100 and had durations from 1 to 15 s. These events are interpreted as a consequence from the top-supplied creeping (TSC) of the solution feeding the growth of efflorescence-like crystals. This phenomenon occurred when the solution was no longer macroscopically visible. In this case, efflorescence-like crystals with a spherulite shape grew around previously formed cubic crystals. Other crystal morphologies were also observed but were likely fed by mass diffusion or bottom-supplied creeping (BSC) and were not associated with "pop-cold events"; these morphologies included the cubic crystals at the centre, ring-shaped at the edge of droplets and fan-shaped crystals. After complete evaporation, an analysis of the numbers and sizes of the different types of crystals was performed using image processing. Clear differences in their sizes and distribution were observed in relation to the salt concentration. Infrared thermography permitted a level of quantification that previously was only possible using other techniques. As example, the intermittent efflorescence growth process was clearly observed and measured for the first time using infrared thermography.

  5. In-Flight Flow Visualization Using Infrared Thermography

    NASA Technical Reports Server (NTRS)

    vanDam, C. P.; Shiu, H. J.; Banks D. W.

    1997-01-01

    The feasibility of remote infrared thermography of aircraft surfaces during flight to visualize the extent of laminar flow on a target aircraft has been examined. In general, it was determined that such thermograms can be taken successfully using an existing airplane/thermography system (NASA Dryden's F-18 with infrared imaging pod) and that the transition pattern and, thus, the extent of laminar flow can be extracted from these thermograms. Depending on the in-flight distance between the F-18 and the target aircraft, the thermograms can have a spatial resolution of as little as 0.1 inches. The field of view provided by the present remote system is superior to that of prior stationary infrared thermography systems mounted in the fuselage or vertical tail of a subject aircraft. An additional advantage of the present experimental technique is that the target aircraft requires no or minimal modifications. An image processing procedure was developed which improves the signal-to-noise ratio of the thermograms. Problems encountered during the analog recording of the thermograms (banding of video images) made it impossible to evaluate the adequacy of the present imaging system and image processing procedure to detect transition on untreated metal surfaces. The high reflectance, high thermal difussivity, and low emittance of metal surfaces tend to degrade the images to an extent that it is very difficult to extract transition information from them. The application of a thin (0.005 inches) self-adhesive insulating film to the surface is shown to solve this problem satisfactorily. In addition to the problem of infrared based transition detection on untreated metal surfaces, future flight tests will also concentrate on the visualization of other flow phenomena such as flow separation and reattachment.

  6. Eddy current step heating thermography for quantitatively evaluation

    NASA Astrophysics Data System (ADS)

    He, Yunze; Pan, Mengchun; Chen, Dixiang; Tian, GuiYun; Zhang, Hong

    2013-11-01

    This Letter proposed eddy current step heating thermography (ECSHT) combing eddy current excitation with SHT. It has been verified through numerical and experimental studies that the temperature-time1/2 curve can be used to detect the subsurface defects. Separation time was defined and extracted from temperature responses as characteristic feature. Experiment studies with mild steel sample were conducted, and the experimental results showed that two features representing separation time can be used to measure the defect's depth based on their linear relationships.

  7. Crack detection using pulsed eddy current stimulated thermography

    SciTech Connect

    Kostson, E.; Weekes, B.; Almond, D. P.; Wilson, J.; Tian, G. Y.

    2011-06-23

    This contribution presents results from studies investigating factors that influence the detection of surface breaking cracks using pulsed eddy current thermography. The influences of the current strength and crack orientation in both ferromagnetic and non-ferromagnetic metals have been investigated. It has been found that crack detection is far more sensitive to crack orientation in non-ferromagnetic metals than in ferromagnetic metals. The effects of crack size on detectability are presented for a large number of steel, nickel alloy and titanium samples. Results of studies comparing crack images obtained prior and after coating a nickel alloy sample with a thermal barrier coating are presented.

  8. Applications of infrared thermography for petrochemical process heaters

    NASA Astrophysics Data System (ADS)

    Weigle, Robert K.

    2005-03-01

    Process heaters are a critical component in the refining of crude oil. Traditional means of monitoring these high temperature vessels have frequently been more art than science, often relying on highly subjective analyses and/or frequently inaccurate thermocouple data. By utilizing an imaging radiometer specifically designed for heater inspections, valuable performance information can be obtained for operating heaters. In the hands of a knowledgeable engineering team, accurate infrared data can be utilized to significantly increase heater throughput while helping to ensure safe operation of the heater. This paper discusses the use of infrared thermography for online monitoring of operating crude heaters and the special challenges associated with this application.

  9. Visualization of In-Flight Flow Phenomena Using Infrared Thermography

    NASA Technical Reports Server (NTRS)

    Banks, D. W.; vanDam, C. P.; Shiu, H. J.; Miller, G. M.

    2000-01-01

    Infrared thermography was used to obtain data on the state of the boundary layer of a natural laminar flow airfoil in supersonic flight. In addition to the laminar-to-turbulent transition boundary, the infrared camera was able to detect shock waves and present a time dependent view of the flow field. A time dependent heat transfer code was developed to predict temperature distributions on the test subject and any necessary surface treatment. A commercially available infrared camera was adapted for airborne use in this application. Readily available infrared technology has the capability to provide detailed visualization of various flow phenomena in subsonic to hypersonic flight regimes.

  10. Applications and development of IR techniques for building research in Finland

    NASA Astrophysics Data System (ADS)

    Kaasinen, Harri I.; Kauppi, Ari; Nykanen, Esa

    1991-03-01

    Infrared thermography has been used in building research at the Technical Research Centre of Finland (VTT) since 1975. Traditionally this technique has been used to localize defects in thermal insulation and air tightness in the external envelope of buildings. During the past few years it has also been applied successfully to assessing the condition of facades and detecting moisture in structures. This paper briefly describes our experiences with thermography in building research. Multispectral technique has been applied to concrete facades. The principle of this method is also presented in this paper.

  11. Application of spectroscopic methods for identification (FT-IR, Raman spectroscopy) and determination (UV, EPR) of quercetin-3-O-rutinoside. Experimental and DFT based approach

    NASA Astrophysics Data System (ADS)

    Paczkowska, Magdalena; Lewandowska, Kornelia; Bednarski, Waldemar; Mizera, Mikołaj; Podborska, Agnieszka; Krause, Anna; Cielecka-Piontek, Judyta

    2015-04-01

    Vibrational (FT-IR, Raman) and electronic (UV, EPR) spectral measurements were performed for an analysis of rutin (quercetin-3-O-rutinoside) obtained from Rutaofficinalis. The identification of rutin was done with the use of FT-IR and Raman spectra. Those experimental spectra were determined with the support of theoretical calculations based on a DFT method with the B3LYP hybrid functional and 6-31G(d,p) basis set. The application of UV and EPR spectra was found to be a suitable analytical approach to the evaluation of changes in rutin exposed to certain physicochemical factors. Differences in absorbance observed in direct UV spectra were used to monitor changes in the concentration of rutin in degraded samples. Spectra of electron paramagnetic resonance allowed studying the process of free-radical quenching in rutin following its exposure to light. The molecular electrostatic potential (MEP) and frontier molecular orbitals (LUMO-HOMO) were also determined in order to predict structural changes and reactive sites in rutin.

  12. Application of spectroscopic methods for identification (FT-IR, Raman spectroscopy) and determination (UV, EPR) of quercetin-3-O-rutinoside. Experimental and DFT based approach.

    PubMed

    Paczkowska, Magdalena; Lewandowska, Kornelia; Bednarski, Waldemar; Mizera, Mikołaj; Podborska, Agnieszka; Krause, Anna; Cielecka-Piontek, Judyta

    2015-04-01

    Vibrational (FT-IR, Raman) and electronic (UV, EPR) spectral measurements were performed for an analysis of rutin (quercetin-3-O-rutinoside) obtained from Rutaofficinalis. The identification of rutin was done with the use of FT-IR and Raman spectra. Those experimental spectra were determined with the support of theoretical calculations based on a DFT method with the B3LYP hybrid functional and 6-31G(d,p) basis set. The application of UV and EPR spectra was found to be a suitable analytical approach to the evaluation of changes in rutin exposed to certain physicochemical factors. Differences in absorbance observed in direct UV spectra were used to monitor changes in the concentration of rutin in degraded samples. Spectra of electron paramagnetic resonance allowed studying the process of free-radical quenching in rutin following its exposure to light. The molecular electrostatic potential (MEP) and frontier molecular orbitals (LUMO-HOMO) were also determined in order to predict structural changes and reactive sites in rutin. PMID:25589394

  13. Neonatal non-contact respiratory monitoring based on real-time infrared thermography

    PubMed Central

    2011-01-01

    Background Monitoring of vital parameters is an important topic in neonatal daily care. Progress in computational intelligence and medical sensors has facilitated the development of smart bedside monitors that can integrate multiple parameters into a single monitoring system. This paper describes non-contact monitoring of neonatal vital signals based on infrared thermography as a new biomedical engineering application. One signal of clinical interest is the spontaneous respiration rate of the neonate. It will be shown that the respiration rate of neonates can be monitored based on analysis of the anterior naris (nostrils) temperature profile associated with the inspiration and expiration phases successively. Objective The aim of this study is to develop and investigate a new non-contact respiration monitoring modality for neonatal intensive care unit (NICU) using infrared thermography imaging. This development includes subsequent image processing (region of interest (ROI) detection) and optimization. Moreover, it includes further optimization of this non-contact respiration monitoring to be considered as physiological measurement inside NICU wards. Results Continuous wavelet transformation based on Debauches wavelet function was applied to detect the breathing signal within an image stream. Respiration was successfully monitored based on a 0.3°C to 0.5°C temperature difference between the inspiration and expiration phases. Conclusions Although this method has been applied to adults before, this is the first time it was used in a newborn infant population inside the neonatal intensive care unit (NICU). The promising results suggest to include this technology into advanced NICU monitors. PMID:22243660

  14. Plantar thermography is useful in the early diagnosis of diabetic neuropathy

    PubMed Central

    Balbinot, Luciane Fachin; Canani, Luis Henrique; Robinson, Caroline Cabral; Achaval, Matilde; Zaro, Milton Antônio

    2012-01-01

    OBJECTIVES: This study evaluated plantar thermography sensitivity and specificity in diagnosing diabetic polyneuropathy using cardiac tests (heart rate variability) as a reference standard because autonomic small fibers are affected first by this disease. METHODS: Seventy-nine individuals between the ages of 19 and 79 years old (28 males) were evaluated and divided into three groups: control (n = 37), pre-diabetics (n = 13) and type 2 diabetics (n = 29). The plantar images were recorded at baseline and then minutes after a provocative maneuver (Cold Stress Test) using an infrared camera that is appropriate for clinical use. Two thermographic variables were studied: the thermal recovery index and the interdigital anisothermal technique. Heart rate variability was measured in a seven-test battery that included three spectral indexes (in the frequency domain) and four Ewing tests (the Valsalva maneuver, the orthostatic test, a deep breathing test, and the orthostatic hypotension test). Other classically recommended tests were applied, including electromyography (EMG), Michigan inventory, and a clinical interview that included a neurological physical examination. RESULTS: Among the diabetic patients, the interdigital anisothermal technique alone performed better than the thermal recovery index alone, with a better sensitivity (81.3%) and specificity (46.2%). For the pre-diabetic patients, the three tests performed equally well. None of the control subjects displayed abnormal interdigital anisothermal readouts or thermal recovery indices, which precluded the sensitivity estimation in this sample of subjects. However, the specificity (70.6%) was higher in this group. CONCLUSION: In this study, plantar thermography, which predominately considers the small and autonomic fibers that are commonly associated with a sub-clinical condition, proved useful in diagnosing diabetic neuropathy early. The interdigital anisothermal test, when used alone, performed best

  15. Modeling static and dynamic thermography of the human breast under elastic deformation

    NASA Astrophysics Data System (ADS)

    Jiang, Li; Zhan, Wang; Loew, Murray H.

    2011-01-01

    An abnormal thermogram has been shown to be a reliable indicator of increased risk of breast cancer. Numerical modeling techniques for thermography are proposed to quantify the complex relationships between the breast thermal behaviors and the underlying physiological/pathological conditions. Previous thermal modeling techniques did not account for gravity-induced elastic deformation arising from various body postures, nor did they suggest that a dynamic thermal procedure may be used to enhance clinical diagnosis. In this paper, 3D finite element method (FEM)-based thermal and elastic modeling techniques are developed to characterize comprehensively both the thermal and elastic properties of normal and tumorous breast tissues during static and dynamic thermography. In the steady state, gravity-induced breast deformation is found to cause an upper-lower asymmetric surface temperature contrast for sitting/standing up body posture, even though all the thermal and elastic properties are assumed uniform. Additionally, the tumor-induced surface temperature alterations are found to be caused primarily by shallow tumors and to be less sensitive to tumor size than to tumor depth. In the dynamic state, the breast exhibits distinctive temporal patterns that are associated with distinct thermal events: cold stress and thermal recovery induced by changes in the ambient temperature. Specifically, the tumor-induced thermal contrast shows an opposite initial change and delayed peak as compared with the deformation-induced thermal contrast. These findings are expected to provide a stronger foundation for, and greater specificity and precision in, thermographic diagnosis, and treatment of breast cancer.

  16. Infrared thermography sensing for mapping open fractures in deep-seated rockslides and unstable cliffs

    NASA Astrophysics Data System (ADS)

    Baroň, Ivo; Bečkovský, David; Míča, Lumír

    2013-04-01

    The contribution presents in detail the new approach of infrared thermography (IRT) mapping open cracks, tension fractures and pseudo-karst caves within rock slope instabilities presented by Baroň et al. (2012). The method consists in high-resolution ground-based and airborne IRT sensing and it is restricted to cold seasons. Its utility is demonstrated through case studies from the Flysch Belt of the Outer West Carpathians (rockslides at Kopce Hill, Mt. Kněhyně, Křížový Hill, Smrdutá Hill, Pustevny Rockslide and Záryje Rockslide in E Czech Republic) and from the Northern Calcareous Alps (deep-seated gravitational slope deformations in Gschliefgraben / Mt. Traunstein in Austria). The approach is based on a contrast between temperatures deep within the rock, which at a depth of several meters represent local mean annual values, and winter-time temperatures of the ground surface. In winter, warmer, buoyant air from depth rises to the ground surface through open cracks and joints, and the temperature contrast can be detected by IRT. For temperature sensing, we used a Flir B360 thermal camera. Our test survey was conducted in February and December 2012, in order to achieve the best contrast between temperatures around open tension cracks and the adjacent ground surfaces. IRT results conclusively revealed the presence of open cracks, loosened rock zones, and pseudo-karst caves over a distance sometimes greater than 1 km. The IRT approach proved to be useful for rapidly assessing the distribution of open cracks and tension fractures, which is key information required for assessing rockfall and rockslide hazard. Baroň I., Bečkovský D. & Míča L. (2012): Application of infrared thermography for mapping open fractures in deep-seated rockslides and unstable cliffs. - Landslides, Springer Verlag. On-line First. DOI 10.1007/s10346-012-0367-z

  17. Technical note: Relationship between infrared thermography and heat production in young bulls.

    PubMed

    Gomes, R A; Busato, K C; Ladeira, M M; Johnson, K A; Galvão, M C; Rodrigues, A C; Lourençoni, D; Chizzotti, M L

    2016-03-01

    The traditional techniques to measure heat production (HP) are calorimetry (direct and indirect) and comparative slaughter. Both methods are expensive and require extensive amounts of time and infrastructure. Infrared thermography (IRT) could be a faster and less expensive alternative to estimate cattle HP. The objective of this project was to evaluate the use of the IRT technique as an indicator of HP in cattle. A total of 24 bulls (12 Nellore and 12 Black Angus) with initial BW of 380 ± 7 kg were used. Initially, 4 animals of each breed were harvested (baseline animals) and simple regressions were developed for each breed from these baseline animals to estimate the initial chemical composition of the remaining bulls. Eight animals of each breed were fed a silage/concentrate diet for ad libitum intake in individual stalls. On the 25th, 50th, and 75th experimental day, infrared thermal images (Fluke Ti 55ft; Fluke Corporation) were taken of each animal's face to access skin and ocular surface temperatures. A metabolism trial was conducted to estimate the ME intake (MEI). After 84 experimental days, the cattle were harvested and retained energy (RE) and HP were calculated. The data were analyzed using the MIXED and REG procedures of SAS adopting a significance level of 0.05. Angus cattle had a greater daily MEI, HP, and skin and eye temperatures than Nellore. We found significant correlations ( ≤ 0.005) between daily HP and maximum ( = 0.65) and average skin temperatures ( = 0.65) and maximum ( = 0.65) and average ocular surface ( = 0.69) temperatures recorded on d 50. Infrared thermography has potential to be used to evaluate HP in cattle. PMID:27065272

  18. The uses of infrared thermography to evaluate the effects of climatic variables in bull's reproduction

    NASA Astrophysics Data System (ADS)

    Menegassi, Silvio Renato Oliveira; Pereira, Gabriel Ribas; Dias, Eduardo Antunes; Koetz, Celso; Lopes, Flávio Guiselli; Bremm, Carolina; Pimentel, Concepta; Lopes, Rubia Branco; da Rocha, Marcela Kuczynski; Carvalho, Helena Robattini; Barcellos, Júlio Otavio Jardim

    2016-01-01

    The objective of this study was to evaluate the seasonal effects of the environment on sperm quality in subtropical region determined by temperature and humidity index (THI). We used 20 Brangus bulls (5/8 Angus × 3/8 Nellore) aged approximately 24 months at the beginning of the study. Semen evaluations were performed twice per season during 1 year. Climate THI data were collected from an automatic weather station from the National Institute of Meteorology. Infrared thermography images were used to determine the temperature of the proximal and distal poles of the testis to assess the testicular temperature gradient (TG). The seasonal effects on seminal and climatic variables were analyzed with ANOVA using MIXED procedure of SAS. Sperm motility in spring (60.1 %), summer (57.6 %), and autumn (64.5 %) showed difference compared to winter (73.0 %; P < 0.01). TG was negatively correlated with THI at 18 days (spermiogenesis) (-0.76; P < 0.05) and at 12 days (epididymal transit) (-0.85; P < 0.01). Ocular temperature (OcT) had a positive correlation with THI at 18 days (0.78; P < 0.05) and at 12 days (0.84; P < 0.01). Motility showed a negative correlation with THI only at 18 days (-0.79; P < 0.05). During spermiogenesis, the TG had higher negative correlation compared to OcT (-0.97; P < 0.01) and rectal temperature (-0.72; P < 0.05). Spermatozoa with distal midpiece reflex were correlated with THI during transit epididymis (0.72; P < 0.05). Seminal parameters are not affected when THI reaches 93.0 (spermiogenesis) and 88.0 (epididymal transit). We concluded that infrared thermography can be adopted as an indirect method in order to assess the effect of environmental changes in TG and OcT of Brangus bulls.

  19. Thermography And Ultrasonics Find Flaws In Composites

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.; Zalameda, Joseph N.; Smith, Barry T.; Winfree, William P.

    1993-01-01

    Flaws first located in infrared imagery, then probed ultrasonically to reveal details. Thermographic and ultrasonic techniques, applied sequentially, constitute basis of developmental method of nondestructive inspection of structures made of lightweight composite materials like carbon-fiber/epoxy-matrix laminates. Method enables rapid detection and evaluation of damage and other flaws in composite structures. Does not require access to both sides of structure to be inspected.

  20. Investigation of various essential factors for optimum infrared thermography.

    PubMed

    Okada, Keiji; Takemura, Kei; Sato, Shigeru

    2013-10-01

    We investigated various essential factors for optimum infrared thermography for cattle clinics. The effect of various factors on the detection of surface temperature was investigated in an experimental room with a fixed ambient temperature using a square positioned on a wall. Various factors of animal objects were examined using cattle to determine the relationships among presence of hair, body surface temperature, surface temperature of the eyeball, the highest temperature of the eye circle, rectum temperature and ambient temperature. Also, the surface temperature of the flank at different time points after eating was examined. The best conditions of thermography for cattle clinics were determined and were as follows: (1) The distance between a thermal camera and an object should be fixed, and the camera should be set within a 45-degree angle with respect to the objects using the optimum focal length. (2) Factors that affect the camera temperature, such as extreme cold or heat, direct sunshine, high humidity and wind, should be avoided. (3) For the comparison of thermographs, imaging should be performed under identical conditions. If this is not achievable, hairless parts should be used. PMID:23759714

  1. Analysis of signal processing techniques in pulsed thermography

    NASA Astrophysics Data System (ADS)

    Lopez, Fernando; Ibarra-Castanedo, Clemente; Maldague, Xavier; de Paulo Nicolau, Vicente

    2013-05-01

    Pulsed Thermography (PT) is one of the most widely used approaches for the inspection of composites materials, being its main attraction the deployment in transient regime. However, due to the physical phenomena involved during the inspection, the signals acquired by the infrared camera are nearly always affected by external reflections and local emissivity variations. Furthermore, non-uniform heating at the surface and thermal losses at the edges of the material also represent constraints in the detection capability. For this reason, the thermographics signals should be processed in order to improve - qualitatively and quantitatively - the quality of the thermal images. Signal processing constitutes an important step in the chain of thermal image analysis, especially when defects characterization is required. Several of the signals processing techniques employed nowadays are based on the one-dimensional solution of Fourier's law of heat conduction. This investigation brings into discussion the three-most used techniques based on the 1D Fourier's law: Thermographic Signal Reconstruction (TSR), Differential Absolute Contrast (DAC) and Pulsed Phase Thermography (PPT), applied on carbon fiber laminated composites. It is of special interest to determine the detection capabilities of each technique, allowing in this way more reliable results when performing an inspection by PT.

  2. 3D thermography imaging standardization technique for inflammation diagnosis

    NASA Astrophysics Data System (ADS)

    Ju, Xiangyang; Nebel, Jean-Christophe; Siebert, J. Paul

    2005-01-01

    We develop a 3D thermography imaging standardization technique to allow quantitative data analysis. Medical Digital Infrared Thermal Imaging is very sensitive and reliable mean of graphically mapping and display skin surface temperature. It allows doctors to visualise in colour and quantify temperature changes in skin surface. The spectrum of colours indicates both hot and cold responses which may co-exist if the pain associate with an inflammatory focus excites an increase in sympathetic activity. However, due to thermograph provides only qualitative diagnosis information, it has not gained acceptance in the medical and veterinary communities as a necessary or effective tool in inflammation and tumor detection. Here, our technique is based on the combination of visual 3D imaging technique and thermal imaging technique, which maps the 2D thermography images on to 3D anatomical model. Then we rectify the 3D thermogram into a view independent thermogram and conform it a standard shape template. The combination of these imaging facilities allows the generation of combined 3D and thermal data from which thermal signatures can be quantified.

  3. Distance makes the difference in thermography for ecological studies.

    PubMed

    Faye, E; Dangles, O; Pincebourde, S

    2016-02-01

    Surface temperature drives many ecological processes and infrared thermography is widely used by ecologists to measure the thermal heterogeneity of different species' habitats. However, the potential bias in temperature readings caused by distance between the surface to be measured and the camera is still poorly acknowledged. We examined the effect of distance from 0.3 to 80m on a variety of thermal metrics (mean temperature, standard deviation, patch richness and aggregation) under various weather conditions and for different structural complexity of the studied surface types (various surfaces with vegetation). We found that distance is a key modifier of the temperature measured by a thermal infrared camera. A non-linear relationship between distance and mean temperature, standard deviation and patch richness led to a rapid under-estimation of the thermal metrics within the first 20m and then only a slight decrease between 20 and 80m from the object. Solar radiation also enhanced the bias with increasing distance. Therefore, surface temperatures were under-estimated as distance increased and thermal mosaics were homogenized at long distances with a much stronger bias in the warmer than the colder parts of the distributions. The under-estimation of thermal metrics due to distance was explained by atmospheric composition and the pixel size effect. The structural complexity of the surface had little effect on the surface temperature bias. Finally, we provide general guidelines for ecologists to minimize inaccuracies caused by distance from the studied surface in thermography. PMID:26857971

  4. Investigation of Various Essential Factors for Optimum Infrared Thermography

    PubMed Central

    OKADA, Keiji; TAKEMURA, Kei; SATO, Shigeru

    2013-01-01

    ABSTRACT We investigated various essential factors for optimum infrared thermography for cattle clinics. The effect of various factors on the detection of surface temperature was investigated in an experimental room with a fixed ambient temperature using a square positioned on a wall. Various factors of animal objects were examined using cattle to determine the relationships among presence of hair, body surface temperature, surface temperature of the eyeball, the highest temperature of the eye circle, rectum temperature and ambient temperature. Also, the surface temperature of the flank at different time points after eating was examined. The best conditions of thermography for cattle clinics were determined and were as follows: (1) The distance between a thermal camera and an object should be fixed, and the camera should be set within a 45-degree angle with respect to the objects using the optimum focal length. (2) Factors that affect the camera temperature, such as extreme cold or heat, direct sunshine, high humidity and wind, should be avoided. (3) For the comparison of thermographs, imaging should be performed under identical conditions. If this is not achievable, hairless parts should be used. PMID:23759714

  5. Noninvasive diagnosis of seed viability using infrared thermography

    PubMed Central

    Kranner, Ilse; Kastberger, Gerald; Hartbauer, Manfred; Pritchard, Hugh W.

    2010-01-01

    Recent advances in the noninvasive analyses of plant metabolism include stress imaging techniques, mainly developed for vegetative tissues. We explored if infrared thermography can be used to predict whether a quiescent seed will germinate or die upon water uptake. Thermal profiles of viable, aged, and dead Pisum sativum seeds were recorded, and image analysis of 22,000 images per individual seed showed that infrared thermography can detect imbibition- and germination-associated biophysical and biochemical changes. These “thermal fingerprints” vary with viability in this species and in Triticum aestivum and Brassica napus seeds. Thermogenesis of the small individual B. napus seeds was at the limit of the technology. We developed a computer model of “virtual pea seeds,” that uses Monte Carlo simulation, based on the heat production of major seed storage compounds to unravel physico-chemical processes of thermogenesis. The simulation suggests that the cooling that dominates the early thermal profiles results from the dissolution of low molecular-weight carbohydrates. Moreover, the kinetics of the production of such “cooling” compounds over the following 100 h is dependent on seed viability. We also developed a deterministic tool that predicts in the first 3 hours of water uptake, when seeds can be redried and stored again, whether or not a pea seed will germinate. We believe that the early separation of individual, ungerminated seeds (live, aged, or dead) before destructive germination assessment creates unique opportunities for integrative studies on cell death, differentiation, and development. PMID:20133712

  6. Karst Groundwater Hydrologic Analyses Based on Aerial Thermography

    NASA Technical Reports Server (NTRS)

    Campbell, C. Warren; Keith, A. G.

    2000-01-01

    On February 23, 1999, thermal imagery of Marshall Space Flight Center, Alabama was collected using an airborne thermal camera. Ground resolution was I in. Approximately 40 km 2 of thermal imagery in and around Marshall Space Flight Center (MSFC) was analyzed to determine the location of springs for groundwater monitoring. Subsequently, forty-five springs were located ranging in flow from a few ml/sec to approximately 280 liter/sec. Groundwater temperatures are usually near the mean annual surface air temperature. On thermography collected during the winter, springs show up as very warm spots. Many of the new springs were submerged in lakes, streams, or swamps; consequently, flow measurements were difficult. Without estimates of discharge, the impacts of contaminated discharge on surface streams would be difficult to evaluate. An approach to obtaining an estimate was developed using the Environmental Protection Agency (EPA) Cornell Mixing Zone Expert System (CORMIX). The thermography was queried to obtain a temperature profile down the center of the surface plume. The spring discharge was modeled with CORMIX, and the flow adjusted until the surface temperature profile was matched. The presence of volatile compounds in some of the new springs also allowed MSFC to unravel the natural system of solution cavities of the karst aquifer. Sampling results also showed that two springs on either side of a large creek had the same water source so that groundwater was able to pass beneath the creek.

  7. Computed Tomography and Thermography Increases CMC Material and Process Development Efficiency and Testing Effectiveness

    NASA Technical Reports Server (NTRS)

    Effinger, Michael; Beshears, Ron; Hufnagle, David; Walker, James; Russell, Sam; Stowell, Bob; Myers, David

    2002-01-01

    Nondestructive characterization techniques have been used to steer development and testing of CMCs. Computed tomography is used to determine the volumetric integrity of the CMC plates and components. Thermography is used to determine the near surface integrity of the CMC plates and components. For process and material development, information such as density uniformity, part delamination, and dimensional tolerance conformity is generated. The information from the thermography and computed tomography is correlated and then specimen cutting maps are superimposed on the thermography images. This enables for tighter data and potential explanation of off nominal test data. Examples of nondestructive characterization utilization to make decisions in process and material development and testing are presented.

  8. Differentiation between used motor oils on the basis of their IR spectra with application of the correlation method.

    PubMed

    Zieba-Palus, J; Kościelniak, P; Lacki, M

    2001-10-15

    Two brands of motor oils (Elf and Castrol) that had been used for various periods of time were examined. The aim was to differentiate these samples (of varying degree of use) on the basis of their infrared spectra, for criminalistic purposes. The correlation method was used. It was found that the FTIR method is capable of providing sufficiently detailed information if some specific fragments of spectra are examined. Hence, it can be concluded that the investigation procedure proposed is adequate. PMID:11587863

  9. Development of a New Crack Identification Technique Based on Near-Tip Singular Electrothermal Field Measured by Lock-in Infrared Thermography

    NASA Astrophysics Data System (ADS)

    Sakagami, Takahide; Kubo, Shiro

    A new thermographic NDT technique was proposed, in which singular electrothermal field near crack tips under the application of periodically modulated electric current was measured using an infrared thermography combined with lock-in data processing technique. Experimental investigations were made on the resolution and the applicability in the identification of through-thickness artificial cracks and fatigue cracks embedded in steel and aluminum alloy plate samples. Modulated electric current was applied to the cracked sample by an induction coli. Lock-in thermal images synchronized to the reference current modulation signal were taken by the lock-in thermography. Significant singular electrothermal field was observed at the crack tip in the lock-in thermal image. The fatigue cracks as well as artificial cracks were found to be sensitively identified by the proposed technique in good resolution compared with the singular method using a conventional thermographic temperature measurement.

  10. Effects of peripheral dynamic movements on the lower-limb circulation assessed by thermography: three one-group studies

    NASA Astrophysics Data System (ADS)

    Kaerki, Anne; Laehdeniemi, Matti

    2002-03-01

    Peripheral dynamic movements are used as part of postoperative protocols and for preventing vascular complications during bed rest. The effects of peripheral movements have not been studied. The purposes of these studies were to explain the effects of peripheral dynamic movements on lower limb circulation. The aim was also to explain how other factors like sex, age, BMI, medication, smoking, sports activity etc. affect the circulation. Healthy young subjects (N=19), healthy elderly subjects (N=19) and diabetic subjects (N=21) participated in the studies between 1997 and 1999. The study design was the same in each study. Infrared technology and image processing belong to our focus fields of applied research and IR is widely used in our real time industrial applications including also ongoing research of new possibilities. This paper presents the results of our newest application of IR thermography, where it was used to measure the skin temperature over the soleus muscle during and after dynamic ankle movements. The results showed that the skin temperature increased further during the recovery period after movements, and temperature was highest after 3- 5 minutes. Diabetic male subjects were the only subgroup that had immediate decrease during recovery period. The studies showed that smoking had a negative effect on circulation. BMI had also negative correlation (-0,356), showing that subjects with higher BMI had less increase. The results proved that peripheral movements were effective for increasing circulation in the soleus muscle and the effect was still seen after 15 minutes.

  11. Coal liquefaction process streams characterization and evaluation: FT-IR methods for characterization of coal liquefaction products

    SciTech Connect

    Serio, M.A.; Teng, H.; Bassilakis, R.; Solomon, P.R.

    1992-04-01

    This study was designed to demonstrate the use of two FTIR techniques for the analysis of direct coal liquefaction process-derived materials. The two methods were quantitative FTIR analysis and themogravimetric (TG) analysis with FTIR analysis of evolved products (TG-FTIR). The quantitative FTIR analyses of both whole resids and THF-soluble resids provided quantitation of total hydrogen, aliphatic and aromatic hydrogen, total carbon, total oxygen, hydroxyl and etheric oxygen, and ash contents. The FTIR results were usually in agreement with values derived by other, more conventional methods. However, the accuracies of specific measurements, in comparisons with results from conventional methods, ranged from good to poor. The TG-FTIR method provided approximate analyses of coals and resids. The data provided included the time dependent evolution profiles of the volatile species and the elemental composition of the char. Reproducible data of gaseous species and pyrolysis tar yields for whole resid samples larger than 10 mg were obtainable. The yields and evolution profiles of certain volatiles (tar, CO, and methane) provided structural information on the samples. There were some experimental and interpretational difficulties associated with both techniques. Optimization of the curve-resolving routine for coal-liquefaction samples would improve the quantitative FTIR accuracy. Aerosol formation limited the full application of the TG-FTIR technique with the THF-soluble resid samples. At this time, further development of these analytical methods as process development tools will be required before their use for that purpose can be recommended. The use of FTIR as an on-line analytical technique for coal liquefaction process streams requires demonstration before it can be recommended; however, such a demonstration may be warranted.

  12. Sensing cocaine in saliva with attenuated total reflection infrared (ATR-IR) spectroscopy combined with a one-step extraction method

    NASA Astrophysics Data System (ADS)

    Hans, Kerstin M.-C.; Gianella, Michele; Sigrist, Markus W.

    2012-03-01

    On-site drug tests have gained importance, e.g., for protecting the society from impaired drivers. Since today's drug tests are majorly only positive/negative, there is a great need for a reliable, portable and preferentially quantitative drug test. In the project IrSens we aim to bridge this gap with the development of an optical sensor platform based on infrared spectroscopy and focus on cocaine detection in saliva. We combine a one-step extraction method, a sample drying technique and infrared attenuated total reflection (ATR) spectroscopy. As a first step we have developed an extraction technique that allows us to extract cocaine from saliva to an almost infrared-transparent solvent and to record ATR spectra with a commercially available Fourier Transform-infrared spectrometer. To the best of our knowledge this is the first time that such a simple and easy-to-use one-step extraction method is used to transfer cocaine from saliva into an organic solvent and detect it quantitatively. With this new method we are able to reach a current limit of detection around 10 μg/ml. This new extraction method could also be applied to waste water monitoring and controlling caffeine content in beverages.

  13. Physical profiling and IR spectroscopy: simple and effective methods to discriminate between genuine and counterfeit samples of Viagra® and Cialis®.

    PubMed

    Custers, Deborah; Vandemoortele, Suzanne; Bothy, Jean-Luc; De Beer, Jacques O; Courselle, Patricia; Apers, Sandra; Deconinck, Eric

    2016-03-01

    Counterfeit medicines are a global threat to public health. High amounts enter the European market, enforcing the need for simple techniques to help customs detect these pharmaceuticals. This study focused on physical profiling and IR spectroscopy to obtain a prime discrimination between genuine and illegal Viagra® and Cialis® medicines. Five post-tableting characteristics were explored: colour, mass, long length, short length, and thickness. Hypothesis testing showed that most illegal samples (between 60 and 100%) significantly differ from the genuine medicines, in particular for mass and long length. Classification and Regression Trees (CART) analysis resulted in a good discrimination between genuine and illegal medicines (98.93% correct classification rate for Viagra®, 99.42% for Cialis®). Moreover, CART confirmed the observation that mass and long length are the key physical characteristics which determine the observed discrimination. IR analysis was performed on tablets without blister and on tablets in intact blister. These data were analyzed using Soft Independent Modelling of Class Analogy (SIMCA) and Partial Least Squares - Discriminant Analysis (PLS-DA). Supervised techniques needed to be applied since Principal Component Analysis (PCA) was not able to generate the desired discrimination. Our study shows that a perfect discrimination between genuine and illegal medicines can be made by both SIMCA and PLS-DA without removing the tablets from the blister. This approach has the advantage of keeping the blister intact. Our study demonstrates that these user friendly techniques are reliable methods to aid customs to obtain a prime distinction between genuine and illegal samples on the spot. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26033891

  14. Quantifying heat losses using aerial thermography

    SciTech Connect

    Haigh, G.A.; Pritchard, S.E.

    1980-01-01

    A theoretical model is described for calculating flat roof total heat losses and thermal conductances from aerial infrared data. Three empirical methods for estimating convective losses are described. The disagreement between the methods shows that they are prone to large (20%) errors, and that the survey should be carried out in low wind speeds, in order to minimize the effect of these errors on the calculation of total heat loss. The errors associated with knowledge of ground truth data are discussed for a high emissivity roof and three sets of environmental conditions. It is shown that the error in the net radiative loss is strongly dependent on the error in measuring the broad-band radiation incident on the roof. This is minimized for clear skies, but should be measured. Accurate knowledge of roof emissivity and the radiation reflected from the roof is shown to be less important. Simple techniques are described for measuring all three factors. Using these techniques in good conditions it should be possible to measure total heat losses to within 15%.

  15. YBa2Cu3O6+xSemiconductors Fabricated Using the Aerosol Deposition Method for IR Sensors.

    PubMed

    Jung, Hye-Rin; Lee, Tae-He; Lee, Sung-Gap

    2015-03-01

    In this study, YBa2Cu306+x (YBCO) thick films were investigated for their application in uncooled microbolometers. YBCO powders were prepared using the conventional mixed oxide method and were deposited on an SiO2/Si substrate using the aerosol deposition method (ADM) at room temperature. As a result of thermogravimetry and differential thermal analysis (TG-DTA) of YBCO powder, an endothermic peak was observed at approximately 820 °C. The powder was calcined at 880 °C. The deposited film were annealed at 600-750 °C (O2:Ar = 1:1, pO2) and their structural and electrical properties were investigated at varying annealing temperatures. From X-ray diffraction (XRD) results, all films displayed the typical XRD patterns of the tetragonal phase and the second phase was observed. The thickness of all the YBCO thick films was approximately 15.7 µm. As a result of the temperature coefficient of resistance (TCR = 1/R * dR/dT), the YBCO thick films annealed at 700 °C showed the maximum value of -3.1%/°C and all YBCO thick films showed typical NTCR (negative temperature coefficient of resistance) properties, displaying decreased electrical resistance with an increase in temperature. PMID:26413677

  16. Air Coupled Acoustic Thermography (acat) Inspection Technique

    NASA Astrophysics Data System (ADS)

    Zalameda, J. N.; Winfree, W. P.; Yost, W. T.

    2008-02-01

    The scope of this effort is to determine the viability of a new heating technique using a noncontact acoustic excitation source. Because of low coupling between air and the structure, a synchronous detection method is employed. Any reduction in the out of plane stiffness improves the acoustic coupling efficiency and as a result, defective areas have an increase in temperature relative to the surrounding area. Hence a new measurement system, based on air-coupled acoustic energy and synchronous detection is presented. An analytical model of a clamped circular plate is given, experimentally tested, and verified. Repeatability confirms the technique with a measurement uncertainty of +/-6.2 percent. The range of frequencies used was 800-2,000 Hertz. Acoustic excitation and consequent thermal detection of flaws in a helicopter blade is examined and results indicate that air coupled acoustic excitation enables the detection of core damage in sandwich honeycomb structures.

  17. Mastitis detection in sheep by infrared thermography.

    PubMed

    Martins, Rafhael Felipe Saraiva; do Prado Paim, Tiago; de Abreu Cardoso, Cyntia; Stéfano Lima Dallago, Bruno; de Melo, Cristiano Barros; Louvandini, Helder; McManus, Concepta

    2013-06-01

    This study aims to evaluate the use of an infrared thermograph for mastitis diagnosis in sheep. Thirty-seven Santa Inês ewes were evaluated weekly through infrared images obtained with thermograph FLIR System Series-i®. Milk was collected for somatic cell count and milk compound level determination. The clinical mastitis group had the highest fat and protein level, as well as the lowest lactose level. The udder temperatures were higher for subclinical mastitis group. The udder temperature data was able to correctly classify the animals into the mastitis groups and the canonical analysis showed that these temperatures clearly differentiated the subclinical mastitis groups from the others. Therefore, this study showed that udder infrared temperatures can be used as diagnostic method to mastitis in sheep. PMID:23178047

  18. Air Coupled Acoustic Thermography (ACAT) Inspection Technique

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph; Winfree, William P.; Yost, William T.

    2007-01-01

    The scope of this effort is to determine the viability of a new heating technique using a noncontact acoustic excitation source. Because of low coupling between air and the structure, a synchronous detection method is employed. Any reduction in the out of plane stiffness improves the acoustic coupling efficiency and as a result, defective areas have an increase in temperature relative to the surrounding area. Hence a new measurement system, based on air-coupled acoustic energy and synchronous detection is presented. An analytical model of a clamped circular plate is given, experimentally tested, and verified. Repeatability confirms the technique with a measurement uncertainty of plus or minus 6.2 percent. The range of frequencies used was 800-2,000 Hertz. Acoustic excitation and consequent thermal detection of flaws in a helicopter blade is examined and results indicate that air coupled acoustic excitation enables the detection of core damage in sandwich honeycomb structures.

  19. NMR, FT-IR, FT-Raman, UV spectroscopic, HOMO-LUMO and NBO analysis of cumene by quantum computational methods

    NASA Astrophysics Data System (ADS)

    Sivaranjani, T.; Xavier, S.; Periandy, S.

    2015-03-01

    This work presents the investigation of cumene using the FT-IR, FT-Raman, NMR and UV spectra obtained through various spectroscopic techniques. The theoretical vibrational frequencies and optimized geometric parameters have been calculated by using HF and density functional theory with the hybrid methods B3LYP, B3PW91 and 6-311+G(d,p)/6-311++G(d,p) basis sets. The theoretical vibrational frequencies have been scaled and compared with the corresponding experimental data. 1H and 13C NMR spectra were recorded and chemical shifts of the molecule were compared to TMS by using the Gauge-Independent Atomic Orbital (GIAO) method. A study on the electronic and optical properties, absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, and potential energy surface (PES) is performed using HF and DFT methods. The thermodynamic properties (heat capacity, entropy and enthalpy) at different temperatures are also calculated. NBO analysis is carried out to picture the charge transfer between the localized bonds and lone pairs. NLO properties related to polarizability and hyperpolarizability are also discussed.

  20. Defect detection in pulsed thermography: a comparison of Kohonen and Perceptron neural networks

    NASA Astrophysics Data System (ADS)

    Vallerand, Steve; Darabi, A.; Maldague, Xavier P.

    1999-03-01

    In this paper, two neural network approaches are compared for defect detection using thermal evolution, phase and amplitude data acquired in the pulsed thermography approach with pulsed phase thermography processing. The tested approaches are based on Perceptron and Kohonen neural networks. Examples of results are presented for each technique with the three types of available data, in the case of flat-bottom holes in aluminum. Results show that the Perceptron using phase data gives better results being less influenced by disturbances.

  1. ALBERMARLE PAMLICO IR 2002

    EPA Science Inventory

    The 2002 Albermarle Pamlico Implementation Review (IR) highlights recent successes and challenges with the estuary program. Various components within the IR include: CCMP implementation, outlining priority management actions, public involvement, stakeholder contribution, and limi...

  2. A reference-free micro defect visualization using pulse laser scanning thermography and image processing

    NASA Astrophysics Data System (ADS)

    Yang, Jinyeol; Choi, Jaemook; Hwang, Soonkyu; An, Yun-Kyu; Sohn, Hoon

    2016-08-01

    As quality control of micro devices and early detection of micro defects in these devices are becoming increasingly important, the demand for a fast and automated online inspection technique to detect micro defects with high spatial resolution is increasing. In this study, a reference-free micro defect visualization algorithm is developed based on laser scanning thermography to detect micro defects in devices instantaneously and automatically with high spatial resolution. A pulse modulated continuous wave laser generates thermal waves in a target device, and the corresponding thermal responses are recorded by an infrared (IR) camera. When the thermal wave encounters a micro defect, the propagation of the thermal wave is blocked at the interface of the micro defect. The blockage of the thermal wave is detected by the proposed reference-free micro defect visualization algorithm. First, an edge detection algorithm is applied to a raw thermal image obtained at a specific time point to extract the thermal discontinuities formed at the boundaries of the defect. The edge images obtained from all time sequences are then assembled into a single accumulated edge image to accentuate defect-induced thermal disturbances in the form of edge features. Finally, the accumulated edge image is automatically processed using a binary imaging algorithm to visualize the micro defect in the target device. The performance of the proposed reference-free micro defect visualization algorithm is examined using two types of specimens, semiconductor chips and ceramic-epoxy composites. The proposed algorithm successfully diagnoses micro defects ranging from 4 μm to 40 μm in width.

  3. Modeling of the Multiparameter Inverse Task of Transient Thermography

    NASA Technical Reports Server (NTRS)

    Plotnikov, Y. A.

    1998-01-01

    Transient thermography employs preheated surface temperature variations caused by delaminations, cracks, voids, corroded regions, etc. Often, it is enough to detect these changes to declare a defect in a workpiece. It is also desirable to obtain additional information about the defect from the thermal response. The planar size, depth, and thermal resistance of the detected defects are the parameters of interest. In this paper a digital image processing technique is applied to simulated thermal responses in order to obtain the geometry of the inclusion-type defects in a flat panel. A three-dimensional finite difference model in Cartesian coordinates is used for the numerical simulations. Typical physical properties of polymer graphite composites are assumed. Using different informative parameters of the thermal response for depth estimation is discussed.

  4. Aerial thermography studies of power plant heated lakes

    SciTech Connect

    Villa-Aleman, E.

    2000-01-26

    Remote sensing temperature measurements of water bodies is complicated by the temperature differences between the true surface or skin water and the bulk water below. Weather conditions control the reduction of the skin temperature relative to the bulk water temperature. Typical skin temperature depressions range from a few tenths of a degree Celsius to more than one degree. In this research project, the Savannah River Technology Center (SRTC) used aerial thermography and surface-based meteorological and water temperature measurements to study a power plant cooling lake in South Carolina. Skin and bulk water temperatures were measured simultaneously for imagery calibration and to produce a database for modeling of skin temperature depressions as a function of weather and bulk water temperatures. This paper will present imagery that illustrates how the skin temperature depression was affected by different conditions in several locations on the lake and will present skin temperature modeling results.

  5. Infrared-thermography imaging system multiapplications for manufacturing

    NASA Astrophysics Data System (ADS)

    Stern, Sharon A.

    1990-03-01

    Imaging systems technology has been utilized traditionally for diagnosing structural envelope or insulation problems in the general thermographic comunity. Industrially, new applications for utilizing thermal imaging technology have been developed i n pred i cti ve/preventi ye mai ntenance and prod uct moni tori ng prociures at Eastman Kodak Company, the largest photographic manufacturering producer in the world. In the manufacturing processes used at Eastman Kodak Company, new applications for thermal imaging include: (1) Fluid transfer line insulation (2) Web coating drying uniformity (3) Web slitter knives (4) Heating/cooling coils (5) Overheated tail bearings, and (6) Electrical phase imbalance. The substantial cost benefits gained from these applications of infrared thermography substantiate the practicality of this approach and indicate the desirability of researching further appl i cati ons.

  6. Air-coupled acoustic thermography for in-situ evaluation

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N. (Inventor); Winfree, William P. (Inventor); Yost, William T. (Inventor)

    2010-01-01

    Acoustic thermography uses a housing configured for thermal, acoustic and infrared radiation shielding. For in-situ applications, the housing has an open side adapted to be sealingly coupled to a surface region of a structure such that an enclosed chamber filled with air is defined. One or more acoustic sources are positioned to direct acoustic waves through the air in the enclosed chamber and towards the surface region. To activate and control each acoustic source, a pulsed signal is applied thereto. An infrared imager focused on the surface region detects a thermal image of the surface region. A data capture device records the thermal image in synchronicity with each pulse of the pulsed signal such that a time series of thermal images is generated. For enhanced sensitivity and/or repeatability, sound and/or vibrations at the surface region can be used in feedback control of the pulsed signal applied to the acoustic sources.

  7. Standing wave in evaporating meniscus detected by infrared thermography

    NASA Astrophysics Data System (ADS)

    Buffone, Cosimo; Sefiane, Khellil; Minetti, Christophe; Mamalis, Dimitrios

    2015-07-01

    A standing wave has been detected in the evaporating meniscus formed on an organic liquid (acetone) inside a horizontally positioned capillary tube of 1 mm internal diameter. The standing wave is believed to originate from the interaction between surface tension and gravitational forces. We found that the standing wave ensues only at the upper part of the meniscus interface where gravity and surface tension act in the opposite direction. This experimental observation is similar to standing waves observed in floating zones in microgravity but different from travelling waves reported recently in volatile drops; in both cases the waves are produced by temperature differences along a liquid-vapour interface. By employing InfraRed thermography, we recorded the temperature distribution of the meniscus interface, and we found that the first characteristic frequency of the standing wave is around 0.3 Hz.

  8. Localization of wood floor structure by infrared thermography

    NASA Astrophysics Data System (ADS)

    Cochior Plescanu, C.; Klein, M.; Ibarra-Castanedo, C.; Bendada, A.; Maldague, X.

    2008-03-01

    One of our industrial partners, Assek Technologie, is interested in developing a technique that would improve the drying process of wood floor in basements after flooding. In order to optimize the procedure, the floor structure and the damaged (wet) area extent must first be determined with minimum intrusion (minimum or no dismantling). The present study presents the use of infrared thermography to reveal the structure of (flooded) wood floors. The procedure involves opening holes in the floor. Injecting some hot air through those holes reveals the framing structure even if the floor is covered by vinyl or ceramic tiles. This study indicates that thermal imaging can also be used as a tool to validate the decontamination process after drying. Thermal images were obtained on small-scale models and in a demonstration room.

  9. Porosity Measurement in Laminated Composites by Thermography and FEA

    NASA Technical Reports Server (NTRS)

    Chu, Tsuchin Philip; Russell, Samuel S.; Walker, James L.; Munafo, Paul M. (Technical Monitor)

    2001-01-01

    This paper presents the correlation between the through-thickness thermal diffusivity and the porosity of composites. Finite element analysis (FEA) was used to determine the transient thermal response of composites that were subjected to laser heating. A series of finite element models were built and thermal responses for isotropic and orthographic materials with various thermal diffusivities subjected to different heating conditions were investigated. Experiments were conducted to verify the models and to estimate the unknown parameters such as the amount of heat flux. The analysis and experimental results show good correlation between thermal diffusivity and porosity in the composite materials. They also show that both laser and flash heating can be used effectively to obtain thermal diffusivity. The current infrared thermography system is developed for use with flash heating. The laser heating models and the FEA results can provide useful tools to develop practical thermal diffusivity measurement scheme using laser heat.

  10. The Study of Hypersonic Heat Transfer by Liquid Crystals Thermography

    NASA Astrophysics Data System (ADS)

    Kovrizhina, V. N.; Kharitonov, A. M.; Petrov, A. P.; Schpack, S. I.; Zharkova, G. M.; Zvegintsev, V. I.

    2009-01-01

    The results of experimental application of the Liquid Crystal Thermography in short-duration facility AT-303 of ITAM Novosibirsk (Russia) are presented. Experiments were carried out at free stream Mach number M∞ ≍ 10.9, unit Reynolds number Re1≍2.9*106M-1, run duration 350 MC and temperature factor Tw/To ≍ 0.2 on a semi-spherically blunted cone. Polymer dispersed liquid crystals (PDLC), developed at ITAM, have been used as thermosensitive coating. Transient technique and color pattern video acquisition was realized at different framing rates. It was obtained that high temperature sensitivity of PDLC allows visualize the fine features of the temperature field on the model surface. The heat flux in comparison with semi- empirical estimation are presented and discussed too.

  11. Optimized laser application in dermatology using infrared thermography

    NASA Astrophysics Data System (ADS)

    Thomas, Roderick A.; Donne, Kelvin E.; Clement, Marc; Kiernan, Michael N.

    2002-03-01

    Infrared thermography can be used to optimize the application of lasers in dermatology with particular reference to the treatment of certain skin disorders such as vascular lesions and depilation. The efficacy of treatment is dependent upon a number of factors including: Optimization and correct selection of laser parameters such as wavelength and spot size. Human factors, such as laser operator skill, patient's skin type and anatomical location. By observing the thermal effects of laser irradiation on the skins surface during treatment results in improved efficacy and minimizes the possible threshold to skin damage, reducing the possibility of burning and scarring. This is of particular significance for example, in the control of purpura for the treatment of vascular lesions. The optimization is validated with reference to a computer model that predicts various skin temperatures based on two different laser spot sizes.

  12. Simple method for highlighting the temperature distribution into a liquid sample heated by microwave power field

    SciTech Connect

    Surducan, V.; Surducan, E.; Dadarlat, D.

    2013-11-13

    Microwave induced heating is widely used in medical treatments, scientific and industrial applications. The temperature field inside a microwave heated sample is often inhomogenous, therefore multiple temperature sensors are required for an accurate result. Nowadays, non-contact (Infra Red thermography or microwave radiometry) or direct contact temperature measurement methods (expensive and sophisticated fiber optic temperature sensors transparent to microwave radiation) are mainly used. IR thermography gives only the surface temperature and can not be used for measuring temperature distributions in cross sections of a sample. In this paper we present a very simple experimental method for temperature distribution highlighting inside a cross section of a liquid sample, heated by a microwave radiation through a coaxial applicator. The method proposed is able to offer qualitative information about the heating distribution, using a temperature sensitive liquid crystal sheet. Inhomogeneities as smaller as 1°-2°C produced by the symmetry irregularities of the microwave applicator can be easily detected by visual inspection or by computer assisted color to temperature conversion. Therefore, the microwave applicator is tuned and verified with described method until the temperature inhomogeneities are solved.

  13. Determination of stomatal conductance by means of infrared thermography

    NASA Astrophysics Data System (ADS)

    Bajons, P.; Klinger, G.; Schlosser, V.

    2005-06-01

    The leaf energy balance equation is extended to obtain the boundary layer resistances to heat transfer and the stomatal resistance, the stomatal conductance respectively, of leaves in vivo. Calculations are based on the determination of temperature rise and fall times (thermal time constants of leaves in different states) which are caused by a sudden change of irradiation intensity. The change in the irradiation was performed by turning on/off a laser diode (675 nm). To measure the temperature and its changes without direct contact with the leaves, a commercial IR-imaging system (thermo-camera) was employed. Experiments were made on ivy leaves under laboratory conditions. The advantages and the applicability of the new method are demonstrated and experienced experimental difficulties are discussed.

  14. Dual-band infrared thermography for quantitative nondestructive evaluation

    SciTech Connect

    Durbin, P.F.; Del Grande, N.K.; Dolan, K.W.; Perkins, D.E.; Shapiro, A.B.

    1993-04-01

    The authors have developed dual-band infrared (DBIR) thermography that is being applied to quantitative nondestructive evaluation (NDE) of aging aircraft. The DBIR technique resolves 0.2 degrees C surface temperature differences for inspecting interior flaws in heated aircraft structures. It locates cracks, corrosion sites, disbonds or delaminations in metallic laps and composite patches. By removing clutter from surface roughness effects, the authors clarify interpretation of subsurface flaws. To accomplish this, the authors ratio images recorded at two infrared bands, centered near 5 microns and 10 microns. These image ratios are used to decouple temperature patterns associated with interior flaw sites from spatially varying surface emissivity noise. They also discuss three-dimensional (3D) dynamic thermal imaging of structural flaws using dual-band infrared (DBIR) computed tomography. Conventional thermography provides single-band infrared images which are difficult to interpret. Standard procedures yield imprecise (or qualitative) information about subsurface flaw sites which are typically masked by surface clutter. They use a DBIR imaging technique pioneered at LLNL to capture the time history of surface temperature difference patterns for flash-heated targets. They relate these patterns to the location, size, shape and depth of subsurface flaws. They have demonstrated temperature accuracies of 0.2{degree}C, timing synchronization of 3 ms (after onset of heat flash) and intervals of 42 ms, between images, during an 8 s cooling (and heating) interval characterizing the front (and back) surface temperature-time history of an epoxy-glue disbond site in a flash-heated aluminum lap joint.

  15. Infrared micro-thermography of an actively heated preconcentrator device

    NASA Astrophysics Data System (ADS)

    Furstenberg, Robert; Kendziora, C. A.; Stepnowski, Stanley V.; Mott, David R.; McGill, R. Andrew

    2008-03-01

    We report infrared micro-thermography measurements and analysis of static and transient temperature maps of an actively heated micro-fabricated preconcentrator device that incorporates a dual serpentine platinum heater trace deposited on a perforated polyimide membrane and suspended over a silicon frame. The sorbent coated perforated membrane is used to collect vapors and gases that flow through the preconcentrator. After heating, a concentrated pulse of analyte is released into the detector. Due to its small thermal mass, precise thermal management of the preconcentrator is critical to its performance. The sizes of features, the semi-transparent membrane, the need to flow air through the device, and changes in surface emissivity on a micron scale present many challenges for traditional infrared micro-thermography. We report an improved experimental test-bed. The hardware incorporates a custom-designed miniature calibration oven which, in conjunction with spatial filtering and a simple calibration algorithm, allows accurate temperature maps to be obtained. The test-bed incorporates a micro-bolometer array as the infrared imager. Instrumentation design, calibration and image processing algorithms are discussed and analyzed. The procedure does not require prior knowledge of the emissivity. We show that relatively inexpensive uncooled bolometers arrays can be used in certain radiometric applications. Heating profiles were examined with both uniform and non-uniform air flow through the device. The conclusions from this study provide critical information for optimal integration of the preconcentrator within a detection system, and in the design of the heater trace layout to achieve a more even temperature distribution across the device.

  16. Infrared thermography analysis of thermal diffusion induced by RF magnetic field on agar phantoms loaded with magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Bante-Guerra, Jose; Macías, J. D.; Caballero-Aguilar, L.; Vales-Pinzón, C.; Alvarado-Gil, J. J.

    2013-02-01

    Recently, several treatments for fighting malignant tumors have been designed. However these procedures have well known inconveniences, depending on their applicability, tumor size and side effects, among others. Magnetic hyperthermia is a safe, non-invasive method for cancer therapy. This treatment is applied via elevation of target tissue temperature by dissipation of heat from Magnetic Nanoparticles (MNPs), previously located within the tumor. The induction of heat causes cell death and therefore the removal of the tumor. In this work the thermal diffusion in phantoms of agar loaded with magnetic nanoparticles (MNPs) is studied using the infrared thermography technique, which is widely used in biology/medicine (e.g. skin temperature mapping). Agar is one of the materials used to simulate different types of body tissues, these samples are known as "phantoms". Agar is of natural origin, low cost and high degree of biocompatibility. In this work the agar gel was embedded with MNPs by coprecipitation and placed in an alternating magnetic field radiation. As a consequence, the energy from the radiation source is dissipated as heat and then transferred from the MNP to the gel, increasing its temperature. For the temperature analysis, the samples of agar gel were stimulated by RF magnetic field generated by coils. Heating was measured with infrared thermography using a Thermovision A20M infrared camera. Thermographic images allowed obtaining the dependence of thermal diffusion in the phantom as a function of the magnitude of the applied RF magnetic field and the load of magnetic particles.

  17. Estimate of the diameter of surface defects on a pattern specimen made of Plexiglas through active infrared thermography

    NASA Astrophysics Data System (ADS)

    Medina-Barreto, M. H.; Giraldo, J. M.; Ramírez-Hurtado, A. L.; Llamosa, L.; Cruz, B.

    2016-02-01

    In recent years the use of Infrared Thermography (IRT) has reached a special importance in the industrial sector as a method of Non-Destructive Testing (NDT), for inspection of surface and subsurface defects of different types of materials. In order to determine the size of such defects by implementing the technique of Infrared Active Thermography, a Plexiglass sample (PMMA) with circular defects of different diameters and depths was designed and built. The sample was thermally stimulated by a continuous radiation from a halogen lamp, and subsequently the thermographic images were acquired by using the time-resolved infrared radiometry technique (TRIR). Images were obtained using Fluke TI-30 and TI-32 cameras, and a program was designed in Matlab for its further processing. Through a user interface, the program can display and filter the image; then it chooses a particular defect and calculates the diameter with their respective uncertainties. The best results for the calculated diameter were obtained with Ti-32 camera. The estimated uncertainties were below of 1.2mm, regard of defect diameter. Importantly, uncertainties grew when the diameter/depth ratio was 1 for depths of 4.0mm.

  18. Non-destructive inspection of drilled holes in reinforced honeycomb sandwich panels using active thermography

    NASA Astrophysics Data System (ADS)

    Usamentiaga, R.; Venegas, P.; Guerediaga, J.; Vega, L.; López, I.

    2012-11-01

    The aerospace industry is in constant need of ever-more efficient inspection methods for quality control. Product inspection is also essential to maintain the safe operation of aircraft components designed to perform for decades. This paper proposes a method for non-destructive inspection of drilled holes in reinforced honeycomb sandwich panels. Honeycomb sandwich panels are extensively employed in the aerospace industry due to their high strength and stiffness to weight ratios. In order to attach additional structures to them, panels are reinforced by filling honeycomb cells and drilling holes into the reinforced areas. The proposed procedure is designed to detect the position of the holes within the reinforced area and to provide a robust measurement of the distance between each hole and the boundary of the reinforced area. The result is a fast, safe and clean inspection method for drilled holes in reinforced honeycomb sandwich panels that can be used to robustly assess a possible displacement of the hole from the center of the reinforced area, which could have serious consequences. The proposed method is based on active infrared thermography, and uses state of the art methods for infrared image processing, including signal-to-nose ratio enhancement, hole detection and segmentation. Tests and comparison with X-ray inspections indicate that the proposed system meets production needs.

  19. Selective IR multiphoton dissociation of molecules in a pulsed gas-dynamically cooled molecular flow interacting with a solid surface as an alternative to low-energy methods of molecular laser isotope separation

    NASA Astrophysics Data System (ADS)

    Makarov, G. N.; Petin, A. N.

    2016-03-01

    We report the results of studies on the isotope-selective infrared multiphoton dissociation (IR MFD) of SF6 and CF3I molecules in a pulsed, gas-dynamically cooled molecular flow interacting with a solid surface. The productivity of this method in the conditions of a specific experiment (by the example of SF6 molecules) is evaluated. A number of low-energy methods of molecular laser isotope separation based on the use of infrared lasers for selective excitation of molecules are analysed and their productivity is estimated. The methods are compared with those of selective dissociation of molecules in the flow interacting with a surface. The advantages of this method compared to the low-energy methods of molecular laser isotope separation and the IR MPD method in the unperturbed jets and flows are shown. It is concluded that this method could be a promising alternative to the low-energy methods of molecular laser isotope separation.

  20. Detection of IR target by fusing multispectral IR data

    NASA Astrophysics Data System (ADS)

    Li, Liya; Qi, Meng; Gao, Xuhui

    2011-08-01

    Detection of the small target in clutter, usually regarded as singular points in the infrared image, is an important issue in infrared searching and tracking (IRST) system. Because of the far range of the target to the sensor, the stealth technology, the effects of inherent sensor noise and the phenomena of nature, the target is more difficult to be detected. Multispectral sensor system has been proved it could greatly improve detection of the small, hard-to-find targets by multispectral processing techniques (such as sensor or image fusion). Aiming at the problem of multispectral IR Target Detection, a kind method of the multispectral IR target detection is proposed, based on the existed detection systems. In this method, the image registration is done firstly to make the different sensors have a same scene. Then, a fusion rule, named as adaptive weighted voting theory, is developed to combine the target detection results from the different spectral sensors. The adaptive weighted voting theory can give the different weights, based on the different spectral IR characteristics, and these weights decide the detected target is identified as real target or background. The experimental results show that the proposed method can reduce the detection uncertainty and improve the detection performance. Compared with the single spectral detection results and the others fusion detection methods, it can decrease the lost alarm rate and the false alarm rate effectively. The proposed method has been employed in our IR surveillance system, and it is easy to be used in the various circumstances.

  1. Transient thermography testing of unpainted thermal barrier coating surfaces

    NASA Astrophysics Data System (ADS)

    Ptaszek, Grzegorz; Cawley, Peter; Almond, Darryl; Pickering, Simon

    2013-01-01

    This paper has investigated the effects of uneven surface discolouration of a thermal barrier coating (TBC) and of its IR translucency on the thermal responses observed by using mid and long wavelength IR cameras. It has been shown that unpainted blades can be tested satisfactorily by using a more powerful flash heating system and a long wavelength IR camera. The problem of uneven surface emissivity can be overcome by applying 2nd derivative processing of the log-log surface cooling curves.

  2. An empirical research in application of dynamic, multispectral-band IR thermal images for investigations of petrochemical furnaces

    NASA Astrophysics Data System (ADS)

    Pregowski, P.; Goleniewski, G.; Komosa, W.; Korytkowski, W.; Zwolenik, Sl.

    2008-09-01

    A few years ago we have developed a patent pending method that allows to increase the reliability of the heater's tube temperature measurements through flames. The applications of this method showed additional potential for investigation of heating medium, i.e. mixture of various gases and aerosols inside flames and flue gases. This paper presents the recently developed, new version of the measuring system based on PtSi IRFPA commercial thermographic type camera. Two additional optical (8 filter wheel) and digital interfaces have been applied. The main special feature of elaborated techniques is the dynamic spectrally matched IR thermography, which bases on forming single images that consist of pixels of chosen statistical value, minimum and maximum, noted during adequately long sequence of thermograms with total independence to the moment of their capture. Sets of these data can be used either directly or as inputs to other artificial images. In this way, additive or suppressed interferences of fluctuating character could be minimized or exhibited, depending on the type of investigations i.e. studying tubes' temperature or energetic features of the flames and flue gases. Some of the results emerged as very promising - in the future they may help in creating a new field of thermal cameras application for furnaces control or steering to further enhance safety and efficiency of furnaces running.

  3. IR technique for detection of wall thinning in service water piping

    NASA Astrophysics Data System (ADS)

    Zayicek, Paul A.; Shepard, Steven M.

    1997-04-01

    The service water piping system at nuclear power plants provides cooling for a variety of safety and non-safety related components and systems. Reliability of service water piping systems is a key consideration for safe and reliable plant operations. Conventional inspection techniques for detection of pipe wall thinning usually involve the time- intensive process of ultrasonic thickness measurements, based on a grid system, of the entire pipe length. An alternative to this process may lie in the use of active infrared thermography techniques for detection of thin wall areas in the pipe. Infrared thermography (IR), in a passive mode, has been widely used by utilities for a variety of predictive maintenance applications. For assessment of service water piping, an active IR technique, thermal injection, can be used. Application of this IRNDE technique for material evaluation can provide a rapid screening technique for identification of thin wall areas in service water piping. The EPRI NDE Center participated in a preliminary evaluation of this technology at Vermont Yankee Nuclear Power Plant. Based on the promising results of the Vermont Yankee activity, the Center worked with Thermal Wave Imaging, Inc. in an effort to optimize the IR thermal injection technique for service water piping applications. A series of representative pipe mock-ups were used for evaluation. Subsequent modification of the thermal injection hardware and technique yielded more uniform thermal energy transfer, improved detection capabilities, and increased effective inspection area.

  4. Automatic detection of impact damage in carbon fiber composites using active thermography

    NASA Astrophysics Data System (ADS)

    Usamentiaga, R.; Venegas, P.; Guerediaga, J.; Vega, L.; López, I.

    2013-05-01

    Accidental impacts can severely reduce the structural strength and stability of composite materials, which can lead to severe consequences due to the degradation of the mechanical properties of components designed to perform for decades. Because accidental impacts are difficult to avoid, robust and reliable inspection methods to detect impact damage are required. Many methods have been proposed recently. However, most of them require an experienced technician to analyze the data, which leads to a significant decrease in manufacturing productivity. This work proposes a method to automatically detect impact damage in carbon fiber composites using active thermography. The proposed system detects defects caused by impact damage in the infrared images without human intervention. Impact damage detection is performed using a robust method based on an active thermographic inspection. Thermographic data is preprocessed to improve signal-to-noise ratio and to remove non-uniform background caused by non-uniform heating. Then, peaks and edges are identified and clustered, and regions corresponding to impact damage are detected. The proposed procedure has been applied to three specimens that contain 6 and 12 plies, different types of cores, and damage caused by energies from 6 J to 50 J. All defects are detected correctly.

  5. Is It Possible to Detect Activated Brown Adipose Tissue in Humans Using Single-Time-Point Infrared Thermography under Thermoneutral Conditions? Impact of BMI and Subcutaneous Adipose Tissue Thickness

    PubMed Central

    Gatidis, Sergios; Schmidt, Holger; Pfannenberg, Christina A.; Nikolaou, Konstantin; Schick, Fritz; Schwenzer, Nina F.

    2016-01-01

    Purpose To evaluate the feasibility to detect activated brown adipose tissue (BAT) using single-time-point infrared thermography of the supraclavicular skin region under thermoneutral conditions. To this end, infrared thermography was compared with 18-F-FDG PET, the current reference standard for the detection of activated BAT. Methods 120 patients were enrolled in this study. After exclusion of 18 patients, 102 patients (44 female, 58 male, mean age 58±17 years) were included for final analysis. All patients underwent a clinically indicated 18F-FDG-PET/CT examination. Immediately prior to tracer injection skin temperatures of the supraclavicular, presternal and jugular regions were measured using spatially resolved infrared thermography at room temperature. The presence of activated BAT was determined in PET by typical FDG uptake within the supraclavicular adipose tissue compartments. Local thickness of supraclavicular subcutaneous adipose tissue (SCAT) was measured on CT. Measured skin temperatures were statistically correlated with the presence of activated BAT and anthropometric data. Results Activated BAT was detected in 9 of 102 patients (8.8%). Local skin temperature of the supraclavicular region was significantly higher in individuals with active BAT compared to individuals without active BAT. However, after statistical correction for the influence of BMI, no predictive value of activated BAT on skin temperature of the supraclavicular region could be observed. Supraclavicular skin temperature was significantly negatively correlated with supraclavicular SCAT thickness. Conclusion We conclude that supraclavicular SCAT thickness influences supraclavicular skin temperature and thus makes a specific detection of activated BAT using single-time-point thermography difficult. Further studies are necessary to evaluate the possibility of BAT detection using alternative thermographic methods, e.g. dynamic thermography or MR-based thermometry taking into account BMI

  6. Relaxation dynamics of the LH2 complex from a photosynthetic purple bacterium Thiorhodospira sibirica studied by the near-IR femtosecond pump-probe method

    SciTech Connect

    Razjivin, A P; Pishchal'nikov, R Yu; Kozlovskii, V S; Kompanets, V O; Chekalin, Sergei V; Moskalenko, A A; Makhneva, Z K

    2005-01-31

    Photoinduced changes in the absorption spectrum of the LH2 (B800-830-850) complex from a Thiorhodospira sibirica (Trs. sibirica) bacterium are studied by the pump-probe method. The complex has the anomalous absorption spectrum exhibiting three bands in the near-IR region at 793, 826.5, and 846.5 nm. At room temperature, the excitation energy transfer from the B800, B830, and B859 bands was detected with the time constants {tau}{sub 1{approx}}0.5 ps, {tau}{sub 2{approx}}2.5 ps, and {tau}{sub 3} of the order of a few hundreds of picoseconds, respectively. A rapid energy transfer from the B830 band compared to energy transfer from the B850 band ({tau}{sub 2}||{tau}{sub 3}) suggests that all the three bands belong to the same complex (i.e., that the LH2 complex from Trs. sibirica is homogeneous). A slower energy transfer (by three - five times) from the B830 band of the LH2 complex from Trs. sibirica compared to energy transfer from the B800 band of the LH2 complexes (B800-850 and especially B800-820) from other purple bacteria suggests that the electronic structures of ensembles of bacteriochlorophyll molecules in these complexes are substantially different. (laser applications and other topics in quantum electronics)

  7. Spectroscopic (FT-IR, FT-Raman, FT-NMR and UV-Vis) investigation on benzil dioxime using quantum computational methods

    NASA Astrophysics Data System (ADS)

    Bakkiyaraj, D.; Periandy, S.; Xavier, S.

    2016-03-01

    The spectral analysis of benzil dioxime is carried out using the FTIR, FT Raman, FT NMR and UV-Vis spectra of the compound with the help of quantum computations by density functional theories. The FT-IR (4000 - 400 cm-1) and FT-Raman (4000-100 cm-1) spectra are recorded in solid phase, the 1H and 13C NMR spectra in DMSO phase and the UV spectrum (200-400 nm) in ethanol phase. The different conformers of the compound and their minimum energies are studied by potential energy surface scan, using semi-empirical method PM6. The computed wavenumbers from different methods are scaled so as to agree with the experimental values and the scaling factors are reported. All the fundamental modes have been assigned based on the potential energy distribution (PED) values and the structure the molecule is analyzed interms of parameters like bond length, bond angle and dihedral angles predicted byB3LYP and CAM-B3LYP methods with cc-pVDZ basis sets. The values of dipole moment (μ), polarizability (α) and hyperpolarizability (β) of the molecule are reported, using which the non -linear optical property of the molecule is discussed. The HOMO-LUMO mappings are reported which reveals the different charge transfer possibilities within the molecule. The isotropic chemical shifts predicted for 1H and 13C atoms using gauge invariant atomic orbital (GIAO) theory show good agreement with experimental shifts and the same is discussed in comparison with atomic charges, predicted by Mullikan and APT charge analysis. NBO analysis is carried out to picture the probable electronic transitions in the molecule.

  8. Experimental (X-ray, FT-IR and UV-vis spectra) and theoretical methods (DFT study) of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol

    NASA Astrophysics Data System (ADS)

    Demircioğlu, Zeynep; Albayrak, Çiğdem; Büyükgüngör, Orhan

    2014-07-01

    A suitable single crystal of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol, formulated as C15H15N1O2, reveals that the structure is adopted to its E configuration about the azomethine Cdbnd N double bond. The compound adopts a enol-imine tautomeric form with a strong intramolecular Osbnd H⋯N hydrogen bond. The single crystal X-ray diffraction analysis at 296 K crystallizes in the monoclinic space group P21/c with a = 13.4791(11) Å, b = 6.8251(3) Å, c = 18.3561(15) Å, α = 90°, β = 129.296(5)°, γ = 90° and Z = 4. Comprehensive theoretical and experimental structural studies on the molecule have been carried out by FT-IR and UV-vis spectrometry. Optimized molecular structure and harmonic vibrational frequencies have been investigated by DFT/B3LYP method with 6-31G(d,p) basis set. Stability of the molecule, hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed by using natural bond orbital (NBO) analysis. Electronic structures were discussed by TD-DFT method and the relocation of the electron density were determined. The energetic behavior of the title compound has been examined in solvent media using polarizable continuum model (PCM). Molecular electrostatic potential (MEP), Mulliken population method and natural population analysis (NPA) have been studied. Nonlinear optical (NLO) properties were also investigated. In addition, frontier molecular orbitals analysis have been performed from the optimized geometry. An ionization potential (I), electron affinity (A), electrophilicity index (ω), chemical potential (μ), electronegativity (χ), hardness (η), and softness (S), have been investigated.

  9. Comparisons of 2D IR measured spectral diffusion in rotating frames using pulse shaping and in the stationary frame using the standard method

    NASA Astrophysics Data System (ADS)

    Karthick Kumar, S. K.; Tamimi, A.; Fayer, M. D.

    2012-11-01

    Multidimensional visible spectroscopy using pulse shaping to produce pulses with stable controllable phases and delays has emerged as an elegant tool to acquire electronic spectra faster and with greatly reduced instrumental and data processing errors. Recent migration of this approach using acousto-optic modulator (AOM) pulse shaping to the mid-infrared region has proved useful for acquiring two dimensional infrared (2D IR) vibrational echo spectra. The measurement of spectral diffusion in 2D IR experiments hinges on obtaining accurate 2D line shapes. To date, pulse shaping 2D IR has not been used to study the time-dependent spectral diffusion of a vibrational chromophore. Here we compare the spectral diffusion data obtained from a standard non-collinear 2D IR spectrometer using delay lines to the data obtained from an AOM pulse shaper based 2D IR spectrometer. The pulse shaping experiments are performed in stationary, partially rotating, and fully rotating reference frames and are the first in the infrared to produce 2D spectra collected in a fully rotating frame using a phase controlled pulse sequence. Rotating frame experiments provide a dramatic reduction in the number of time points that must be measured to obtain a 2D IR spectrum, with the fully rotating frame giving the greatest reduction. Experiments were conducted on the transition metal carbonyl complex tricarbonylchloro(1,10-phenanthroline)rhenium(I) in chloroform. The time dependent data obtained from the different techniques and with different reference frames are shown to be in agreement.

  10. IR imaging of blood circulation of patients with vascular disease

    NASA Astrophysics Data System (ADS)

    Wang, Hsin; Wade, Dwight R., Jr.; Kam, Jack

    2004-04-01

    We conducted a preliminary IR imaging study of blood circulation in patients with peripheral vascular diseases. Abnormal blood flow is common in older adults, especially those with elevated blood lipids, diabetes, hypertension, and a history of smoking. All of these conditions have a high prevalence in our population, often with more than one condition in the same individual. The differences in blood flow is revealed by temperature differences in areas of the extremities as well as other regions of the body. However, what is needed is an imaging technique that is relatively inexpensive and can reveal the blood flow in real time. The IR imaging can show detailed venous system and small tempearture changes associated with blood flow. Six patients with vascular diseases were tested in a clinic set up. Their legs and feet were imaged. We observed large temperature differences (cooling of more than 10° C) at the foot, especially toes. More valuable information were obtained from the temperature distribution maps. IR thermography is potentially a very valuable tool for medical application, especially for vascular diseases.

  11. Uncertainty of temperature measurements by infrared thermography for metal cutting applications

    NASA Astrophysics Data System (ADS)

    Lane, B.; Whitenton, E.; Madhavan, V.; Donmez, A.

    2013-12-01

    This paper presents a comprehensive analysis of the uncertainty in the measurement of the peak temperature on the side face of a cutting tool, during the metal cutting process, by infrared thermography. The analysis considers the use of a commercial off-the-shelf camera and optics, typical of what is used in metal cutting research. A physics-based temperature measurement equation is considered and an analytical method is used to propagate the uncertainties associated with measurement variables to determine the overall temperature measurement uncertainty. A Monte Carlo simulation is used to expand on the analytical method by incorporating additional sources of uncertainty such as a point spread function (PSF) of the optics, difference in emissivity of the chip and tool, and motion blur. Further discussion is provided regarding the effect of sub-scenel averaging and magnification on the measured temperature values. It is shown that a typical maximum cutting tool temperature measurement results in an expanded uncertainty of U = 50.1 °C (k = 2). The most significant contributors to this uncertainty are found to be uncertainties in cutting tool emissivity and PSF of the imaging system.

  12. Defects inspection of the solder bumps using self reference technology in active thermography

    NASA Astrophysics Data System (ADS)

    Lu, Xiangning; Shi, Tielin; Han, Jiguang; Liao, Guanglan; Su, Lei; Wang, Suya

    2014-03-01

    With the decrease of solder bumps in dimension and pitch, defects inspection of the solder bumps become more difficult. A nondestructive detection system based on the active thermography has been developed for solder bumps inspection. However, heating non-uniformities and emissivity differences may impede the defects recognition. In this paper, we propose a method using a self reference technology based on a source distribution image (SDI) to eliminate the influence of unevenness in emissivity values and heating power distribution. Three thermograms captured right after the heat pulse are averaged to create the SDI. Then the SDI is subtracted from the original thermograms, and we get the thermal contrast images, in which eight points on the edge of each hot spot are selected as the feature points for the corresponding bump. Thermal difference between the feature points and the central point are adopted to quantify the thermal behaviors of the solder bumps, by which the missing bump is distinguished from the reference bumps. The results show that it is effective using the method to eliminate the impacts of emissivity unevenness and heating non-uniformities on defects identification in the active infrared test.

  13. Real-time quantification of viable bacteria in liquid medium using infrared thermography

    NASA Astrophysics Data System (ADS)

    Salaimeh, Ahmad A.; Campion, Jeffrey J.; Gharaibeh, Belal Y.; Evans, Martin E.; Saito, Kozo

    2011-11-01

    Quantifying viable bacteria in liquids is important in environmental, food processing, manufacturing, and medical applications. Since vegetative bacteria generate heat as a result of biochemical reactions associated with cellular functions, thermal sensing techniques, including infrared thermography (IRT), have been used to detect viable cells in biologic samples. We developed a novel method that extends the dynamic range and improves the sensitivity of bacterial quantification by IRT. The approach uses IRT video, thermodynamics laws, and heat transfer mechanisms to directly measure, in real-time, the amount of energy lost as heat from the surface of a liquid sample containing bacteria when the specimen cools to a lower temperature over 2 min. We show that the Energy Content ( EC) of liquid media containing as few as 120 colony-forming units (CFU) of Escherichia coli per ml was significantly higher than that of sterile media ( P < 0.0001), and that EC and viable counts were strongly positively correlated ( r = 0.986) over a range of 120 to approximately 5 × 10 8 CFU/ml. Our IRT approach is a unique non-contact method that provides real-time bacterial enumeration over a wide dynamic range without the need for sample concentration, modification, or destruction. The approach could be adapted to quantify other living cells in a liquid milieu and has the potential for automation and high throughput.

  14. Evaluation of occupational knee-joint stress using liquid crystal thermography: a case study.

    PubMed

    Habes, D J; Bhattacharya, A; Milliron, M

    1994-04-01

    This paper describes a method to detect knee stress using liquid crystal thermography and presents the results of a case study in which the system was applied to two carpet installers. The method involves placing heat-sensitive sheets of film on the knees of workers at various intervals during the work day. The thermographic sheets react to variations in heat by changing colour. The measurements are taken with the worker's knee positioned in an illuminated, enclosed box. Once the patch stabilizes, the exhibited colours are recorded with an 8 mm video camera. The colour pattern, ranging from brown to blue, provides a thermal record of what is believed to be knee stress resulting from installing carpet. The thermographic records are stored in computer memory for subsequent analysis using an AT&T TARGA 16 video board. Custom software allows computation of the area of each distinct colour pattern as a percentage of total patch size. These records provide a characterization of knee response (inflammation) resulting from the biomechanical load sustained by the knee during the carpet installation task. PMID:15676958

  15. The uses of infrared thermography to evaluate the effects of climatic variables in bull's reproduction.

    PubMed

    Menegassi, Silvio Renato Oliveira; Pereira, Gabriel Ribas; Dias, Eduardo Antunes; Koetz, Celso; Lopes, Flávio Guiselli; Bremm, Carolina; Pimentel, Concepta; Lopes, Rubia Branco; da Rocha, Marcela Kuczynski; Carvalho, Helena Robattini; Barcellos, Júlio Otavio Jardim

    2016-01-01

    The objective of this study was to evaluate the seasonal effects of the environment on sperm quality in subtropical region determined by temperature and humidity index (THI). We used 20 Brangus bulls (5/8 Angus × 3/8 Nellore) aged approximately 24 months at the beginning of the study. Semen evaluations were performed twice per season during 1 year. Climate THI data were collected from an automatic weather station from the National Institute of Meteorology. Infrared thermography images were used to determine the temperature of the proximal and distal poles of the testis to assess the testicular temperature gradient (TG). The seasonal effects on seminal and climatic variables were analyzed with ANOVA using MIXED procedure of SAS. Sperm motility in spring (60.1%), summer (57.6%), and autumn (64.5%) showed difference compared to winter (73.0%; P < 0.01). TG was negatively correlated with THI at 18 days (spermiogenesis) (-0.76; P < 0.05) and at 12 days (epididymal transit) (-0.85; P < 0.01). Ocular temperature (OcT) had a positive correlation with THI at 18 days (0.78; P < 0.05) and at 12 days (0.84; P < 0.01). Motility showed a negative correlation with THI only at 18 days (-0.79; P < 0.05). During spermiogenesis, the TG had higher negative correlation compared to OcT (-0.97; P < 0.01) and rectal temperature (-0.72; P < 0.05). Spermatozoa with distal midpiece reflex were correlated with THI during transit epididymis (0.72; P < 0.05). Seminal parameters are not affected when THI reaches 93.0 (spermiogenesis) and 88.0 (epididymal transit). We concluded that infrared thermography can be adopted as an indirect method in order to assess the effect of environmental changes in TG and OcT of Brangus bulls. PMID:26049285

  16. Acquisition of the spatial temperature distribution of rock faces by using infrared thermography

    NASA Astrophysics Data System (ADS)

    Beham, Michael; Rode, Matthias; Schnepfleitner, Harald; Sass, Oliver

    2013-04-01

    Rock temperature plays a central role for weathering and therefore influences the risk potential originating from rockfall processes. So far, for the acquisition of temperature mainly point-based measuring methods have been used and accordingly, two-dimensional temperature data is rare. To overcome this limitation, an infrared camera was used to collect and analyse data on the spatial temperature distribution on 10 x 10 m sections of rock faces in the Gesäuse (900m a.s.l.) and in the Dachsteingebirge (2700m a.s.l.) within the framework of the research project ROCKING ALPS (FWF-P24244). The advantage of infrared thermography to capture area-wide temperatures has hardly ever been used in this context. In order to investigate the differences between north-facing and south-facing rock faces at about the same period of time it was necessary to move the camera between the sites. The resulting offset of the time lapse infrared images made it necessary to develop a sophisticated methodology to rectify the captured images in order to create matching datasets for future analysis. With the relatively simple camera used, one of the main challenges was to find a way to convert the colour-scale or grey-scale values of the rectified image back to temperature values after the rectification process. The processing steps were mainly carried out with MATLAB. South-facing rock faces generally experienced higher temperatures and amplitudes compared to the north facing ones. In view of the spatial temperature distribution, the temperatures of shady areas were clearly below those of sunny ones, with the latter also showing the highest amplitudes. Joints and sun-shaded areas were characterised by attenuated diurnal temperature fluctuations closely paralleled to the air temperature. The temperature of protruding rock parts and of loose debris responded very quick to changes in radiation and air temperatures while massive rock reacted more slowly. The potential effects of temperature on

  17. Rapid Fabrication of Flat Plate Cavity Phosphor Thermography Test Models for Shuttle Return-to-Flight Aero-Heating

    NASA Technical Reports Server (NTRS)

    Buck, Gregory M.; Powers, Michael A.; Nevins, Stephen C.; Griffith, Mark S.; Wainwright, Gary A.

    2006-01-01

    Methods, materials and equipment are documented for fabricating flat plate test models at NASA Langley Research Center for Shuttle return-to-flight aeroheating experiments simulating open and closed cavity interactions in Langley s hypersonic 20-Inch Mach 6 air wind tunnel. Approximately 96 silica ceramic flat plate cavity phosphor thermography test models have been fabricated using these methods. On one model, an additional slot is machined through the back of the plate and into the cavity and vented into an evacuated plenum chamber to simulate a further opening in the cavity. After sintering ceramic to 2150 F, and mounting support hardware, a ceramic-based two-color thermographic phosphor coating is applied for global temperature and heat transfer measurements, with fiducial markings for image registration.

  18. Comparisons of 2D IR measured spectral diffusion in rotating frames using pulse shaping and in the stationary frame using the standard method.

    PubMed

    Karthick Kumar, S K; Tamimi, A; Fayer, M D

    2012-11-14

    Multidimensional visible spectroscopy using pulse shaping to produce pulses with stable controllable phases and delays has emerged as an elegant tool to acquire electronic spectra faster and with greatly reduced instrumental and data processing errors. Recent migration of this approach using acousto-optic modulator (AOM) pulse shaping to the mid-infrared region has proved useful for acquiring two dimensional infrared (2D IR) vibrational echo spectra. The measurement of spectral diffusion in 2D IR experiments hinges on obtaining accurate 2D line shapes. To date, pulse shaping 2D IR has not been used to study the time-dependent spectral diffusion of a vibrational chromophore. Here we compare the spectral diffusion data obtained from a standard non-collinear 2D IR spectrometer using delay lines to the data obtained from an AOM pulse shaper based 2D IR spectrometer. The pulse shaping experiments are performed in stationary, partially rotating, and fully rotating reference frames and are the first in the infrared to produce 2D spectra collected in a fully rotating frame using a phase controlled pulse sequence. Rotating frame experiments provide a dramatic reduction in the number of time points that must be measured to obtain a 2D IR spectrum, with the fully rotating frame giving the greatest reduction. Experiments were conducted on the transition metal carbonyl complex tricarbonylchloro(1,10-phenanthroline)rhenium(I) in chloroform. The time dependent data obtained from the different techniques and with different reference frames are shown to be in agreement. PMID:23163363

  19. IOT Overview: IR Instruments

    NASA Astrophysics Data System (ADS)

    Mason, E.

    In this instrument review chapter the calibration plans of ESO IR instruments are presented and briefly reviewed focusing, in particular, on the case of ISAAC, which has been the first IR instrument at VLT and whose calibration plan served as prototype for the coming instruments.

  20. AN EVALUATION OF INFRARED THERMOGRAPHY FOR DETECTION OF BUMBLEFOOT (PODODERMATITIS) IN PENGUINS.

    PubMed

    Duncan, Ann E; Torgerson-White, Lauri L; Allard, Stephanie M; Schneider, Tom

    2016-06-01

    The objective of this study was to evaluate infrared thermography as a noninvasive screening tool for detection of pododermatitis during the developing and active stages of disease in three species of penguins: king penguin (Aptenodytes patagonicus) , macaroni penguin (Eudyptes chrysolophus), and rockhopper penguin (Eudyptes chrysocome). In total, 67 penguins were examined every 3 mo over a 15-mo period. At each exam, bumblefoot lesions were characterized and measured, and a timed series of thermal images were collected over a 4-min period. Three different methods were compared for analysis of thermograms. Feet with active lesions that compromise the surface of the foot were compared to feet with inactive lesions and no lesions. The hypothesis was that feet with active lesions would have warmer surface temperatures than the other conditions. Analysis of the data showed that although feet with active bumblefoot lesions are warmer than feet with inactive or no lesions, the variability seen in each individual penguin from one exam day to the next and the overlap seen between temperatures from each condition made thermal imaging an unreliable tool for detection of bumblefoot in the species studied. PMID:27468019

  1. Numerical simulation of phase images and depth reconstruction in pulsed phase thermography

    NASA Astrophysics Data System (ADS)

    Hernandez-Valle, Saul; Peters, Kara

    2015-11-01

    In this work we apply the finite element (FE) method to simulate the results of pulsed phase thermography experiments on laminated composite plates. Specifically, the goal is to simulate the phase component of reflected thermal waves and therefore verify the calculation of defect depth through the identification of the defect blind frequency. The calculation of phase components requires a higher spatial and temporal resolution than that of the calculation of the reflected temperature. An FE modeling strategy is presented, including the estimation of the defect thermal properties, which in this case is represented as a foam insert impregnated with epoxy resin. A comparison of meshing strategies using tetrahedral and hexahedral elements reveals that temperature errors in the tetrahedral results are amplified in the calculation of phase images and blind frequencies. Finally, we investigate the linearity of the measured diffusion length (based on the blind frequency) as a function of defect depth. The simulations demonstrate a nonlinear relationship between the defect depth and diffusion length, calculated from the blind frequency, consistent with previous experimental observations.

  2. Use of infrared thermography in children with shock: A case series

    PubMed Central

    Ortiz-Dosal, Alejandra; Rivera-Vega, Rosalina; Simón, Jorge; González, Francisco J

    2014-01-01

    Shock is a complex clinical syndrome caused by an acute failure of circulatory function resulting in inadequate tissue and organ perfusion. Digital infrared thermal imaging is a non-invasive technique that can detect changes in blood perfusion by detecting small changes in the temperature of the skin. In this preliminary study, eight pediatric patients (five boys, three girls), ages ranging from 6 to 14 years (average: 9.8 years), were admitted to the Intensive Care Unit at “Dr. Ignacio Morones Prieto” Central Hospital; here, the patients were examined using digital infrared thermal imaging. Patients in shock showed a significant decrease in distal temperature (at least 7°), compared to critically ill patients without shock. The latter group presented a skin temperature pattern very similar to the one previously reported for healthy children. The results show that infrared thermography can be used as a non-invasive method for monitoring the temperature in pediatric patients in intensive care units in order to detect shock in its early stages. PMID:27489669

  3. Frescoes diagnostic using laser Doppler vibrometry and infrared thermography: experimental and numerical approaches

    NASA Astrophysics Data System (ADS)

    Agnani, Alexia; De Andrade, Roberto M.; Esposito, Enrico; Feligiotti, Mara; Tavares, Sinthya G.

    2006-06-01

    In this work laser Doppler vibrometry has been used for damage detection in frescoes. Results were compared with the ones obtained through infrared thermography, and, for both techniques, mathematical models were implemented to simulate the physical domains and conditions of the employed test sample. The limitations of each methodology are also discussed. The numerical model of the vibrometric investigations has been constructed using Finite Elements Method modeling. A new procedure based on the observation of Rayleigh waves propagation velocities allowed to acquire sample mechanical parameters. Comparison of experimental and simulated data and independent defect diameter measurement by echographic equipment, allowed to establish the confidence level and the discrepancies in the developed model. Also operational limits of the vibrometric technique have been studied by acquisition of Signal-to-Noise ratio on different areas of a sample. The Fourier equation has been used for the mathematical model employed for the numerical simulation of the thermographic investigations. Numerical technique with formularization in finite volumes has been employed and a FORTRAN code has been developed to solve the thermal problem.

  4. Infrared thermography of evaporative fluxes and dynamics of salt deposition on heterogeneous porous surfaces

    NASA Astrophysics Data System (ADS)

    Nachshon, Uri; Shahraeeni, Ebrahim; Or, Dani; Dragila, Maria; Weisbrod, Noam

    2011-12-01

    Evaporation of saline solutions from porous media, common in arid areas, involves complex interactions between mass transport, energy exchange and phase transitions. We quantified evaporation of saline solutions from heterogeneous sand columns under constant hydraulic boundary conditions to focus on effects of salt precipitation on evaporation dynamics. Mass loss measurements and infrared thermography were used to quantify evaporation rates. The latter method enables quantification of spatial and temporal variability of salt precipitation to identify its dynamic effects on evaporation. Evaporation from columns filled with texturally-contrasting sand using different salt solutions revealed preferential salt precipitation within the fine textured domains. Salt precipitation reduced evaporation rates from the fine textured regions by nearly an order of magnitude. In contrast, low evaporation rates from coarse-textured regions (due to low capillary drive) exhibited less salt precipitation and consequently less evaporation rate suppression. Experiments provided insights into two new phenomena: (1) a distinct increase in evaporation rate at the onset of evaporation; and (2) a vapor pumping mechanism related to the presence of a salt crust over semidry media. Both phenomena are related to local vapor pressure gradients established between pore water and the surface salt crust. Comparison of two salts: NaCl and NaI, which tend to precipitate above the matrix surface and within matrix pores, respectively, shows a much stronger influence of NaCl on evaporation rate suppression. This disparity reflects the limited effect of NaI precipitation on matrix resistivity for solution and vapor flows.

  5. Infra-red Thermography for High Throughput Field Phenotyping in Solanum tuberosum

    PubMed Central

    Prashar, Ankush; Yildiz, Jane; McNicol, James W.; Bryan, Glenn J.; Jones, Hamlyn G.

    2013-01-01

    The rapid development of genomic technology has made high throughput genotyping widely accessible but the associated high throughput phenotyping is now the major limiting factor in genetic analysis of traits. This paper evaluates the use of thermal imaging for the high throughput field phenotyping of Solanum tuberosum for differences in stomatal behaviour. A large multi-replicated trial of a potato mapping population was used to investigate the consistency in genotypic rankings across different trials and across measurements made at different times of day and on different days. The results confirmed a high degree of consistency between the genotypic rankings based on relative canopy temperature on different occasions. Genotype discrimination was enhanced both through normalising data by expressing genotype temperatures as differences from image means and through the enhanced replication obtained by using overlapping images. A Monte Carlo simulation approach was used to confirm the magnitude of genotypic differences that it is possible to discriminate. The results showed a clear negative association between canopy temperature and final tuber yield for this population, when grown under ample moisture supply. We have therefore established infrared thermography as an easy, rapid and non-destructive screening method for evaluating large population trials for genetic analysis. We also envisage this approach as having great potential for evaluating plant response to stress under field conditions. PMID:23762433

  6. Precise Temperature Mapping of GaN-Based LEDs by Quantitative Infrared Micro-Thermography

    PubMed Central

    Chang, Ki Soo; Yang, Sun Choel; Kim, Jae-Young; Kook, Myung Ho; Ryu, Seon Young; Choi, Hae Young; Kim, Geon Hee

    2012-01-01

    A method of measuring the precise temperature distribution of GaN-based light-emitting diodes (LEDs) by quantitative infrared micro-thermography is reported. To reduce the calibration error, the same measuring conditions were used for both calibration and thermal imaging; calibration was conducted on a highly emissive black-painted area on a dummy sapphire wafer loaded near the LED wafer on a thermoelectric cooler mount. We used infrared thermal radiation images of the black-painted area on the dummy wafer and an unbiased LED wafer at two different temperatures to determine the factors that degrade the accuracy of temperature measurement, i.e., the non-uniform response of the instrument, superimposed offset radiation, reflected radiation, and emissivity map of the LED surface. By correcting these factors from the measured infrared thermal radiation images of biased LEDs, we determined a precise absolute temperature image. Consequently, we could observe from where the local self-heat emerges and how it distributes on the emitting area of the LEDs. The experimental results demonstrated that highly localized self-heating and a remarkable temperature gradient, which are detrimental to LED performance and reliability, arise near the p-contact edge of the LED surface at high injection levels owing to the current crowding effect. PMID:22666050

  7. Infrared thermography fails to visualize stimulation-induced meridian-like structures

    PubMed Central

    Litscher, Gerhard

    2005-01-01

    Background According to Traditional Chinese Medicine (TCM) the vital energy flows through a system of channels also called meridians. Generally accepted proof for meridians cannot be considered as being given. Goal of this study was to examine whether possible stimulation-induced meridian-like structures, as recently described by other authors, can be visualized and objectified simultaneously at different infrared wavelength ranges. Methods The study analyses evidence for the existence of acupuncture-specific, meridian-like artifacts in 6 healthy volunteers (mean age ± SD 28.7 ± 3.7 years; range 25 – 35 years). Two infrared cameras at different wavelength ranges were used for thermographic control of possible stimulation effects (moxibustion-cigar, infrared warmth stimulation, needle and laserneedle stimulation). In addition to thermography, temperature and microcirculatory parameters were registered at a selected point using laser-Doppler flowmetry. Results and Conclusion After moxibustion (or infrared light stimulation) of the body at 2 – 5 μm and 7.5 – 13 μm ranges, different structures appear on thermographic images of the human body which are technical artifacts and which are not identical to what are known as meridians in all textbooks of TCM. Further scientific studies are required regarding the possible visualization of meridians. PMID:15958163

  8. Assessment of anxiety in open field and elevated plus maze using infrared thermography.

    PubMed

    Lecorps, Benjamin; Rödel, Heiko G; Féron, Christophe

    2016-04-01

    Due to their direct inaccessibility, affective states are classically assessed by gathering concomitant physiological and behavioral measures. Although such a dual approach to assess emotional states is frequently used in different species including humans, the invasiveness of procedures for physiological recordings particularly in smaller-sized animals strongly restricts their application. We used infrared thermography, a non-invasive method, to assess physiological arousal during open field and elevated plus maze tests in mice. By measuring changes in surface temperature indicative of the animals' emotional response, we aimed to improve the inherently limited and still controversial information provided by behavioral parameters commonly used in these tests. Our results showed significant and consistent thermal responses during both tests, in accordance with classical physiological responses occurring in stressful situations. Besides, we found correlations between these thermal responses and the occurrence of anxiety-related behaviors. Furthermore, initial temperatures measured at the start of each procedure (open field, elevated plus maze), which can be interpreted as a measure of the animals' initial physiological arousal, predicted the levels of activity and of anxiety-related behaviors displayed during the tests. Our results stress the strong link between physiological correlates of emotions and behaviors expressed during unconditioned fear tests. PMID:26884121

  9. Classification of electrical problems detected by infrared thermography using a risk assessment process

    NASA Astrophysics Data System (ADS)

    McIntosh, Gregory B.; Huff, Roy

    2016-05-01

    For more than 40 years thermography has been used for electrical problem detection. In addition, since radiometric infrared cameras can establish apparent surface temperature of the problem, a classification system is often utilized based upon surface temperature, or temperature rise above normal operating temperature or ambient air temperature. This however can be an extremely unreliable classification method for a number of reasons including: emissivity and background energy; a lack of regard for failure modes and stressors; surface temperature variability with load and ambient conditions; temperature gradient from internal source to surface; and the presence of convection, just to name a few. Standards, such as NFPA 70B, try to address some of these issues by having very low threshold temperature limits, but this as well has issues including identifying an over-abundance of non-critical problems for immediate repair. This paper will present a risk assessment process and matrix which classifies electrical problems based upon a variety of factors affecting both probability and consequence of electrical component failure. Inherent in this process will be a discussion of understanding and analysing electrical connection failure modes and failure stressors, as well as consideration of both heat energy flow and stored energy rather than only considering surface temperature as a single point predictor of catastrophic failure.

  10. Precise temperature mapping of GaN-based LEDs by quantitative infrared micro-thermography.

    PubMed

    Chang, Ki Soo; Yang, Sun Choel; Kim, Jae-Young; Kook, Myung Ho; Ryu, Seon Young; Choi, Hae Young; Kim, Geon Hee

    2012-01-01

    A method of measuring the precise temperature distribution of GaN-based light-emitting diodes (LEDs) by quantitative infrared micro-thermography is reported. To reduce the calibration error, the same measuring conditions were used for both calibration and thermal imaging; calibration was conducted on a highly emissive black-painted area on a dummy sapphire wafer loaded near the LED wafer on a thermoelectric cooler mount. We used infrared thermal radiation images of the black-painted area on the dummy wafer and an unbiased LED wafer at two different temperatures to determine the factors that degrade the accuracy of temperature measurement, i.e., the non-uniform response of the instrument, superimposed offset radiation, reflected radiation, and emissivity map of the LED surface. By correcting these factors from the measured infrared thermal radiation images of biased LEDs, we determined a precise absolute temperature image. Consequently, we could observe from where the local self-heat emerges and how it distributes on the emitting area of the LEDs. The experimental results demonstrated that highly localized self-heating and a remarkable temperature gradient, which are detrimental to LED performance and reliability, arise near the p-contact edge of the LED surface at high injection levels owing to the current crowding effect. PMID:22666050

  11. Surface temperature/heat transfer measurement using a quantitative phosphor thermography system

    NASA Technical Reports Server (NTRS)

    Buck, G. M.

    1991-01-01

    A relative-intensity phosphor thermography technique developed for surface heating studies in hypersonic wind tunnels is described. A direct relationship between relative emission intensity and phosphor temperature is used for quantitative surface temperature measurements in time. The technique provides global surface temperature-time histories using a 3-CCD (Charge Coupled Device) video camera and digital recording system. A current history of technique development at Langley is discussed. Latest developments include a phosphor mixture for a greater range of temperature sensitivity and use of castable ceramics for inexpensive test models. A method of calculating surface heat-transfer from thermal image data in blowdown wind tunnels is included in an appendix, with an analysis of material thermal heat-transfer properties. Results from tests in the Langley 31-Inch Mach 10 Tunnel are presented for a ceramic orbiter configuration and a four-inch diameter hemisphere model. Data include windward heating for bow-shock/wing-shock interactions on the orbiter wing surface, and a comparison with prediction for hemisphere heating distribution.

  12. International standards for pandemic screening using infrared thermography

    NASA Astrophysics Data System (ADS)

    Pascoe, D. D.; Ring, E. F.; Mercer, J. B.; Snell, J.; Osborn, D.; Hedley-Whyte, J.

    2010-03-01

    The threat of a virulent strain of influenza, severe acute respiratory syndrome (SARS), tuberculosis, H1N1/A virus (swine flu) and possible mutations are a constant threat to global health. Implementation of pandemic infrared thermographic screening is based on the detection of febrile temperatures (inner canthus of the eyes) that are correlated with an infectious disease. Previous attempts at pandemic thermal screening have experienced problems (e.g. SARS outbreak, Singapore 2003) associated with the deployment plan, implementation and operation of the screening thermograph. Since this outbreak, the International Electrotechnical Commission has developed international standards that set minimum requirements for thermographic system fever screening and procedures that insure reliable and reproducible measurements. These requirements are published in IEC 80601-2-59:2008, Medical electrical equipment - Part 2-59: Particular requirements for the basic safety and essential performance of screening thermographs for human febrile temperature screening. The International Organization for Standardization has developed ISO/TR 13154:2009, Medical Electrical Equipment - which provides deployment, implementation and operational guidelines for identifying febrile humans using a screening thermograph. These new standards includes recommendations for camera calibrations, use of black body radiators, view field, focus, pixels within measurement site, image positioning, and deployment locations. Many current uses of thermographic screening at airports do not take into account critical issues addressed in the new standard, and are operating below the necessary effectiveness and efficiency. These documents, related thermal research, implications for epidemiology screening, and the future impact on medical thermography are discussed.

  13. Monitoring Sintering Burn-Through Point Using Infrared Thermography

    PubMed Central

    Usamentiaga, Rubén; Molleda, Julio; Garcia, Daniel F.; Bulnes, Francisco G.

    2013-01-01

    Sintering is a complex industrial process that applies heat to fine particles of iron ore and other materials to produce sinter, a solidified porous material used in blast furnaces. The sintering process needs to be carefully adjusted, so that the combustion zone reaches the bottom of the material just before the discharge end. This is known as the burn-through point. Many different parameters need to be finely tuned, including the speed and the quantities of the materials mixed. However, in order to achieve good results, sintering control requires precise feedback to adjust these parameters. This work presents a sensor to monitor the sintering burn-through point based on infrared thermography. The proposed procedure is based on the acquisition of infrared images at the end of the sintering process. At this position, infrared images contain the cross-section temperatures of the mixture. The objective of this work is to process this information to extract relevant features about the sintering process. The proposed procedure is based on four steps: key frame detection, region of interest detection, segmentation and feature extraction. The results indicate that the proposed procedure is very robust and reliable, providing features that can be used effectively to control the sintering process. PMID:23939585

  14. Infrared thermography based studies on mobile phone induced heating

    NASA Astrophysics Data System (ADS)

    Lahiri, B. B.; Bagavathiappan, S.; Soumya, C.; Jayakumar, T.; Philip, John

    2015-07-01

    Here, we report the skin temperature rise due to the absorption of radio frequency (RF) energy from three handheld mobile phones using infrared thermography technique. Experiments are performed under two different conditions, viz. when the mobile phones are placed in soft touch with the skin surface and away from the skin surface. Additionally, the temperature rise of mobile phones during charging, operation and simultaneous charging and talking are monitored under different exposure conditions. It is observed that the temperature of the cheek and ear regions monotonically increased with time during the usage of mobile phones and the magnitude of the temperature rise is higher for the mobile phone with higher specific absorption rate. The increase in skin temperature is higher when the mobile phones are in contact with the skin surface due to the combined effect of absorption of RF electromagnetic power and conductive heat transfer. The increase in the skin temperature in non-contact mode is found to be within the safety limit of 1 °C. The measured temperature rise is in good agreement with theoretical predictions. The empirical equation obtained from the temperature rise on the cheek region of the subjects correlates well with the specific absorption rate of the mobile phones. Our study suggests that the use of mobile phones in non-contact mode can significantly lower the skin temperature rise during its use and hence, is safer compared to the contact mode.

  15. Remote monitoring of breathing dynamics using infrared thermography.

    PubMed

    Pereira, Carina Barbosa; Yu, Xinchi; Czaplik, Michael; Rossaint, Rolf; Blazek, Vladimir; Leonhardt, Steffen

    2015-11-01

    An atypical or irregular respiratory frequency is considered to be one of the earliest markers of physiological distress. In addition, monitoring of this vital parameter plays a major role in diagnosis of respiratory disorders, as well as in early detection of sudden infant death syndrome. Nevertheless, the current measurement modalities require attachment of sensors to the patient's body, leading to discomfort and stress. The current paper presents a new robust algorithm to remotely monitor breathing rate (BR) by using thermal imaging. This approach permits to detect and to track the region of interest (nose) as well as to estimate BR. In order to study the performance of the algorithm, and its robustness against motion and breathing disorders, three different thermal recordings of 11 healthy volunteers were acquired (sequence 1: normal breathing; sequence 2: normal breathing plus arbitrary head movements; and sequence 3: sequence of specific breathing patterns). Thoracic effort (piezoplethysmography) served as "gold standard" for validation of our results. An excellent agreement between estimated BR and ground truth was achieved. Whereas the mean correlation for sequence 1-3 were 0.968, 0.940 and 0.974, the mean absolute BR errors reached 0.33, 0.55 and 0.96 bpm (breaths per minute), respectively. In brief, this work demonstrates that infrared thermography is a promising, clinically relevant alternative for the currently available measuring modalities due to its performance and diverse remarkable advantages. PMID:26601003

  16. Pulse Phase Thermography for Defect Detection and Visualization

    NASA Technical Reports Server (NTRS)

    Marinetti, Sergio; Plotnikov, Yuri A.; Winfree, William P.; Braggiotti, Alberto

    1999-01-01

    Pulse Phase Thermography (PPT) has been reported as a novel powerful technique of the thermal NDE. It employs application of the Discrete Fourier Transform (DFT) to thermal images obtained following flash heating of the front surface of a specimen. The computed phasegrams are excellent for defect visualization in a wide range of materials. This is in part due to their low sensitivity to uneven heating. This work is an attempt to analyze advantages and limitations of PPT. Results of application of the DFT to simulated temperature decays are presented. The temperature evolution on a surface has been simulated based on an analytical solution of the one-dimensional heat diffusion problem. A more sophisticated study has been done for different sizes of defects using numerical solution of the three-dimensional mathematical model. Capabilities of PPT for in-depth scanning and for monitoring of the material loss are discussed. The recommendations for the practical application of the PPT are presented. Experimental results obtained following these recommendations are reported.

  17. Pulsed phase thermography for defect detection of honeycomb structure

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Feng, Lichun; Li, Yanhong; Zhang, Cunlin

    2009-07-01

    Pulse Phase Thermography (PPT) has been reported as a powerful technique of the thermal NDE. In this paper, the authors show that the original phase-images of two kinds of honeycomb structure defects by PPT based on Fast Fourier Transform (FFT) for the signal of temperature-time of each pixel. One is the artificial defects in honeycomb structure core under surface skin, and the defects can be identified easily. The other is disbonding defect between surface skin and core, and the difference is apparent compared with bonding and no-bonding between surface skin and core. To improve the signal to noise ratio for defect inspection of honeycomb structure, the temperature decay curve of each pixel is smoothed by moving average filter and then fitted by exponential function. After FFT on the fitted data of temperature, the fitted phase-images of two kinds of honeycomb structure defects are given. Compared with the original thermal-images of PT and original phase-images, the calculated phase-images are much more improved. Another advantage is the data could be represented by coefficients of fitting functions, and the storage of data could be greatly reduced. At last, the calculation process of temperature decay curve and analysis of the influence caused by increasing sampling time and frequency are given.

  18. Application Of Thermography In The Builing Trade - Possibilities And Limitations

    NASA Astrophysics Data System (ADS)

    Specht, Herbert E.

    1983-11-01

    During recent years civil application of thermography in Germany has experienced a remarkable development in general but especially in the building trade. On the one hand there was an increase of user-oriented know-how,and on the other hand a growing public knowledge and acceptance mainly induced by a lot of governmental and commercial publications on energy conservation. From a practical viewpoint a description of interesting possibilities but also narrow limitations of four present-day application areas is given : 1. scanning of buildings from inside and outside - for fault analysis and all kinds of expertises including popular energy conservation consulting 2. mapping of plastered half-timbered houses (constructed in 13.-17. century, plastered in some parts of germany in 18. and 19. century) - for renovation and re-establishment of original historical shape 3. visualization of reinforcement in concrete for careful hole-drilling In large structures f.i. nuclear power plants according to safety regulations 4. localization of leakages in floor heating and tap water systems - for cost effective repair and status reports, mainly by order of insurance-companies.

  19. Analysis of solar collector array systems using thermography

    SciTech Connect

    Eden, A.

    1980-01-01

    The use of thermography to analyze large solar collector array systems under dynamic operating conditions is discussed. The research has focused on thermographic techniques and equipment to determine temperature distributions, flow patterns, and air blockages in solar collectors. The results of this extensive study, covering many sites and types of collectors, illustrate the capabilities of infrared analysis as an analysis tool and operation and maintenance procedure when applied to large arrays. Thermographic analysis of most collector systems showed temperature distributions that indicated balanced flow patterns with both the thermographs and the hand-held unit. In three significant cases, blocked or broken collector arrays, which previously had gone undetected, were discovered. Using this analysis, validation studies of large computer codes could examine collector arrays for flow patterns or blockages that could cause disagreement between actual and predicted performance. Initial operation and balancing of large systems could be accomplished without complicated sensor systems not needed for normal operations. Maintenance personnel could quickly check their systems without climbing onto the roof and without complicated sensor systems.

  20. Remote monitoring of breathing dynamics using infrared thermography

    PubMed Central

    Pereira, Carina Barbosa; Yu, Xinchi; Czaplik, Michael; Rossaint, Rolf; Blazek, Vladimir; Leonhardt, Steffen

    2015-01-01

    An atypical or irregular respiratory frequency is considered to be one of the earliest markers of physiological distress. In addition, monitoring of this vital parameter plays a major role in diagnosis of respiratory disorders, as well as in early detection of sudden infant death syndrome. Nevertheless, the current measurement modalities require attachment of sensors to the patient’s body, leading to discomfort and stress. The current paper presents a new robust algorithm to remotely monitor breathing rate (BR) by using thermal imaging. This approach permits to detect and to track the region of interest (nose) as well as to estimate BR. In order to study the performance of the algorithm, and its robustness against motion and breathing disorders, three different thermal recordings of 11 healthy volunteers were acquired (sequence 1: normal breathing; sequence 2: normal breathing plus arbitrary head movements; and sequence 3: sequence of specific breathing patterns). Thoracic effort (piezoplethysmography) served as “gold standard” for validation of our results. An excellent agreement between estimated BR and ground truth was achieved. Whereas the mean correlation for sequence 1–3 were 0.968, 0.940 and 0.974, the mean absolute BR errors reached 0.33, 0.55 and 0.96 bpm (breaths per minute), respectively. In brief, this work demonstrates that infrared thermography is a promising, clinically relevant alternative for the currently available measuring modalities due to its performance and diverse remarkable advantages. PMID:26601003

  1. Surface temperatures of insulated glazing units: Infrared thermography laboratory measurements

    SciTech Connect

    Griffith, B.T.; Tuerler, D.; Arasteh, D.

    1995-12-01

    Data are presented for the distribution of surface temperatures on the warm-side surface of seven different insulated glazing units. Surface temperatures are measured using infrared thermography and an external referencing technique. This technique allows detailed mapping of surface temperatures that is non-intrusive. The glazings were placed between warm and cold environmental chambers that were operated at conditions corresponding to standard design conditions for winter heating. The temperatures conditions are 2 1.1{degrees}C (70{degrees}F) and -17.8{degrees}C (0{degrees}F) on the warm and cold sides, respectively. Film coefficients varied somewhat with average conditions of about 7.6 W/m{sup 2}{circ}K (1.34 Btu/h-ft{sup 2}{circ}{degrees}F) for the warm-side and 28.9 W/m{sup 2}{circ}K (5.1 Btu/h{circ}ft{sup 2}{circ}{degrees}F) for the cold-side. Surface temperature data are plotted for the vertical distribution along the centerline of the IG and for the horizontal distribution along the centerline. This paper is part of larger collaborative effort that studied the same set of glazings.

  2. IR Hot Wave

    SciTech Connect

    Graham, T. B.

    2010-04-01

    The IR Hot Wave{trademark} furnace is a breakthrough heat treatment system for manufacturing metal components. Near-infrared (IR) radiant energy combines with IR convective heating for heat treating. Heat treatment is an essential process in the manufacture of most components. The controlled heating and cooling of a metal or metal alloy alters its physical, mechanical, and sometimes chemical properties without changing the object's shape. The IR Hot Wave{trademark} furnace offers the simplest, quickest, most efficient, and cost-effective heat treatment option for metals and metal alloys. Compared with other heat treatment alternatives, the IR Hot Wave{trademark} system: (1) is 3 to 15 times faster; (2) is 2 to 3 times more energy efficient; (3) is 20% to 50% more cost-effective; (4) has a {+-}1 C thermal profile compared to a {+-}10 C thermal profile for conventional gas furnaces; and (5) has a 25% to 50% smaller footprint.

  3. Thermophysical analysis of II-VI semiconductors by PPE calorimetry and lock-in thermography

    SciTech Connect

    Streza, M.; Dadarlat, D.; Strzałkowski, K.

    2013-11-13

    An accurate determination of thermophysical properties such as thermal diffusivity, thermal effusivity and thermal conductivity is extremely important for characterization and quality assurance of semiconductors. Thermal diffusivity and effusivity of some binary semiconductors have been investigated. Two experimental techniques were used: a contact technique (PPE calorimetry) and a non contact technique (lock-in thermography). When working with PPE, in the back (BPPE) configuration and in the thermally thick regim of the pyroelectric sensor, we can get the thermal diffusivity of the sample by performing a scanning of the excitation frequency of radiation. Thermal effusivity is obtained in front configuration (sensor directly irradiated and sample in back position) by performing a thickness scan of a coupling fluid. By using the lock-in thermography technique, the thermal diffusivity of the sample is obtained from the phase image. The results obtained by the two techniques are in good agreement. Nevertheless, for the determination of thermal diffusivity, lock-in thermography is preferred.

  4. Passive and active infrared thermography: An overview of applications for the inspection of mosaic structures

    NASA Astrophysics Data System (ADS)

    Theodorakeas, P.; Cheilakou, E.; Ftikou, E.; Koui, M.

    2015-11-01

    Infrared Thermography is a non destructive testing and evaluation (NDT&E) technique, which has been widely used for the investigation of cultural heritage and art objects. The main purpose of this study is to present the capabilities of both passive and active thermography for the inspection of mosaic structures, evaluating the performance of each testing approach through its application in representative mosaic structures. In situ passive thermography was applied on mosaic pavements in an attempt to acquire knowledge about their preservation state, while the active approach was used in order to study plastered mosaics and characterise the tesserae layer beneath the plaster. The results from this study revealed that passive approach can be efficiently applied as a moisture detection tool and a rapid monitoring technique of the mosaic condition, while the active thermographic investigation showed much more potentiality as quantitative information for the detected feature was further retrieved.

  5. Evaluation of paint coating thickness variations based on pulsed Infrared thermography laser technique

    NASA Astrophysics Data System (ADS)

    Mezghani, S.; Perrin, E.; Vrabie, V.; Bodnar, J. L.; Marthe, J.; Cauwe, B.

    2016-05-01

    In this paper, a pulsed Infrared thermography technique using a homogeneous heat provided by a laser source is used for the non-destructive evaluation of paint coating thickness variations. Firstly, numerical simulations of the thermal response of a paint coated sample are performed. By analyzing the thermal responses as a function of thermal properties and thickness of both coating and substrate layers, optimal excitation parameters of the heating source are determined. Two characteristic parameters were studied with respect to the paint coating layer thickness variations. Results obtained using an experimental test bench based on the pulsed Infrared thermography laser technique are compared with those given by a classical Eddy current technique for paint coating variations from 5 to 130 μm. These results demonstrate the efficiency of this approach and suggest that the pulsed Infrared thermography technique presents good perspectives to characterize the heterogeneity of paint coating on large scale samples with other heating sources.

  6. Thermography for estimating near-surface soil moisture under developing crop canopies

    NASA Technical Reports Server (NTRS)

    Heilman, J. L.; Moore, D. G.

    1980-01-01

    Previous investigations of thermal infrared techniques using remote sensors (thermography) for estimating soil water content have been limited primarily to bare soil. Ground-based and aircraft investigations were conducted to evaluate the potential for extending the thermography approach to developing crop canopies. A significant exponential relationship was found between the volumetric soil water content in the 0-4 cm soil layer and the diurnal difference between surface soil temperature measured at 0230 and 1330 LST (satellite overpass times of NASA's Heat Capacity Mapping Mission - HCMM). Surface soil temperatures were estimated using minimum air temperature, percent cover of the canopy and remote measurements of canopy temperature. Results of the investigation demonstrated that thermography can potentially be used to estimate soil temperature and soil moisture throughout a complete growing season for a number of different crops and soils.

  7. Experimental study using infrared thermography on the convective heat transfer of a TGV brake disc in the actual environment

    NASA Astrophysics Data System (ADS)

    Siroux, Monica; Harmand, Souad; Desmet, Bernard

    2001-03-01

    Local and mean convective heat transfer from a rotating TGV brake disc model in the actual environment and submitted to an air flow parallel to the disc surface is studied experimentally in this paper. The experimental technique is based on the use of a heated thermally thick disc combined with the technique of temperature measurement by infrared thermography. The local convective heat transfer coefficient from the disc surface is identified by solving the steady state heat equation by finite difference method using the experimental temperature distribution as boundary conditions. These tests were carried out for rotational speed (omega) between 325 and 2000 rpm (rotational Reynolds number Re between 88500 and 545000) so as to obtain laminar and turbulent flow on the disc, and for air flow velocity U ranging between 0 and 12 m s-1 (air flow Reynolds number Re0 between 0 and 153000).

  8. In situ assessment of structural timber elements of a historic building by infrared thermography and ultrasonic velocity

    NASA Astrophysics Data System (ADS)

    Kandemir-Yucel, A.; Tavukcuoglu, A.; Caner-Saltik, E. N.

    2007-01-01

    The infrared thermography (IRT) and the ultrasonic velocity measurements (UVM) promise to be particularly important to assess the state of deterioration and the adequacy of the boundary and microclimatic conditions for timber elements. These non-destructive methods supported by laboratory analyses of timber samples were conducted on a 13th century monument, Aslanhane Mosque in Ankara, Turkey. The combined interpretation of the results was done to assess the condition of structural timber elements in terms of their state of preservation, the dampness problems and the recent incompatible repairs affecting them. Results indicated that moist areas in the structure were associated with roof drainage problems and the repairs undertaken with cement-based mortars and plasters and oil-based paints. Juxtaposition of the IRT and UVM together with laboratory analyses was found to be useful to assess the soundness of timber, enhanced the accuracy and effectiveness of the survey and facilitated to build up the urgent and long-term conservation programs.

  9. Experimental and numerical simulations of flow and heat transfer in heat exchanger elements using liquid crystal thermography

    NASA Astrophysics Data System (ADS)

    Stasiek, Jan; Ciofalo, Michele; Wierzbowski, Maciej

    2004-05-01

    Experimental and numerical investigation of heat transfer and fluid flow were conducted for classic heat exchanger elements (flat plate with fin-tubes in-line, staggered and with vortex generators) and corrugated-undulated ducts under transitional and weakly turbulent conditions. The dependence of average heat transfer and pressure drop on Reynolds number and geometrical parameters was investigated. Distributions of local heat transfer coefficient were obtained by using liquid crystal thermography and surface-averaged values were computed. Three-dimensional numerical simulations were conducted by a finite-volume method using a low-Reynolds number k-ɛ model under the assumption of fully developed flow. Computed flow fields provided otherwise inaccessible information on the flow patterns and the mechanisms of heat transfer enhancement.

  10. Development of an Extra-vehicular (EVA) Infrared (IR) Camera Inspection System

    NASA Technical Reports Server (NTRS)

    Gazarik, Michael; Johnson, Dave; Kist, Ed; Novak, Frank; Antill, Charles; Haakenson, David; Howell, Patricia; Pandolf, John; Jenkins, Rusty; Yates, Rusty

    2006-01-01

    Designed to fulfill a critical inspection need for the Space Shuttle Program, the EVA IR Camera System can detect crack and subsurface defects in the Reinforced Carbon-Carbon (RCC) sections of the Space Shuttle s Thermal Protection System (TPS). The EVA IR Camera performs this detection by taking advantage of the natural thermal gradients induced in the RCC by solar flux and thermal emission from the Earth. This instrument is a compact, low-mass, low-power solution (1.2cm3, 1.5kg, 5.0W) for TPS inspection that exceeds existing requirements for feature detection. Taking advantage of ground-based IR thermography techniques, the EVA IR Camera System provides the Space Shuttle program with a solution that can be accommodated by the existing inspection system. The EVA IR Camera System augments the visible and laser inspection systems and finds cracks and subsurface damage that is not measurable by the other sensors, and thus fills a critical gap in the Space Shuttle s inspection needs. This paper discusses the on-orbit RCC inspection measurement concept and requirements, and then presents a detailed description of the EVA IR Camera System design.

  11. Laser lock-in thermography for thermal contact characterisation of surface layer

    NASA Astrophysics Data System (ADS)

    Semerok, A.; Jaubert, F.; Fomichev, S. V.; Thro, P.-Y.; Courtois, X.; Grisolia, C.

    2012-11-01

    Lock-in thermography was applied to determine the thermal contact conductance of a W-layer (140 μm) on a CFC-substrate. A lock-in thermography system together with a pulse repetition rate Nd:YAG laser (1064 nm, 1-500 Hz pulse repetition rate) for layer heating was applied for phase shift measurements on the W-layer. A numerical model for direct phase shift calculations was developed and applied to rapid determination of the Fourier amplitudes and phases of the temperature. Thermal conductance coefficients were obtained by comparing the experimental and simulation phase shifts.

  12. Emissivity-corrected power loss calibration for lock-in thermography measurements on silicon solar cells

    NASA Astrophysics Data System (ADS)

    Kasemann, Martin; Walter, Benjamin; Meinhardt, Christoph; Ebser, Jan; Kwapil, Wolfram; Warta, Wilhelm

    2008-06-01

    This paper describes power loss calibration procedures with implemented emissivity correction. The determination of our emissivity correction matrix does neither rely on blackbody reference measurements nor on the knowledge of any sample temperatures. To describe the emissivity-corrected power calibration procedures in detail, we review the theory behind lock-in thermography and show experimentally that the lock-in signal is proportional to the power dissipation in the solar cell. Experiments show the successful application of our emissivity correction procedure, which significantly improves the informative value of lock-in thermography images and the reliability of the conclusions drawn from these images.

  13. Characterization of uncertainties when measuring metal cutting temperatures using infrared radiation thermography

    NASA Astrophysics Data System (ADS)

    Whitenton, Eric P.

    2009-05-01

    There are many error sources when using infrared radiation thermography to measure the temperature distribution of the tool, workpiece, and chip during metal cutting. It is important to understand how these error sources affect the measurement uncertainty. Some are familiar to anyone performing thermography measurements, such as uncertainties in the basic camera calibration. However, metal cutting presents unique measurement challenges due to factors such as the high magnification required, high surface speeds, polarization effects, micro-blackbody effects, and changing emissivity as chips form. This paper presents highlights of the current state of efforts at NIST to catalog and characterize error sources and the resulting uncertainties.

  14. Inductive pulsed phase thermography for reducing or enlarging the effect of surface emissivity variation

    NASA Astrophysics Data System (ADS)

    Yang, Ruizhen; He, Yunze; Gao, Bin; Tian, Gui Yun

    2014-11-01

    Emissivity variation introduces illusory temperature inhomogeneity and results in false alarms in infrared thermography, thus, it is important to separate the influence of surface emissivity variation. This letter experimentally demonstrates the advantages of phase information to reduce or enlarge the effect of surface emissivity variation with inductive pulsed phase thermography, where inductive excitation is emissivity-independent and avoids the effect of emissivity variation in heating process. The directly heated area and the indirectly heated area are divided in the phasegrams. The emissivity variation is removed or enlarged perfectly at the specific frequency and defect detectability is improved remarkably.

  15. Combination Of Thermography And Pressure Tests To Combat Air Leakage Problems In Building Enclosures

    NASA Astrophysics Data System (ADS)

    Spruin, W. G.

    1987-05-01

    Uncontrolled air leakage in a building enclosure is the main component of space heating and cooling costs. In Atlantic Canada, Public Works Canada has combined thermography and pressure testing to identify design and construction problems in new construction and to identify specific areas of air leakage in existing housing stock. A study case shows how thermography and pressure testing has been utilized to locate and compare specific areas of air leakage in a residence before and after air sealing. The study provides both quantitative and qualitative evidence of how air sealing increases the air tightness in building enclosures.

  16. Application of Air Coupled Acoustic Thermography (ACAT) for Inspection of Honeycomb Sandwich Structures

    NASA Technical Reports Server (NTRS)

    Winfree, William P.; Zalameda, Joseph N.; Pergantis, Charles; Flanagan, David; Deschepper, Daniel

    2009-01-01

    The application of a noncontact air coupled acoustic heating technique is investigated for the inspection of advanced honeycomb composite structures. A weakness in the out of plane stiffness of the structure, caused by a delamination or core damage, allows for the coupling of acoustic energy and thus this area will have a higher temperature than the surrounding area. Air coupled acoustic thermography (ACAT) measurements were made on composite sandwich structures with damage and were compared to conventional flash thermography. A vibrating plate model is presented to predict the optimal acoustic source frequency. Improvements to the measurement technique are also discussed.

  17. Structure of complex of N-methylpiperidine betaine with p-hydroxybenzoic acid studied by X-ray, FT-IR and DFT methods

    NASA Astrophysics Data System (ADS)

    Dega-Szafran, Z.; Dutkiewicz, G.; Kosturkiewicz, Z.; Szafran, M.

    2008-03-01

    Crystal structure of the complex of N-methylpiperidine betaine ( N-carboxymethyl- N-methylpiperidinium inner salt, MPB) with p-hydroxybenzoic acid (HBA) has been determined by X-ray diffraction. The crystals are triclinic, space group Pī, with a = 6.1156(5), b = 10.6869(10), c = 12.0320(10) Å, α = 109.55(1)°, β = 95.25(1)°, γ = 99.22(1)°, Z = 2, R = 0.034. Two molecules of p-hydroxybenzoic acid and two molecules of N-methylpiperidine betaine are linked together forming a centrosymmetric dimer, (MPB·HBA) 2, by four O-H···O hydrogen bonds of lengths 2.622(1) and 2.617(1) Å, between the carboxylic and hydroxy groups of HBA and both oxygen atoms of the carboxylate group of MPB, respectively. The piperidine ring has a chair conformation with the CH 2COO - substituent in the axial position and the CH 3 group in the equatorial one. Two parallel aromatic rings in (MPB·HBA) 2 are distanced by 3.457 Å. In the crystals the complexes form "islands" related to the neighboring complexes by the inversion centers, weak C-H···O bonds and van der Waals forces. A broad band in the 3100-2400 cm -1 region and two bands attributed to the νC dbnd O (1689 cm -1) and νasCOO (1607 cm -1) vibrations in the FT-IR spectrum confirm the structure of the title complex. The two structures of MPB·HBA, denoted as A and B, have been optimized by the B3LYP/6-31G(d,p) method. In A, MPB forms a O-H···O hydrogen bond (2.562 Å) with the carboxylic group of HBA shorter than in the crystals, while in B it interacts with the phenolic group of HBA by a longer O-H···O hydrogen bond (2.661 Å) than in the crystals. Complex A is slightly more stable than B (0.15 kcal/mol).

  18. PKC{delta}-mediated IRS-1 Ser24 phosphorylation negatively regulates IRS-1 function

    SciTech Connect

    Greene, Michael W. . E-mail: michael.greene@bassett.org; Ruhoff, Mary S.; Roth, Richard A.; Kim, Jeong-a; Quon, Michael J.; Krause, Jean A.

    2006-10-27

    The IRS-1 PH and PTB domains are essential for insulin-stimulated IRS-1 Tyr phosphorylation and insulin signaling, while Ser/Thr phosphorylation of IRS-1 disrupts these signaling events. To investigate consensus PKC phosphorylation sites in the PH-PTB domains of human IRS-1, we changed Ser24, Ser58, and Thr191 to Ala (3A) or Glu (3E), to block or mimic phosphorylation, respectively. The 3A mutant abrogated the inhibitory effect of PKC{delta} on insulin-stimulated IRS-1 Tyr phosphorylation, while reductions in insulin-stimulated IRS-1 Tyr phosphorylation, cellular proliferation, and Akt activation were observed with the 3E mutant. When single Glu mutants were tested, the Ser24 to Glu mutant had the greatest inhibitory effect on insulin-stimulated IRS-1 Tyr phosphorylation. PKC{delta}-mediated IRS-1 Ser24 phosphorylation was confirmed in cells with PKC{delta} catalytic domain mutants and by an RNAi method. Mechanistic studies revealed that IRS-1 with Ala and Glu point mutations at Ser24 impaired phosphatidylinositol-4,5-bisphosphate binding. In summary, our data are consistent with the hypothesis that Ser24 is a negative regulatory phosphorylation site in IRS-1.

  19. Evaluation of Microbolometer-Based Thermography for Gossamer Space Structures

    NASA Technical Reports Server (NTRS)

    Miles, Jonathan J.; Blandino, Joseph R.; Jenkins, Christopher H.; Pappa, Richard S.; Banik, Jeremy; Brown, Hunter; McEvoy, Kiley

    2005-01-01

    In August 2003, NASA's In-Space Propulsion Program contracted with our team to develop a prototype on-board Optical Diagnostics System (ODS) for solar sail flight tests. The ODS is intended to monitor sail deployment as well as structural and thermal behavior, and to validate computational models for use in designing future solar sail missions. This paper focuses on the thermography aspects of the ODS. A thermal model was developed to predict local sail temperature variations as a function of sail tilt to the sun, billow depth, and spectral optical properties of front and back sail surfaces. Temperature variations as small as 0.5 C can induce significant thermal strains that compare in magnitude to mechanical strains. These thermally induced strains may result in changes in shape and dynamics. The model also gave insight into the range and sensitivity required for in-flight thermal measurements and supported the development of an ABAQUS-coupled thermo-structural model. The paper also discusses three kinds of tests conducted to 1) determine the optical properties of candidate materials; 2) evaluate uncooled microbolometer-type infrared imagers; and 3) operate a prototype imager with the ODS baseline configuration. (Uncooled bolometers are less sensitive than cooled ones, but may be necessary because of restrictive ODS mass and power limits.) The team measured the spectral properties of several coated polymer samples at various angles of incidence. Two commercially available uncooled microbolometer imagers were compared, and it was found that reliable temperature measurements are feasible for both coated and uncoated sides of typical sail membrane materials.

  20. Evaluation of microbolometer-based thermography for gossamer space structures

    NASA Astrophysics Data System (ADS)

    Miles, Jonathan J.; Blandino, Joseph R.; Jenkins, Christopher H. M.; Pappa, Richard S.; Banik, Jeremy; Brown, Hunter; McEvoy, Kiley

    2005-08-01

    In August 2003, NASA's In-Space Propulsion Program contracted with our team to develop a prototype on-board Optical Diagnostics System (ODS) for solar sail flight tests. The ODS is intended to monitor sail deployment as well as structural and thermal behavior, and to validate computational models for use in designing future solar sail missions. This paper focuses on the thermography aspects of the ODS. A thermal model was developed to predict local sail temperature variations as a function of sail tilt to the sun, billow depth, and spectral optical properties of front and back sail surfaces. Temperature variations as small as 0.5 oC can induce significant thermal strains that compare in magnitude to mechanical strains. These thermally induced strains may result in changes in shape and dynamics. The model also gave insight into the range and sensitivity required for in-flight thermal measurements and supported the development of an ABAQUS-coupled thermo-structural model. The paper also discusses three kinds of tests conducted to 1) determine the optical properties of candidate materials; 2) evaluate uncooled microbolometer-type infrared imagers; and 3) operate a prototype imager with the ODS baseline configuration. (Uncooled bolometers are less sensitive than cooled ones, but may be necessary because of restrictive ODS mass and power limits.) The team measured the spectral properties of several coated polymer samples at various angles of incidence. Two commercially available uncooled microbolometer imagers were compared, and it was found that reliable temperature measurements are feasible for both coated and uncoated sides of typical sail membrane materials.