Science.gov

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. Moisture map by IR thermography

    NASA Astrophysics Data System (ADS)

    Grinzato, E.; Cadelano, G.; Bison, P.

    2010-10-01

    A new approach to moisture detection in buildings by an optical method is presented. Limits of classical and new methods are discussed. The state of the art about the use of IR thermography is illustrated as well. The new technique exploits characteristics of the materials and takes into account explicitly the heat and mass exchange between surface and environment. A set of experiments in controlled laboratory conditions on different materials is used to better understand the physical problem. The testing procedure and the data reduction are illustrated. A case study on a heritage building points up the features of this technique.

  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. Seismic risk evaluation aided by IR thermography

    NASA Astrophysics Data System (ADS)

    Grinzato, E.; Cadelano, G.; Bison, P.; Petracca, A.

    2009-05-01

    Conservation of buildings in areas at seismic risk must take prevention into account. The safeguard architectonic heritage is an ambitious objective, but a priority for planning programmes at varying levels of decision making. Preservation and restoration activities must be optimized to cover a vast and widespread historical and architectonic heritage present in many countries. Masonry buildings requires an adequate level of knowledge based on the importance of structural geometry, which may include the damage, details of construction and properties of materials. For identification and classification of masonry is necessary to find shape, type and size of the elements, texture, size of mortar joints, assemblage. The recognition can be done through a visual inspection of the surface of walls, which can be examined, where is not visible, removing a layer of plaster. Thermography is an excellent tool for a fast survey and collection of vital information for this purpose, but it is extremely important define a precise procedure in the development of more efficient monitoring tools. Thermography is a non-destructive method that allows recognizing the structural damage below plaster, detecting the presence of discontinuity in masonry, for added storeys, cavity, filled openings, and repairs. Furthermore, the fast identification of subsurface state allows to select areas where other methods either more penetrating or partially destructive have to be applied. The paper reports experimental results achieved in the mainframe of the European project RECES Modiquus. The main aim of the project is to improve methods, techniques and instruments for facing antiseismic options. Both passive and active thermographic techniques have been applied in different weather conditions and time schemes. A dedicated algorithm has been developed to enhance the visibility of wall bonding.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Microwave thermography: principles, methods and clinical applications.

    PubMed

    Myers, P C; Sadowsky, N L; Barrett, A H

    1979-06-01

    We review the physical principles, method of operation, measurement limitations, and potential medical applications of microwave thermography. We present detailed results of a study of breast cancer detection at 1.3 and 3.3 GHz, including the dependence of detection rates on microwave frequency, time, tumor depth, and tumor size. At 1.3 GHz, microwave thermography detects breast cancer as well as infrared thermography (true-positive rate = 0.76 when true-negative rate = 0.63). When the two methods are combined, the true-positive rate increases by about 0.1 over that of either method alone.

  12. IR thermography as a tool for the pest management professional

    NASA Astrophysics Data System (ADS)

    Grossman, Jon L.

    2005-03-01

    For years the pest Management Professional has relied on visual and manual inspections to locate insect pest infestations. As building materials have improved, the ability to locate pest problems has become more difficult since building materials are often able to mask the existence of pest infestation. Additionally, these improved building materials have contributed to the pest problem by providing a convenient food and nesting source. Within the past five years, the Pest Management Industry has become aware that IR thermography can aid in the detection of pest infestation by detecting evidence of latent moisture within structures. This paper discusses the use of thermal imaging to detect thermal patterns associated with insect infestation, verification of data and special challenges associated with the inspection process.

  13. 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)

  14. 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.

  15. CURVATURE EFFECT QUANTIFICATION FOR IN-VIVO IR THERMOGRAPHY

    PubMed Central

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

    2013-01-01

    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

  16. Detecting and localizing failure points in proton exchange membrane fuel cells using IR thermography

    NASA Astrophysics Data System (ADS)

    Bender, Guido; Felt, Wyatt; Ulsh, Michael

    2014-05-01

    An understanding of the potentially serious long-term performance degradation effects that coating and/or other fabrication irregularities might have in mass produced proton exchange membrane fuel cells (PEMFC) is essential to determine manufacturing tolerances of fuel cell components. An experimental setup and methodology is described that employs accelerated stress tests (ASTs) and IR thermography to accurately determine the location and severity of developing failure points in PEMFCs. The method entails a novel hardware that allows the spatial observation of a hydrogen crossover experiment within a fuel cell hardware. The application of the method is demonstrated by comparing the effects of an AST on pristine as well as defect-containing MEAs. The presented method is shown to be valuable for determining the areas within a fuel cell that are most stressed by aging processes.

  17. 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.

  18. Assessment of the effect of housing on feather damage in laying hens using IR thermography.

    PubMed

    Pichová, K; Bilčík, B; Košt'ál, L'

    2017-04-01

    Plumage damage represents one of the animal-based measures of laying hens welfare. Damage occurs predominantly due to age, environment and damaging pecking. IR thermography, due to its non-invasiveness, objectivity and repeatability is a promising alternative to feather damage scoring systems such as the system included in the Welfare Quality ® assessment protocol for poultry. The aim of this study was to apply IR thermography for the assessment of feather damage in laying hens kept in two housing systems and to compare the results with feather scoring. At the start of the experiment, 16-week-old laying hens (n=30) were divided into two treatments such as deep litter pen and enriched cage. During 4 months, feather damage was assessed regularly in 2-week intervals. One more single assessment was done nine and a half months after the start of the experiment. The feather damage on four body regions was assessed by scoring and IR thermography: head and neck, back and rump, belly, and underneck and breast. Two variables obtained by IR thermography were used: the difference between the body surface temperature and ambient temperature (ΔTB) and the proportion of featherless areas, which were defined as areas with a temperature >33.5°C. Data were analyzed using a GLM model. The effects of housing, time, region and their interactions on feather damage, measured by the feather scoring and by both IR thermography measures, were all significant (P<0.001). The ΔTB in all assessed regions correlated positively with the feather score. Feather scoring revealed higher damage in enriched cages compared with deep litter pens starting from week 6 of the experiment on the belly and back and rump regions, whereas ΔTB from week 6 in the belly and from week 8 on the back and rump region. The proportion of featherless areas in the belly region differed significantly between the housings from week 8 of the experiment and on the back and rump region from week 12. The IR thermography

  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. Application of Pyrometry and IR-Thermography to High Surface Temperature Measurements

    DTIC Science & Technology

    2000-04-01

    Division in Cologne Porz-Wahnheide, Linder H6he D-51147 Cologne, Germany Summary d distance E energy In this document the non- intrusive temperature...interaction with the supersonic Some main parameters of the thermal radiation are flow, non- intrusive temperature measurement tech- defined below [1...ing a time duration dt into a hemisphere: well. S= dW / dt [W /m2]. (1) IR-thermography and pyrometry are two well de- veloped non- intrusive techniques

  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. Detecting defects in marine structures by using eddy current infrared thermography.

    PubMed

    Swiderski, W

    2016-12-01

    Eddy current infrared (IR) thermography is a new nondestructive testing (NDT) technique used for the detection of cracks in electroconductive materials. By combining the well-established inspection methods of eddy current NDT and IR thermography, this technique uses induced eddy currents to heat test samples. In this way, IR thermography allows the visualization of eddy current distribution that is distorted in defect sites. This paper discusses the results of numerical modeling of eddy current IR thermography procedures in application to marine structures.

  3. Building material characterization by using IR thermography for efficient heating systems

    NASA Astrophysics Data System (ADS)

    Bison, Paolo; Grinzato, Ermanno

    2008-03-01

    Thermography is excellent for a fast characterisation of building materials, both at laboratory or in situ. A great advantage is the possibility to analyse many samples at the same conditions and time. A technique has been applied for new materials, oriented to radiating floor systems, evaluating different approaches. Samples are submitted to a stepwise, uniform heating. Surface excess temperature is recorded by thermography evaluating thermal inertia. At first, thermal diffusivity has been measured using a modified version of the Flash Method, then applied on a single face, for in situ application. Heat capacity and thermal conductivity have been inferred for each samples by definitions and the independent measure of the volumic mass.

  4. 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.

  5. Advanced techniques in IR thermography as a tool for the pest management professional

    NASA Astrophysics Data System (ADS)

    Grossman, Jon L.

    2006-04-01

    Within the past five years, the Pest Management industry has become aware that IR thermography can aid in the detection of pest infestations and locate other conditions that are within the purview of the industry. This paper will review the applications that can be utilized by the pest management professional and discuss the advanced techniques that may be required in conjunction with thermal imaging to locate insect and other pest infestations, moisture within structures, the verification of data and the special challenges associated with the inspection process.

  6. Simultaneous monitoring of ice accretion and thermography of an airfoil: an IR imaging methodology

    NASA Astrophysics Data System (ADS)

    Mohseni, M.; Frioult, M.; Amirfazli, A.

    2012-10-01

    A novel image analysis methodology based on infrared (IR) imaging was developed for simultaneous monitoring of ice accretion and thermography of airfoils. In this study, an IR camera was calibrated and used to measure the surface temperature of the energized airfoils, and monitor the ice accretion and growth pattern on the airfoils’ surfaces. The methodology comprises the automatic processing of a series of IR video frames with the purpose of detecting ice pattern evolution during the icing test period. A specially developed MATLAB code was used to detect the iced areas in the IR images, and simultaneously monitor surface temperature evolution of the airfoil during an icing test. Knowing the correlation between the icing pattern and surface temperature changes during an icing test is essential for energy efficient design of thermal icing mitigation systems. Processed IR images were also used to determine the ice accumulation rate on the airfoil's surface in a given icing test. The proposed methodology has been demonstrated to work successfully, since the optical images taken at the end of icing tests from the airfoils’ surfaces compared well with the processed IR images detecting the ice grown outward from the airfoils’ leading edge area.

  7. 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.

  8. 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.

  9. 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.

  10. Thermography is not a feasible method for breast cancer screening.

    PubMed

    Brkljacić, Boris; Miletić, Damir; Sardanelli, Francesco

    2013-06-01

    Breast cancer is a common malignancy causing high mortality in women especially in developed countries. Due to the contribution of mammographic screening and improvements in therapy, the mortality rate from breast cancer has decreased considerably. An imaging-based early detection of breast cancer improves the treatment outcome. Mammography is generally established not only as diagnostic but also as screening tool, while breast ultrasound plays a major role in the diagnostic setting in distinguishing solid lesions from cysts and in guiding tissue sampling. Several indications are established for contrast-enhanced magnetic resonance imaging. Thermography was not validated as a screening tool and the only study performed long ago for evaluating this technology in the screening setting demonstrated very poor results. The conclusion that thermography might be feasible for screening cannot be derived from studies with small sample size, unclear selection of patients, and in which mammography and thermography were not blindly compared as screening modalities. Thermography can not be used to aspirate, biopsy or localize lesions preoperatively since no method so far was described to accurately transpose the thermographic location of the lesion to the mammogram or ultrasound and to surgical specimen. Thermography cannot be proclaimed as a screening method, without any evidence whatsoever.

  11. Thermography--a feasible method for screening breast cancer?

    PubMed

    Kolarić, Darko; Herceg, Zeljko; Nola, Iskra Alexandra; Ramljak, Vesna; Kulis, Tomislav; Holjevac, Jadranka Katancić; Deutsch, Judith A; Antonini, Svetlana

    2013-06-01

    Potential use of thermography for more effective detection of breast carcinoma was evaluated on 26 patients scheduled for breast carcinoma surgery. Ultrasonographic scan, mammography and thermography were performed at the University Hospital for Tumors. Thermographic imaging was performed using a new generation of digital thermal cameras with high sensitivity and resolution (ThermoTracer TH7102WL, NEC). Five images for each patient were recorded: front, right semi-oblique, right oblique, left- semi oblique and left oblique. While mammography detected 31 changes in 26 patients, thermography was more sensitive and detected 6 more changes in the same patients. All 37 changes were subjected to the cytological analysis and it was found that 16 of samples were malignant, 8 were suspected malignant and 11 were benign with atypia or proliferation while only 2 samples had benign findings. The pathohistological method (PHD) recorded 75.75% malignant changes within the total number of samples. Statistical analysis of the data has shown a probability of a correct mammographic finding in 85% of the cases (sensitivity of 85%, specificity of 84%) and a probability of a correct thermographic finding in 92% of the cases (sensitivity of 100%, specificity of 79%). As breast cancer remains the most prevalent cancer in women and thermography exhibited superior sensitivity, we believe that thermography should immediately find its place in the screening programs for early detection of breast carcinoma, in order to reduce the sufferings from this devastating disease.

  12. Quantitative thermal wave phase imaging of an IR semi-transparent GaAs wafer using IR lock-in thermography

    NASA Astrophysics Data System (ADS)

    Pawlak, Michal; Streza, Mihaela; Morari, Cristian; Strzałkowski, Karol; Depriester, Michael; Chirtoc, Mihai

    2017-02-01

    In this paper, the simultaneous measurement of out-of-plane thermal diffusivity and effective infrared absorption coefficient of an IR semi-transparent GaAs wafer using infrared lock-in thermography technique (LIT) is presented. The method relies on analysis of the generated LIT phase images recorded at different modulation frequencies, using the thermal wave model in the transmission configuration. The out-of-plane thermal diffusivity and effective infrared absorption coefficient are estimated from the best fit of the theoretical model to the experimental data. The obtained values are in good agreement with those obtained by supplementary measurement using the modulated photothermal infrared radiometry technique (PTR) in the reflection mode, and also with data reported in the literature. In addition, simple modification of the LIT experiment set up allows one to determinate the in-plane thermal diffusivity of n-GaAs wafer. It was found that in-plane and out-of-plane thermal diffusivities of the GaAs wafer are very close, as expected, within the limit of measurement errors. The results show that the LIT technique in transmission configuration can provide spatial information about both the (effective) infrared absorption coefficient and thermal diffusivity of semiconductor crystals.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Early events in plant hypersensitive response leaves revealed by IR thermography

    NASA Astrophysics Data System (ADS)

    Boccara, Martine; Boue, Christine; De Paepe, Rosine; Boccara, Albert C.

    2001-10-01

    Infrared thermography is used to reveal the establishment of Erwinia amylovora harpin-induced hypersensitive response (HR) in Nicotiana sylvestris leaves. We observed a decrease in temperature (1-2 degree(s)C) in the harpin infiltrated zone, correlated with an increase in stomatal opening, strongly suggesting that the temperature decrease is due to higher transpiration rate. IRT experiments were conducted in a laboratory environment and could be widely applied for genotype screening and monitoring drug effects.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. High-performance IR thermography system based on Class II Thermal Imaging Common Modules

    NASA Astrophysics Data System (ADS)

    Bell, Ian G.

    1991-03-01

    The Class II Thermal Imaging Common Modules were originally developed for the U.K. Ministry of Defence as the basis of a number of high performance thermal imaging systems for use by the British Armed Forces. These systems are characterized by high spatial resolution, high thermal resolution and real time thermal image update rate. A TICM II thermal imaging system uses a cryogenically cooled eight element Cadmium- Mercury-Telluride (CMT) SPRITE (Signal PRocessing In The Element) detector which is mechanically scanned over the thermal scene to be viewed. The TALYTHERM system is based on a modified TICM II thermal image connected to an IBM PC-AT compatible computer having image processing hardware installed and running the T.E.M.P.S. (Thermal Emission Measurement and Processing System) software package for image processing and data analysis. The operation of a TICM II thermal imager is briefly described highlighting the use of the SPRITE detector which coupled with a serial/parallel scanning technique yields high temporal, spatial and thermal resolutions. The conversion of this military thermal image into thermography system is described, including a discussion of the modifications required to a standard imager. The technique for extracting temperature information from a real time thermal image and how this is implemented in a TALYTHERM system is described. The D.A.R.T. (Discrete Attenuation of Radiance Thermography) system which is based on an extensively modified TICM II thermal imager is also described. This system is capable of measuring temperatures up to 1000 degrees C whilst maintaining the temporal and spatial resolutions inherent in a TICM II imager. Finally applications of the TALYTHERM in areas such as NDT (Non Destructive Testing), medical research and military research are briefly described.

  4. Applications of IR Thermography in Capturing Thermal Transients and Other High-Speed Thermal Events

    SciTech Connect

    Dinwiddie, R.B.; Graham, S.; Wang, H.

    1999-06-07

    The high-speed, snap-shot mode, and the external triggering capability of an IR camera allows thermal transients to be captured. These advanced features were used to capture thermal transients during electrical breakdown of ZnO varistors and to freeze the rotation of an automobile disk brake in order to study thermoplastic instability in the braking system. The IR camera also showed the thermoplastic effect during cyclic fatigue testing of a glass matrix composite.

  5. Non-destructive testing of composite materials used in military applications by eddy current thermography method

    NASA Astrophysics Data System (ADS)

    Swiderski, Waldemar

    2016-10-01

    Eddy current thermography is a new NDT-technique for the detection of cracks in electro conductive materials. It combines the well-established inspection techniques of eddy current testing and thermography. The technique uses induced eddy currents to heat the sample being tested and defect detection is based on the changes of induced eddy currents flows revealed by thermal visualization captured by an infrared camera. The advantage of this method is to use the high performance of eddy current testing that eliminates the known problem of the edge effect. Especially for components of complex geometry this is an important factor which may overcome the increased expense for inspection set-up. The paper presents the possibility of applying eddy current thermography method for detecting defects in ballistic covers made of carbon fiber reinforced composites used in the construction of military vehicles.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Calibration and Evaluation of Ultrasound Thermography using Infrared Imaging

    PubMed Central

    Hsiao, Yi-Sing; Deng, Cheri X.

    2015-01-01

    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 (IR) thermography for calibration and validation of ultrasound thermography. Using phantoms and cardiac tissue specimens subjected to high-intensity focused ultrasound (HIFU) heating, we simultaneously acquired ultrasound and IR 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 IR-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 IR 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 – 50 °C in cardiac tissues. Unlike previous studies where thermocouples or water-bath techniques were used to evaluate the performance of ultrasound thermography, our results show that high resolution IR thermography provides a useful tool that can be applied to evaluate and understand the limitations of ultrasound thermography methods. PMID:26547634

  12. 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

  13. A new method of infrared thermography for quantification of brown adipose tissue activation in healthy adults (TACTICAL): a randomized trial.

    PubMed

    Ang, Qi Yan; Goh, Hui Jen; Cao, Yanpeng; Li, Yiqun; Chan, Siew-Pang; Swain, Judith L; Henry, Christiani Jeyakumar; Leow, Melvin Khee-Shing

    2017-05-01

    The ability to alter the amount and activity of brown adipose tissue (BAT) in human adults is a potential strategy to manage obesity and related metabolic disorders associated with food, drug, and environmental stimuli with BAT activating/recruiting capacity. Infrared thermography (IRT) provides a non-invasive and inexpensive alternative to the current methods (e.g. (18)F-FDG PET) used to assess BAT. We have quantified BAT activation in the cervical-supraclavicular (C-SCV) region using IRT video imaging and a novel image computational algorithm by studying C-SCV heat production in healthy young men after cold stimulation and the ingestion of capsinoids in a prospective double-blind placebo-controlled randomized trial. Subjects were divided into low-BAT and high-BAT groups based on changes in IR emissions in the C-SCV region induced by cold. The high-BAT group showed significant increases in energy expenditure, fat oxidation, and heat output in the C-SCV region post-capsinoid ingestion compared to post-placebo ingestion, but the low-BAT group did not. Based on these results, we conclude that IRT is a promising tool for quantifying BAT activity.

  14. 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.

  15. Thermography instruments for predictive maintenance

    SciTech Connect

    Palko, E.

    1993-08-12

    Thermography (infrared imaging, or IR scanning) is not only the most versatile predictive maintenance technology available today; it is, in general, the most cost-effective. Plant engineering can apply a virtually unlimited variety of predictive maintenance instruments, but all are restricted regarding the types of existing and incipient problems they can detect. Inplant applications of thermography, however, are truly limited only by the extent of the plant engineer's imagination. Here are ways that thermography can be used to fight downtime in plants, and factors to consider when selecting the best instrument for particular circumstances.

  16. A novel calibration method for an infrared thermography system applied to heat transfer experiments

    NASA Astrophysics Data System (ADS)

    Ochs, M.; Horbach, T.; Schulz, A.; Koch, R.; Bauer, H.-J.

    2009-07-01

    In heat transfer measurements with highly non-uniform wall heat fluxes, high spatial resolution of wall temperatures is required to fully capture the complex thermal situation. Infrared thermography systems provide that spatial resolution. To meet the thermal accuracy, they are usually calibrated in situ using thermocouples embedded in the test surface, which have to cover the complete temperature range of interest. However, thermocouples which are placed in regions of high temperature and heat flux gradients often cannot be used for the calibration and the overall accuracy of the calibration decreases significantly. Therefore, in the present work a novel in situ calibration method is presented which does not require thermocouples over the complete surface temperature range. The number of free parameters of the calibration function is reduced by an optimized insensitivity of the system with respect to changes in operating conditions. Reference measurements demonstrate the advantages of the new method.

  17. Nondestructive testing: use of IR and acoustics methods in buildings pathology

    NASA Astrophysics Data System (ADS)

    Esposti, Walter; Meroni, Italo

    1995-03-01

    In the paper the authors present some experiences made using IR and acoustics methods in a non destructive way for the evaluation of situations of degradation in building materials and components. Two studies are presented: (1) detection of the delamination of wall renderings, especially those supporting frescos, by means of IR and sonic investigation; (2) use of infrared thermography for the visualization of fracture zones of walls and steel components under cyclic loads. The possibility of detecting rendering delaminations is based on the different path of the heat diffusion in part of the wall affected by the delamination, compared to the rest of the wall. The difference is caused by the presence of small pockets containing still air. The case study showed makes reference to the analysis of adhesion conditions of a rendering dating back to the IV century, applied on the bell towers of the ancient basilica dedicated to S. Lorenzo in Milan, Italy. The use of infrared thermography for detecting the strength status of materials and components is based on the fact that the strength status of parts of building components can become evident because of heat losses which appear where the component is weaker. The IR observation was made on steel bars subject to traction testing and on lightweight concrete prismatic samples subject to compression testing. The experiences indicate that there is room for this NdT technique to provide some useful answers. Nevertheless it is sure that more experimental work is needed in order to increase the full comprehension of the phenomena which are the basis of their applications for alternative uses.

  18. 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

  19. Infrared thermography based on artificial intelligence as a screening method for carpal tunnel syndrome diagnosis.

    PubMed

    Jesensek Papez, B; Palfy, M; Mertik, M; Turk, Z

    2009-01-01

    This study further evaluated a computer-based infrared thermography (IRT) system, which employs artificial neural networks for the diagnosis of carpal tunnel syndrome (CTS) using a large database of 502 thermal images of the dorsal and palmar side of 132 healthy and 119 pathological hands. It confirmed the hypothesis that the dorsal side of the hand is of greater importance than the palmar side when diagnosing CTS thermographically. Using this method it was possible correctly to classify 72.2% of all hands (healthy and pathological) based on dorsal images and > 80% of hands when only severely affected and healthy hands were considered. Compared with the gold standard electromyographic diagnosis of CTS, IRT cannot be recommended as an adequate diagnostic tool when exact severity level diagnosis is required, however we conclude that IRT could be used as a screening tool for severe cases in populations with high ergonomic risk factors of CTS.

  20. 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.

  1. 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.

  2. 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.

  3. Lock-in thermography as a rapid and reproducible thermal characterization method for magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Lemal, Philipp; Geers, Christoph; Monnier, Christophe A.; Crippa, Federica; Daum, Leopold; Urban, Dominic A.; Rothen-Rutishauser, Barbara; Bonmarin, Mathias; Petri-Fink, Alke; Moore, Thomas L.

    2017-04-01

    Lock-in thermography (LIT) is a sensitive imaging technique generally used in engineering and materials science (e.g. detecting defects in composite materials). However, it has recently been expanded for investigating the heating power of nanomaterials, such as superparamagnetic iron oxide nanoparticles (SPIONs). Here we implement LIT as a rapid and reproducible method that can evaluate the heating potential of various sizes of SPIONs under an alternating magnetic field (AMF), as well as the limits of detection for each particle size. SPIONs were synthesized via thermal decomposition and stabilized in water via a ligand transfer process. Thermographic measurements of SPIONs were made by stimulating particles of varying sizes and increasing concentrations under an AMF. Furthermore, a commercially available SPION sample was included as an external reference. While the size dependent heating efficiency of SPIONs has been previously described, our objective was to probe the sensitivity limits of LIT. For certain size regimes it was possible to detect signals at concentrations as low as 0.1 mg Fe/mL. Measuring at different concentrations enabled a linear regression analysis and extrapolation of the limit of detection for different size nanoparticles.

  4. 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%.

  5. 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.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. 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.

  8. 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

  9. The Effectiveness of Infrared Thermography in Patients with Whiplash Injury

    PubMed Central

    Lee, Young Seo; Farhadi, Hooman F.; Lee, Won Hee; Kim, Sung Tae; Lee, Kun Su

    2015-01-01

    Objective This study aims to visualize the subjective symptoms before and after the treatment of whiplash injury using infrared (IR) thermography. Methods IR thermography was performed for 42 patients who were diagnosed with whiplash injury. There were 19 male and 23 female patients. The mean age was 43.12 years. Thermal differences (ΔT) in the neck and shoulder and changes in the thermal differences (ΔdT) before and after treatment were analyzed. Pain after injury was evaluated using visual analogue scale (VAS) before and after treatment (ΔVAS). The correlations between ΔdT and ΔVAS results before and after the treatment were examined. We used Digital Infrared Thermal Imaging equipment of Dorex company for IR thermography. Results The skin temperature of the neck and shoulder immediately after injury showed 1-2℃ hyperthermia than normal. After two weeks, the skin temperature was normal range. ΔT after immediately injuy was higher than normal value, but it was gradually near the normal value after two weeks. ΔdT before and after treatment were statistically significant (p<0.05). VAS of the neck and shoulder significantly reduced after 2 week (p=0.001). Also, there was significant correlation between ΔdT and reduced ΔVAS (the neck; r=0.412, p<0.007) (the shoulder; r=0.648, p<0.000). Conclusion The skin temperature of sites with whiplash injury is immediately hyperthermia and gradually decreased after two weeks, finally it got close to normal temperature. These were highly correlated with reduced VAS. IR thermography can be a reliable tool to visualize the symptoms of whiplash injury and the effectiveness of treatment in clinical settings. PMID:25932296

  10. [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.

  11. A Novel Method for Extracting Respiration Rate and Relative Tidal Volume from Infrared Thermography

    PubMed Central

    Lewis, Gregory F.; Gatto, Rodolfo G.; Porges, Stephen W.

    2010-01-01

    In psychophysiological research, measurement of respiration has been dependent on transducers having direct contact with the participant. The current study provides empirical data demonstrating that a noncontact technology, infrared video thermography, can accurately estimate breathing rate and relative tidal volume across a range of breathing patterns. Video tracking algorithms were applied to frame-by-frame thermal images of the face to extract time series of nostril temperature and to generate breath-by-breath measures of respiration rate and relative tidal volume. The thermal indices of respiration were contrasted with criterion measures collected with inductance plethysmography. The strong correlations observed between the technologies demonstrate the potential use of facial video thermography as a noncontact technology to monitor respiration. PMID:21214587

  12. Research on lock-in thermography for aerospace materials of nondestructive test based on image sequence processing

    NASA Astrophysics Data System (ADS)

    Liu, Junyan; Dai, Jingmin; Wang, Yang

    2008-11-01

    IR Lock in thermography is an active thermography technology based on thermal wave signal processing, especially, it has many advantages for nondestructive test of composite materials and compound structure application and has been applied on aerospace, automotive, mechanics and electric fields. In lock in thermography, given sufficient time for periodic heating, the surface temperature will evolve periodically in a sinusoidal pattern form the transient state to the steady state. In this paper, the principle of lock in thermography is introduced and the heat transferring process is analyzed by the sinusoidal variation heating flow transferred in materials by means of FEM method. In experiment, the modulating optical stimulation is applied to sample, and image sequences are collected by Jade MWIR 550 FPA IR camera. The digital filter algorithm which is Savitzky-Golay digital smoothness filters is used to remove the effects of high frequency noise. A phase image at the frequency of periodic heating can be calculated using a Fourier transform of the periodic heating frequency in transient state for defect detection. The IR lock in thermography processing software is developed by using of visual C++ programmed based image sequence collected. The experimental results show that the developed system reached up to high level of conventional steady state Lock in method.

  13. 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

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

    This work is focused on the integration of infrared thermography and ground penetrating radar for the inspection of architectonic structures. First, laboratory tests were carried out with both techniques by considering an ad hoc specimen made of concrete and with the insertion of anomalies of a different nature and at different depths. Such tests provided helpful information for ongoing inspections in situ, which were later performed in two important Italian archaeological sites, namely Pompeii (Naples) and Nora (Cagliari). In the first site, the exploration was devoted to the analysis of the wall paintings of Villa Imperiale with the aim of evaluating the state of conservation of frescoes as well of the underneath masonry structure. As main findings, the applied techniques allowed outlining some areas, which were damaged by ingression in-depth of moisture and/or by disaggregation of the constituent materials, and also for recognition of previous restoration. In the archaeological area of Nora, instead, the attention was driven towards the evaluation of the state of degradation of the theatre remnants. Our prospections show that the front side of the theatre, being more strongly affected by degradation, needs a massive restoration work. As a general result, we demonstrated that a joint interpretation of infrared thermography and ground penetrating radar data supplies detailed 3D information from near-surface to deep layers, which may assist in restoration planning.

  15. Investigation on a new inducer of pulsed eddy current thermography

    NASA Astrophysics Data System (ADS)

    He, Min; Zhang, Laibin; Zheng, Wenpei; Feng, Yijing

    2016-09-01

    In this paper, a new inducer of pulsed eddy current thermography (PECT) is presented. The use of the inducer can help avoid the problem of blocking the infrared (IR) camera's view in eddy current thermography technique. The inducer can also provide even heating of the test specimen. This paper is concerned with the temperature distribution law around the crack on a specimen when utilizing the new inducer. Firstly, relative mathematical models are provided. In the following section, eddy current distribution and temperature distribution around the crack are studied using the numerical simulation method. The best separation distance between the inducer and the specimen is also determined. Then, results of temperature distribution around the crack stimulated by the inducer are gained by experiments. Effect of current value on temperature rise is studied as well in the experiments. Based on temperature data, temperature features of the crack are discussed.

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

    PubMed

    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 f(acq) (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.

  17. 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.

  18. 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

  19. Monitoring of microvascular free flaps following oropharyngeal reconstruction using infrared thermography: first clinical experiences.

    PubMed

    Just, Maren; Chalopin, Claire; Unger, Michael; Halama, Dirk; Neumuth, Thomas; Dietz, Andreas; Fischer, Miloš

    2016-09-01

    The aim of this study is to investigate static and dynamic infrared (IR) thermography for intra- and postoperative free-flap monitoring following oropharyngeal reconstruction. Sixteen patients with oropharyngeal reconstruction by free radial forearm flap were included in this prospective, clinical study (05/2013-08/2014). Prior ("intraop_pre") and following ("intraop_post") completion of the microvascular anastomoses, IR thermography was performed for intraoperative flap monitoring. Further IR images were acquired one day ("postop_1") and 10 days ("postop_10") after surgery for postoperative flap monitoring. Of the 16, 15 transferred free radial forearm flaps did not show any perfusion failure. A significant decreasing mean temperature difference (∆T: temperature difference between the flap surface and the surrounding tissue in Kelvin) was measured at all investigation points in comparison with the temperature difference at "intraop_pre" (mean values on all patients: ∆T intraop_pre = -2.64 K; ∆T intraop_post = -1.22 K, p < 0.0015; ∆T postop_1 = -0.54 K, p < 0.0001; ∆T postop_10 = -0.58 K, p < 0.0001). Intraoperative dynamic IR thermography showed typical pattern of non-pathological rewarming due to re-established flap perfusion after completion of the microvascular anastomoses. Static and dynamic IR thermography is a promising, objective method for intraoperative and postoperative monitoring of free-flap reconstructions in head and neck surgery and to detect perfusion failure, before macroscopic changes in the tissue surface are obvious. A lack of significant decrease of the temperature difference compared to surrounding tissue following completion of microvascular anastomoses and an atypical rewarming following a thermal challenge are suggestive of flap perfusion failure.

  20. The use of infrared thermography as a non-invasive method for fever detection in sheep infected with bluetongue virus.

    PubMed

    Pérez de Diego, Ana C; Sánchez-Cordón, Pedro J; Pedrera, Miriam; Martínez-López, Beatriz; Gómez-Villamandos, José C; Sánchez-Vizcaíno, José M

    2013-10-01

    Fever, which is closely linked to viraemia, is considered to be both the main and the earliest clinical sign in sheep infected with bluetongue virus (BTV). The aim of this study was to evaluate the potential use of infrared thermography (IRT) for early detection of fever in sheep experimentally infected with bluetongue virus serotype 1 (BTV-1) and serotype 8 (BTV-8). This would reduce animal stress during experimental assays and assist in the development of a screening method for the identification of fever in animals suspected of being infected with BTV. Rectal and infrared eye temperatures were collected before and after BTV inoculation. The two temperature measures were positively correlated (r=0.504, P<0.05). The highest correlation between rectal and infrared temperatures was observed when temperatures were above physiological levels. IRT discriminated between febrile and non-febrile sheep with a sensitivity of 85% and specificity of 97%. The results showed that eye temperature measured using IRT was a useful non-invasive method for the assessment of fever in sheep infected with BTV under experimental conditions. Further research is required to evaluate the use of IRT under field conditions to identify potentially infected animals in bluetongue surveillance programmes.

  1. Assessing the reliability of thermography to infer internal body temperatures of lizards.

    PubMed

    Barroso, Frederico M; Carretero, Miguel A; Silva, Francisco; Sannolo, Marco

    2016-12-01

    For many years lizard thermal ecology studies have relied on the use of contact thermometry to obtain internal body temperature (Tb) of the animals. However, with progressing technology, an interest grew in using new, less invasive methods, such as InfraRed (IR) pyrometry and thermography, to infer Tb of reptiles. Nonetheless few studies have tested the reliability of these new tools. The present study tested the use of IR cameras as a non-invasive tool to infer Tb of lizards, using three differently body-sized lacertid species (Podarcis virescens, Lacerta schreiberi and Timon lepidus). Given the occurrence of regional heterothermy, we pairwise compared thermography readings of six body parts (snout, eye, head, dorsal, hind limb, tail base) to cloacal temperature (measured by a thermometer-associated thermocouple probe) commonly employed to measure Tb in field and lab studies. The results showed moderate to strong correlations (R(2)=0.84-0.99) between all body parts and cloacal temperature. However, despite the readings on the tail base showed the strongest correlation in all three species, it was the eye where the absolute values and pattern of temperature change most consistently followed the cloacal measurements. Hence, we concluded that the eye would be the body location whose IR camera readings more closely approximate that of the animal's internal environment. Alternatively, other body parts can be used, provided that a careful calibration is carried out. We provide guidelines for future research using thermography to infer Tb of lizards.

  2. 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.

  3. 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.

  4. IR decoys modeling method based on particle system

    NASA Astrophysics Data System (ADS)

    Liu, Jun-yu; Wu, Kai-feng; Dong, Yan-bing

    2016-10-01

    Due to the complexity in combustion processes of IR decoys, it is difficult to describe its infrared radiation characteristics by deterministic model. In this work, the IR decoys simulation based on particle system was found. The measured date of the IR decoy is used to analyze the typical characteristic of the IR decoy. A semi-empirical model of the IR decoy motion law has been set up based on friction factors and a IR decoys simulation model has been build up based on particle system. The infrared imaging characteristic and time varying characteristic of the IR decoy were simulated by making use of the particle feature such as lifetime, speed and color. The dynamic IR decoys simulation is realized with the VC++6.0 and OpenGL.

  5. 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

    2016-05-21

    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.

  6. 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

  7. Comparison of Detection Capability for Acoustic Thermography, Visual Inspection and Fluorescent Penetrant Inspection on Gas Turbine Components

    NASA Astrophysics Data System (ADS)

    Guo, Y.; Ruhge, F. R.

    2009-03-01

    The innovative NDE inspection system Acoustic Thermography is developed with Sonic Infrared (Sonic IR) technology. Since the probability of detection is sensitive to the flaw characteristics, the fabricated flaws could not simulated the nature flaws with accuracy. The study is focus on gas turbine blades with service induced fatigue cracks. The detection capability of this innovative NDE inspection system is compared with two traditional NDE methods: Visual Inspection and Fluorescent Penetrant Inspection. POD curves for each technique were generated and compared.

  8. 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.

  9. 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.

  10. High-frequency heterodyne lock-in thermography (HeLIT): A highly sensitive method to detect early caries

    NASA Astrophysics Data System (ADS)

    Wang, Fei; Liu, Jun-yan; Yang, Jun-han; Oliullah, Md.; Wang, Xiao-chun; Wang, Yang

    2016-10-01

    In this letter, a nonlinear photothermal characteristic of dental tissues has been verified by photothermal radiometry at a given frequency with changing of the laser intensity. Subsequently, the high-frequency heterodyne lock-in thermography (HeLIT) scheme has been introduced to overcome shortages of the low infrared camera frame rate and the poor signal-noise ratio. The smooth surface tooth was artificially demineralized at a different time, and then it was detected by HeLIT, Results illustrated that the phase delay increases with the extension of the demineralized treatment time. The comparison experiments between HeLIT and the homodyne lock-in thermography for detecting artificial caries were carried out. Experimental results illustrated that the HeLIT has the merits of high sensitivity and specificity in detecting early caries.

  11. 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.

  12. 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.

  13. Infrared thermography on ocular surface temperature: A review

    NASA Astrophysics Data System (ADS)

    Tan, Jen-Hong; Ng, E. Y. K.; Rajendra Acharya, U.; Chee, C.

    2009-07-01

    Body temperature is a good indicator of human health. Thermal imaging system (thermography) is a non-invasive imaging procedure used to record the thermal patterns using Infrared (IR) camera. It provides visual and qualitative documentation of temperature changes in the vascular tissues, and is beginning to play an important role in the field of ophthalmology. This paper deals with the working principle, use and advantages of IR thermography in the field of ophthalmology. Different algorithms to acquire the ocular surface temperature (OST), that can be used for the diagnosis of ocular diseases are discussed.

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

    PubMed

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

    2014-11-07

    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.

  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. 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.

  17. A new method of dynamic and static stall detection using infrared thermography

    NASA Astrophysics Data System (ADS)

    Gardner, A. D.; Wolf, C. C.; Raffel, M.

    2016-09-01

    A new method of detecting flow separation for static and pitching airfoils is described, with application to the generation of stall maps for helicopter rotors. An airfoil is heated using a lamp, and a high-speed infrared camera monitors the surface temperature. Subtracting consecutive images and performing a spatial standard deviation over a region of interest yields a single σ {DIT} value which is used to detect boundary layer separation on the airfoil. The data can be analysed to identify attached flow (low values of σ {DIT}) and separated flow (high values of σ {DIT}). Although appropriate filtering can significantly improve the signal-to-noise ratio, the method is robust regarding the exact method of analysis and the unfiltered data are sufficiently clear to be analysed without additional processing. For the test airfoil used, stall was measured up to a pitching frequency of 5 Hz, and signal-to-noise ratios indicate that it should be possible to measure stall for a pitching frequency of 20 Hz for a carbon-fibre surface with the thermal properties used.

  18. Automated Spot Weld Inspection using Infrared Thermography

    SciTech Connect

    Chen, Jian; Zhang, Wei; Yu, Zhenzhen; Feng, Zhili

    2012-01-01

    An automated non-contact and non-destructive resistance spot weld inspection system based on infrared (IR) thermography was developed for post-weld applications. During inspection, a weld coupon was heated up by an auxiliary induction heating device from one side of the weld, while the resulting thermal waves on the other side were observed by an IR camera. The IR images were analyzed to extract a thermal signature based on normalized heating time, which was then quantitatively correlated to the spot weld nugget size. The use of normalized instead of absolute IR intensity was found to be useful in minimizing the sensitivity to the unknown surface conditions and environment interference. Application of the IR-based inspection system to different advanced high strength steels, thickness gauges and coatings were discussed.

  19. 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.

  20. A method of selecting acupoints for acupuncture treatment of peripheral facial paralysis by thermography.

    PubMed

    Zhang, Dong

    2007-01-01

    The purpose of this study is to select acupoints for acupuncture treatment of peripheral facial paralysis according to the temperature on the face of the patient detected by thermogram, to determine an objective acupoint selection method for acupuncture treatment. In the test group of 60 cases of facial paralysis, the infrared thermogram on the face was detected at the first visit, and then acupuncture was given at the acupoints on the affected side with a temperature difference of over 0.5 degrees C from the healthy side for one therapeutic course, and in each successive course the acupoints were re-determined according to the results of thermogram examination and were administrated till the end of the total therapeutic course, and 120 cases of the control group were treated with acupuncture at conventionally selected acupoints. The results showed that the cured and basically cured rate was 90.0% (54 cases) in the test group and 77.5% (93 cases) in the control group with a significant difference between the two groups (p < 0.05); and the total sessions of acupuncture were less and the course of treatment was shorter in the test group than those in the control group (both p < 0.001). The utilization rate of the acupoints selected by facial thermogram in the test group was in order of Dicang (ST 4, 92.3%), Yingxiang (LI 20, 90.6%), Taiyang (EX-HN 5, 85.5%), Yangbai (GB 14, 76.6%), Quanliao (SI 18, 72.3%), and so on. In conclusion, acupuncture at the acupoints selected by thermogram for treatment of facial paralysis in the cured rate, the therapeutic course and sessions of acupuncture is significantly superior to acupuncture at the conventionally selected acupoints, and the thermogram-aided acupoint selection method is beneficial to objectivity and modernization of acupoint selection for acupuncture and moxibustion treatments.

  1. Infrared thermography of the udder surface of dairy cattle: characteristics, methods, and correlation with rectal temperature.

    PubMed

    Metzner, Moritz; Sauter-Louis, Carola; Seemueller, Andrea; Petzl, Wolfram; Klee, Wolfgang

    2014-01-01

    Thermograms of the caudal udder surface were taken of five healthy cows before and after inoculation of Escherichia coli into the right hind quarter. Images in clinically normal udder quarters from cows without fever (CN) were compared with those post inoculation when cows had fever (⩾ 39.5°C) and showed elevation of somatic cell counts (⩾ 400,000 cells/mL) in the inoculated quarter (CM). Using graphic software tools, different geometric analysis tools (GATs: polygons, rectangles, lines) were set within the thermographic images. The following descriptive parameters (DPs) were employed: minimum value ('min'), maximum value ('max'), range ('max-min'), and arithmetic mean ('am'). Surface temperatures in group CN were between 34.1°C ('polygons'/'min') and 37.9°C ('polygons'/'max'), and in group CM between 34.5°C ('polygons'/'min') and 40.0°C ('polygons'/'max'). The greatest differences in the temperatures between CN and CM (2.06°C) were found in 'polygons' and 'rectangles' using 'max'. The smallest coefficient of variation in triplicate determinations was found in GAT 'polygons' with DP 'max' (Tmax) (0.15%), and the relationship to the rectal body temperature (Tr) could be described by Tr=5.68+0.874*Tmax. The results show that significant changes can be displayed best using the GAT 'polygons' and the DP 'max'. These methods should be considered for automated monitoring of udder health in dairy cows.

  2. 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.

  3. 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.

  4. Different imaging methods in the comparative assessment of vascular lesions: color-coded duplex sonography, laser Doppler perfusion imaging, and infrared thermography

    NASA Astrophysics Data System (ADS)

    Urban, Peter; Philipp, Carsten M.; Weinberg, Lutz; Berlien, Hans-Peter

    1997-12-01

    Aim of the study was the comparative investigation of cutaneous and subcutaneous vascular lesions. By means of color coded duplex sonography (CCDS), laser doppler perfusion imaging (LDPI) and infrared thermography (IT) we examined hemangiomas, vascular malformations and portwine stains to get some evidence about depth, perfusion and vascularity. LDI is a helpful method to get an impression of the capillary part of vascular lesions and the course of superficial vessels. CCDS has disadvantages in the superficial perfusion's detection but connections to deeper vascularizations can be examined precisely, in some cases it is the only method for visualizing vascular malformations. IT gives additive hints on low blood flow areas or indicates arterial-venous-shunts. Only the combination of all imaging methods allows a complete assessment, not only for planning but also for controlling the laser treatment of vascular lesions.

  5. Narrative review: Diabetic foot and infrared thermography

    NASA Astrophysics Data System (ADS)

    Hernandez-Contreras, D.; Peregrina-Barreto, H.; Rangel-Magdaleno, J.; Gonzalez-Bernal, J.

    2016-09-01

    Diabetic foot is one of the major complications experienced by diabetic patients. An early identification and appropriate treatment of diabetic foot problems can prevent devastating consequences such as limb amputation. Several studies have demonstrated that temperature variations in the plantar region can be related to diabetic foot problems. Infrared thermography has been successfully used to detect complication related to diabetic foot, mainly because it is presented as a rapid, non-contact and non-invasive technique to visualize the temperature distribution of the feet. In this review, an overview of studies that relate foot temperature with diabetic foot problems through infrared thermography is presented. Through this research, it can be appreciated the potential of infrared thermography and the benefits that this technique present in this application. This paper also presents the different methods for thermogram analysis and the advantages and disadvantages of each one, being the asymmetric analysis the method most used so far.

  6. Infrared thermography of solid surfaces in a fire

    NASA Astrophysics Data System (ADS)

    Meléndez, J.; Foronda, A.; Aranda, J. M.; López, F.; López del Cerro, F. J.

    2010-10-01

    Fire resistance tests are commonplace in industry. The aerospace sector is particularly active in this area, since the behaviour of advanced materials, such as composites, when in a fire is not fully understood yet. Two of the main obstacles are the inherent difficulty of direct surface measurements in such a harsh environment (especially on the exposed side of the specimens) and the lack of spatial resolution of the usual measuring devices, namely thermocouples (TCs). This paper presents a way to overcome these problems by using an infrared (IR) camera to study the exposed side of composite plates exposed to fire. A method for minimizing the effect of the flame (thus making it as 'transparent' as possible) was developed, resulting in 2D temperature maps of the plate surface. The assumptions that the method relies on were verified by data analysis and ad hoc emission-transmission experiments. The errors associated with two slightly different versions of the method were studied, and comparisons with TC measurements were performed. It was found that the IR method provides better results than TCs, not only due to its spatial resolution capability but also because of the non-intrusive nature of IR thermography, as opposed to the local effects caused by TCs, which became evident during the experiments.

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. [Infrared thermography and electroneuromyography in occupational polyneuropathy diagnosis].

    PubMed

    Loginova, N N; Voitenkov, V B

    2013-01-01

    We have evaluated diagnostic value of the combination of infrared thermography and electromyography in professional polyneuropathy diagnosis. 20 patients with working-hand syndrome and 5 controls were enrolled. In 18 cases (90%) both methods were sensitive: on EMG CNV slowing and amplitudes drop were seen, as well as M-response shape changes, and thermography have detected focal hypothermia in hands in some cases and appearance of obscure hypothermia in others. Thus, both methods demonstrated good sensitivity. We recommend using thermography as a screening test and EMG as a following investigation.

  12. 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.

  13. Real view thermography

    NASA Astrophysics Data System (ADS)

    Bienkowski, L.; Homma, C.

    2013-01-01

    In this paper we present a novel approach for enhancing active thermography for nondestructive testing. In order to make the evaluation of the data more intuitive a Real View setup is presented that uses a projection technique to let the inspector view and interact with the measurement results directly on the part in a very intuitive way. Moreover we present an analysis approach using a Sobel filter of the pulse-phase result data in order to investigate the detectability of flaws by induction thermography. By projecting this information we give a visual feedback to the operator for optimizing the probability of detection.

  14. 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.

  15. Active thermography in qualitative evaluation of protective materials.

    PubMed

    Gralewicz, Grzegorz; Wiecek, Bogusław

    2009-01-01

    This is a study of the possibilities of a qualitative evaluation of protective materials with active thermography. It presents a simulation of a periodic excitation of a multilayer composite material. Tests were conducted with lock-in thermography on Kevlar composite consisting of 16 layers of Kevlar fabric reinforced with formaldehyde resin with implanted delamination defects. Lock-in thermography is a versatile tool for nondestructive evaluation. It is a fast, remote and nondestructive procedure. Hence, it was used to detect delaminations in the composite structure of materials used in the production of components designed for personal protection. This method directly contributes to an improvement in safety.

  16. 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

  17. Extended hidden Markov model for optimized segmentation of breast thermography images

    NASA Astrophysics Data System (ADS)

    Mahmoudzadeh, E.; Montazeri, M. A.; Zekri, M.; Sadri, S.

    2015-09-01

    Breast cancer is the most commonly diagnosed form of cancer in women. Thermography has been shown to provide an efficient screening modality for detecting breast cancer as it is able to detect small tumors and hence can lead to earlier diagnosis. This paper presents a novel extended hidden Markov model (EHMM), for optimized segmentation of breast thermogram for more effective image interpretation and easier analysis of Infrared (IR) thermal patterns. Competitive advantage of EHMM method refers to handling random sampling of the breast IR images with re-estimation of the model parameters. The performance of the algorithm is illustrated by applying EHMM segmentation method on the images of IUT_OPTIC database and compared with previously related methods. Simulation results indicate the remarkable capabilities of the proposed approach. It is worth noting that the presented algorithm is able to map semi hot regions into distinct areas and extract the regions of breast thermal images significantly, while the execution time is reduced.

  18. Limits of Spatial Resolution for Thermography and Other Non-destructive Imaging Methods Based on Diffusion Waves.

    PubMed

    Burgholzer, Peter; Hendorfer, Günther

    2013-01-01

    In this work the measured variable, such as temperature, is a random variable showing fluctuations. The loss of information caused by diffusion waves in non-destructive testing can be described by stochastic processes. In non-destructive imaging, the information about the spatial pattern of a samples interior has to be transferred to the sample surface by certain waves, e.g., thermal waves. At the sample surface these waves can be detected and the interior structure is reconstructed from the measured signals. The amount of information about the interior of the sample, which can be gained from the detected waves on the sample surface, is essentially influenced by the propagation from its excitation to the surface. Diffusion causes entropy production and information loss for the propagating waves. Mandelis has developed a unifying framework for treating diverse diffusion-related periodic phenomena under the global mathematical label of diffusion-wave fields, such as thermal waves. Thermography uses the time-dependent diffusion of heat (either pulsed or modulated periodically) which goes along with entropy production and a loss of information. Several attempts have been made to compensate for this diffusive effect to get a higher resolution for the reconstructed images of the samples interior. In this work it is shown that fluctuations limit this compensation. Therefore, the spatial resolution for non-destructive imaging at a certain depth is also limited by theory.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Development Of Economic Techniques For Residential Thermography

    NASA Astrophysics Data System (ADS)

    Allen, Lee R.; Allen, Sharon

    1983-03-01

    Infrared thermography has proven to be a valuable tool in the detection of heat loss in both commercial and residential buildings. The field of residential thermography has needed a simple method with which to report the deficiencies found during an infrared scan. Two major obstacles hindering the cost effectiveness of residential thermography have been 1) the ability to quickly transport some high resolution imaging system equipment from job site to job site without having to totally dismount the instruments at each area, and 2) the lack of a standard form with which to report the findings of the survey to the customer. Since the industry has yet to provide us with either, we believed it necessary to develop our own. Through trial and error, we have come up with a system that makes interior residential thermography a profitable venture at a price the homeowner can afford. Insulation voids, or defects can be instantly spotted with the use of a thermal imaging system under the proper conditions. A special hand-held device was developed that enables the thermographer to carry the equipment from house to house without the need to dismantle and set up at each stop. All the necessary components are attached for a total weight of about 40 pounds. The findings are then conveyed to a form we have developed. The form is simple enough that the client without special training in thermography can understand. The client is then able to locate the problems and take corrective measures or give it to a con-tractor to do the work.

  4. 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.

  5. 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.

  6. Convective heat transfer and infrared thermography.

    PubMed

    Carlomagno, Giovanni M; Astarita, Tommaso; Cardone, Gennaro

    2002-10-01

    Infrared (IR) thermography, because of its two-dimensional and non-intrusive nature, can be exploited in industrial applications as well as in research. This paper deals with measurement of convective heat transfer coefficients (h) in three complex fluid flow configurations that concern the main aspects of both internal and external cooling of turbine engine components: (1) flow in ribbed, or smooth, channels connected by a 180 degrees sharp turn, (2) a jet in cross-flow, and (3) a jet impinging on a wall. The aim of this study was to acquire detailed measurements of h distribution in complex flow configurations related to both internal and external cooling of turbine components. The heated thin foil technique, which involves the detection of surface temperature by means of an IR scanning radiometer, was exploited to measure h. Particle image velocimetry was also used in one of the configurations to precisely determine the velocity field.

  7. Bonding quality evaluation of wind turbine blades by pulsed thermography

    NASA Astrophysics Data System (ADS)

    He, Rui-gang; Kong, De-juan; Zeng, Zhi; Tao, Ning; Zhang, Cun-lin; Feng, Li-chun

    2011-08-01

    The glue defects of the wind turbine blades which are composed of the glass fiber reinforced plastic (GFRP) composite plates make its strength greatly reduced, so security issues could be caused. To improve the safety of wind turbine blades, nondestructive testing technique using pulsed thermography is being investigated in this study. The results of ultrasonic C scan test were compared with the results of thermography. The current results indicated that both methods can successfully detect two gluing situations. However, the inspect specimens need to be putted in the water in the detection process by ultrasonic C scan, and the detection time lasts much longer than pulsed thermography. And in situ applications, the measured wind turbine blades are normally in the size of several tens meter, and also only one side is available for the inspection especially at the tip of blades. Thus, ultrasonic C scan of current experimental setup is not suitable for the applications in the field. Pulsed thermography is not necessary to contact with inspected specimens. The infrared results by pulsed thermography indicate that the shape and size of deficiency glue defects in the specimens show good agreement with the real situation, so it is more suitable for the inspection in the field. The preliminary results in this study indicate that pulse thermography can be used to detect glue faults of GFRP which are not too thick.

  8. Monitoring the fracture behavior in ceramic matrix composites by infrared thermography and acoustic emission

    NASA Astrophysics Data System (ADS)

    Dassios, Konstantinos G.; Kordatos, Evangelos Z.; Aggelis, Dimitris G.; Exarchos, Dimitris A.; Matikas, Theodore E.

    2014-04-01

    In this work an innovative methodology was employed for monitoring the fracture behavior in silicon carbide fiberreinforced ceramic matrix composites. This new methodology was based on the combined use of IR thermography and acoustic emission. Compact tension SiC/BMAS specimens were tested with unloading/reloading loops and the thermal dissipation due to crack propagation and other damage mechanisms was monitored by IR thermography. The accuracy of this technique was benchmarked by optical measurements of crack length. In addition, using acoustic emission descriptors, such as activity during the unloading part of the cycles, provided the critical level of damage accumulation in the material. Acoustic emission allowed to closely follow the actual crack growth monitored by IR thermography, enabling quantitative measurements.

  9. A novel method to prevent secondary exposure of medical and rescue personnel to toxic materials under biochemical hazard conditions using microwave radar and infrared thermography.

    PubMed

    Matsui, Takemi; Hagisawa, Kousuke; Ishizuka, Toshiaki; Takase, Bonpei; Ishihara, Masayuki; Kikuchi, Makoto

    2004-12-01

    In order to prevent secondary exposure of medical personnel to toxic materials under biochemical hazard conditions, we performed a noncontact determination of exposure to toxic conditions via 1215-MHz microwave radar and thermography. A toxic condition was induced by intravenous administration of lipopolysaccharide (LPS) in rabbits. The exposure to LPS was determined by linear discriminant analysis using non-contact derived variables.

  10. Infrared Thermography of Thermomechanical Couplings in Solids

    NASA Astrophysics Data System (ADS)

    Luong, M. P.; Parganin, D.; Loizeau, J.

    The present paper aims to illustrate three advantages of infrared thermography as a non destructive, real-time and non-contact technique to mechanically characterise solid materials. It permits observation of the macrostructural aspects of. thermoplasticity describing damage and failure processes in diverse and various engineering materials and their components subjected to monotonous, cyclic or vibratory loading. It usefully suggests the definition of a threshold of acceptable damage TAD for materials related to sport equipment such as leather shoe, leather-like composites or sail synthetics. Particularly in case of metallic products or automotive components subjected to fatigue loading, this newly proposed method could evaluate in a non-destructive manner the fatigue limit FL in a very short time compared to traditional fatigue testing techniques that are much more time-consuming and excessively expensive. In addition owing to the thermomechanical coupling, infrared thermography readily describes the damage location, the dissipative regime and the evolution of structural failure.

  11. 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.

  12. 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.

  13. Investigation of the mineralization process of biosystems by IR diffuse reflection spectroscopy methods

    NASA Astrophysics Data System (ADS)

    Zolotarev, V. M.

    2014-04-01

    Particular features of the application of Fourier-transform IR diffuse reflection spectroscopy methods to the in situ investigation of spectra of porous rough objects have been considered. The reciprocal influence of the scattering and absorption of porous objects on the formation of the impurity-band contour in the diffuse reflection spectrum when the impurity center is in the vicinity of the fundamental IR absorption band has been analyzed. Using methods of Fourier-transform IR diffuse reflection spectroscopy, processes of mineralization of fragments of mammoth tusks from a multilayer paleolithic site at Yudinovo (Bryansk oblast, Russia) and fragments of mammoth tusks from Yakutia (Russia) have been investigated. Particular features of mineralization processes (carbonate formation and silicification) on the surface and in the volume of objects at different conditions of their burial (humidity, temperature, soil acidity) have been studied.

  14. 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

  15. Biomechanical stress maps of an artificial femur obtained using a new infrared thermography technique validated by strain gages.

    PubMed

    Shah, Suraj; Bougherara, Habiba; Schemitsch, Emil H; Zdero, Rad

    2012-12-01

    Femurs are the heaviest, longest, and strongest long bones in the human body and are routinely subjected to cyclic forces. Strain gages are commonly employed to experimentally validate finite element models of the femur in order to generate 3D stresses, yet there is little information on a relatively new infrared (IR) thermography technique now available for biomechanics applications. In this study, IR thermography validated with strain gages was used to measure the principal stresses in the artificial femur model from Sawbones (Vashon, WA, USA) increasingly being used for biomechanical research. The femur was instrumented with rosette strain gages and mechanically tested using average axial cyclic forces of 1500 N, 1800 N, and 2100 N, representing 3 times body weight for a 50 kg, 60 kg, and 70 kg person. The femur was oriented at 7° of adduction to simulate the single-legged stance phase of walking. Stress maps were also obtained using an IR thermography camera. Results showed good agreement of IR thermography vs. strain gage data with a correlation of R(2)=0.99 and a slope=1.08 for the straight line of best fit. IR thermography detected the highest principal stresses on the superior-posterior side of the neck, which yielded compressive values of -91.2 MPa (at 1500 N), -96.0 MPa (at 1800 N), and -103.5 MPa (at 2100 N). There was excellent correlation between IR thermography principal stress vs. axial cyclic force at 6 locations on the femur on the lateral (R(2)=0.89-0.99), anterior (R(2)=0.87-0.99), and posterior (R(2)=0.81-0.99) sides. This study shows IR thermography's potential for future biomechanical applications.

  16. Investigations of single and multilayer structures using lock-in thermography--possible applications.

    PubMed

    Gralewicz, Grzegorz; Owczarek, Grzegorz; Wiecek, Bogusław

    2005-01-01

    This paper presents a study of the possibilities of evaluating thermal parameters of single and multilayer structures using dynamic thermography. It also discusses potential uses of lock-in thermography. It presents a simulation of a periodic excitation of a multilayer composite material. In practice, the described methods can be employed in various applications, for example, in multilayer nonwoven microelectronic components manufactured from hemp fibers, chemical fibers, with an addition of electrically conducting fibers, and in medicine and biology. This paper describes tests conducted with lock-in thermography on carbon fibre reinforced composites with implanted delamination defects. Lock-in thermography is a versatile tool for non-destructive evaluation (NDE). Lock-in thermography is a fast, remote and non-destructive procedure. Hence, it has been used to detect delaminations in the composite structure of aircraft. This method directly contributes to an improvement in safety.

  17. 3D thermography in non-destructive testing of composite structures

    NASA Astrophysics Data System (ADS)

    Hellstein, Piotr; Szwedo, Mariusz

    2016-12-01

    The combination of 3D scanners and infrared cameras has lead to the introduction of 3D thermography. Such analysis produces results in the form of three-dimensional thermograms, where the temperatures are mapped on a 3D model reconstruction of the inspected object. All work in the field of 3D thermography focused on its utility in passive thermography inspections. The authors propose a new real-time 3D temperature mapping method, which for the first time can be applied to active thermography analyses. All steps required to utilise 3D thermography are discussed, starting from acquisition of three-dimensional and infrared data, going through image processing and scene reconstruction, finishing with thermal projection and ray-tracing visualisation techniques. The application of the developed method was tested during diagnosis of several industrial composite structures—boats, planes and wind turbine blades.

  18. 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

  19. Clinical application of infrared thermography in diagnosis and therapeutic assessment of vascular ischemic pain.

    PubMed

    Hsieh, J C; Chan, K H; Lui, P W; Lee, T Y

    1990-12-01

    Temperature is a very important and useful manifestation of various disease entities. The importance of body temperature as an indicator of disease has been known for centuries but in recent years attention has also been paid to how to conveniently and effectively make use of skin temperature as a diagnostic tool. Skin temperature can be measured with thermocouples, electronic thermistor-thermometers, electronic integrators, liquid crystal thermography, and infrared thermography. The temperature of extremities is largely dependent on the blood flow through peripheral vessels, and in the study of vascular diseases thermography has been, therefore, found to be useful. Blood flow can be assessed by many methods including washout techniques or laser Doppler flowmetry. Of these, infrared thermography has the advantages of being noninvasive, remote from the patient when in use, and capable of producing multiple recordings at short time intervals. Here we present a case of vascular ischemic pain which was diagnosed and therapeutically assessed by thermography.

  20. Research of distortion rectification method for large vision angle IR imaging system

    NASA Astrophysics Data System (ADS)

    Zhang, Xue-yuan; Ren, Zhen; Zhang, Zheng-hui; Sun, Guang-li

    2013-09-01

    During the large visual angle IR image distortion rectification process there are some difficulties, first pick-up rectifying points is hard, second measuring and rectifying distortion are wasting time, third rectifying screen is difficult to make and it costs much. In order to overcome those disadvantages an IR imaging distortion rectification method, which using asterisk rectifying screen, is proposed. This method takes the image of a special made asterisk rectifying screen at first, then using SIFT operator to detect the real imaging positions of rectifying points in the image. Based on the real positions mean slope is used to compute theoretical imaging positions of those rectifying points. After that least square arithmetic is adopted to calculate the distortion parameters. The experiment result has shown that: the proposed method has the advantages of high precision, low cost, simple process and universal applicability.

  1. 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.

  2. 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.

  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. Detection of cold cracks in the cast-steels by the methods of ultrasonic and eddy-current infrared thermography

    NASA Astrophysics Data System (ADS)

    Cheprasov, A. I.; Knyazev, S. V.; Usoltsev, A. A.; Dolgopolov, A. E.; Mamedov, R. O.

    2016-09-01

    The aim of this study was to investigate the possibility of detection of cold cracks in the massive steel products using ultrasonic and eddy-current excitation, as well as the thermal imaging method of temperature recording, that in the perspective should be completed by the development of requirements for the monitoring equipment.

  5. 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.

  6. 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.

  7. A novel target LOS calibration method for IR scanning sensor based on control points

    NASA Astrophysics Data System (ADS)

    Xue, Yong-Hong; An, Wei; Zhang, Yin-Sheng; Zhang, Tao

    2012-12-01

    Space based IR system uses the information of target LOS (line of sight) for target location. Recent researches show that the measuring precision of target LOS is usually determined by measuring precision of platform's position and attitude, and deformation of sensor etc. Most methods for improving target location precision are either through improving platform's position and attitude measuring precision or through calib rating the whole image obtained by IR sensor. With the development of measuring technology, it is harder to make a further improvement on the measuring precision of position and attitude of the platform and the expansion of the sensor view make calibrat ion of the whole image with a larger computation cost. In this paper, a method using control points to calibrate target LOS was proposed. Based on the analysis of the imaging process of the scanning sensor of space based IR system, this paper established a modify model of target LOS based on control points, used a bias filter to estimate the bias value of sensor boresight, and finally achieved the mission of target LOS calibrat ion. Different from the traditional calibration method of remote sensing image, the proposed method only made a correct ion on the LOS of suspicious target, but not established the accurate relationship between the all pixels and their real location, and has a similar calibration performance, but more lower computational complexity.

  8. Subsurface Defect Detection in FRP Composites Using Infrared Thermography

    NASA Astrophysics Data System (ADS)

    Halabe, U. B.; Vasudevan, A.; GangaRao, H. V. S.; Klinkhachorn, P.; Lonkar, G.

    2005-04-01

    This paper demonstrates the use of digital infrared thermography to detect subsurface defects such as debonds and delaminations in Fiber Reinforced Polymer (FRP) bridge decks. Simulated sub-surface debonds and delaminations were inserted between the wearing surface and the underlying FRP deck specimens. The infrared thermography technique was used to detect these embedded subsurface defects. The use of various cooling and heating methods, including solar radiation, was explored. Surface temperature-time curves were established for different types and sizes of subsurface defects.

  9. 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.

  10. 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

  11. Method and Characterization of Pyroelectric Coefficients for Determining Material Figures of Merit for Infrared (IR) Detectors

    DTIC Science & Technology

    2013-12-01

    iii Contents List of Figures iv 1. Introduction 1 2. Pyroelectric Effect 2 3. IR Detector Figure-of-Merits 2 4. Pyroelectric Measurement 4 5...accuracy and internal consistency of the characterization setup. Also, the basic pyroelectric effect , the material FoM for pyroelectric detectors...and methods to measure the material pyroelectric coefficient are briefly reviewed. 2. Pyroelectric Effect Pyroelectricity is a property of polar

  12. Skin temperature evaluation by infrared thermography: Comparison of two image analysis methods during the nonsteady state induced by physical exercise

    NASA Astrophysics Data System (ADS)

    Formenti, Damiano; Ludwig, Nicola; Rossi, Alessio; Trecroci, Athos; Alberti, Giampietro; Gargano, Marco; Merla, Arcangelo; Ammer, Kurt; Caumo, Andrea

    2017-03-01

    The most common method to derive a temperature value from a thermal image in humans is the calculation of the average of the temperature values of all the pixels confined within a demarcated boundary defined region of interest (ROI). Such summary measure of skin temperature is denoted as Troi in this study. Recently, an alternative method for the derivation of skin temperature from the thermal image has been developed. Such novel method (denoted as Tmax) is based on an automated (software-driven) selection of the warmest pixels within the ROI. Troi and Tmax have been compared under basal, steady-state conditions, resulting very well correlated and characterized by a bias of approximately 1 °C (Tmax > Troi). Aim of this study was to investigate the relationship between Tmax and Troi under the nonsteady-state conditions induced by physical exercise. Thermal images of quadriceps of 13 subjects performing a squat exercise were recorded for 120 s before (basal steady state) and for 480 s after the initiation of the exercise (nonsteady state). The thermal images were then analysed to extract Troi and Tmax. Troi and Tmax changed almost in parallel during the nonstead -state. At a closer inspection, it was found that during the nonsteady state the bias between the two methods slightly increased (from 0.7 to 1.1 °C) and the degree of association between them slightly decreased (from Pearson's r = 0.96 to 0.83). Troi and Tmax had different relationships with the skin temperature histogram. Whereas Tmax was the mean, which could be interpreted as the centre of gravity of the histogram, Tmax was related with the extreme upper tail of the histogram. During the nonsteady state, the histogram increased its spread and became slightly more asymmetric. As a result, Troi deviated a little from the 50th percentile, while Tmax remained constantly higher than the 95th percentile. Despite their differences, Troi and Tmax showed a substantial agreement in assessing the changes in skin

  13. Lasers and infrared thermography: advantageous cooperation.

    PubMed

    Vainer, Boris G

    2016-12-01

    In a brief review, the beneficial outcomes that have arisen from simultaneous use of laser- and infrared thermography (IRT)-based techniques are demonstrated. The most recent literary and original experimental results collected from different research and practical areas are presented. It is shown that modern IRT acts as an indispensable laser partner in various biomedical and many other applications and technologies. And vice versa, the laser-based methods and techniques often serve as an appropriate research instrument enriching IRT measurement data with independently obtained information.

  14. 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.

  15. 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

  16. 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.

  17. Research of Recognition Method of Discrete Wavelet Feature Extraction and PNN Classification of Rats FT-IR Pancreatic Cancer Data

    PubMed Central

    Wan, Chayan; Cao, Wenqing; Cheng, Cungui

    2014-01-01

    Sprague-Dawley (SD) rats' normal and abnormal pancreatic tissues are determined directly by attenuated total reflectance Fourier transform infrared (ATR-FT-IR) spectroscopy method. In order to diagnose earlier stage of SD rats pancreatic cancer rate with FT-IR, a novel method of extraction of FT-IR feature using discrete wavelet transformation (DWT) analysis and classification with the probability neural network (PNN) was developed. The differences between normal pancreatic and abnormal samples were identified by PNN based on the indices of 4 feature variants. When error goal was 0.01, the total correct rates of pancreatic early carcinoma and advanced carcinoma were 98% and 100%, respectively. It was practical to apply PNN on the basis of ATR-FT-IR to identify abnormal tissues. The research result shows the feasibility of establishing the models with FT-IR-DWT-PNN method to identify normal pancreatic tissues, early carcinoma tissues, and advanced carcinoma tissues. PMID:25548717

  18. Research of Recognition Method of Discrete Wavelet Feature Extraction and PNN Classification of Rats FT-IR Pancreatic Cancer Data.

    PubMed

    Wan, Chayan; Cao, Wenqing; Cheng, Cungui

    2014-01-01

    Sprague-Dawley (SD) rats' normal and abnormal pancreatic tissues are determined directly by attenuated total reflectance Fourier transform infrared (ATR-FT-IR) spectroscopy method. In order to diagnose earlier stage of SD rats pancreatic cancer rate with FT-IR, a novel method of extraction of FT-IR feature using discrete wavelet transformation (DWT) analysis and classification with the probability neural network (PNN) was developed. The differences between normal pancreatic and abnormal samples were identified by PNN based on the indices of 4 feature variants. When error goal was 0.01, the total correct rates of pancreatic early carcinoma and advanced carcinoma were 98% and 100%, respectively. It was practical to apply PNN on the basis of ATR-FT-IR to identify abnormal tissues. The research result shows the feasibility of establishing the models with FT-IR-DWT-PNN method to identify normal pancreatic tissues, early carcinoma tissues, and advanced carcinoma tissues.

  19. 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.

  20. 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...

  1. 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

  2. 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.

  3. Infrared thermography to evaluate lameness in pregnant sows.

    PubMed

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

    2014-03-01

    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.

  4. 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.

  5. Review of industrial and research applications of thermography

    NASA Astrophysics Data System (ADS)

    Ahlstrom, John

    1990-10-01

    The background and advantages of commercial thermography are reviewed, and applications of thermography in basic research, product development, and medicine are discussed. Industrial applications of thermography to preventive maintenance and production monitoring are also covered.

  6. A preliminary biomechanical assessment of a polymer composite hip implant using an infrared thermography technique validated by strain gage measurements.

    PubMed

    Bougherara, Habiba; Rahim, Ehsan; Shah, Suraj; Dubov, Anton; Schemitsch, Emil H; Zdero, Rad

    2011-07-01

    With the resurgence of composite materials in orthopaedic applications, a rigorous assessment of stress is needed to predict any failure of bone-implant systems. For current biomechanics research, strain gage measurements are employed to experimentally validate finite element models, which then characterize stress in the bone and implant. Our preliminary study experimentally validates a relatively new nondestructive testing technique for orthopaedic implants. Lock-in infrared (IR) thermography validated with strain gage measurements was used to investigate the stress and strain patterns in a novel composite hip implant made of carbon fiber reinforced polyamide 12 (CF/PA12). The hip implant was instrumented with strain gages and mechanically tested using average axial cyclic forces of 840 N, 1500 N, and 2100 N with the implant at an adduction angle of 15 deg to simulate the single-legged stance phase of walking gait. Three-dimensional surface stress maps were also obtained using an IR thermography camera. Results showed almost perfect agreement of IR thermography versus strain gage data with a Pearson correlation of R(2) = 0.96 and a slope = 1.01 for the line of best fit. IR thermography detected hip implant peak stresses on the inferior-medial side just distal to the neck region of 31.14 MPa (at 840 N), 72.16 MPa (at 1500 N), and 119.86 MPa (at 2100 N). There was strong correlation between IR thermography-measured stresses and force application level at key locations on the implant along the medial (R(2) = 0.99) and lateral (R(2) = 0.83 to 0.99) surface, as well as at the peak stress point (R(2) = 0.81 to 0.97). This is the first study to experimentally validate and demonstrate the use of lock-in IR thermography to obtain three-dimensional stress fields of an orthopaedic device manufactured from a composite material.

  7. Normalized Temperature Contrast Processing in Flash Infrared Thermography

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay M.

    2016-01-01

    The paper presents further development in normalized contrast processing of flash infrared thermography method by the author given in US 8,577,120 B1. The method of computing normalized image or pixel intensity contrast, and normalized temperature contrast are provided, including converting one from the other. Methods of assessing emissivity of the object, afterglow heat flux, reflection temperature change and temperature video imaging during flash thermography are provided. Temperature imaging and normalized temperature contrast imaging provide certain advantages over pixel intensity normalized contrast processing by reducing effect of reflected energy in images and measurements, providing better quantitative data. The subject matter for this paper mostly comes from US 9,066,028 B1 by the author. Examples of normalized image processing video images and normalized temperature processing video images are provided. Examples of surface temperature video images, surface temperature rise video images and simple contrast video images area also provided. Temperature video imaging in flash infrared thermography allows better comparison with flash thermography simulation using commercial software which provides temperature video as the output. Temperature imaging also allows easy comparison of surface temperature change to camera temperature sensitivity or noise equivalent temperature difference (NETD) to assess probability of detecting (POD) anomalies.

  8. 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...

  9. A New Method for Wide-field Near-IR Imaging with the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Momcheva, Ivelina G.; van Dokkum, Pieter G.; van der Wel, Arjen; Brammer, Gabriel B.; MacKenty, John; Nelson, Erica J.; Leja, Joel; Muzzin, Adam; Franx, Marijn

    2017-01-01

    We present a new technique for wide and shallow observations using the near-infrared channel of Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). Wide-field near-IR surveys with HST are generally inefficient, as guide star acquisitions make it impractical to observe more than one pointing per orbit. This limitation can be circumvented by guiding with gyros alone, which is possible as long as the telescope has three functional gyros. The method presented here allows us to observe mosaics of eight independent WFC3-IR pointings in a single orbit by utilizing the fact that HST drifts by only a very small amount in the 25 s between non-destructive reads of unguided exposures. By shifting the reads and treating them as independent exposures the full resolution of WFC3 can be restored. We use this “drift and shift” (DASH) method in the Cycle 23 COSMOS-DASH program, which will obtain 456 WFC3 H 160 pointings in 57 orbits, covering an area of 0.6 degree in the COSMOS field down to H 160 = 25. When completed, the program will more than triple the area of extra-galactic survey fields covered by near-IR imaging at HST resolution. We demonstrate the viability of the method with the first four orbits (32 pointings) of this program. We show that the resolution of the WFC3 camera is preserved, and that structural parameters of galaxies are consistent with those measured in guided observations.

  10. 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.

  11. 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.

  12. Infrared Thermography-based Biophotonics: Integrated Diagnostic Technique for Systemic Reaction Monitoring

    NASA Astrophysics Data System (ADS)

    Vainer, Boris G.; Morozov, Vitaly V.

    A peculiar branch of biophotonics is a measurement, visualisation and quantitative analysis of infrared (IR) radiation emitted from living object surfaces. Focal plane array (FPA)-based IR cameras make it possible to realize in medicine the so called interventional infrared thermal diagnostics. An integrated technique aimed at the advancement of this new approach in biomedical science and practice is described in the paper. The assembled system includes a high-performance short-wave (2.45-3.05 μm) or long-wave (8-14 μm) IR camera, two laser Doppler flowmeters (LDF) and additional equipment and complementary facilities implementing the monitoring of human cardiovascular status. All these means operate synchronously. It is first ascertained the relationship between infrared thermography (IRT) and LDF data in humans in regard to their systemic cardiovascular reactivity. Blood supply real-time dynamics in a narcotized patient is first visualized and quantitatively represented during surgery in order to observe how the general hyperoxia influences thermoregulatory mechanisms; an abrupt increase in temperature of the upper limb is observed using IRT. It is outlined that the IRT-based integrated technique may act as a take-off runway leading to elaboration of informative new methods directly applicable to medicine and biomedical sciences.

  13. Evaluation of low-speed impact damage in CFRP with pulsed and lock-in thermography

    NASA Astrophysics Data System (ADS)

    Lichun, Feng; Wei, He; Ning, Tao

    2008-08-01

    Low speed impact subjected to carbon-fiber reinforced plastics could lead to delamination, matrix crack and other damages which would degrade the performance of composite structure. Fast and reliable evaluation methods are important for in-service inspections. In the paper, six CFRP plates with different impact energy was inspected with pulsed and lock-in thermography, respectively. The results showed thermography method was suitable for fast and large scale inspection of low-speed impact damage.

  14. Determining the material parameters for the reconstruction of defects in carbon fiber reinforced polymers from data measured by flash thermography

    NASA Astrophysics Data System (ADS)

    Müller, Jan P.; Götschel, Sebastian; Maierhofer, Christiane; Weiser, Martin

    2017-02-01

    Flash thermography is a fast and reliable non-destructive testing method for the investigation of defects in carbon fiber reinforced polymer (CFRP) materials. In this paper numerical simulations of transient thermography data are presented, calculated for a quasi-isotropic flat bottom hole sample. They are compared to experimental data. These simulations are one important step towards the quantitative reconstruction of a flaw by assessing thermographic data. The applied numerical model is based on the finite-element method, extended by a semi-analytical treatment of the boundary of the sample, which is heated by the flash light. A crucial part for a reliable numerical model is the prior determination of the material parameters of the specimen as well as of the experimental parameters of the set-up. The material parameters in plane and in depth diffusivity are measured using laser line excitation. In addition, the absorption and heat transfer process of the first layers is investigated using an IR microscopic lens. The performance of the two distinct components of CFRP during heating - epoxy resin and carbon fibers - is examined. Finally, the material parameters are optimized by variation and comparison of the simulation results to the experimental data. The optimized parameters are compared to the measured ones and further methods to ensure precise material parameter measurements are discussed.

  15. Clinical use of thermography in the diagnosis of soft tissue lesions

    PubMed Central

    Kobrossi, Toffy

    1984-01-01

    Thermography is a non-invasive method of recording and interpreting the distribution of surface temperature. First used clinically in the diagnosis of breast disease, thermography has been spreading steadily in a variety of diagnostic applications. Various investigators claim that thermography: 1) can document soft tissue injury, infection and inflammation, 2) has a place in pre-employment screening for back disorders and high risk backs, 3) is more sensitive than electromyography in the diagnosis of disc disease and radiculopathy, 4) is exceedingly more accurate than myelography in judging a patient’s disc problem, and 5) may be a useful supplement to present clinical methods for objectively documenting soft tissue trauma in the patient with low back pain. This review attempts to evaluate the state of thermography today and assess its value in the diagnosis of musculoskeletal pain. ImagesFigure 1

  16. WFC3/IR Reference Pixel Characterization #1: Comparison of Bias Subtraction Methods

    NASA Astrophysics Data System (ADS)

    Hilbert, B.

    2012-03-01

    In this first of two ISRs about the WFC3/IR reference pixel performance, we compare five different methods for using the reference pixels on the detector to remove bias signal from the measured signal in the light-sensitive science pixels. None of these methods produce a significant improvement over the current approach in the calwf3 calibration pipeline. We also note the existence of an extra signal in addition to the bias signal in the inboard reference pixels. Thought to be a "signal memory", this signal was observed in ground tests of early, non-flight detectors but was thought not to be present in the current flight detector. The extra signal does not degrade the WFC3/IR calibration. Large (~100DN), long-lasting (~weeks) signal jumps in a subset of the reference pixels as well as nearby science pixels were also observed. A subsequent ISR will report on efforts to characterize these jumps and the long-term behavior of the reference pixels.

  17. 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.

  18. Comparison of lock-in and pulse-phase thermography for defect characterization in FRP composites applied to concrete

    NASA Astrophysics Data System (ADS)

    Brown, Jeff; Chittineni, Sai Harsha

    2015-05-01

    Thermal imaging is a well-established technique for the non-destructive evaluation of FRP composites applied to reinforced concrete. Defect characterization using IR thermography, however, remains a topic of on-going research, and there are currently no universally accepted standards for data collection or interpretation. This research involved large scale thermography inspection of two FRP strengthened bridge girders that were removed from service after approximately 10 years of service in a potentially corrosive marine environment. Trial inspections were performed on test areas where defects could be identified using sounding methods. Two procedures showed the most promise for identifying and characterizing defects: sinusoidal (lock-in style) heating with periods ranging from 5 s to 40 s and constant step heating for 30 s followed by 60 s of cooling. Both methods resulted in a series of phase images that provided insight into the depth and general nature of detected defects. This paper presents the findings of a comparison study between these two thermal imaging techniques.

  19. Identification and classification of textile fibres using ATR-FT-IR spectroscopy with chemometric methods.

    PubMed

    Peets, Pilleriin; Leito, Ivo; Pelt, Jaan; Vahur, Signe

    2017-02-15

    The possibility of classification of single- and two-component textile materials using ATR-FT-IR spectra and chemometric methods, principal component analysis (PCA) and discriminant analysis, was assessed. Altogether 89 textile samples belonging to 26 different types (11 one- and 15 two-component textiles) were investigated. It was found that PCA classification using only two or three principal components (PCs) enables identifying different one- and two-component textiles, although with two important limitations: it was not always possible to distinguish between the cellulose-based fibres (cotton, linen and in some cases viscose) and it was only partly possible to distinguish between silk and wool. The statistical discriminant analysis can use as many PCs as there are sample classes and due to that can discriminate between single-component fibres, including viscose from linen and cotton as well as silk from wool. Besides that, in both of these cases, involving optical microscopy as an additional technique enabled unequivocal identification of the fibres. The possibilities of semi-quantitative analysis of mixed fibres (cotton-polyester, wool-polyester and wool-polyamide) with PCA were investigated and it was found that approximate quantitative composition is obtainable if for the mixed fibre sample a number of spectra are averaged in order to minimize the effect of structural inhomogeneity. For approximate content determination 25 spectra of selected two-component samples were registered for calibration and the averaged spectrum for each sample was computed. Due to the structural inhomogeneity of mixed textiles, obtaining accurate quantitative composition from real samples is not possible with ATR-FT-IR. The main problems with ATR-FT-IR-PCA classification are (1) difficulties in getting high quality spectra from some textiles (e.g. polyacrylic), (2) inhomogeneity of the textile fibres in the case of two-component fibres and (3) intrinsic similarity between the

  20. Identification and classification of textile fibres using ATR-FT-IR spectroscopy with chemometric methods

    NASA Astrophysics Data System (ADS)

    Peets, Pilleriin; Leito, Ivo; Pelt, Jaan; Vahur, Signe

    2017-02-01

    The possibility of classification of single- and two-component textile materials using ATR-FT-IR spectra and chemometric methods, principal component analysis (PCA) and discriminant analysis, was assessed. Altogether 89 textile samples belonging to 26 different types (11 one- and 15 two-component textiles) were investigated. It was found that PCA classification using only two or three principal components (PCs) enables identifying different one- and two-component textiles, although with two important limitations: it was not always possible to distinguish between the cellulose-based fibres (cotton, linen and in some cases viscose) and it was only partly possible to distinguish between silk and wool. The statistical discriminant analysis can use as many PCs as there are sample classes and due to that can discriminate between single-component fibres, including viscose from linen and cotton as well as silk from wool. Besides that, in both of these cases, involving optical microscopy as an additional technique enabled unequivocal identification of the fibres. The possibilities of semi-quantitative analysis of mixed fibres (cotton-polyester, wool-polyester and wool-polyamide) with PCA were investigated and it was found that approximate quantitative composition is obtainable if for the mixed fibre sample a number of spectra are averaged in order to minimize the effect of structural inhomogeneity. For approximate content determination 25 spectra of selected two-component samples were registered for calibration and the averaged spectrum for each sample was computed. Due to the structural inhomogeneity of mixed textiles, obtaining accurate quantitative composition from real samples is not possible with ATR-FT-IR. The main problems with ATR-FT-IR-PCA classification are (1) difficulties in getting high quality spectra from some textiles (e.g. polyacrylic), (2) inhomogeneity of the textile fibres in the case of two-component fibres and (3) intrinsic similarity between the

  1. 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.

  2. 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

    2016-01-05

    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.

  3. Carbon fiber composites inspection and defect characterization using active infrared thermography: numerical simulations and experimental results.

    PubMed

    Fernandes, Henrique; Zhang, Hai; Figueiredo, Alisson; Ibarra-Castanedo, Clemente; Guimarares, Gilmar; Maldague, Xavier

    2016-12-01

    Composite materials are widely used in the aeronautic industry. One of the reasons is because they have strength and stiffness comparable to metals, with the added advantage of significant weight reduction. Infrared thermography (IT) is a safe nondestructive testing technique that has a fast inspection rate. In active IT, an external heat source is used to stimulate the material being inspected in order to generate a thermal contrast between the feature of interest and the background. In this paper, carbon-fiber-reinforced polymers are inspected using IT. More specifically, carbon/PEEK (polyether ether ketone) laminates with square Kapton inserts of different sizes and at different depths are tested with three different IT techniques: pulsed thermography, vibrothermography, and line scan thermography. The finite element method is used to simulate the pulsed thermography experiment. Numerical results displayed a very good agreement with experimental results.

  4. Integration of active thermography into the assessment of cultural heritage buildings

    NASA Astrophysics Data System (ADS)

    Maierhofer, Christiane; Röllig, Mathias; Krankenhagen, Rainer

    2010-10-01

    Applications of infrared thermography in civil engineering are not limited to the identification of heat losses in building envelopes. Active infrared thermography methods enable structural investigations of building elements with one-sided access up to a depth of about 10 cm. Masonry and especially historical masonry has a very heterogeneous structure containing several different materials (brick, stone, mortar, plaster, wood, metal, etc.) with various thermal properties. As many classes of damage originate from defects that are close to the surface, active thermography is in general very well suited to assessing different test problems in cultural heritage buildings. In this paper, the physical background, equipment, environmental influences and material properties are discussed. Several application results are presented. It is shown how active thermography can be integrated into a holistic approach for the assessment of historical structures.

  5. Noninvasive Assessment of Tissue Heating During Cardiac Radiofrequency Ablation Using MRI Thermography

    PubMed Central

    Kolandaivelu, Aravindan; Zviman, Menekhem M.; Castro, Valeria; Lardo, Albert C.; Berger, Ronald D.; Halperin, Henry R.

    2010-01-01

    Background Failure to achieve properly localized, permanent tissue destruction is a common cause of arrhythmia recurrence after cardiac ablation. Current methods of assessing lesion size and location during cardiac radiofrequency ablation are unreliable or not suited for repeated assessment during the procedure. MRI thermography could be used to delineate permanent ablation lesions because tissue heating above 50°C is the cause of permanent tissue destruction during radiofrequency ablation. However, image artifacts caused by cardiac motion, the ablation electrode, and radiofrequency ablation currently pose a challenge to MRI thermography in the heart. In the current study, we sought to demonstrate the feasibility of MRI thermography during cardiac ablation. Methods and Results An MRI-compatible electrophysiology catheter and filtered radiofrequency ablation system was used to perform ablation in the left ventricle of 6 mongrel dogs in a 1.5-T MRI system. Fast gradient-echo imaging was performed before and during radiofrequency ablation, and thermography images were derived from the preheating and postheating images. Lesion extent by thermography was within 20% of the gross pathology lesion. Conclusions MR thermography appears to be a promising technique for monitoring lesion formation and may allow for more accurate placement and titration of ablation, possibly reducing arrhythmia recurrences. PMID:20657028

  6. Method of fabricating a PbS-PbSe IR detector array

    NASA Technical Reports Server (NTRS)

    Barrett, John R. (Inventor)

    1987-01-01

    A silicon wafer is provided which does not employ individually bonded leads between the IR sensitive elements and the input stages of multiplexers. The wafer is first coated with lead selenide in a first detector array area and is thereafter coated with lead sulfide within a second detector array area. The described steps result in the direct chemical deposition of lead selenide and lead sulfide upon the silicon wafer to eliminate individual wire bonding, bumping, flip chiping, planar interconnecting methods of connecting detector array elements to silicon chip circuitry, e.g., multiplexers, to enable easy fabrication of very long arrays. The electrode structure employed, produces an increase in the electrical field gradient between the electrodes for a given volume of detector material, relative to conventional electrode configurations.

  7. Film dosimetry calibration method for pulsed-dose-rate brachytherapy with an 192Ir source.

    PubMed

    Schwob, Nathan; Orion, Itzhak

    2007-05-01

    192Ir sources have been widely used in clinical brachytherapy. An important challenge is to perform dosimetric measurements close to the source despite the steep dose gradient. The common, inexpensive silver halide film is a classic two-dimensional integrator dosimeter and would be an attractive solution for these dose measurements. The main disadvantage of film dosimetry is the film response to the low-energy photon. Since the photon energy spectrum is known to vary with depth, the sensitometric curves are expected to be dependent on depth. The purpose of this study is to suggest a correction method for silver halide film dosimetry that overcomes the response changes at different depths. Sensitometric curves have been obtained at different depths with verification film near a 1 Ci 192Ir pulsed-dose-rate source. The depth dependence of the film response was observed and a correction function was established. The suitability of the method was tested through measurement of the radial dose profile and radial dose function. The results were compared to Monte Carlo-simulated values according to the TG43 formalism. Monte Carlo simulations were performed separately for the beta and gamma source emissions, using the EGS4 code system, including the low-energy photon and electron transport optimization procedures. The beta source emission simulation showed that the beta dose contribution could be neglected and therefore the film-depth dependence could not be attributed to this part of the source radioactivity. The gamma source emission simulations included photon-spectra collection at several depths. The results showed a depth-dependent softening of the photon spectrum that can explain the film-energy dependence.

  8. 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.

  9. Fusion of the Dhfr/Mtx and IR/MAR gene amplification methods produces a rapid and efficient method for stable recombinant protein production.

    PubMed

    Noguchi, Chiemi; Araki, Yoshio; 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.

  10. 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.

  11. PLS-LS-SVM based modeling of ATR-IR as a robust method in detection and qualification of alprazolam

    NASA Astrophysics Data System (ADS)

    Parhizkar, Elahehnaz; Ghazali, Mohammad; Ahmadi, Fatemeh; Sakhteman, Amirhossein

    2017-02-01

    According to the United States pharmacopeia (USP), Gold standard technique for Alprazolam determination in dosage forms is HPLC, an expensive and time-consuming method that is not easy to approach. In this study chemometrics assisted ATR-IR was introduced as an alternative method that produce similar results in fewer time and energy consumed manner. Fifty-eight samples containing different concentrations of commercial alprazolam were evaluated by HPLC and ATR-IR method. A preprocessing approach was applied to convert raw data obtained from ATR-IR spectra to normal matrix. Finally, a relationship between alprazolam concentrations achieved by HPLC and ATR-IR data was established using PLS-LS-SVM (partial least squares least squares support vector machines). Consequently, validity of the method was verified to yield a model with low error values (root mean square error of cross validation equal to 0.98). The model was able to predict about 99% of the samples according to R2 of prediction set. Response permutation test was also applied to affirm that the model was not assessed by chance correlations. At conclusion, ATR-IR can be a reliable method in manufacturing process in detection and qualification of alprazolam content.

  12. 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.

  13. 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.

  14. Crawling spot thermal nondestructive testing (NDT) for plaster inspection and comparison with dynamic thermography with extended heating

    NASA Astrophysics Data System (ADS)

    Bison, Paolo G.; Braggiotti, Alberto; Bressan, Chiara; Grinzato, Ermanno G.; Marinetti, Sergio; Mazzoldi, Andrea; Vavilov, Vladimir P.

    1995-03-01

    Defects in building materials located parallel to the front surface, like plaster detachment, or perpendicularly, such as cracks, are detected creating a space-varying heat flux. A variant of the `flying spot' technique called `crawling spot' was developed in order to fit requirements of these materials. This nondestructive method is performed with a localized radiant heating of the surface and synchronized local temperature measurement in the IR band. The identification of delaminations and cracks was theoretically and experimentally studied using two different procedures. Results obtained for plaster detachments were compared with dynamic thermography, applied with an extended excitation of the surface and analysis of the normalized thermal contrast both in amplitude and time. Another technique requires a continuously moving spot to heat the surface while a sequence of thermograms is recorded. The temperature profile of each pixel has to be reconstructed according to the spot speed and trajectory. This procedure was applied to stone crack detection. The experimental apparatus is thoroughly described.

  15. New electrocatalysts for unitized regenerative fuel cell: Pt-Ir alloy deposited on the proton exchange membrane surface by impregnation-reduction method.

    PubMed

    Wan, Chieh-Hao; Wu, Chun-Lin; Lin, Meng-Tsun; Shih, Chihhsiong

    2010-07-01

    In this paper, a modified technique to prepare Pt-Ir catalyst layer on the proton exchange membrane (PEM) surface using the impregnation-reduction (IR) method is proposed to improve the electrocatalytic activity as well as the life cycle of the bifunctional oxygen electrode (BOE). The resulted electrocatalysts were characterized by the Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Electron Probe Micro-Analysis (EPMA), and Transmission Electron Microscope (TEM). The electrocatalytic properties of the Pt-Ir layer on PEM surface for the oxygen reduction and water oxidation reactions as well as the life cycle of MEA were investigated. Experimental results showed that the Ir particles were dispersed densely in the platinum layer through the modified IR technique. The atomic ratio of Pt over Ir elements was 9:1, and the resulted thickness of the obtained Pt-Ir catalyst layer was about 1.0 microm. The Pt-Ir catalyst layer was composed of Pt layer doped with Ir nano-particles comprising nano Pt-Ir alloy phase. The large surface area of Ir core with Pt shell particles and the presence of nano Pt-Ir alloy phase led to a higher electrocatalytic activity of BOE. Due to the good binding between the Nafion membrane and the Pt-Ir alloy catalyst, as well as the composite structure of the resulted Pt-Ir, the life cycle of Unitized Regenerative Fuel Cell (URFC) is improved through this novel BOE.

  16. Laser active thermography for non-destructive testing

    NASA Astrophysics Data System (ADS)

    Semerok, A.; Grisolia, C.; Fomichev, S. V.; Thro, P.-Y.

    2013-11-01

    Thermography methods have found their applications in different fields of human activity. The non-destructive feature of these methods along with the additional advantage by automated remote control and tests of nuclear installations without personnel attendance in the contaminated zone are of particular interest. Laser active pyrometry and laser lock-in thermography for in situ non-destructive characterization of micrometric layers on graphite substrates from European tokamaks were under extensive experimental and theoretical studies in CEA (France). The studies were aimed to obtain layer characterization with cross-checking the layer thermal contact coefficients determined by active laser pyrometry and lock-in thermography. The experimental installation comprised a Nd-YAG pulsed repetition rate laser (1 Hz - 10 kHz repetition rate frequency, homogeneous spot) and a home-made pyrometer system based on two pyrometers for the temperature measurements in 500 - 2600 K range. For both methods, the layer characterization was provided by the best fit of the experimental results and simulations. The layer thermal contact coefficients determined by both methods were quite comparable. Though there was no gain in the measurements accuracy, lock-in measurements have proved their advantage as being much more rapid. The obtained experimental and theoretical results are presented. Some practical applications and possible improvements of the methods are discussed.

  17. Liquid ingress recognition in honeycomb structure by pulsed thermography

    NASA Astrophysics Data System (ADS)

    Chen, Dapeng; Zeng, Zhi; Tao, Ning; Zhang, Cunlin; Zhang, Zheng

    2013-05-01

    Pulsed thermography has been proven to be a fast and effective method to detect fluid ingress in aircraft honeycomb structure; however, water and hydraulic oil may have similar appearance in the thermal image sequence. It is meaningful to identify what kind of liquid ingress it is for aircraft maintenance. In this study, honeycomb specimens with glass fiber and aluminum skin are injected different kinds of liquids: water and oil. Pulsed thermography is adopted; a recognition method is proposed to first get the reference curve by linear fitting the beginning of the logarithmic curve, and then an algorithm based on the thermal contrast between liquid and reference is used to recognize what kind of fluid it is by calculating their thermal properties. It is verified with the results of theory and the finite element simulation.

  18. Moisture detection in wood and plaster by IR thermography

    NASA Astrophysics Data System (ADS)

    Ludwig, N.; Redaelli, V.; Rosina, E.; Augelli, F.

    2004-12-01

    In the last decade, many research have been carried on the application of IRT to detect moisture in the materials of historic buildings, but only few studies are comprehensive of IRT application on wood. The thermal characteristics of timber are highly different from the porous materials ones; particularly, the thermal capacity of wood is lower than bricks, stone and mortar. Laboratory researches and scientific literature determined that the water content detection in porous materials is more related the evaporation rate of the surfaces and the presence of soluble salts than to the absorption capability of the materials. Moreover a correlation between moisture content, evaporation and boundary conditions was studied by analyzing evaporation fluxes at different environmental conditions and water content. Because of the lower heat capacity of the timber, the thermographic shot after the heating can be affected by the influence of water presence. Lab tests and study cases show the advantages and the limit of the IRT techniques, and the results obtained permit the comparison between the different heating systems applied.

  19. 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.

  20. Evaluation of the limit of acceptable damage for leather products using infrared thermography

    NASA Astrophysics Data System (ADS)

    Luong, Phong M.

    1999-02-01

    The paper aims to illustrate three advantages of IR thermography as a nondestructive, noncontact and real time technique, (a) to observe the progressive damage processes and mechanisms of leather failure, and (b) to detect the occurrence of intrinsic dissipation localization. The parameter, investigated in this paper, is the heat generation due to intrinsic dissipation caused by inelasticity and/or inelasticity of leather. It readily describes the damage location and the failure evolution of leather for sport foot-wear.

  1. Comparisons of Three Indicators for Frey's Syndrome: Subjective Symptoms, Minor's Starch Iodine Test, and Infrared Thermography

    PubMed Central

    Choi, Hyo Geun; Kwon, Sae Young; Won, Jung Youn; Yoo, Seung Woo; Lee, Min Gu; Kim, Si Whan

    2013-01-01

    Objectives To correlate Frey's syndrome with subjective symptoms, Minor's starch iodine test results, and infrared thermography measurements, and to discuss the utility of thermography as a quantitative diagnostic method. Methods This study included 59 patients who underwent unilateral parotidectomy. A subjective clinical questionnaire and an objective Minor's starch iodine test were performed to evaluate the incidence of Frey's syndrome. Infrared thermography was performed, and the subjects were divided into seven groups according to the temperature differences between operated and unoperated sites. The thermal differences were correlated with the results from Minor's starch iodine test and the subjective symptoms questionnaire. Results Of the 59 patients, 20 patients (33.9%) reported subjective symptoms after eating; 30 patients (50.8%) tested positive for Minor's starch iodine test, 19 patients (63.3%) of which reported subjective symptoms. Of the 29 patients who were negative for the iodine test, 2 patients (6.9%) reported subjective symptoms. Thus, subjective symptoms were well correlated with Minor's starch iodine test (r=0.589, P<0.001). As the thermal differences with infrared thermography increased, the number of patients with subjective symptoms increased (χ2=22.5, P<0.001). Using infrared thermography, the mean temperature difference in the positive group for the iodine test was 0.82℃±0.26℃, and that in the negative group was 0.10℃±0.47℃. With increased thermal differences, more patients showed positivity in the iodine test (χ2=29.9, P<0.001). Conclusion Subjective symptoms, Minor's starch iodine test, and infrared thermography are well correlated with one another. Quantitative thermography provides clues for the wide variation in the incidence of Frey's syndrome, and could be a useful method for diagnosing and studying Frey's syndrome. PMID:24353866

  2. An IR thermal imaging method to investigate spreading process of ethanol solution droplets on carbon fiber mats

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Lu, Longsheng; Teh, Kwok Siong; Wang, Hongfei; Wan, Zhenping; Tang, Yong

    2016-12-01

    Porous media are a class of basic engineering material, and the applications of a porous medium are significantly influenced by its surface and bulk wettabilities. Conventionally, the surface wettability and dynamics of a liquid droplet on a stationary material surface can be observed by performing a dyed droplet spreading test captured with a high-speed camera. Such a method, however, is not effective in the quantification of droplet dynamics within a porous medium. In this work, we propose an infrared (IR) thermal imaging method to investigate the spreading of colorless droplet beneath the surface of, and within, the porous network of the porous medium. The spreading rim of a colorless droplet is accurately detected by the locations of extreme points in its temperature gradient curve, as deduced from temperature distribution data collected by an IR camera imaging from the top. Compared with the images captured simultaneously by a high-speed camera from the side, the droplet spreading rim is revealed to be an inner precursor rim located inside the porous media. To evaluate this method, carbon fiber (CF) mats with different porosities are used as the porous media. The spreading velocities of droplets in CF mats are measured successfully and coincide exactly with conclusions obtained by the background subtraction method. This finding validates the effectiveness of IR thermal imaging method in a droplet spreading test. This work demonstrates that IR imaging holds great promise in the visualization of the inner precursor rim of droplets in porous media.

  3. 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...

  4. The effective method based on IR annealing for manufacturing novel carbon nanocrystalline material and multifunctional metal-polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Kozhitov, L. V.; Kozlov, V. V.; Kostishyn, V. G.; Morchenko, A. T.; Muratov, D. G.

    2009-09-01

    Metal-containing polymeric nanomaterials were prepared by the two methods: infrared-irradiation pyrolysis and metals reduction from their salts in hydrazine on substrates. The composite consist of polymer matrix with 3d-metal nanoparticles. The structure and morphology of nanocomposites were investigated for the powder samples using X-ray diffraction, scanning and transmission electron microscopy, and Mössbauer spectroscopy (MS). It is shown that technology of preparing the nanocomposite under IR-irradiation is more effective than a thermal treatment under resistance-type heating, as the synergetic effect of influencing IR-radiation and heat leads to faster polymer transformations. The results of MS data comparison for the samples prepared by IR-radiation-stimulated pyrolysis and by means of salt reduction in hydrazine are discussed.

  5. 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.

  6. Repeatability of Infrared Plantar Thermography in Diabetes Patients: A Pilot Study

    PubMed Central

    Balbinot, Luciane Fachin; Robinson, Caroline Cabral; Achaval, Matilde; Zaro, Milton Antônio; Brioschi, Marcos Leal

    2013-01-01

    Objective Infrared (IR) thermography has been used as a complementary diagnostic method in several pathologies, including distal diabetic neuropathy, by tests that induce thermoregulatory responses, but nothing is known about the repeatability of these tests. This study aimed to assess the repeatability of the rewarming index in subjects with type 2 diabetes mellitus (T2DM) and nondiabetic control subjects. Methods Using an IR camera, plantar IR images were collected at baseline (pre-) and 10 min after (post-) cold stress testing on two different days with 7 days interval. Plantar absolute average temperatures pre- and post-cold stress testing, the difference between them (ΔT), and the rewarming index were obtained and compared between days. Repeatability of the rewarming index after the cold stress test was assessed by Bland–Altman plot limits of agreement. Results Ten T2DM subjects and ten nondiabetic subjects had both feet analyzed. Mean age did not differ between groups (p = .080). Absolute average temperatures of plantar region pre- (p = .033) and post-cold stress test (p = .019) differed between days in nondiabetic subjects, whereas they did not differ in T2DM subjects (pretest, p = .329; post-test, p = .540). ΔT and rewarming index did not differ between days for both groups, and the rewarming index presented a 100% agreement of day-to-day measurements from T2DM subjects and 95% with nondiabetic subjects. Conclusions The rewarming index after cold stress testing presented good repeatability between two days a week in both groups. Despite T2DM subjects presenting no differences on absolute temperature values between days, ΔT or rewarming index after cold stress testing remain recommended beside absolute temperature values for clinical use. PMID:24124938

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. The early stage wheel fatigue crack detection using eddy current pulsed thermography

    NASA Astrophysics Data System (ADS)

    Peng, Jianping; Zhang, Kang; Yang, Kai; He, Zhu; Zhang, Yu; Peng, Chaoyong; Gao, Xiaorong

    2017-02-01

    The in-service wheel-set quality is one of critical challenges for railway safety, especially for the high-speed train. The defect in wheel tread, initiated by rolling contact fatigue (RCF) damage, is one of the most significant phenomena and has serious influence on rail industry. Eddy current pulsed thermography is studied to compensate the UT method for detection these early stage of fatigue cracks in wheel tread surface. This paper proposes approximately uniform magnetic field, excited by Helmholtz coils, based pulsed eddy current thermography to achieve open-view image and meet the irregular surface in wheel tread through numerical way. Some features are extracted and studied also to quantify the fatigue crack in term of eddy current pulsed thermography. The proposed method enhances the capability for cracks detection and quantitative evaluation compared with previous NDT method in railway.

  12. 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.

  13. Potential applications of ocular thermography.

    PubMed

    Morgan, P B; Soh, M P; Efron, N; Tullo, A B

    1993-07-01

    Thermography is an investigative technique which allows rapid color-coded display of the temperature across a wide surface by means of infrared detection. We describe an ocular thermographic study of a normal population and present case studies describing the application of this technique for patients with ocular disease. We found that 95% of the normal population have an interocular temperature difference (temperature of center of right cornea minus temperature of center of left cornea) of 0.60 degrees or less. There appears to be a greater difference in temperature between the limbus and the center of the cornea in patients with dry eyes. This technique has potential for evaluating tear film disorders and inflammatory conditions, for monitoring the progress of such conditions, and for evaluating the efficacy of various treatments.

  14. 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.

  15. 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, and

  16. Effect of perspiration on skin temperature measurements by infrared thermography and contact thermometry during aerobic cycling

    NASA Astrophysics Data System (ADS)

    Priego Quesada, Jose Ignacio; Martínez Guillamón, Natividad; Cibrián Ortiz de Anda, Rosa M.a.; Psikuta, Agnes; Annaheim, Simon; Rossi, René Michel; Corberán Salvador, José Miguel; Pérez-Soriano, Pedro; Salvador Palmer, Rosario

    2015-09-01

    The aim of the present study was to compare infrared thermography and thermal contact sensors for measuring skin temperature during cycling in a moderate environment. Fourteen cyclists performed a 45-min cycling test at 50% of peak power output. Skin temperatures were simultaneously recorded by infrared thermography and thermal contact sensors before and immediately after cycling activity as well as after 10 min cooling-down, representing different skin wetness and blood perfusion states. Additionally, surface temperature during well controlled dry and wet heat exchange (avoiding thermoregulatory responses) using a hot plate system was assessed by infrared thermography and thermal contact sensors. In human trials, the inter-method correlation coefficient was high when measured before cycling (r = 0.92) whereas it was reduced immediately after the cycling (r = 0.82) and after the cooling-down phase (r = 0.59). Immediately after cycling, infrared thermography provided lower temperature values than thermal contact sensors whereas it presented higher temperatures after the cooling-down phase. Comparable results as in human trials were observed for hot plate tests in dry and wet states. Results support the application of infrared thermography for measuring skin temperature in exercise scenarios where perspiration does not form a water film.

  17. A novel automated method for doing registration and 3D reconstruction from multi-modal RGB/IR image sequences

    NASA Astrophysics Data System (ADS)

    Kirby, Richard; Whitaker, Ross

    2016-09-01

    In recent years, the use of multi-modal camera rigs consisting of an RGB sensor and an infrared (IR) sensor have become increasingly popular for use in surveillance and robotics applications. The advantages of using multi-modal camera rigs include improved foreground/background segmentation, wider range of lighting conditions under which the system works, and richer information (e.g. visible light and heat signature) for target identification. However, the traditional computer vision method of mapping pairs of images using pixel intensities or image features is often not possible with an RGB/IR image pair. We introduce a novel method to overcome the lack of common features in RGB/IR image pairs by using a variational methods optimization algorithm to map the optical flow fields computed from different wavelength images. This results in the alignment of the flow fields, which in turn produce correspondences similar to those found in a stereo RGB/RGB camera rig using pixel intensities or image features. In addition to aligning the different wavelength images, these correspondences are used to generate dense disparity and depth maps. We obtain accuracies similar to other multi-modal image alignment methodologies as long as the scene contains sufficient depth variations, although a direct comparison is not possible because of the lack of standard image sets from moving multi-modal camera rigs. We test our method on synthetic optical flow fields and on real image sequences that we created with a multi-modal binocular stereo RGB/IR camera rig. We determine our method's accuracy by comparing against a ground truth.

  18. Evaluation of scatter contribution and distance error by iterative methods for strength determination of HDR 192Ir brachytherapy source.

    PubMed

    Kumar, Sudhir; Srinivasan, Panchapakesan; Sharma, Sunil D; Subbaiah, Kamatam V; Mayya, Yelia S

    2010-01-01

    High-dose rate (HDR) 192Ir brachytherapy sources are commonly used for management of malignancies by brachytherapy applications. Measurement of source strength at the hospital is an important dosimetry requirement. The use of 0.6-cm(3) cylindrical ionization chamber is one of the methods of measuring the source strength at the hospitals because this chamber is readily available for beam calibration and dosimetry. While using the cylindrical chamber for this purpose, it is also required to determine the positioning error of the ionization chamber, with respect to the source, commonly called a distance error (c). The contribution of scatter radiation (M(s)) from floor, walls, ceiling, and other materials available in the treatment room also need to be determined accurately so that appropriate correction can be applied while calculating the source strength from the meter reading. Iterative methods of Newton-Raphson and least-squares were used in this work to determine scatter contribution in the experimentally observed meter reading (pC/s) of a cylindrical ionization chamber. Monte Carlo simulation was also used to cross verify the results of the least-squares method. The experimentally observed, least-squares calculated and Monte Carlo estimated values of meter readings from HDR 192Ir brachytherapy source were in good agreement. Considering procedural simplicity, the method of least-squares is recommended for use at the hospitals to estimate values of f (constant of proportionality), c, and M(s) required to determine the strength of HDR 192Ir brachytherapy sources.

  19. 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.

  20. 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.

  1. Investigation of Some New Nonlinear Optical Crystals by Means of NQR, IR and X-Ray Diffraction Methods

    NASA Astrophysics Data System (ADS)

    Petrosyan, A. M.; Terzyan, S. S.; Burbelo, V. M.; Sukiasyan, R. P.

    1998-07-01

    Some new analogues of the nonlinear optical crystal L-arginine phosphate monohydrate (LAP) (Arg • HIO3 , Arg • 2HIO3 , Lys • HIO3 , Lys • 2HIO3 , Lys • 3HIO3 , Bet • 3HIO3) were obtained and investigated by means of IR, NQR, X-ray diffraction and SHG methods. The importance of this class of crystals for revealing new nonlinear optical crystals is pointed out.

  2. 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.

  3. Electromagnetic pulsed thermography for natural cracks inspection.

    PubMed

    Gao, Yunlai; Tian, Gui Yun; Wang, Ping; Wang, Haitao; Gao, Bin; Woo, Wai Lok; Li, Kongjing

    2017-02-07

    Emerging integrated sensing and monitoring of material degradation and cracks are increasingly required for characterizing the structural integrity and safety of infrastructure. However, most conventional nondestructive evaluation (NDE) methods are based on single modality sensing which is not adequate to evaluate structural integrity and natural cracks. This paper proposed electromagnetic pulsed thermography for fast and comprehensive defect characterization. It hybrids multiple physical phenomena i.e. magnetic flux leakage, induced eddy current and induction heating linking to physics as well as signal processing algorithms to provide abundant information of material properties and defects. New features are proposed using 1st derivation that reflects multiphysics spatial and temporal behaviors to enhance the detection of cracks with different orientations. Promising results that robust to lift-off changes and invariant features for artificial and natural cracks detection have been demonstrated that the proposed method significantly improves defect detectability. It opens up multiphysics sensing and integrated NDE with potential impact for natural understanding and better quantitative evaluation of natural cracks including stress corrosion crack (SCC) and rolling contact fatigue (RCF).

  4. Electromagnetic pulsed thermography for natural cracks inspection

    PubMed Central

    Gao, Yunlai; Tian, Gui Yun; Wang, Ping; Wang, Haitao; Gao, Bin; Woo, Wai Lok; Li, Kongjing

    2017-01-01

    Emerging integrated sensing and monitoring of material degradation and cracks are increasingly required for characterizing the structural integrity and safety of infrastructure. However, most conventional nondestructive evaluation (NDE) methods are based on single modality sensing which is not adequate to evaluate structural integrity and natural cracks. This paper proposed electromagnetic pulsed thermography for fast and comprehensive defect characterization. It hybrids multiple physical phenomena i.e. magnetic flux leakage, induced eddy current and induction heating linking to physics as well as signal processing algorithms to provide abundant information of material properties and defects. New features are proposed using 1st derivation that reflects multiphysics spatial and temporal behaviors to enhance the detection of cracks with different orientations. Promising results that robust to lift-off changes and invariant features for artificial and natural cracks detection have been demonstrated that the proposed method significantly improves defect detectability. It opens up multiphysics sensing and integrated NDE with potential impact for natural understanding and better quantitative evaluation of natural cracks including stress corrosion crack (SCC) and rolling contact fatigue (RCF). PMID:28169361

  5. Electromagnetic pulsed thermography for natural cracks inspection

    NASA Astrophysics Data System (ADS)

    Gao, Yunlai; Tian, Gui Yun; Wang, Ping; Wang, Haitao; Gao, Bin; Woo, Wai Lok; Li, Kongjing

    2017-02-01

    Emerging integrated sensing and monitoring of material degradation and cracks are increasingly required for characterizing the structural integrity and safety of infrastructure. However, most conventional nondestructive evaluation (NDE) methods are based on single modality sensing which is not adequate to evaluate structural integrity and natural cracks. This paper proposed electromagnetic pulsed thermography for fast and comprehensive defect characterization. It hybrids multiple physical phenomena i.e. magnetic flux leakage, induced eddy current and induction heating linking to physics as well as signal processing algorithms to provide abundant information of material properties and defects. New features are proposed using 1st derivation that reflects multiphysics spatial and temporal behaviors to enhance the detection of cracks with different orientations. Promising results that robust to lift-off changes and invariant features for artificial and natural cracks detection have been demonstrated that the proposed method significantly improves defect detectability. It opens up multiphysics sensing and integrated NDE with potential impact for natural understanding and better quantitative evaluation of natural cracks including stress corrosion crack (SCC) and rolling contact fatigue (RCF).

  6. 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.

  7. [Application of FT-IR pattern recognition method for the quality control of pharmaceutical ingredients].

    PubMed

    Horgos, József; Kóger, Péter; Zelkó, Romána

    2009-01-01

    Nowadays infrared spectroscopy and chemometrics have proven their effectiveness for both qualitative and quantitative analyses in different fields like agriculture, food, chemical and oil industry. Furier Transformation Infrared Spectroscopy (FT-IR) combined with Attenuated Total Reflectance (ATR) plate is a fast identification instrument. It is suitable for analysis of solid and liquid phase, too. Associated with chemometrics, it would be a powerful tool for the pharmaceutical wholesalers to detect the insufficient quality of pharmaceutical ingredients. In the present study beside the review of the infra red technology, pharmaceutical ingredients were examined with the help of our spectra library.

  8. Infrared Thermography in High Level Waste

    SciTech Connect

    GLEATON, DAVIDT.

    2004-08-24

    The Savannah River Site is a Department of Energy, government-owned, company-operated industrial complex built in the 1950s to produce materials used in nuclear weapons. Five reactors were built to support the production of nuclear weapons material. Irradiated materials were moved from the reactors to one of the two chemical separation plants. In these facilities, known as ''canyons,'' the irradiated fuel and target assemblies were chemically processed to separate useful products from waste. Unfortunately, the by-product waste of nuclear material production was a highly radioactive liquid that had to be stored and maintained. In 1993 a strategy was developed to implement predictive maintenance technologies in the Liquid Waste Disposition Project Division responsible for processing the liquid waste. Responsibilities include the processing and treatment of 51 underground tanks designed to hold 750,000 to1,300,000 gallons of liquid waste and operation of a facility that vitrifies highly radioactive liquid waste into glass logs. Electrical and mechanical equipment monitored at these facilities is very similar to that found in non-nuclear industrial plants. Annual inspections are performed on electrical components, roof systems, and mechanical equipment. Troubleshooting and post installation and post-maintenance infrared inspections are performed as needed. In conclusion, regardless of the industry, the use of infrared thermography has proven to be an efficient and effective method of inspection to help improve plant safety and reliability through early detection of equipment problems.

  9. 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.

  10. Thermal Integrity Assessment of Building Envelopes of Experimental Houses Using Infrared Thermography

    SciTech Connect

    Biswas, Kaushik; Kosny, Jan; Miller, William A

    2010-01-01

    Zero Energy Building Research Alliance, or ZEBRAlliance, is a joint DOE-ORNL-construction industry initiative to develop and demonstrate new energy efficiency technologies for residential buildings, as well as fine-tune and integrate existing technologies, to lower energy costs. Construction of residential envelopes, the diaphragms that separate the inside from outdoors, can have enormous impact on whole-building energy usage. Consequently, post-construction thermal integrity assessment of the building envelopes in the experimental ZEBRAlliance homes is an integral part of the research and development cycle. Nondestructive infrared (IR) thermography provides a relatively easy and quick means of inspecting the experimental homes for thermal bridging, insulation imperfections, moisture penetration, air leakage, etc. Two experimental homes located in Oak Ridge, TN were inspected using IR thermography. The homes are designed with two different envelope systems: (i) Structural Insulated Panels (SIP home) consisting of an insulating foam core sandwiched between oriented strand boards, and (ii) Optimal Value Framing (OVF home) using innovatively spaced wood studs, which are designed to minimize the amount of wood framing, reduce thermal bridging, and lower material costs. IR thermal imaging was performed from both outside and inside of the homes. In this paper, IR images of roof and wall sections of the homes are presented and discussed with respect to identification of areas of thermal bridging and any insulation deficiencies.

  11. 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

  12. Efficient reconstruction of corrosion profiles by infrared thermography

    NASA Astrophysics Data System (ADS)

    Marcuzzi, F.; Marinetti, S.

    2008-07-01

    In this paper, we propose a novel algorithm to solve the hidden corrosion estimation problem from experimental data produced by infrared thermography. This is therefore a thermal inverse problem. The algorithm is put in a predictor-corrector form and uses an Adaptive Finite Element model as the reference model. The adaptation is done in the (linear) predictor step, while the parameter estimation is done in the (nonlinear) corrector step. An ad-hoc regularization strategy has been developed. Experiments with real data have confirmed the effectiveness of the method. Considerable computational savings have been achieved compared to a standard algorithm formulation.

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

    PubMed

    Vainer, Boris G

    2005-12-07

    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

  14. Gapped smoothing algorithm applied to defect identification using pulsed thermography

    NASA Astrophysics Data System (ADS)

    Li, Bing; Ye, Lin; Li, Eric; Shou, Dahua; Li, Zheng; Chang, Li

    2015-04-01

    On the basis of pulsed thermography, this article presents the development of a quantitative detection method for sub-surface defects. A two dimensional gapped smoothing algorithm (GSA) applied in this method to process the surface thermal distribution and no reference information is needed. A new thermal contrast is defined and a damage index based on the thermal contrast is proposed to estimate the probability of location of a defect, and differential curves of thermal contrast are applied for further quantification of defect size. One aluminium plate and one glass fibre reinforced composite laminate containing different depths of flat-bottom holes, delaminations and impurities are introduced to assess the performance of proposed method. Numerical and experimental results indicate that the influence of non-uniform heating is clearly suppressed. Compared with the differentiated absolute contrast approach, distinct enhancement of thermal contrast is achieved, and the location and size of sub-surface instances of damage can be quantitatively determined using the proposed method. The relation of damage index and flaw depth is investigated and a general expression is presented for the evaluation of flaw depth. The influence of the distribution density of the gapped grid on detection accuracy is further discussed. The proposed method, which is less dependent on the capture time, can be used for automatic detection and characterisation of defects. The reliability and applicability of the GSA applied to pulsed thermography are verified.

  15. Investigation of the Rotation of Molecular Groups in Polymers of Methyl Acrylate and Vinyl Acetate by the Method of IR-Spectroscopy,

    DTIC Science & Technology

    1987-08-27

    BY THE METHOD OF IR- SPECTROSCOPY by O.N. Trapeznikova, T.V. Belopol’skaya OTtO ELECTE NOV 1 71987 ED Approved for public release; Distribution...MOLECULAR GROUPS IN POLYMERS OF METHYL ACRYLATE AND VINYL ACETATE BY THE METHOD OF IR- SPECTROSCOPY By: O.N. Trapeznikova, T.V. Belopol’skaya English...THE METHOD OF IR- SPECTROSCOPY O.N. Trapeznikova, T.V. Belopol’skaya Physics Institute of Leningrad State University in. A.A. Zhdanov Submitted 17 July

  16. Gain determination of non-linear IR detectors with the differential photon transfer curve (dPTC) method

    NASA Astrophysics Data System (ADS)

    Rest, Armin; Hilbert, Bryan; Leisenring, Jarron M.; Misselt, Karl; Rieke, Marcia; Robberto, Massimo

    2016-07-01

    Conversion gain is a basic detector property which relates the raw counts in a pixel in data numbers (DN) to the number of electrons detected. The standard method for determining the gain is called the Photon Transfer Curve (PTC) method and involves the measurement the change in variance as a function of signal level. For non-linear IR detectors, this method depends strongly on the non-linearity correction and is therefore susceptible to systematic biases due to calibration issues. We have developed a new, robust, and fast method, the differential Photon Transfer Curve (dPTC) method, which is independent of non-linearity corrections, but still delivers gain values similar in precision but higher in accuracy.

  17. 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.

  18. Micro-thermography in millimeter-scale animals by using orally-dosed fluorescent nanoparticle thermosensors.

    PubMed

    Arai, Satoshi; Ferdinandus; Takeoka, Shinji; Ishiwata, Shin'ichi; Sato, Hirotaka; Suzuki, Madoka

    2015-11-21

    We propose an instant micro-thermography method using a fluorescent-nanoparticle thermosensor capable of reporting temperature as the fluorescence intensity ratio of the temperature-sensitive dye to the reference. We demonstrate "temperature mapping" inside a fruit fly larva that was orally dosed with nanoparticle thermosensors.

  19. 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.

  20. 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.

  1. Analytical laboratories method No. 3008 - the determination of carbon in uranium metal using the IR-212 LECO carbon analyzer model 784-400

    SciTech Connect

    Not Available

    1986-10-02

    This method is designed for the determination of micro amounts of carbon in uranium metal. Training under the direction of a qualified analyst and an understanding of the instrument's instruction manual are required prior to use of the IR-212.

  2. 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.

  3. Scrotal infrared digital thermography in assessment of varicocele--pilot study to assess diagnostic criteria.

    PubMed

    Kulis, T; Kolaric, D; Karlovic, K; Knezevic, M; Antonini, S; Kastelan, Z

    2012-05-01

    The aim of this study was to assess scrotal thermography in diagnostics of varicocele and suggest potential diagnostic criteria. Twelve patients with clinically diagnosed varicocele were examined with scrotal infrared digital thermography, physical examination and ultrasound/doppler. The main outcome measure was evaluation of thermography diagnostic criteria for varicocele. Mean temperature at left pampiniform plexus was ≥ 34 °C in 83%, and at right pampiniform plexus in all cases was ≤ 34 °C. In 92% of patients, temperature at the left testicle was ≥ 32 °C, whereas at the right testicle it was >32 °C in 50% patients. Temperatures between left and right pampiniform plexus and between left and right testicle were significantly different with P < 0.0001 and P < 0.006 respectively. In all patients, temperature difference between pampiniform plexuses was ≥ 0.6 °C. In 92% of patients, temperature at left pampiniform plexus was equal or higher to thigh temperature with the mean temperature difference of 1.1 ± 1.1 °C. Temperature at right pampiniform plexus was colder than the thigh in 92% of patients. This study suggests diagnostic criteria of five thermographic signs to easily diagnose varicocele. Scrotal thermography presents feasible, short and low cost diagnostic method for varicocele. Further study on a larger number of patients and healthy participants is needed to evaluate sensitivity and specificity of this method.

  4. Thermography investigations and numerical analysis of turbulent and laminar flow at light weight structures

    NASA Astrophysics Data System (ADS)

    Arndt, Ralf; Gaulke, Alexander

    2008-03-01

    Thermography (IR) allows global visualization of temperature distribution on surfaces with high accuracy. This potential can be used for visualization of fluid mechanics effects at the intersection of laminar and turbulent flows, where temperature jumps appear due to convection and friction i.e. for the optimization in the design of airplane geometries. In civil engineering too it is the aspiration of the modern engineer of light weight structures to meet singular loads like wind peaks rather by intelligent structures and materials than by massive structures. Therefore the "Institute of Conceptual and Structural Design" of the Technical University of Berlin (TUB) is working on the development of adaptive structures, optimized geometry and intelligent microstructures on surfaces of structural elements. The paper shows the potential of modern computational fluid dynamics (CFD) in combination with thermography (IR) to optimize structures by visualization of laminar-tumultuous border layer currents. Therefore CFD simulations and IR wind tunnel experiments will be presented and discussed. For simulations and experiments - artificial and structural elements of the cable-stayed Strelasund Bridge, Germany, are used.

  5. 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.

  6. 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.

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

    PubMed

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

    2015-01-01

    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.

  8. Comparison of pulse phase and thermographic signal reconstruction processing methods

    NASA Astrophysics Data System (ADS)

    Oswald-Tranta, Beata; Shepard, Steven M.

    2013-05-01

    Active thermography data for nondestructive testing has traditionally been evaluated by either visual or numerical identification of anomalous surface temperature contrast in the IR image sequence obtained as the target sample cools in response to thermal stimulation. However, in recent years, it has been demonstrated that considerably more information about the subsurface condition of a sample can be obtained by evaluating the time history of each pixel independently. In this paper, we evaluate the capabilities of two such analysis techniques, Pulse Phase Thermography (PPT) and Thermographic Signal Reconstruction (TSR) using induction and optical flash excitation. Data sequences from optical pulse and scanned induction heating are analyzed with both methods. Results are evaluated in terms of signal-tobackground ratio for a given subsurface feature. In addition to the experimental data, we present finite element simulation models with varying flaw diameter and depth, and discuss size measurement accuracy and the effect of noise on detection limits and sensitivity for both methods.

  9. [Digital noninvasive microwave thermography in the diagnosis of breast disease].

    PubMed

    Fan, K H; Fan, J H; Yao, D D; Jin, W D; Yang, B G; Meng, C X; Qu, D B

    1988-05-01

    Thermography is a noninvasive technic of examination. Liquid-Crystal Thermography and Infrared Thermography have provided great help in the general survey of breast diseases during the past twenty years but not without some limitations. Recently, by applying the microwave technic clinically, progress has been made to measure minute temperature changes in the deeper tissues. Differential diagnosis of breast disease is possible by statistical calculating the temperature difference of the two breasts. A prospective study was done in 96 women who had both X ray mammography and digital noninvasive microwave thermography. 70/96 were proved by pathology. In this group of patients, the accuracy rate was 70.00% for digital microwave thermography, 81.82% for X ray mammography and 95.50% for the two combined. The false positive rates and false negative rates, advantages, disadvantages and the for general survey of breast disease of the digital microwave thermography discussed.

  10. 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

  11. Thermography Improves Clinical Assessment in Patients with Systemic Sclerosis Treated with Ozone Therapy

    PubMed Central

    2017-01-01

    Objective. Treatment of scleroderma is challenging and limited. The aim of our study was to evaluate the usefulness of thermography in assessment of the clinical condition (joints movability and skin thickness) in clinically advanced patients with systemic sclerosis before and after ozone therapy. Method. The study included 42 patients aged 32 to 73 years with advanced systemic sclerosis hospitalized in the university clinic between 2003 and 2006. Thermography and clinical examinations were conducted at baseline and after two series of bath in water with ozone. Results. The comparison of results showed significant increase in skin temperature by 2.5°C, significant increase in interphalangeal joints movability by 18 degrees, and significant decrease in skin score by 14.7 points. The skin temperature was correlated with skin score (r = −0.59) and joints movability (r = +0.8). Conclusions. Ozone therapy shows positive effect on clinical parameters and skin temperature as measured with thermography. The study indicated possibility of introducing ozonotherapy as an independent therapy in cases with low level of progression or during remission periods and as additional treatment in patients with advanced disease requiring immunosuppressive treatment. Thermography is useful in assessment of skin condition showing strong correlation between skin temperature and clinical parameters. PMID:28349063

  12. Thermography Improves Clinical Assessment in Patients with Systemic Sclerosis Treated with Ozone Therapy.

    PubMed

    Nowicka, Danuta

    2017-01-01

    Objective. Treatment of scleroderma is challenging and limited. The aim of our study was to evaluate the usefulness of thermography in assessment of the clinical condition (joints movability and skin thickness) in clinically advanced patients with systemic sclerosis before and after ozone therapy. Method. The study included 42 patients aged 32 to 73 years with advanced systemic sclerosis hospitalized in the university clinic between 2003 and 2006. Thermography and clinical examinations were conducted at baseline and after two series of bath in water with ozone. Results. The comparison of results showed significant increase in skin temperature by 2.5°C, significant increase in interphalangeal joints movability by 18 degrees, and significant decrease in skin score by 14.7 points. The skin temperature was correlated with skin score (r = -0.59) and joints movability (r = +0.8). Conclusions. Ozone therapy shows positive effect on clinical parameters and skin temperature as measured with thermography. The study indicated possibility of introducing ozonotherapy as an independent therapy in cases with low level of progression or during remission periods and as additional treatment in patients with advanced disease requiring immunosuppressive treatment. Thermography is useful in assessment of skin condition showing strong correlation between skin temperature and clinical parameters.

  13. Near UV-near IR Fourier transform spectrometer using the beam-folding position-tracking method based on retroreflectors.

    PubMed

    Wang, Xuzhu; Chan, Robert K Y; Cheng, Amelia S K

    2008-12-01

    A near UV-near IR Fourier transform spectrometer based on a beam-folding position-tracking method realized by using retroreflectors is reported. The use of retroreflectors maintains all beams in the beam-fold arrangement in parallel with the incident beams. The beam-folding interferometer used for position tracking is arranged to have optical path symmetry with the measurement interferometer in the zero path difference position of the measurement interferometer, and the vertex of the movable retroreflector in the measurement interferometer is arranged very close to the midpoint of the vertices of two movable retroreflectors in the position-tracking interferometer. These measures keep the equivalent optical axis of the position-tracking interferometer well in line with that of the measurement interferometer even with translational misalignments. Therefore, the change in the optical path difference of the position-tracking interferometer is always synchronous to that of the measurement interferometer during the scanning process. That is, the position-tracking error can be suppressed to very small values during a scan. We have demonstrated a UV-near IR Fourier transform spectrometer with a standard quality ball-bearing translation stage achieving a resolution close to the theoretical resolution of approximately 0.28 cm(-1) at the He-Ne laser wavelength when the scan distance reaches the travel distance of over 2 cm. This was achieved without the need for elaborate optics, sophisticated detecting electronics, and high-precision servomotion control.

  14. 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

  15. 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.

  16. The use of thermography to design tissue flaps – experimental studies on animals

    PubMed Central

    Łokaj, Marek; Falkowski, Aleksander; Prowans, Piotr

    2014-01-01

    Introduction Methods allowing one to locate the position of a cutaneous perforator do not allow one to determine the boundaries of the vascularized skin. In clinical practice this causes complications in the form of marginal necrosis of the flap. Aim To examine the usefulness of thermography to assess the extent of vascularization of the skin and subcutaneous tissue by a single perforator. Material and methods Thirty-one male rats were used. Using dynamic thermography the perforators on the abdominal skin were located. Afterwards the flap was prepared on a randomly chosen perforator. After 24 h the extent of vascularization of the skin by a single perforator was examined. Results In 22.5% of cases the number of perforators marked in the thermography was equal to the number of perforators marked intraoperatively, in 64.5% it was lower and in 13% higher. The use of thermography has shown that basing the flap vascularization on the perforator with low efficiency resulted in statistically more frequent occurrence of ischemia and partial necrosis of the flap (p = 0.024). Partial necrosis of the flap occurred in 12 of 31 cases, always in the area in which during the preoperative thermography no perforators were found. The areas of necrosis occurred irrespectively of the distance from the supplying vessel. Conclusions When designing the shape of the flap, the distribution of all perforators must be considered. The perforators need to be included in the area of prepared tissues because their location indicates the area with a more efficient network of vessels. PMID:25337153

  17. Validation of IRS PCR, a molecular typing method, for the study of the diversity and population dynamics of Legionella in industrial cooling circuits.

    PubMed

    Jakubek, D; Le Brun, M; Leblon, G; Dubow, M; Binet, M

    2013-02-01

    Legionella bacteria are ubiquitous in aquatic environments. Members of the species Legionella pneumophila are responsible for more than 98% of cases of Legionnaires' disease in France. Our objective was to validate a molecular typing method called infrequent restriction site PCR (IRS PCR), applied to the study of the ecology of Legionella and to compare this method with reference typing methods, pulsed-field gel electrophoresis (PFGE) and sequence-based Typing (SBT). PFGE and SBT are considered as gold methods for the epidemiological typing of Leg. pneumophila strains. However, these methods are not suitable to an ecological monitoring of Legionella in natural environments where a large number of strains has to be typed. Validation of IRS PCR method was performed by the identification of 45 Leg. pneumophila isolates from cooling circuits of thermal power plants by IRS PCR, PFGE and SBT. The parameters of each method were measured and compared to evaluate the effectiveness of IRS PCR. The results of this study showed that IRS PCR has a discriminating power similar or better than that of the reference methods and thus that, by its speed and low cost represents an appropriate tool for the study of the ecology of Legionella in cooling circuits.

  18. 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.

  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. Assessment of the Sensitivity, Specificity, and Accuracy of Thermography in Identifying Patients with TMD

    PubMed Central

    Woźniak, Krzysztof; Szyszka-Sommerfeld, Liliana; Trybek, Grzegorz; Piątkowska, Dagmara

    2015-01-01

    Background The purpose of the present study was to evaluate the sensitivity, specificity, and accuracy of thermography in identifying patients with temporomandibular dysfunction (TMD). Material/Methods The study sample consisted of 50 patients (27 women and 23 men) ages 19.2 to 24.5 years (mean age 22.43±1.04) with subjective symptoms of TMD (Ai II–III) and 50 patients (25 women and 25 men) ages 19.3 to 25.1 years (mean age 22.21±1.18) with no subjective symptoms of TMD (Ai I). The anamnestic interviews were conducted according to the three-point anamnestic index of temporomandibular dysfunction (Ai). The thermography was performed using a ThermaCAM TMSC500 (FLIR Systems AB, Sweden) independent thermal vision system. Thermography was closely combined with a 10-min chewing test. Results The results of our study indicated that the absolute difference in temperature between the right and left side (ΔT) has the highest diagnostic value. The diagnostic effectiveness of this parameter increased after the chewing test. The cut-off points for values of temperature differences between the right and left side and identifying 95.5% of subjects with no functional disorders according to the temporomandibular dysfunction index Di (specificity 95.5%) were 0.26°C (AUC=0.7422, sensitivity 44.3%, accuracy 52.4%) before the chewing test and 0.52°C (AUC=0.7920, sensitivity 46.4%, accuracy 56.3%) after it. Conclusions The evaluation of thermography demonstrated its diagnostic usefulness in identifying patients with TMD with limited effectiveness. The chewing test helped in increasing the diagnostic efficiency of thermography in identifying patients with TMD. PMID:26002613

  2. Infrared thermography in the architectural field.

    PubMed

    Meola, Carosena

    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.

  3. Urban Heat Islands and Urban Thermography

    NASA Astrophysics Data System (ADS)

    Manunta, Paolo; Ceriola, Giulio; Daglis, Ioannis A.; de Ridder, Koen; Giannaros, Theodoros; Keramitsoglou, Iphigenia; Maiheu, Bino; Melas, Dimitrios; Montero Herrero, Enrique; Paganini, Marc; Palacios, Marino; Radius, Andrea; Sapage, Tania; Tamame, Maria; Tambuyzer, Han; Viel, Monique

    2010-12-01

    The Urban Heat Island (UHI) and Urban Thermography project is a project funded by ESA under the DUE program. The project started on 1st November 2008 and will last 2.5 years. The UHI project is relying on all satellite missions that embark TIR sensors to analyse the spatial variability of the Urban Heat Islands in the metropolitan areas of 10 European cities over the last 10 years. Moreover, thermography mapping using airborne data have been or will be performed for Athens, Madrid and Brussels. The project is contributing to the 'Reorientation of the Fuegosat Consolidation Phase', through the collection and synthesis of user requirements for a frequent and routine observation of surface and air temperatures in the core of the major European cities and in the surrounding peri-urban areas.

  4. 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

  5. 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.

  6. 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.

  7. IR image quality assessment and real-time optimum seeking method based on dynamic visual characteristics

    NASA Astrophysics Data System (ADS)

    Li, Bin; Liu, Gang; Gao, Yongmin; Lei, Hao; Wu, Haiying; Wang, Yu; Rong, Xiaolong

    2016-10-01

    Image quality is an important factor that influences the dynamic target information perception; it is the key factor of real-time target state analysis and judgment. In order to solve the multi-observation station comparison and video optimum seeking problem in the process of target information perception and recognition, an image quality assessment method based on visual characteristics is proposed for infrared target tracking. First, it analyses the basic infrared target image characteristics and application requirements, analyses the status and problems of the multi station optimum seeking technology. According to the expected research results, the processing flow of image processing is established. Then, the image quality objective assessment index is established, which reflects the basic characteristics of the target image, and the assessment index is integrated into the normalized assessment function. According to the quality assessment function, the infrared image quality assessment based on infrared target recognition and image analysis processing is realized, which is mainly characterized by the region of interest and dynamic visual characteristics. And on the basis of this technology, the real-time optimum seeking of multi station infrared target tracking image is completed. In order to verify the effectiveness of the method and the practical application effect, it designs the quality assessment and comparison of different station infrared images. Example shows that the method proposed in this paper can realize multi-observation station infrared image assessment comparison, image quality sorting, the optimum seeking of the infrared image based on the quality assessment. The results accord with the characteristics of infrared target image and dynamic visual characteristics.

  8. 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.

  9. 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.

  10. 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.

  11. Infrared Thermography User Group (IRUG) 2003 Meeting Proceedings

    SciTech Connect

    2003-10-01

    Infrared thermography is a key component of predictive maintenance programs for fossil and nuclear utilities. EPRI's Technology for Equipment Assessment and Maintenance (TEAM) group and their Maintenance Management & Technology (MM&T) program supported the 13th Infrared Thermography Users' Group (IRUG) meeting, which was hosted and also supported by Progress Energy.

  12. 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.

  13. Infrared thermography non-destructive evaluation of lithium-ion battery

    NASA Astrophysics Data System (ADS)

    Wang, Zi-jun; Li, Zhi-qiang; Liu, Qiang

    2011-08-01

    The power lithium-ion battery with its high specific energy, high theoretical capacity and good cycle-life is a prime candidate as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs). Safety is especially important for large-scale lithium-ion batteries, especially the thermal analysis is essential for their development and design. Thermal modeling is an effective way to understand the thermal behavior of the lithium-ion battery during charging and discharging. With the charging and discharging, the internal heat generation of the lithium-ion battery becomes large, and the temperature rises leading to an uneven temperature distribution induces partial degradation. Infrared (IR) Non-destructive Evaluation (NDE) has been well developed for decades years in materials, structures, and aircraft. Most thermographic methods need thermal excitation to the measurement structures. In NDE of battery, the thermal excitation is the heat generated from carbon and cobalt electrodes in electrolyte. A technique named "power function" has been developed to determine the heat by chemical reactions. In this paper, the simulations of the transient response of the temperature distribution in the lithium-ion battery are developed. The key to resolving the security problem lies in the thermal controlling, including the heat generation and the internal and external heat transfer. Therefore, three-dimensional modelling for capturing geometrical thermal effects on battery thermal abuse behaviour is required. The simulation model contains the heat generation during electrolyte decomposition and electrical resistance component. Oven tests are simulated by three-dimensional model and the discharge test preformed by test system. Infrared thermography of discharge is recorded in order to analyze the security of the lithium-ion power battery. Nondestructive detection is performed for thermal abuse analysis and discharge analysis.

  14. Total sulfur determination in residues of crude oil distillation using FT-IR/ATR and variable selection methods.

    PubMed

    Müller, Aline Lima Hermes; Picoloto, Rochele Sogari; de Azevedo Mello, Paola; Ferrão, Marco Flores; de Fátima Pereira dos Santos, Maria; Guimarães, Regina Célia Lourenço; Müller, Edson Irineu; Flores, Erico Marlon Moraes

    2012-04-01

    Total sulfur concentration was determined in atmospheric residue (AR) and vacuum residue (VR) samples obtained from petroleum distillation process by Fourier transform infrared spectroscopy with attenuated total reflectance (FT-IR/ATR) in association with chemometric methods. Calibration and prediction set consisted of 40 and 20 samples, respectively. Calibration models were developed using two variable selection models: interval partial least squares (iPLS) and synergy interval partial least squares (siPLS). Different treatments and pre-processing steps were also evaluated for the development of models. The pre-treatment based on multiplicative scatter correction (MSC) and the mean centered data were selected for models construction. The use of siPLS as variable selection method provided a model with root mean square error of prediction (RMSEP) values significantly better than those obtained by PLS model using all variables. The best model was obtained using siPLS algorithm with spectra divided in 20 intervals and combinations of 3 intervals (911-824, 823-736 and 737-650 cm(-1)). This model produced a RMSECV of 400 mg kg(-1) S and RMSEP of 420 mg kg(-1) S, showing a correlation coefficient of 0.990.

  15. Hygroscopic Behavior of Substrate-Deposited Particles Studied by micro-FT-IR Spectroscopy and Complementary Methods of Particle Analysis

    SciTech Connect

    Liu, Yong; Yang, Zhiwei; Dessiaterik, Yury; Gassman, Paul L.; Wang, Hai; Laskin, Alexander

    2008-02-01

    The application of Microscopic Fourier Transform Infrared (micro-FTIR) spectroscopy combined with complementary methods of particle analysis is demonstrated here for investigations of phase transitions and hygroscopic growth of micron-sized particles. The approach utilizes the exposure of substrate-deposited, isolated particles to humidified nitrogen inside a sample cell followed by micro-FTIR spectroscopy over selected sample area. Phase transitions of NaCl, sea salt, NaNO3 and (NH)4SO4 particles are monitored with this technique to evaluate its utility and applicability for particle hydration studies. The results are found in excellent agreement with literature data in terms of (a) reliable and reproducible detection of deliquescence and efflorescence phase transitions, (b) quantitative measurements of water-to-solute ratios in particles as a function of relative humidity, and (c) changes in the IR spectra resulting from phase transitions and changing relative humidity. Additional methods of particle analysis are employed to complement and assist in the interpretation of particle hygroscopicity data obtained from micro-FTIR measurements. The analytical approach and the experimental setup presented here are relatively simple, inexpensive, readily available, and therefore may be practical for hydration studies of environmental particles collected in both laboratory and field studies.

  16. Total sulfur determination in residues of crude oil distillation using FT-IR/ATR and variable selection methods

    NASA Astrophysics Data System (ADS)

    Müller, Aline Lima Hermes; Picoloto, Rochele Sogari; Mello, Paola de Azevedo; Ferrão, Marco Flores; dos Santos, Maria de Fátima Pereira; Guimarães, Regina Célia Lourenço; Müller, Edson Irineu; Flores, Erico Marlon Moraes

    2012-04-01

    Total sulfur concentration was determined in atmospheric residue (AR) and vacuum residue (VR) samples obtained from petroleum distillation process by Fourier transform infrared spectroscopy with attenuated total reflectance (FT-IR/ATR) in association with chemometric methods. Calibration and prediction set consisted of 40 and 20 samples, respectively. Calibration models were developed using two variable selection models: interval partial least squares (iPLS) and synergy interval partial least squares (siPLS). Different treatments and pre-processing steps were also evaluated for the development of models. The pre-treatment based on multiplicative scatter correction (MSC) and the mean centered data were selected for models construction. The use of siPLS as variable selection method provided a model with root mean square error of prediction (RMSEP) values significantly better than those obtained by PLS model using all variables. The best model was obtained using siPLS algorithm with spectra divided in 20 intervals and combinations of 3 intervals (911-824, 823-736 and 737-650 cm-1). This model produced a RMSECV of 400 mg kg-1 S and RMSEP of 420 mg kg-1 S, showing a correlation coefficient of 0.990.

  17. 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.

  18. 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.

  19. Infrared ocular thermography in dogs with and without keratoconjunctivitis sicca.

    PubMed

    Biondi, Flávia; Dornbusch, Peterson T; Sampaio, Manuella; Montiani-Ferreira, Fabiano

    2015-01-01

    Infrared thermography was used to measure temperature differences of the corneal surface between nasal and temporal limbus regions and central cornea of normal dogs and dogs with keratoconjunctivitis sicca (KCS), in order to establish temperature values in normal canine eyes and in patients with decreased Schirmer tear tests (STT) values. Dogs investigated were all either patients seen at the Veterinary Teaching Hospital of Federal University of Paraná or normal dogs that belonged to the same institution. STT were performed in all eyes. A total of 40 control eyes (STT ≥15 mm/min) and 20 eyes with low STT values (STT ≤14 mm/min) were examined. The mean STT value for eyes with normal STT values was 22.9 ± 3.9 mm/min (mean ± standard deviation), and the mean STT value for eyes with low STT value was 7.2 ± 4.8 mm/min. The mean corneal temperature was significantly lower in eyes with low STT values than in control eyes (P < 0.0001). The following significant correlations were found: (i) Schirmer and breakup time (BUT) (P = 0.0001, r = 0.5); (ii) STT values and corneal surface temperature (P = 0.001, r = 0.256); (iii) STT values and age (P = 0.0001, r = -0.448); (iv) age and corneal surface temperature (P = 0.0001, r = -0.281); and (v) BUT and corneal surface temperature (P = 0.0001, r = 0.36). Thermography is a method that can differentiate between eyes with normal and abnormal STT values. In the future, thermography might be incorporated as part of the ophthalmic examination and perhaps become a popular ancillary test for the diagnoses of ocular surface disorders.

  20. Technical design note: differential infrared thermography of methane jets

    NASA Astrophysics Data System (ADS)

    Golzke, Hendrik; Leick, Philippe; Dreizler, Andreas

    2016-10-01

    In this note a novel approach for temperature measurements of methane jets is presented. Differential infrared thermography (DIT) is a contactless, tracer-free temperature determination method for semi-transparent objects, based on an infrared camera. DIT does not rely on a specific a priori value for the emissivity, but typically assumes constant emissivity within the relevant wavelength band. This is reasonable for complex hydrocarbons (i.e. as in liquid fuel sprays) but no longer justified for the discrete absorption spectrum of simple molecules such as methane. An alternative approximation is suggested and discussed, and the feasibility of DIT for the study of supercritical methane jets in a pressure chamber at conditions relevant for internal combustion engines is demonstrated. As DIT also determines the gas emissivity, a combined two-dimensional temperature and projected density visualisation becomes possible and is shown to highlight supersonic structurues such as Mach disks.

  1. 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.

  2. Dynamic deep temperature recovery by acoustic thermography using neural networks

    NASA Astrophysics Data System (ADS)

    Anosov, A. A.; Belyaev, R. V.; Vilkov, V. A.; Kazanskii, A. S.; Mansfel'd, A. D.; Subochev, P. V.

    2013-11-01

    In an experiment, the deep temperature, which changed with time, was recovered for a model object, bovine liver. The liver was heated for 6 min by laser radiation (810 nm), transmitted via a light guide to a depth of 1 cm. During heating and subsequent cooling, the deep temperature was measured by acoustic thermography. For independent control, we used three electronic telemeters, the indications of which were also subsequently recovered. Deep temperature was recovered using a neural network with a time delay. During the last 2 min of heating, the mean square error of recovery for an averaging time of 50 s did not exceed 0.5°C. Such a result makes it possible to use this method for solving a number of medical problems.

  3. Active thermography inspection of protective glass contamination on laser scanning heads.

    PubMed

    Skala, J; Svantner, M; Tesar, J; Franc, A

    2016-12-01

    Industrial lasers are an expanding technology of welding and other materials processing. Lasers with optical scanning heads are often used, as these provide more versatility, accuracy, and speed. The output part of the scanning head is covered by a protective glass, which might get contaminated by various particles from the laser processing. This decreases the transmissivity of the glass, and it can affect the production quality. The contamination needs to be checked regularly, but a visual inspection might not always be effective. This paper proposes two alternative methods of inspecting the protective glass: flash-pulse active thermography, and laser active thermography. They are based on the thermal excitation of the glass and measuring the response with an infrared camera. The experimental setup and practical results are described and the advantages and disadvantages are discussed. The presented methods are proven to be effective in detecting the contamination of the glass.

  4. Reconstruction of a nonlinear heat transfer law from uncomplete boundary data by means of infrared thermography

    NASA Astrophysics Data System (ADS)

    Clarelli, Fabrizio; Inglese, Gabriele

    2016-11-01

    Heat exchange between a conducting plate and the environment is described here by means of an unknown nonlinear function F of the temperature u. In this paper we construct a method for recovering F by means of polynomial expansion, perturbation theory and the toolbox of thermal inverse problems. We test our method on two examples: In the first one, we heat the plate (initially at 20 ^\\circ {{C}}) from one side, read the temperature on the same side and identify the heat exchange law on the opposite side (active thermography); in the second example we measure the temperature of one side of the plate (initially at 1500 ^\\circ {{C}}) and study the heat exchange while cooling (passive thermography).

  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. 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.

  7. 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

  8. Development of nondestructive crack inspection technique for conveyance roll using vibro-thermography

    NASA Astrophysics Data System (ADS)

    Imanishi, Daisuke; Nishina, Yoshiaki; Yoshinaga, Youichi

    2012-06-01

    In recent study, active thermography has reached a high status as an easy and speedy defects inspection method in a NDT field. This paper newly proposes a non-disassembly and non-contact NDT method using the Vibro-Thermography for detecting and evaluating of fatigue cracks at neck parts of the conveyance roll in the steel making plant. In this method, fatigue cracks are detected as localized high temperature areas caused by friction and impact at crack surfaces with an infrared thermography, applying a high-amplitude ultrasonic vibration. In the case of the roll surface is covered with lubricating grease or dust, the crack detectability is shown. Self reference lock-in data processing technique is applied for improvement of signal noise ratio in the crack detection process. This technique makes it possible to perform correlating process without an external reference signal. Time and cost saving inspection method in the neck part of conveyance roll is carried out using this NDT technique.

  9. Surface temperature measurement of the plasma facing components with the multi-spectral infrared thermography diagnostics in tokamaks

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Gauthier, E.; Pocheau, C.; Balorin, C.; Pascal, J. Y.; Jouve, M.; Aumeunier, M. H.; Courtois, X.; Loarer, Th.; Houry, M.

    2017-03-01

    For the long-pulse high-confinement discharges in tokamaks, the equilibrium of plasma requires a contact with the first wall materials. The heat flux resulting from this interaction is of the order of 10 MW/m2 for steady state conditions and up to 20 MW/m2 for transient phases. The monitoring on surface temperatures of the plasma facing components (PFCs) is a major concern to ensure safe operation and to optimize performances of experimental operations on large fusion facilities. Furthermore, this measurement is also required to study the physics associated to the plasma material interactions and the heat flux deposition process. In tokamaks, infrared (IR) thermography systems are routinely used to monitor the surface temperature of the PFCs. This measurement requires an accurate knowledge of the surface emissivity. However, and particularly for metallic materials such as tungsten, this emissivity value can vary over a wide range with both the surface condition and the temperature itself, which makes instantaneous measurement challenging. In this context, the multi-spectral infrared method appears as a very promising alternative solution. Indeed, the system has the advantage to carry out a non-intrusive measurement on thermal radiation while evaluating surface temperature without requiring a mandatory surface emissivity measurement. In this paper, a conceptual design for the multi-spectral infrared thermography is proposed. The numerical study of the multi-channel system based on the Levenberg-Marquardt (LM) nonlinear curve fitting is applied. The numerical results presented in this paper demonstrate the design allows for measurements over a large temperature range with a relative error of less than 10%. Furthermore, laboratory experiments have been performed from 200 °C to 740 °C to confirm the feasibility for temperature measurements on stainless steel and tungsten. In these experiments, the unfolding results from the multi-channel detection provide good

  10. Airborne thermography or infrared remote sensing.

    PubMed

    Goillot, C C

    1975-01-01

    Airborne thermography is part of the more general remote sensing activity. The instruments suitable for image display are infrared line scanners. A great deal of interest has developed during the past 10 years in airborne thermal remote sensing and many applications are in progress. Infrared scanners on board a satellite are used for observation of cloud cover; airborne infrared scanners are used for forest fire detection, heat budget of soils, detecting insect attack, diseases, air pollution damage, water stress, salinity stress on vegetation, only to cite some main applications relevant to agronomy. Using this system it has become possible to get a 'picture' of our thermal environment.

  11. Infrared thermography in the restoration of cultural properties

    NASA Astrophysics Data System (ADS)

    Carlomagno, Giovanni M.; Carosena, Meola

    2001-03-01

    Some of the work carried out at DETEC on the use of infrared thermography in the architectural restoration field is examined. Three different techniques, pulse thermography (PT), modulated thermography (MT) and pulse phase thermography (PPT) are analyzed through the control of some art treasures such as mosaics and frescoes. In particular, the following artifacts are considered: mosaics covering some external walls of the building of the Faculty of Engineering of Naples, frescoes in the Duomo of Sarno, frescoes in the Cripta SS. Stefani in Vaste (Le), mosaics and frescoes in the Archeological Museum of Naples coming from Pompeii and Ruvo. It is found that the choice of the technique depends on the specific surface to be tested: if only qualitative information about detachments and cracks are needed the pulse thermography is sufficient; if the surface is not very sensitive to temperature rising, the pulse phase thermography can be applied which gives information about the location of the defected zone. If instead, the analysis regards rare art treasures, lockin thermography is the only response.

  12. 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.

  13. Thermography and machine learning techniques for tomato freshness prediction.

    PubMed

    Xie, Jing; Hsieh, Sheng-Jen; Wang, Hong-Jin; Tan, Zuojun

    2016-12-01

    The United States and China are the world's leading tomato producers. Tomatoes account for over $2 billion annually in farm sales in the U.S. Tomatoes also rank as the world's 8th most valuable agricultural product, valued at $58 billion dollars annually, and quality is highly prized. Nondestructive technologies, such as optical inspection and near-infrared spectrum analysis, have been developed to estimate tomato freshness (also known as grades in USDA parlance). However, determining the freshness of tomatoes is still an open problem. This research (1) illustrates the principle of theory on why thermography might be able to reveal the internal state of the tomatoes and (2) investigates the application of machine learning techniques-artificial neural networks (ANNs) and support vector machines (SVMs)-in combination with transient step heating, and thermography for freshness prediction, which refers to how soon the tomatoes will decay. Infrared images were captured at a sampling frequency of 1 Hz during 40 s of heating followed by 160 s of cooling. The temperatures of the acquired images were plotted. Regions with higher temperature differences between fresh and less fresh (rotten within three days) tomatoes of approximately uniform size and shape were used as the input nodes for ANN and SVM models. The ANN model built using heating and cooling data was relatively optimal. The overall regression coefficient was 0.99. These results suggest that a combination of infrared thermal imaging and ANN modeling methods can be used to predict tomato freshness with higher accuracy than SVM models.

  14. 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.

  15. 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.

  16. 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

  17. Intra-Examiner and Inter-Examiner Reproducibility of Paraspinal Thermography

    PubMed Central

    McCoy, Matthew; Campbell, Ismay; Stone, Pamela; Fedorchuk, Curtis; Wijayawardana, Sameera; Easley, Kirk

    2011-01-01

    Objective The objective of this study was to evaluate the intra-examiner and inter-examiner reproducibility of paraspinal thermography using an infrared scanner. Materials and Methods The thermal functions of a commercially available infrared scanner (Insight Subluxation Station®) were evaluated for clinical reliability. Two practicing clinicians conducted the measures on 100 subjects. Intra class correlation coefficients (ICCs) and concordance correlation coefficients (CCCs) were calculated from the collected data. Results Mean bilateral paraspinal skin temperature was 89.78° F and ranged from 88.77° F to 91.43° F. Intra class correlation coefficients (ICCs) for agreement and consistency ranged from 0.959 to 0.976. Concordance correlation coefficients (CCCs) ranged from 0.783 to 0.859 with tight confidence intervals indicating robust estimates of these quantities. Conclusion This study revealed excellent intra-examiner and inter-examiner reproducibility of paraspinal thermography using a commercially available unit. PMID:21347290

  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. 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.

  20. 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.

  1. 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.

  2. Inspection of reinforcement concrete structures with active infrared thermography

    NASA Astrophysics Data System (ADS)

    Szymanik, Barbara; Chady, Tomasz; Frankowski, Paweł

    2017-02-01

    In this article the reinforced concrete non-destructive evaluation using active thermography is discussed. There are several aspects of possible non-destructive testing of mentioned structures. One of them is the detection and assessment of the reinforcement itself. In case of active thermography, the external energy source has to be used to induce the thermal response of the inspected specimen. Here, authors propose two different techniques: microwave heating and induction heating. In this article authors will present several experimental results which will allow to compare mentioned two techniques of heating. suitability of each one to assess the reinforced concrete by using the active thermography will be discussed.

  3. 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.

  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. Line Scanning Thermography for Rapid Nondestructive Inspection of Large Scale Composites

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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 in2 per 1 second, and has a resolution of 0.05×0.03 in2. 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.

  6. Infrared thermography--a non-invasive tool to evaluate thermal status of neonatal pigs based on surface temperature.

    PubMed

    Kammersgaard, T S; Malmkvist, J; Pedersen, L J

    2013-12-01

    Hypothermia is a major cause of mortality in neonatal pigs. Infrared (IR) thermography is a promising non-invasive method to assess thermal status, but has not been evaluated for use on neonatal pigs from birth. The aim of this study was to evaluate the application of IR thermography as a non-invasive tool to estimate body temperature and assess the thermal status in newborn pigs by (1) estimating the relationship between surface temperature and rectal temperature (RT) in neonatal pigs; and (2) estimating the influence of air temperature (AT), birth weight and the time from birth on the relationship between surface temperature and RT. The method was evaluated on the basis of 1695 thermograms and 915 RTs on 91 neonatal pigs born in loose farrowing pens with floor heating at 34°C, and three different ATs (15°C, 20°C and 25°C). Full-body thermograms of the back and the side of the pigs and RT were acquired at 11 sampling times between birth and 48 h after birth. The maximum (IRmax), minimum, average of the full body and ear minimum IR surface temperatures were derived from the thermograms. IRmax had the highest correlation with RT (0.82) and was therefore used in the statistical analysis. The relation of RT by IRmax depended on time at: 0 h (slope: 0.20°C, P<0.001), 0.25 h (slope: 0.42°C, P<0.01), and 0.5 and 1 h after birth (slope: 0.68°C, P<0.001). After the 1st hour (1.5 to 48 h) the relation of RT by IRmax was no longer affected by time (slope: 0.63°C, P<0.001). The agreement between RT and IRmax was improved (P<0.001) after the 1st hour (RT-IRmax 0 to 1 h: 2.02 (1.44)°C; 1.5 to 48 h: 0.95 (0.85)°C). IRmax below 30°C was indicative of piglets having RT<32°C (91.3%). The location of IRmax was identified predominantly at the base of the ears (27/50), other sites in the region of the head (12/50) and the axilla area (8/50). There was a small but significant effect of the angle as IRmax_side-IRmax_back: mean 0.20°C (P<0.001). On the basis of the low

  7. 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

    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.

  8. Infrared thermography based on artificial intelligence for carpal tunnel syndrome diagnosis.

    PubMed

    Jesensek Papez, B; Palfy, M; Turk, Z

    2008-01-01

    Thermography for the measurement of surface temperatures is well known in industry, although is not established in medicine despite its safety, lack of pain and invasiveness, easy reproducibility, and low running costs. Promising results have been achieved in nerve entrapment syndromes, although thermography has never represented a real alternative to electromyography. Here an attempt is described to improve the diagnosis of carpal tunnel syndrome with thermography using a computer-based system employing artificial neural networks to analyse the images. Method reliability was tested on 112 images (depicting the dorsal and palmar sides of 26 healthy and 30 pathological hands), with the hand divided into 12 segments and compared relative to a reference. Palmar segments appeared to have no beneficial influence on classification outcome, whereas dorsal segments gave improved outcome with classification success rates near to or over 80%, and finger segments influenced by the median nerve appeared to be of greatest importance. These are preliminary results from a limited number of images and further research will be undertaken as our image database grows.

  9. Infrared digital thermography of scrotum in early selection of progressive varicocele.

    PubMed

    Kulis, T; Knezevic, M; Karlovic, K; Kolaric, D; Antonini, S; Kastelan, Z

    2013-10-01

    Varicocele is frequent but correctable cause of male infertility. Varicocelectomy is the most commonly performed operative procedure for varicocele. Majority of varicocele patients do not have fertility problem, therefore surgical correction is not recommended in all prevalent cases. On the other hand, varicocele is a progressive condition in some cases and individual with varicocele is at risk for developing impairment which can ultimately lead to semen deterioration and consequent infertility. Selection of patients with varicocele that will progress and cause infertility is beyond our current diagnostic capabilities. Diagnostic assessment of varicocele depends on physical examination and scrotal ultrasound/doppler. Infrared digital thermography of scrotum is a non-invasive and objective diagnostic method for early varicocele detection by means of temperature measurement on the scrotal skin surface. The criteria for diagnostic use of scrotal thermography were recently presented. We hypothesize that the infrared digital thermography of scrotum could be the cornerstone in detection of varicoceles that tend to progress with impairment of semen quality and will require surgical correction, among all prevalent varicocele cases.

  10. 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

  11. Infrared thermography for temperature measurement and non-destructive testing.

    PubMed

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

    2014-07-10

    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.

  12. Principal Components of Thermography analyses of the Silk Tomb, Petra (Jordan)

    NASA Astrophysics Data System (ADS)

    Gomez-Heras, Miguel; Alvarez de Buergo, Monica; Fort, Rafael

    2015-04-01

    This communication presents the results of an active thermography survey of the Silk Tomb, which belongs to the Royal Tombs compound in the archaeological city of Petra in Jordan. The Silk Tomb is carved in the variegated Palaeozoic Umm Ishrin sandstone and it is heavily backweathered due to surface runoff from the top of the cliff where it is carved. Moreover, the name "Silk Tomb" was given because of the colourful display of the variegated sandstone due to backweathering. A series of infrared images were taken as the façade was heated by sunlight to perform a Principal Component of Thermography analyses with IR view 1.7.5 software. This was related to indirect moisture measurements (percentage of Wood Moisture Equivalent) taken across the façade, by means of a Protimeter portable moisture meter. Results show how moisture retention is deeply controlled by lithological differences across the façade. Research funded by Geomateriales 2 S2013/MIT-2914 and CEI Moncloa (UPM, UCM, CSIC) through a PICATA contract and the equipment from RedLAbPAt Network

  13. 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.

  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. 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.

  16. 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

  17. Modeling Turbine Blade Crack Detection in Sonic IR Imaging with a Method of Creating Flat Crack Surface in FEA (Preprint)

    DTIC Science & Technology

    2011-11-01

    After the LS - DYNA file produced in ANSYS is imported into Hypermesh, we can follow the typical simulation procedures to define the crack and...excitation source and thermal properties, the simulation of this blade can proceed with LS - DYNA . The cylinder in Figures 4 and 5 represents an ultrasound...on Carbon-Fiber Reinforced Aircraft Composite Panels With Sonic IR," in Review of Progress in Quantitative Nondestructive Evaluation, edited by D

  18. 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.

  19. Strength by joining methods: combining synthesis with NMR, IR, and vibrational circular dichroism spectroscopy for the determination of the relative configuration in hemicalide.

    PubMed

    De Gussem, Ewoud; Herrebout, Wouter; Specklin, Simon; Meyer, Christophe; Cossy, Janine; Bultinck, Patrick

    2014-12-22

    The relative configuration of a key subunit of hemicalide, a recently isolated, highly bioactive marine natural product having potent antiproliferative activity against a panel of human cancer cell lines, was assigned by combining stereocontrolled synthesis of model substrates with NMR, IR, and vibrational circular dichroism (VCD) spectroscopy. The assignment of the absolute configuration of asymmetric carbon center C42 in two structurally complex epimeric substructures containing six stereocenters by VCD analysis illustrates the power and reliability of combining methods.

  20. Study on the properties of vacancies and phonon dispersions by the improved ones of the modified analytic embedded atom method potentials for Al, Ni, and Ir

    NASA Astrophysics Data System (ADS)

    Jin, Hak-Son; Pak, Jae-Yon; Jong, Yon-Song

    2017-04-01

    The properties of the mono- and bi-vacancies and the phonon dispersions are calculated by adopting the improved ones of the modified analytical embedded atom method potentials for facet-centered cubic metals Al, Ni, and Ir. The results mainly agree with the experimental data and the other calculation results. Therefore, the improved potentials are effective in the study on the physical properties of the metals.

  1. Tone burst eddy current thermography for estimation of corrosion defects in aircraft components

    NASA Astrophysics Data System (ADS)

    Libin, M. N.; Balasubramaniam, Krishnan; Krishnamurthy, C. V.; Engelbart, Roger

    2012-05-01

    Tone Burst Eddy Current Thermography (TBET) technique was used for the evaluation of corrosion type damage in Aluminum plate like structures. Both flat and curved components were considered. The effect of the parameters affecting the eddy current generation of head in the metal, including excitation frequency, electrical conductivity, standoff distances, etc were considered in optimizing the heat generation. The thermal diffusivity and thickness of the metal structure were considered while selecting the detection of the signal using a thermal sensitive IR Camera. The experiments were conducted using test samples that had simulated defects with different wall thickness losses. The experiments were supported by a multiphysics 3D Finite Element Model (FEM) using COMSOL. The results were compared with the experimental results. It was determined that this technique has some advantages for the inspection aircraft structural components compared to other modalities, particularly in curved regions.

  2. Analysis of the sensible heat flux from the exterior surface of buildings using time sequential thermography

    NASA Astrophysics Data System (ADS)

    Hoyano, Akira; Asano, Kohichi; Kanamaru, Takehisa

    In this study, the distribution of surface temperature on the surface of two buildings having different characteristics was measured using a thermal infrared camera. Measurements were made in the summer, the period in Japan during which heat flux from buildings is of major interest, and again in the winter for comparison purposes. The heat characteristics of each building were obtained throughout the day by time-sequential thermography (TST), and the surface temperature of each physical element was classified according to temperature, shape, material and position. When the temperature of a surface could not be determined by an infrared camera mounted on the top of a building or a pole, temperature measurements were made using a hand-held IR camera. In addition, the sensible heat flux from each surface was calculated using TST and the surface area of each element as calculated from blueprints of the buildings.

  3. Using Graded Relevance Assessments in IR Evaluation.

    ERIC Educational Resources Information Center

    Kekalalainen, Jaana; Jarvelin, Kalervo

    2002-01-01

    Proposes evaluation methods based on the use of nondichotomous relevance judgements in information retrieval (IR) experiments. Argues that evaluation methods should credit IR methods for their ability to retrieve highly relevant documents. This is desirable from the user point of view in modern large IR environments. (Author/AEF)

  4. 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.

  5. 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.

  6. Stimulated infrared thermography applied to thermophysical characterization of cultural heritage mural paintings

    NASA Astrophysics Data System (ADS)

    Bodnar, Jean-Luc; Nicolas, Jean-Louis; Mouhoubi, Kamel; Detalle, Vincent

    2012-11-01

    The purpose of this paper is to approach stimulated infrared thermography possibilities in terms of measuring longitudinal thermal diffusivity of mural paintings in situ. The measuring method principle is first submitted. It is based on temporal analysis of changes in the characteristic radius beams of spatial profiles of the photothermal signal, measured on the spot of the laser excitation. The feasibility of the method is demonstrated, thanks to a series of simulations. Lastly, the method enables to correctly estimate longitudinal thermal diffusivity in a test sample, and further in a fragment copy of "Saint Christophe" belonging to the Campana collection in the Louvre.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Detection of localized fatigue damage in steel by thermography

    NASA Astrophysics Data System (ADS)

    Medgenberg, Justus; Ummenhofer, Thomas

    2007-04-01

    Fatigue damage of unalloyed steels in the high cycle regime is governed by localized cyclic plastic deformations and subsequent crack initiation. The extent of early microplastic deformations depends on the applied stress level, stress concentration at macroscopic notches, surface treatment, residual stresses etc. The onset of a nonlinear material response can be regarded as an early indicator of fatigue damage. During fatigue loading thermoelastic coupling and thermoplastic dissipation cause characteristic temperature variations in tested specimens which have been assessed by a highly sensitive infrared camera. A specialized data processing method in the time domain has been developed which allows to separate the different contributions to the measured temperature signal. In contrast to other methods - as e.g. measuring the rise of mean temperature during fatigue loading - the proposed methodology is based on measurements during the stabilized temperature regimen and offers very high spatial resolution of localized phenomena. Investigations have been made on mildly notched cylindrical and also on welded specimens. The results confirm the close relation between the local temperature signal and typical fatigue phenomena. The new methodology allows for a much better localization and quantification of effects as cyclic plasticity, crack initiation, crack growth etc. The following paper presents considerations and experimental results of an application of thermography to the local assessment of fatigue damage.

  12. 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.

  13. 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.

  14. 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.

  15. Measurement of the Peltier coefficient of semiconductors by lock-in thermography

    NASA Astrophysics Data System (ADS)

    Straube, Hilmar; Wagner, Jan-Martin; Breitenstein, Otwin

    2009-08-01

    Lock-in thermography is applied to image Joule heating and Peltier-type heat transport separately. Images obtained for a multicrystalline silicon solar cell are quantitatively evaluated using an integration method. The results are interpreted in terms of diffusion and electron/hole drag contributions. The approach presented is especially interesting where the thermal contact resistance to the sample is a problem and where versatility with respect to sample geometry is needed. A further advantage of the method is that it does not need any separate power or temperature calibration.

  16. 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

    2013-01-09

    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.

  17. 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.

  18. Pulsed IR inductive lasers

    NASA Astrophysics Data System (ADS)

    Razhev, A. M.; Churkin, D. S.; Kargapol'tsev, E. S.

    2014-07-01

    Pulsed inductive discharge is a new alternative method of pumping active gas laser media. The work presents results of experimental investigations of near, mid, and far IR inductive gas lasers (H2, HF, and CO2) operating at different transitions of atoms and molecules with different mechanisms of formation of inversion population. The excitation systems of a pulsed inductive cylindrical discharge (pulsed inductively coupled plasma) and pulsed RF inductive discharge in the gases are developed. Various gas mixtures including H2, N2, He, Ne, F2, NF3, and SF6 are used. Characteristics of near IR H2 laser radiation are investigated. Maximal pulse peak power of 7 kW is achieved. The possibility of using a pulsed inductive discharge as a new method of pumping HF laser active medium is demonstrated. The pulsed RF inductive CO2 laser is created and a total efficiency of 17% is achieved.

  19. 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.

  20. Thermography applied acupuncture and qi-gong

    NASA Astrophysics Data System (ADS)

    Qin, Yuwen; Ji, Hong-Wei; Chen, Jin-Long; Li, Hong-Qi

    1997-04-01

    Thermographic technique can be used to measure temperature distribution of body surface in real-time, non-contact and full-field, which has been successfully used in medical diagnosis, remote sensing, and NDT, etc. The authors have developed a thermographic experiment that can be applied to inspect the effect of action of acupuncture and qi-gong (a system of deep breathing exercises) by measuring the temperature of hand and arm. The observation is performed respectively by thermography for the dynamic changes of temperature of the arm and hand after acupuncture therapy and qi-gong therapy. Thermographic results show that the temperature on the collateral channels increases markedly. In the meantime, it can be seen that the above therapies of Chinese medicine can stimulate the channel collateral system. This also contributes a new basis to the effect of action of the therapies of Chinese medicine. The work shows that thermographic technique is a powerful tool for research in Chinese medicine. In this paper, some thermal images are obtained from the persons treated with acupuncture and qi- gong.

  1. Infrared thermography and overloaded neutral conductors

    NASA Astrophysics Data System (ADS)

    McComb, John; Niebla, Hector E.

    1999-03-01

    Present findings of two recent case studies. One involves transformer failures on three computer-stores within eight hours of their grand opening. The second discusses the findings during an infrared thermography-training course for electric utility engineers of a transformer vault serving an industrial customer. Both of these deal with overloaded neutral conductors. Historically, the average neutral conductor carried only the imbalance of the current between the phases of a three-phase system. This current was typically small in relation to the load being served. In fact, for economic reasons many neutrals were installed smaller than their associated phase conductors. Today however, certain types of loads (non-linear loads such as computers) and certain transformer connections (4 bushing single phase with a collector bus) cause the neutral to have up to three times as much amperage as the phase conductors. This paper will discuss the conditions under which such loading occurs and further investigate steps that can be taken/recommended should an infrared test indicate an overloaded neutral conductor.

  2. Time-resolved pulsed stimulated infrared thermography applied to carbon-epoxy non destructive evaluation

    NASA Astrophysics Data System (ADS)

    Krapez, J.-C.; Boscher, D.; Delpech, Ph.; Deom, A.; Gardette, G.; Balageas, D.

    Since several years, time-resolved pulsed stimulated infrared thermography (SIRT) has been developed at ONERA with the aim of combining fast screening and quantitative characterization. The analysis of pixel by pixel thermograms leads to depth-location and thermal resistance images of delaminations. In this paper we present recent enhancements of the portable SIRT system and refinement of the data reduction procedure which demonstrate the possibility of detecting and evaluating delaminations in C-epoxy at depths higher than 3 mm. A 2-D inversion procedure is proposed to better characterize defects of reduced lateral extend as compared to the former 1-D method.

  3. 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.

  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. 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.

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

    SciTech Connect

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

    1999-12-02

    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.

  7. Influence of Surface Properties on the Detection and Quantification of Voids in Concrete Structures Using Active Thermography

    NASA Astrophysics Data System (ADS)

    Maierhofer, Ch.; Röllig, M.; Arndt, R.; Kreutzbruck, M.

    2009-03-01

    Impulse thermography is an active method for quantitative investigations of the near surface region of various structures. It has recently been applied and optimized to applications in civil engineering. For quantitative analysis of data recorded on the building site, the problems are manifold. Here, the influence of the different surface properties on the detection and characterization of voids and honeycombing simulated by polystyrene cubes and cubes prepared of porous concrete are demonstrated.

  8. 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

  9. Application of lock-in thermography for the inspection of disbonds in titanium alloy honeycomb sandwich structure

    NASA Astrophysics Data System (ADS)

    Zhao, Hanxue; Zhou, Zhenggan; Fan, Jin; Li, Gen; Sun, Guangkai

    2017-03-01

    This paper investigates the lock-in thermography testing of skin-to-core disbonds in titanium alloy honeycomb structure. A three-dimensional finite element model of titanium alloy honeycomb sandwich structure is built. The phase difference between the disbond defect region and the nondefective region is used to optimize the excitation frequency. The phase variation of the surface temperature because of the discontinuity of the honeycomb structure is analyzed. And the relationship between the phase difference of the defect and the nondefective region and the thickness of the disbond is obtained. Two titanium alloy honeycomb sandwich structure specimens with skin-to-core disbond defects were manufactured. Different from the conventional method of simulating disbond defects, two methods of prefabricating intimate contact disbond are proposed to form real defects. The lock-in thermography experiments are carried out on the specimens. The digital correlation method is used to process the infrared image sequence. The experimental results show that lock-in thermography is effective in inspecting the intimate contact disbond in titanium alloy honeycomb sandwich structure.

  10. 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

    2016-01-05

    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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Thermography-based blood flow imaging in human skin of the hands and feet: a spectral filtering approach.

    PubMed

    Sagaidachnyi, A A; Fomin, A V; Usanov, D A; Skripal, A V

    2017-02-01

    The determination of the relationship between skin blood flow and skin temperature dynamics is the main problem in thermography-based blood flow imaging. Oscillations in skin blood flow are the source of thermal waves propagating from micro-vessels toward the skin's surface, as assumed in this study. This hypothesis allows us to use equations for the attenuation and dispersion of thermal waves for converting the temperature signal into the blood flow signal, and vice versa. We developed a spectral filtering approach (SFA), which is a new technique for thermography-based blood flow imaging. In contrast to other processing techniques, the SFA implies calculations in the spectral domain rather than in the time domain. Therefore, it eliminates the need to solve differential equations. The developed technique was verified within 0.005-0.1 Hz, including the endothelial, neurogenic and myogenic frequency bands of blood flow oscillations. The algorithm for an inverse conversion of the blood flow signal into the skin temperature signal is addressed. The examples of blood flow imaging of hands during cuff occlusion and feet during heating of the back are illustrated. The processing of infrared (IR) thermograms using the SFA allowed us to restore the blood flow signals and achieve correlations of about 0.8 with a waveform of a photoplethysmographic signal. The prospective applications of the thermography-based blood flow imaging technique include non-contact monitoring of the blood supply during engraftment of skin flaps and burns healing, as well the use of contact temperature sensors to monitor low-frequency oscillations of peripheral blood flow.

  16. Status and Plans for Infrared Thermography and Heat flux Measurements on NSTX-U

    NASA Astrophysics Data System (ADS)

    Gray, Travis; Ahn, Joon-Wook; Gan, Kaifu; McGann, Alistair; Reinke, Matthew; Maingi, Rajesh; Wirth, Brian

    2016-10-01

    Improvements and expansion of IR thermography tools on NSTX-U are being pursued to support a range of boundary physics research. Due to a carbon-lithium mixed material environment and upcoming use of high-Z materials, NSTX-U presents a challenge in determining the deposited power flux to plasma facing components (PFCs). The majority of the PFCs are graphite which has a high surface emissivity but extensive use of lithium wall conditioning creates a mixed material divertor environment. Furthermore, a row of low emissivity/highly reflective molybdenum tiles will be installed in the outboard divertor for the next run campaign. To overcome these challenges as well assess overall power balance in NSTX-U, infrared coverage of the PFCs has been increased. The lower divertor outer strike point (OSP) is observed by a 1.6 kHz IR camera equipped with dual-band optics to account for the changes in surface emissivity introduced with the addition of lithium [AG MCLean, RSI 2012]. A wide-angle view of the lower divertor and a tangential view of the HHFW antenna and limiters has been added for the commencement of plasma operations on the NSTX-U. Measurements of the lower divertor, inner strike point (ISP) as well as the upper diverter OSP will be implemented for the FY17 run campaign. The installation of the molybdenum tiles will also include calorimeters to further constrain the heat flux measurements on those tiles with plans to increase calorimeter coverage.

  17. 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

  18. 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

  19. Measurement of defect thickness of the wall thinning defect pipes by lock-in infrared thermography technique

    NASA Astrophysics Data System (ADS)

    Kim, Kyeongsuk; Kim, Kyungsu; Jung, Hyunchul; Chang, Hosub

    2009-12-01

    Mostly piping which is using for the nuclear power plants are made up of carbon steel pipes. The wall thinning defects occurs by the effect of the flow accelerated corrosion of fluid that flows in carbon steel pipes. The defects could be found on the welding part and anywhere in the pipes. The infrared thermography technique which is one of the non-destructive testing method has used for detecting the defects of various kinds of materials over the years. There is a limitation for measuring the defect of metals that have a big coefficient of thermal diffusion. However, a technique using lock-in method gets over the difficulty. Consequently, the lock-in infrared thermography technique has been applied to the various industry fields. In this paper, the defect thickness of the straight pipe which has an artificial defect the inside of the pipes was measured by using the lock-in infrared thermography technique and the result could be utilized in detecting defects of carbon steel pipes.

  20. Measurement of defect thickness of the wall thinning defect pipes by lock-in infrared thermography technique

    NASA Astrophysics Data System (ADS)

    Kim, Kyeongsuk; Kim, Kyungsu; Jung, Hyunchul; Chang, Hosub

    2010-03-01

    Mostly piping which is using for the nuclear power plants are made up of carbon steel pipes. The wall thinning defects occurs by the effect of the flow accelerated corrosion of fluid that flows in carbon steel pipes. The defects could be found on the welding part and anywhere in the pipes. The infrared thermography technique which is one of the non-destructive testing method has used for detecting the defects of various kinds of materials over the years. There is a limitation for measuring the defect of metals that have a big coefficient of thermal diffusion. However, a technique using lock-in method gets over the difficulty. Consequently, the lock-in infrared thermography technique has been applied to the various industry fields. In this paper, the defect thickness of the straight pipe which has an artificial defect the inside of the pipes was measured by using the lock-in infrared thermography technique and the result could be utilized in detecting defects of carbon steel pipes.

  1. [Objective assessment of facial paralysis using local binary pattern in infrared thermography].

    PubMed

    Liu, Xulong; Hong, Wenxue; Zhang, Tao; Wu, Zhenying

    2013-02-01

    Facial paralysis is a frequently-occurring disease, which causes the loss of the voluntary muscles on one side of the face due to the damages the facial nerve and results in an inability to close the eye and leads to dropping of the angle of the mouth. There have been few objective methods to quantitatively diagnose it and assess this disease for clinically treating the patients so far. The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Facial paralysis usually causes an alteration of the temperature distribution of body with the disease. This paper presents the use of the histogram distance of bilateral local binary pattern (LBP) in the facial infrared thermography to measure the asymmetry degree of facial temperature distribution for objective assessing the severity of facial paralysis. Using this new method, we performed a controlled trial to assess the facial nerve function of the healthy subjects and the patients with Bell's palsy respectively. The results showed that the mean sensitivity and specificity of this method are 0.86 and 0.89 respectively. The correlation coefficient between the asymmetry degree of facial temperature distribution and the severity of facial paralysis is an average of 0.657. Therefore, the histogram distance of local binary pattern in the facial infrared thermography is an efficient clinical indicator with respect to the diagnosis and assessment of facial paralysis.

  2. 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.

  3. Feasibility of determining flat roof heat losses using aerial thermography

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    The utility of aerial thermography for determining rooftop heat losses was investigated experimentally using several completely instrumented test roofs with known thermal resistances. Actual rooftop heat losses were obtained both from in-situ instrumentation and aerial thermography obtained from overflights at an altitude of 305 m. In general, the remotely determined roof surface temperatures agreed very well with those obtained from ground measurements. The roof heat losses calculated using the remotely determined roof temperature agreed to within 17% of those calculated from 1/R delta T using ground measurements. However, this agreement may be fortuitous since the convective component of the heat loss is sensitive to small changes in roof temperature and to the average heat transfer coefficient used, whereas the radiative component is less sensitive. This, at this time, it is felt that an acceptable quantitative determination of roof heat losses using aerial thermography is only feasible when the convective term is accurately known or minimized. The sensitivity of the heat loss determination to environmental conditions was also evaluated. The analysis showed that the most reliable quantitative heat loss determinations can probably be obtained from aerial thermography taken under conditions of total cloud cover with low wind speeds and at low ambient temperatures.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Improving the classification accuracy for IR spectroscopic diagnosis of stomach and colon malignancy using non-linear spectral feature extraction methods.

    PubMed

    Lee, Sanguk; Kim, Kyoungok; Lee, Hyeseon; Jun, Chi-Hyuck; Chung, Hoeil; Park, Jong-Jae

    2013-07-21

    Non-linear feature extraction methods, neighborhood preserving embedding (NPE) and supervised NPE (SNPE), were employed to effectively represent the IR spectral features of stomach and colon biopsy tissues for classification, and improve the classification accuracy for diagnosis of malignancy. The motivation was to utilize the NPE and SNPE's capability of capturing non-linear spectral behaviors by simultaneously preserving local relationships in order that minute spectral differences among classes would be effectively recognized. NPE and SNPE derive an optimal embedding feature such that the local neighborhood structure can be preserved in reduced spaces (variables). The IR spectra collected from stomach and colon tissues were represented by several new variables through NPE and SNPE, and also by using the principal component analysis (PCA). Then, the feature-extracted variables were subsequently classified into normal, adenoma and cancer tissues by using both k-nearest neighbor (k-NN) and support vector machine (SVM), and the resulting accuracies were compared with each other. In both cases, the combination of SNPE-SVM provided the best classification performance, and the accuracy was substantially improved compared to when PCA-SVM was used. Overall results demonstrate that NPE and SNPE could be potential feature-representation strategies useful in biomedical diagnosis based on vibrational spectroscopy where effective recognition of minute spectral differences is critical.

  10. 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.

  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.

    PubMed

    Paczkowska, Magdalena; Lewandowska, Kornelia; Bednarski, Waldemar; Mizera, Mikołaj; Podborska, Agnieszka; Krause, Anna; Cielecka-Piontek, Judyta

    2015-04-05

    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. Vibrational spectra (FT-IR, FT-Raman), frontier molecular orbital, first hyperpolarizability, NBO analysis and thermodynamics properties of Piroxicam by HF and DFT methods.

    PubMed

    Suresh, S; Gunasekaran, S; Srinivasan, S

    2015-03-05

    The solid phase FT-IR and FT-Raman spectra of 4-Hydroxy-2-methyl-N-(2-pyridinyl)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide (Piroxicam) have been recorded in the region 4000-400 and 4000-100cm(-1) respectively. The molecular geometry, harmonic vibrational frequencies and bonding features of piroxicam in the ground state have been calculated by Hartree-Fock (HF) and density functional theory (DFT) methods using 6-311++G(d,p) basis set. The calculated harmonic vibrational frequencies are scaled and they are compared with experimental obtained by FT-IR and FT-Raman spectra. A detailed interpretation of the vibrational spectra of the title compound has been made on the basis of the calculated potential energy distribution (PED). The electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MESP) are also performed. The linear polarizability (α) and the first order hyper polarizability (β) values of the title compound have been computed. The molecular stability arising from hyper conjugative interaction, charge delocalization has been analyzed using natural bond orbital (NBO) analysis.

  13. Comparison of power Doppler and thermography for the selection of thyroid nodules in which fine-needle aspiration biopsy is indicated*

    PubMed Central

    Alves, Maria Lucia D'Arbo; Gabarra, Manoel Henrique Cintra

    2016-01-01

    Objective To compare two methods-power Doppler and thermography-for the analysis of nodule vascularization and subsequent selection of nodules to be biopsied. Materials and Methods A total of 510 subjects with thyroid nodules were analyzed by power Doppler and submitted to fine-needle aspiration biopsy (FNAB). Thirty-seven patients were submitted to nodule excision (29 due to carcinoma or suspected carcinoma and 8 by patient choice). Among those patients, power Doppler had raised the suspicion of malignancy in 39 lesions, compared with 48 for FNAB. Another group, comprising 110 patients, underwent thermography, which raised the suspicion of malignancy in 124 thyroid nodules, as did FNAB. Malignant nodules were excised in all 110 of those patients (95 underwent nodulectomy and 15 underwent thyroidectomy), malignancy being confirmed by intraoperative examination of frozen biopsy samples. Results In relation to the FNAB findings, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of power Doppler were 95.16%, 23.52%, 96.22%, 16.70%, and 89.51%, respectively, compared with 100%, 58.06%, 87.73%, 100%, and 89.51%, respectively, for thermography. Conclusion Thermography was more precise than was power Doppler for the selection of thyroid nodules to be biopsied. PMID:27818545

  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. 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.

  16. Measuring the temperature of high-luminous exitance surfaces with infrared thermography in LED applications

    NASA Astrophysics Data System (ADS)

    Perera, Indika U.; Narendran, Nadarajah

    2016-09-01

    Recently, light-emitting diode (LED) lighting systems have become popular due to their increased system performance. LED lighting system performance is affected by heat; therefore, it is important to know the temperature of a target surface or bulk medium in the LED system. In-situ temperature measurements of a surface or bulk medium using intrusive methods cause measurement errors. Typically, thermocouples are used in these applications to measure the temperatures of the various components in an LED system. This practice leads to significant errors, specifically when measuring surfaces with high-luminous exitance. In the experimental study presented in this paper, an infrared camera was used as an alternative to temperature probes in measuring LED surfaces with high-luminous exitance. Infrared thermography is a promising method because it does not respond to the visible radiation spectrum in the range of 0.38 to 0.78 micrometers. Usually, infrared thermography equipment is designed to operate either in the 3 to 5 micrometer or the 7 to 14 micrometer wavelength bands. To characterize the LED primary lens, the surface emissivity of the LED phosphor surface, the temperature dependence of the surface emissivity, the temperature of the target surface compared to the surrounding temperature, the field of view of the target, and the aim angle to the target surface need to be investigated, because these factors could contribute towards experimental errors. In this study, the effects of the above-stated parameters on the accuracy of the measured surface temperature were analyzed and reported.

  17. 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.

  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. 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

  20. The use of IR thermography to show the mold and part temperature evolution in injection molding

    NASA Astrophysics Data System (ADS)

    Bula, Karol; Różański, Leszek; Marciniak-Podsadna, Lidia; Wróbel, Dawid

    2016-12-01

    This study concerns the application of infrared camera for injection molding analysis by measuring temperatures of both injection molded parts and injection mold cavities in a function of injection cycles. The mold with two cavities, differing in thickness (1 and 3 mm), and a cold direct runner was used. Isotactic polypropylene homopolymer was utilized to produce parts. Mold temperature was set at 22°C and controlled by a water chiller. Five measuring points were determined: SP1, SP2 (placed in the 3 mm cavity), SP3, SP4 (located in the 1 mm cavity) and SP5 around an injection molding gate. Our investigations showed that the highest temperature is localized around SP2 point and the lowest at SP4. Also, it was proved that even after 62 injection molding cycles, temperatures of cavities were not stable, revealing their further increase with each cycle.

  1. Comparison of ultrasonic velocity and IR thermography for the characterisation of stones

    NASA Astrophysics Data System (ADS)

    Grinzato, E.; Marinetti, S.; Bison, P. G.; Concas, M.; Fais, S.

    2004-12-01

    Preliminary results of a study aiming to implement a new non-destructive methodology about physical and elastic characteristics of building materials are presented. Our target is to assess the state of decay of wall stones by means of the correlation of thermal and elastic waves. At first, thermal diffusivity and ultrasound velocities have been measured on samples of known mechanical properties. An effective testing procedure for the evaluation of the stone durability has been performed on a historical Church. In particular, the variation of ultrasonic velocity mainly due to cracks is mapped and compared with thermographic readings.

  2. IR thermography applied to the assessment of thermal conductivity of building materials

    NASA Astrophysics Data System (ADS)

    Bison, P.; Grinzato, E.

    2010-05-01

    A device to measure thermal conductivity of small specimens is presented. The specimen is sandwiched between two thermoelectric cells, one sources heat the other sink it. An infrared camera looks at the device and specimen on its side, determining both the heat flux flowing through it and the temperature gradient due to the unknown thermal resistance. The thermal conductivity is quickly recovered, as soon as the steady thermal regime is reached. The heat flux toward the environment is evaluated and minimized working at zero mean temperature difference. A couple of specimens made of materials used to prepare radiant heating floor screeds are measured. The Maxwell model to determine the thermal conductivity of mixture, based on the knowledge of the conductivity of the different phases and their volume fraction, is used to interpret the results.

  3. 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

    2014-12-24

    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.

  4. Noninvasive thermography of laser-induced hyperthermia using magnetic resonance

    NASA Astrophysics Data System (ADS)

    Maswadi, Saher M.; Glickman, Randolph D.; Dodd, Stephen J.; Gao, Jia Hong

    2004-07-01

    The possibility to induce selective hyperthermia in a target tissue or organ is of great interest for the treatment of cancer and other diseases. An emerging application of thermotherapy is for choroidal neovascularization, a complication of age-related macular degeneration. The therapy is currently limited because the temperature required for optimal tissue response is unknown. We report here an investigation of near infrared laser-induced heating in an ocular phantom. Magnetic resonance thermography (MRT) was used as a non-invasive method to determine the temperature distribution inside the phantom during exposure to a continuous wave diode laser at 806 nm wavelength with 1 watt maximum output. The laser beam had a quasi-gaussian profile, with a radius of 0.8-2.4 mm at target. High quality temperature images were obtained from temperature-dependent phase shifts in the proton resonance frequency with a resolution of 1deg C or better, using a 2T magnet. A phantom with a layer of bovine RPE melanin of 1.5 mm thickness was used to determine the spatial resolution of the MRT measurements. Three dimensional temperature maps were also constructed showing a spatial resolution of 0.25 mm in all direction. The heat distribution depended on the laser parameters, as well as the orientation of the melanin layer with respect to the incident laser beam. The temperature profiles determined by MRT closely followed predictions of a heat diffusion model, based on the optical properties of infrared light in melanin. These results support the use of MRT to optimize laser-induced hyperthermia in a small organ such as the eye.

  5. Mapping the body surface temperature of cattle by infrared thermography.

    PubMed

    Salles, Marcia Saladini Vieira; da Silva, Suelen Corrêa; Salles, Fernando André; Roma, Luiz Carlos; El Faro, Lenira; Bustos Mac Lean, Priscilla Ayleen; Lins de Oliveira, Celso Eduardo; Martello, Luciane Silva

    2016-12-01

    Infrared thermography (IRT) is an alternative non-invasive method that has been studied as a tool for identifying many physiological and pathological processes related to changes in body temperature. The objective of the present study was to evaluate the body surface temperature of Jersey dairy cattle in a thermoneutral environment in order to contribute to the determination of a body surface temperature pattern for animals of this breed in a situation of thermal comfort. Twenty-four Jersey heifers were used over a period of 35 days at APTA Brazil. Measurements were performed on all animals, starting with the physiological parameters. Body surface temperature was measured by IRT collecting images in different body regions: left and right eye area, right and left eye, caudal left foreleg, cranial left foreleg, right and left flank, and forehead. High correlations were observed between temperature and humidity index (THI) and right flank, left flank and forehead temperatures (0.85, 0.81, and 0.81, respectively). The IRT variables that exhibited the five highest correlation coefficients in principal component 1 were, in decreasing order: forehead (0.90), right flank (0.87), left flank (0.84), marker 1 caudal left foreleg (0.83), marker 2 caudal left foreleg (0.74). The THI showed a high correlation coefficient (0.88) and moderate to low correlations were observed for the physiological variables rectal temperature (0.43), and respiratory frequency (0.42). The thermal profile obtained indicates a surface temperature pattern for each region studied in a situation of thermal comfort and may contribute to studies investigating body surface temperature. Among the body regions studied, IRT forehead temperature showed the highest association with rectal temperature, and forehead and right and left flank temperatures are strongly associated with THI and may be adopted in future studies on thermoregulation and body heat production.

  6. 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.

  7. Assessing feed efficiency in beef steers through feeding behavior, infrared thermography and glucocorticoids.

    PubMed

    Montanholi, Y R; Swanson, K C; Palme, R; Schenkel, F S; McBride, B W; Lu, D; Miller, S P

    2010-05-01

    A better understanding of the factors regulating feed efficiency and their potential as predictors of feed efficiency in cattle is needed. Therefore, the potential of three classes of traits, namely, feeding behavior characteristics: daily time at feeder (TF; min/day), time per meal (TM; min), meal size (MS; g DM), eating rate (ER; g DM/min), number of daily meals (NM) and daily visits to the feeder (VF); infrared (IR) thermography traits (°C): eye (EY), cheek (CK), snout (SN), ribs (RB) and hind area (HA); and glucocorticoid levels: fecal cortisol metabolites (FCM; ng/g) and plasma cortisol (PC; ng/ml) as predictors of efficiency were evaluated in 91 steers (436 ± 37 kg) over 2 years (Y1 = 46; Y2 = 45). Additionally, the individual traits of each of these three classes were combined to define three single traits. Individual daily feed intake of a corn silage and high-moisture corn-based diet was measured using an automated feeding system. Body weight and thermographs were taken every 28 days over a period of 140 days. Four productive performance traits were calculated: daily dry matter intake (DMI), average daily gain (ADG), feed to gain ratio (F : G) and residual feed intake (RFI). Steers were also classified into three RFI categories (low-, medium- and high-RFI). Among the feeding behavior characteristics, MS and ER were correlated with all efficiency traits (range: 0.26 to 0.75). Low-RFI (more efficient steers) had smaller MS, lower ER and fewer VF in comparison to high-RFI steers. Less efficient steers (high-RFI) performed more VF during the nocturnal period than more efficient steers. More efficient steers had lower CK and SN temperatures than less efficient steers (28.1°C v. 29.2°C and 30.0°C v. 31.2°C), indicating greater energetic efficiency for low-RFI steers. In terms of glucocorticoids, PC was not correlated with efficiency traits. In contrast, more efficient steers had higher FCM in comparison to less efficient steers (51.1 v. 31.2 ng

  8. Insights into the use of thermography to assess burn wound healing potential: a reliable and valid technique when compared to laser Doppler imaging

    NASA Astrophysics Data System (ADS)

    Jaspers, Mariëlle E. H.; Maltha, Ilse; Klaessens, John H. G. M.; de Vet, Henrica C. W.; Verdaasdonk, Rudolf M.; van Zuijlen, Paul P. M.

    2016-09-01

    Adequate assessment of burn wounds is crucial in the management of burn patients. Thermography, as a noninvasive measurement tool, can be utilized to detect the remaining perfusion over large burn wound areas by measuring temperature, thereby reflecting the healing potential (HP) (i.e., number of days that burns require to heal). The objective of this study was to evaluate the clinimetric properties (i.e., reliability and validity) of thermography for measuring burn wound HP. To evaluate reliability, two independent observers performed a thermography measurement of 50 burns. The intraclass correlation coefficient (ICC), the standard error of measurement (SEM), and the limits of agreement (LoA) were calculated. To assess validity, temperature differences between burned and nonburned skin (ΔT) were compared to the HP found by laser Doppler imaging (serving as the reference standard). By applying a visual method, one ΔT cutoff point was identified to differentiate between burns requiring conservative versus surgical treatment. The ICC was 0.99, expressing an excellent correlation between two measurements. The SEM was calculated at 0.22°C, the LoA at -0.58°C and 0.64°C. The ΔT cutoff point was -0.07°C (sensitivity 80% specificity 80%). These results show that thermography is a reliable and valid technique in the assessment of burn wound HP.

  9. Transient-spatial pattern mining of eddy current pulsed thermography using wavelet transform

    NASA Astrophysics Data System (ADS)

    Yang, Hailong; Gao, Bin; Tian, Guiyun; Ren, Wenwei; Woo, Wai Lok

    2014-07-01

    Eddy current pulsed thermography(ECPT) is an emerging Non-destructive testing and evaluation(NDT & E) technique, which uses hybrid eddy current and thermography NDT & E techniques that enhances the detectability from their compensation. Currently, this technique is limited by the manual selection of proper contrast frames and the issue of improving the efficiency of defect detection of complex structure samples remains a challenge. In order to select a specific frame from transient thermal image sequences to maximize the contrast of thermal variation and defect pattern from complex structure samples, an energy driven approach to compute the coefficient energy of wavelet transform is proposed which has the potential of automatically selecting both optimal transient frame and spatial scale for defect detection using ECPT. According to analysis of the variation of different frequency component and the comparison study of the detection performance of different scale and wavelets, the frame at the end of heating phase is automatically selected as an optimal transient frame for defect detection. In addition, the detection capabilities of the complex structure samples can be enhanced through proper spatial scale and wavelet selection. The proposed method has successfully been applied to low speed impact damage detection of carbon fibre reinforced polymer(CFRP) composite as well as providing the guidance to improve the detectability of ECPT technique.

  10. 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

  11. Inspection of disbonds in multilayer dissimilar metal structure using lock-in thermography.

    PubMed

    Zhou, Zhenggan; Zhao, Hanxue; Sun, Guangkai; He, Pengfei; Fan, Jin; Li, Gen

    2016-06-01

    This paper reports the characterization of disbonds between a steel plate and a lead plate on the surface of the lead using lock-in thermography. Based on the photothermal model, the excitation frequency of the bonding specimen with the steel plate and the lead plate is optimized. A lock-in thermography testing system is established to inspect the specimen. The Fourier transform method is used to process the infrared image sequences. To improve the signal-to-noise ratio (SNR), a fuzzy c-means (FCM) algorithm is used to process the phase matrix. The influence of number of clusters on the processing results is researched, and the optimal value of clusters number is obtained. The shearing phase technique is used to evaluate the size of the disbonds quantitatively. The measurement results of the artificial disbonds in the specimen show good agreement with the actual values. The results prove that FCM is effective in enhancing the SNR of the phase image, which makes it feasible for the quantitative determination of defect size by the shearing phase technique.

  12. 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.

  13. Detection of delamination defect inside timber by sonic IR

    NASA Astrophysics Data System (ADS)

    Choi, M. Y.; Park, J. H.; Kim, W. T.; Kang, K. S.

    2008-03-01

    In ultrasound excitation thermography, the injected ultrasound to an object is transformed to heat by thermo-structure effect and internal friction. The advantage of this technique is selectively sensitive to thermally active defects. The appearance of defects, which can be visualized by thermography camera, depends strongly on the method of excitation. In preliminary studies, ultrasonic excitation horns of ultrasonic manufacturing process are widely adopted for a polymer structure. However, it is needed that these horns are modified for improving the defect detection capability. This paper proposes a new ultrasonic excitation horns with tuning fork shape in NDT of wood material. Geometric conditions are optimized by FEA and application results by the developed horn are described and compared with those by a previous horn.

  14. 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

  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.

  16. 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.

  17. Reflex sympathetic dystrophy of upper extremity: a new diagnostic approach using Flexi-Therm liquid crystal thermography

    PubMed Central

    Kobrossi, T.; Steiman, I.

    1986-01-01

    A case of reflex sympathetic dystrophy syndrome (RSDA), diagnosed by liquid crystal contact thermography (LCT) is presented. The pathogenesis, diagnosis and treatment of the syndrome are reviewed having regard to liquid crystal thermography. ImagesFigure 1

  18. Calculating the melting curves by the thermodynamic data matching method: Platinum-group refractory metals (Ru, Os, and Ir)

    NASA Astrophysics Data System (ADS)

    Kulyamina, E. Yu.; Zitserman, V. Yu.; Fokin, L. R.

    2017-01-01

    A technique for reconstructing thermal properties, including the melting curve, of refractory metals based on the use of experimental data on caloric properties available up to the melting point and some regularities of the Debye-Grüneisen theory has been proposed. The calculation result is the consistent system of high-temperature thermal data, including the thermal expansion coefficient, solid-phase density, and volume jump upon melting. This technique was tried-out on refractory platinum-group metals based on experimental data on the enthalpy of the metals and confirmed by consistency with a thermodynamic calculation using shock-wave experiments and results obtained by the quantum molecular dynamics method.

  19. 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

    2016-01-01

    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.

  20. 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.

  1. International standards pertaining to thermography practices, training and certification

    NASA Astrophysics Data System (ADS)

    West Åkerblom, Lisa

    2008-03-01

    American, European and International societies establish standards for individuals and companies within the field of infrared thermography. Historically addressing non-destructive testing (NDT) applications and personnel, standards exist and are being developed within the fields of condition monitoring (CM) and building diagnostics. Incorrect reference to or application of standards and guidelines create widespread market confusion. What type of claim can be made against which standards? Does the standard apply to a company or an individual? To what or whom is the standard intended? Does reference to a standard guarantee compliance or imply quality? How does one become educated or involved in standards? An overview of international standards within the field of thermography (with brief reference to recognizable guidelines and standards such as ASNT SNT-TC-1A and CEN 473), their status and application will be presented.

  2. Roles For Thermography In Utility Company Residential Energy Audits

    NASA Astrophysics Data System (ADS)

    Schott, William A.

    1981-01-01

    Basin Electric Power Cooperative, Bismarck, North Dakota, provides wholesale electricity to more than 100 rural electric cooperatives of the Missouri Pasin Region. The Cooperative, in cooperation with Aadland*Hoffmann*Pieri Energy Associates, Inc., Minneapolis, MN has developed a three-fold program which involves the analytical approach, the instructional approach and the motivational approach (A'IsM) to an energy audit. This three-fold program utilizes infrared thermography to pinpoint where heat loss is occurring in the home. The auditor can motivate the homeowner to initiate energy conserving improvements and practices by showing where money can be saved. Infrared thermography is a most valuable tool in helping the rural electrics conserve energy and the nation's natural resources. Over 180 energy auditors have been trained through this program in this area and 5,000 trained in the nation.

  3. Multiplexing thermography for International Thermonuclear Experimental Reactor divertor targets

    SciTech Connect

    Itami, K.; Sugie, T.; Vayakis, G.; Walker, C.

    2004-10-01

    The concept of multiplexing thermography is applied to the design of the divertor thermography system for International Thermonuclear Experimental Reactor (ITER). The combination of the front mirror with multiellipticity and a Czerney-Turner spectrometer with a 0.2 mm pitched multichannel detector enables a spatial resolution of 3 mm and a time resolution of 20 {mu}s above a target temperature of 300 deg. C to be achieved. This should be sufficient to measure ELM heat fluxes to the targets in ITER. To satisfy the measurement requirement, it is very important to keep an accurate alignment around the optical axis against movement of the vessel during the plasma discharges. Several key engineering problems, such as the survivability of components against mirror coating by redeposited divertor material, remain to be solved. Potential solutions have been identified.

  4. 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.

  5. 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.

  6. Efficiency of thermography in the study of hydrological connectivity

    NASA Astrophysics Data System (ADS)

    Cantreul, Vincent; Burgeon, Victor; Triquet, Johan; Tuerlinck, Manon; Vaelen, Guillaume; Leemans, Vincent; Degré, Aurore

    2016-04-01

    Hydrologic connectivity is an emerging concept which permits deeper understanding of catchments behavior. However, the measurements of functional connectivity is complex and still needs new developments in order to approach the « dynamic » part of the story. This study aims at assessing the efficiency of thermography to analyze hydrologic connectivity in an agricultural catchment in Belgium (loamy soils). Tests have been performed on experimental tubs at first and on field at second. Under controlled conditions, hot milk was spread on an experimental tub with bare soil and grass. The hot milk permits to compare color tracer with thermic one. The results are quite good. The binarization of pictures from usual camera and from thermic one gives similar percentage of runoff coverage at same locations. The mean difference is about 8% for bare soils and 10% for planted grass. There is a slight overestimation with thermic camera because of time delay of soil cooling after milk passing. In the same time in the planted grass, there are some runoff pixels which are hidden by vegetation. On field, blue colored water was used to simulate a rainfall on a field covered with mustard and on the same field without any coverage. Where runoff flows, the soil appears warmer because of heat extracted by water in the soil. The results comparing visual and thermic pictures are more nuanced. The mean difference reaches 30% on bare soil. Indeed, (i) the rainfall drops seem to hide the runoff during the rain; (ii) the vegetation density (mustard) is quite a problem for runoff detection. However, the difference between successive time pictures permits to distinguish flow paths easily. In conclusion, thermography stands as a good alternative for connectivity study. It's obviously a preliminary study which gives some indications of the possible use of thermography. At present, we are testing real rainfalls (different types) with different camera's positions and different land use (different

  7. Infrared thermography: A non-invasive window into thermal physiology.

    PubMed

    Tattersall, Glenn J

    2016-12-01

    Infrared thermography is a non-invasive technique that measures mid to long-wave infrared radiation emanating from all objects and converts this to temperature. As an imaging technique, the value of modern infrared thermography is its ability to produce a digitized image or high speed video rendering a thermal map of the scene in false colour. Since temperature is an important environmental parameter influencing animal physiology and metabolic heat production an energetically expensive process, measuring temperature and energy exchange in animals is critical to understanding physiology, especially under field conditions. As a non-contact approach, infrared thermography provides a non-invasive complement to physiological data gathering. One caveat, however, is that only surface temperatures are measured, which guides much research to those thermal events occurring at the skin and insulating regions of the body. As an imaging technique, infrared thermal imaging is also subject to certain uncertainties that require physical modelling, which is typically done via built-in software approaches. Infrared thermal imaging has enabled different insights into the comparative physiology of phenomena ranging from thermogenesis, peripheral blood flow adjustments, evaporative cooling, and to respiratory physiology. In this review, I provide background and guidelines for the use of thermal imaging, primarily aimed at field physiologists and biologists interested in thermal biology. I also discuss some of the better known approaches and discoveries revealed from using thermal imaging with the objective of encouraging more quantitative assessment.

  8. 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.

  9. ANALYSIS OF IMPACT DAMAGE USING LINE SCANNING THERMOGRAPHY

    SciTech Connect

    Ley, O.; Valatka, T.; Godinez, V.; Chung, S.; Schutte, J.; Dunne, K.; Caiazzo, A.; Bandos, B.

    2010-02-22

    Impact damage in a composite shaft was studied using Line Scanning Thermography (LST), a novel dynamic thermography technique capable of inspecting large areas in short times. It is expected that projectile impact in a laminate composite will generate a discontinuity that affects heat propagation. Therefore, as heat is deposited over the impacted region, a hot spot will be observed. In this study several impact points were evaluated using UT and LST. Experiments show that assessing impact damage using LST is a dynamic process, which should be accounted for when using dynamic thermography to quantify impact damage extension and severity. The LST images provided information about the region affected by impact damage, which was consistent with the damage region determined using UT. It is seen that the damage areas obtained at early observation time after heat application show small areas with severe damage; and for further times after heat application, the temperature of the hot spots drops and the size of the region affected increases with time following a linear relationship with the observation time.

  10. Molecular structure, FT-IR, FT-Raman, NMR studies and first order molecular hyperpolarizabilities by the DFT method of mirtazapine and its comparison with mianserin

    NASA Astrophysics Data System (ADS)

    Sagdinc, Seda G.; Sahinturk, Ayse Erbay

    2013-03-01

    Mirtazapine (±)-1,2,3,4,10,14b-hexahydro-2-methylpyrazino(2,1-a)pyrido(2,3-c)(2)benzazepine is a compound with antidepressant therapeutic effects. It is the 6-aza derivative of the tetracyclic antidepressant mianserin (±)-2-methyl-1,2,3,4,10,14b-hexahydrodibenzo[c,f]pyrazino[1,2-a]azepine. The FT-IR and FT-Raman spectra of mirtazapine have been recorded in 4000-400 cm-1 and 3500-10 cm-1, respectively. The optimized geometry, energies, nonlinear optical properties, vibrational frequencies, 13C, 1H and 15N NMR chemical shift values of mirtazapine have been determined using the density functional theory (DFT/B3LYP) method. A comparison of the experimental and theoretical results of mirtazapine indicates that the density-functional B3LYP method is able to provide satisfactory results for predicting vibrational and NMR properties. The experimental and calculated results for mirtazapine have also been compared with mianserin.

  11. Methodology for High-Throughput Field Phenotyping of Canopy Temperature Using Airborne Thermography.

    PubMed

    Deery, David M; Rebetzke, Greg J; Jimenez-Berni, Jose A; James, Richard A; Condon, Anthony G; Bovill, William D; Hutchinson, Paul; Scarrow, Jamie; Davy, Robert; Furbank, Robert T

    2016-01-01

    Lower canopy temperature (CT), resulting from increased stomatal conductance, has been associated with increased yield in wheat. Historically, CT has been measured with hand-held infrared thermometers. Using the hand-held CT method on large field trials is problematic, mostly because measurements are confounded by temporal weather changes during the time required to measure all plots. The hand-held CT method is laborious and yet the resulting heritability low, thereby reducing confidence in selection in large scale breeding endeavors. We have developed a reliable and scalable crop phenotyping method for assessing CT in large field experiments. The method involves airborne thermography from a manned helicopter using a radiometrically-calibrated thermal camera. Thermal image data is acquired from large experiments in the order of seconds, thereby enabling simultaneous measurement of CT on potentially 1000s of plots. Effects of temporal weather variation when phenotyping large experiments using hand-held infrared thermometers are therefore reduced. The method is designed for cost-effective and large-scale use by the non-technical user and includes custom-developed software for data processing to obtain CT data on a single-plot basis for analysis. Broad-sense heritability was routinely >0.50, and as high as 0.79, for airborne thermography CT measured near anthesis on a wheat experiment comprising 768 plots of size 2 × 6 m. Image analysis based on the frequency distribution of temperature pixels to remove the possible influence of background soil did not improve broad-sense heritability. Total image acquisition and processing time was ca. 25 min and required only one person (excluding the helicopter pilot). The results indicate the potential to phenotype CT on large populations in genetics studies or for selection within a plant breeding program.

  12. Methodology for High-Throughput Field Phenotyping of Canopy Temperature Using Airborne Thermography

    PubMed Central

    Deery, David M.; Rebetzke, Greg J.; Jimenez-Berni, Jose A.; James, Richard A.; Condon, Anthony G.; Bovill, William D.; Hutchinson, Paul; Scarrow, Jamie; Davy, Robert; Furbank, Robert T.

    2016-01-01

    Lower canopy temperature (CT), resulting from increased stomatal conductance, has been associated with increased yield in wheat. Historically, CT has been measured with hand-held infrared thermometers. Using the hand-held CT method on large field trials is problematic, mostly because measurements are confounded by temporal weather changes during the time required to measure all plots. The hand-held CT method is laborious and yet the resulting heritability low, thereby reducing confidence in selection in large scale breeding endeavors. We have developed a reliable and scalable crop phenotyping method for assessing CT in large field experiments. The method involves airborne thermography from a manned helicopter using a radiometrically-calibrated thermal camera. Thermal image data is acquired from large experiments in the order of seconds, thereby enabling simultaneous measurement of CT on potentially 1000s of plots. Effects of temporal weather variation when phenotyping large experiments using hand-held infrared thermometers are therefore reduced. The method is designed for cost-effective and large-scale use by the non-technical user and includes custom-developed software for data processing to obtain CT data on a single-plot basis for analysis. Broad-sense heritability was routinely >0.50, and as high as 0.79, for airborne thermography CT measured near anthesis on a wheat experiment comprising 768 plots of size 2 × 6 m. Image analysis based on the frequency distribution of temperature pixels to remove the possible influence of background soil did not improve broad-sense heritability. Total image acquisition and processing time was ca. 25 min and required only one person (excluding the helicopter pilot). The results indicate the potential to phenotype CT on large populations in genetics studies or for selection within a plant breeding program. PMID:27999580

  13. 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.

  14. 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.

  15. 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.

  16. Vibration characteristics measurement of beam-like structures using infrared thermography

    NASA Astrophysics Data System (ADS)

    Talai, S. M.; Desai, D. A.; Heyns, P. S.

    2016-11-01

    Infrared thermography (IRT) has matured and is now widely accepted as a condition monitoring tool where temperature is measured in a non-contact way. Since the late 1970s, it has been extensively used in vibrothermography (Sonic IR) non-destructive technique for the evaluation of surface cracks through the observation of thermal imaging of the vibration-induced crack heat generation. However, it has not received research attention on prediction of structural vibration behaviour, hence; the concept to date is not understood. Therefore, this paper explores its ability to fill the existing knowledge gap. To achieve this, two cantilever beam-like structures couple with a friction rod subjected to a forced excitations while infrared cameras capturing the thermal images on the friction interfaces. The analysed frictional temperature evolution using the Matlab Fast Fourier Transform (FFT) algorithm and the use of the heat conduction equation in conjunction with a finite difference approach successfully identifies the structural vibration characteristics; with maximum error of 0.28% and 20.71% for frequencies and displacements, respectively. These findings are particularly useful in overcoming many limitations inherent in some of the current vibration measuring techniques applied in structural integrity management such as strain gauge failures due to fatigue.

  17. 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.

  18. Infrared Flash Thermography Applied to the External Defect Detection on Htr Fuel Particles during the Manufacturing Process

    NASA Astrophysics Data System (ADS)

    Hermosilla-Lara, S.; Piriou, M.; Levesque, P.

    2008-02-01

    The authors propose the use of an adapted flash thermography method to perform the online detection of open cracks on high temperature reactor (HTR) fuel. The method consists, via an infrared camera, in the measurement of the particle temperature increase produced by a heating pulse on the particle external surface. Study is performed on laser notches and real cracks located in the different particle layers. It includes the influence of the defect relative position with respect to the heating source, as well as the influence of operating conditions. It is shown that this technique is able to yield good discrimination between sound and flawed particles at a rate that meets production constraints.

  19. 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

  20. 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

    2016-02-16

    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.

  1. 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)

  2. 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.

  3. Experimental (X-ray, FT-IR and UV-vis spectra) and theoretical methods (DFT study) of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol.

    PubMed

    Demircioğlu, Zeynep; Albayrak, Çiğdem; Büyükgüngör, Orhan

    2014-07-15

    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 C=N double bond. The compound adopts a enol-imine tautomeric form with a strong intramolecular O-H⋯N hydrogen bond. The single crystal X-ray diffraction analysis at 296K 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.

  4. Morphological Pattern Classification System for Plantar Thermography of Patients with Diabetes

    PubMed Central

    Mori, Taketoshi; Nagase, Takashi; Takehara, Kimie; Oe, Makoto; Ohashi, Yumiko; Amemiya, Ayumi; Noguchi, Hiroshi; Ueki, Kohjiro; Kadowaki, Takashi; Sanada, Hiromi

    2013-01-01

    Background A plantar temperature distribution can be obtained by thermography; however, the advantage has not been effectively utilized in the past. We previously proposed a classification method based on the angiosome concept, but the method was insufficient because it was too subjective and complicated for clinicians. In this study, we propose a new classification system of plantar forepart thermographic patterns using an image segmentation technique. Methods A cross-sectional observational study was conducted including 32 healthy volunteers and 129 patients with diabetes mellitus (DM). Individual thermographic variations and trends were evaluated. A comparison was conducted between the patterns obtained by our previous angiosome-based research and the patterns found by the new classification system. Results The system objectively found wider variations of the plantar forepart thermographic patterns in the patients with DM compared with those in the control subjects. In patients with DM, the system showed that the whole-high pattern was most frequent (46%), followed by the butterfly pattern (12%). In the control group, the butterfly pattern was most frequent (44%), followed by the whole-high pattern (19%). Both ankle and toe brachial indices were higher in feet with high temperature area in the inner side of the plantar. Conclusions Thermographic patterns found by the new computer-based system were similar to those obtained in our previous subjective work. The classification system found forefoot-low pattern and tiptoe-low pattern objectively. The system based on infrared thermography will be a screening tool to assess circulatory status in daily foot care of patients with DM. PMID:24124935

  5. 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.

  6. 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.

  7. [The importance of thermography in the diagnosis of lumbar radicular pain syndromes].

    PubMed

    Hildebrandt, J; Horst-Schaper, G; Kaiser, G

    1987-03-01

    This study proved the existence of lateral differences in thermographic recordings of the legs of 83 out of a total of 84 patients with the clinical diagnosis "lumbar disk herniation". In 68.5 per cent only of 71 patients with unilateral symptoms, however, the hypothermic areas occurred in the symptomatic leg. These areas could not be matched with corresponding dermatomas. As regards determination of the level of the herniation, thermography is an unreliable method for differentiation between the different segments, because the site of the dermatoma cannot be identified in relation to the site of the herniation. The mechanism of difference in temperature distribution probably depends on sympathetic reflexes with increased activity in the vasoconstrictor system due to pain. These reflexes are not limited to one dermatoma. This has been confirmed by means of diagnostic nerve blocks of the appropriate root.

  8. 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.

  9. Monitoring of fatigue damage in metal plates by acoustic emission and thermography

    NASA Astrophysics Data System (ADS)

    Kordatos, E. Z.; Aggelis, D. G.; Matikas, T. E.

    2011-04-01

    Acoustic Emission (AE) supplies information on the fracturing behavior of different materials. In this study, AE activity was recorded during fatigue experiments in metal CT specimens with a V-shape notch which were loaded in fatigue until final failure. AE parameters exhibit a sharp increase approximately 1000 cycles before than final failure. Therefore, the use of acoustic emission parameters is discussed both in terms of characterization of the damage mechanisms, as well as a tool for the prediction of ultimate life of the material under fatigue. Additionally, an innovative nondestructive methodology based on lock-in thermography is developed to determine the crack growth rate using thermographic mapping of the material undergoing fatigue. The thermographic results on the crack growth rate of aluminium alloys were then correlated with measurements obtained by the conventional compliance method, and found to be in agreement.

  10. 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.

  11. 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

  12. From Ultrafast Structure Determination to Steering Reactions: Mixed IR/Non-IR Multidimensional Vibrational Spectroscopies.

    PubMed

    van Wilderen, Luuk J G W; Bredenbeck, Jens

    2015-09-28

    Ultrafast multidimensional infrared spectroscopy is a powerful method for resolving features of molecular structure and dynamics that are difficult or impossible to address with linear spectroscopy. Augmenting the IR pulse sequences by resonant or nonresonant UV, Vis, or NIR pulses considerably extends the range of application and creates techniques with possibilities far beyond a pure multidimensional IR experiment. These include surface-specific 2D-IR spectroscopy with sub-monolayer sensitivity, ultrafast structure determination in non-equilibrium systems, triggered exchange spectroscopy to correlate reactant and product bands, exploring the interplay of electronic and nuclear degrees of freedom, investigation of interactions between Raman- and IR-active modes, imaging with chemical contrast, sub-ensemble-selective photochemistry, and even steering a reaction by selective IR excitation. We give an overview of useful mixed IR/non-IR pulse sequences, discuss their differences, and illustrate their application potential.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Mammography, thermography, and ultrasound in breast cancer detection

    SciTech Connect

    Basset, L.W.; Gold, R.H.

    1982-01-01

    The book begins with a brief discussion of the history of mammography and a good review and discussion of the mammorgraphy controversy. The section on diagnosis is excellent with very good anatomic-pathologic correlation of the mammography signs. The preoperative localization is well described. Section 3 on performing the examination is an excellent discussion of the various modes of mammography and their techniques. Magnification mammography, computed tomographic mammography, thermography, sonomammography, and ductography are very well covered. In Section 4, the benefits and risk of mammography are well discussed enabling the reader to understand the controversy surrounding breast cancer detection techniques.

  18. Use of thermography to screen for subclinical bumblefoot in poultry.

    PubMed

    Wilcox, C S; Patterson, J; Cheng, H W

    2009-06-01

    Thermographic imaging is a noninvasive diagnostic tool used to document the inflammatory process in many species and may be useful in the detection of subclinical bumblefoot and other inflammatory diseases. Bumblefoot is a chronic inflammation of the plantar metatarsal or digital pads of the foot (pododermatitis), or both. It is one of the major health problems in birds including chickens and is responsible for significant economic losses in commercial poultry operations. Early diagnosis of bumblefoot is essential for the prevention of economical loss and the improvement of animal well-being. The object of this study was to determine the suitability of thermography for the identification of subclinical bumblefoot in chickens. Experiment 1 was designed to validate thermography as a tool for screening avian populations for bumblefoot. The plantar surface of the feet of 150 randomly selected hens was imaged using a thermal camera. The thermal images were identified as suspect, positive, or negative for bumblefoot based on thermal patterns of the plantar surface. Visual inspection of the feet identified as suspect followed 14 d later. A visual score of clinical, mildly clinical, or negative for bumblefoot was assigned, based on gross pathological changes in the plantar surface. A correlation between initial thermal images identified as suspect for bumblefoot and a visual score of positive 14 d later was 83% (P < 0.01). In experiment 2, hens whose feet were free of lesions were inoculated in the metatarsal foot pad with Staphylococcus aureus. Thermal images and visual clinical scores were taken, prechallenge and 1, 2, 3, 4, and 7 d postchallenge. The correlation between thermal images classified as clinical and a visual score of clinical for bumblefoot was 86.7% (P < 0.001). However, the correlation between the thermal images classified as mild (subclinical) and a visual score of mild was only 26.7%, suggesting that thermography is a more sensitive indicator of

  19. Defect depth measurement of carbon fiber reinforced polymers by thermography

    NASA Astrophysics Data System (ADS)

    Chen, Terry Y.; Chen, Jian-Lun

    2016-01-01

    Carbon fiber reinforced polymers has been widely used in all kind of the industries. However the internal defects can result in the change of material or mechanical properties, and cause safety problem. In this study, step-heating thermography is employed to measure the time series temperature distribution of composite plate. The principle of heat conduction in a flat plate with defect inside is introduced. A temperature separation criterion to determine the depth of defect inside the specimen is obtained experimentally. Applying this criterion to CFRP specimens with embedded defects, the depth of embedded defect in CFRP can be determined quite well from the time series thermograms obtained experimentally.

  20. 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.

  1. Finite Element Modeling of Transient Thermography Inspection of Composite Materials

    NASA Technical Reports Server (NTRS)

    Chu, Tsuchin Philip

    1998-01-01

    Several finite element models of defects such as debond and void have been developed for composite panels subjected to transient thermography inspection. Since the exact nature of the heat generated from the flash lamps is unknown, direct comparison between FEA and experimental results is not possible. However, some similarity of the results has been observed. The shape of the time curve that simulates the heat flux from the flash lamps has minimal effect on the temperature profiles. Double the number of flash lamps could increase the contrast of thermal image and define the shape of defect better.

  2. [Use of distant thermography in uveitis in children].

    PubMed

    Khvatova, A V; Katargina, L A; Lokhmanov, V P; Zibarov, I N

    1991-01-01

    Forty-four children aged 6 months to 14 years, suffering from endogenous uveitis of various sites were examined at different phases of the diseases by a scanning type apparatus, AGA-780M-thermographer (Sweden). The results permit a conclusion that long-distance thermography may be effectively used to assess the ocular status even in small restless children. Uveitis active phase was found associated with a hyperthermal reaction in all the examined sites. Hyperthermia was found related to uveitis localization. The authors suggest that thermoasymmetry parameters and the corneolimbic gradient be used as additional objective criteria for the assessment of uveitis activity and dissemination in children.

  3. Modeling static and dynamic thermography of the human breast under elastic deformation.

    PubMed

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

    2011-01-07

    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.

  4. Characterization of emission microscopy and liquid crystal thermography in IC fault localization

    NASA Astrophysics Data System (ADS)

    Lau, C. K.; Sim, K. S.

    2013-05-01

    This paper characterizes two fault localization techniques - Emission Microscopy (EMMI) and Liquid Crystal Thermography (LCT) by using integrated circuit (IC) leakage failures. The majority of today's semiconductor failures do not reveal a clear visual defect on the die surface and therefore require fault localization tools to identify the fault location. Among the various fault localization tools, liquid crystal thermography and frontside emission microscopy are commonly used in most semiconductor failure analysis laboratories. Many people misunderstand that both techniques are the same and both are detecting hot spot in chip failing with short or leakage. As a result, analysts tend to use only LCT since this technique involves very simple test setup compared to EMMI. The omission of EMMI as the alternative technique in fault localization always leads to incomplete analysis when LCT fails to localize any hot spot on a failing chip. Therefore, this research was established to characterize and compare both the techniques in terms of their sensitivity in detecting the fault location in common semiconductor failures. A new method was also proposed as an alternative technique i.e. the backside LCT technique. The research observed that both techniques have successfully detected the defect locations resulted from the leakage failures. LCT wass observed more sensitive than EMMI in the frontside analysis approach. On the other hand, EMMI performed better in the backside analysis approach. LCT was more sensitive in localizing ESD defect location and EMMI was more sensitive in detecting non ESD defect location. Backside LCT was proven to work as effectively as the frontside LCT and was ready to serve as an alternative technique to the backside EMMI. The research confirmed that LCT detects heat generation and EMMI detects photon emission (recombination radiation). The analysis results also suggested that both techniques complementing each other in the IC fault localization

  5. 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

  6. The use of thermography in early detection of tissue perfusion disorders in rats

    PubMed Central

    Łokaj, Marek; Falkowski, Aleksander; Prowans, Piotr

    2014-01-01

    Introduction Tissue perfusion disorders can be present in various diseases and progress in the form of arterial ischemia or venous stasis with accompanying local changes in temperature. Aim To use of thermography in the diagnostics of early periods of tissue perfusion disorders before the clinical symptoms occur. Material and methods Thirty-two male rats were used. After anesthesia the skin on lower limbs was shaved and femoral vessels of both sides were exposed. In 10 rats the left femoral artery was ligated, in 12 rats the left femoral vein was ligated and in the 10 remaining rats both left femoral vessels were ligated. Thermography of the limbs was performed before the vessels were ligated and after a period of 24 h. The pictures were taken every 5 s during 3 min. Before the measurement, the tissues were cooled down for 20 s with a 5°C water compress. The rate of temperature return to the limbs was evaluated. Results Statistically significant differences were observed after the 24-hour period on the thigh after the ligation of the vein, and on the shank and the foot after ligation of the artery. After the ligature of both vessels, statistically significant differences occurred immediately after their ligature within the thigh and shank and after 24 h on the foot. Conclusions The results show that cameras with an accuracy of 0.05°C can be used to detect tissue perfusion disorders. The special diagnostic value is the ability to detect perfusion disorders before clinical symptoms occur. PMID:25337154

  7. 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.

  8. 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

  9. 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.

  10. Infrared thermography as option for evaluating the treatment effect of percutaneous transluminal angioplasty by patients with peripheral arterial disease.

    PubMed

    Staffa, Erik; Bernard, Vladan; Kubicek, Lubos; Vlachovsky, Robert; Vlk, Daniel; Mornstein, Vojtech; Bourek, Ales; Staffa, Robert

    2017-02-01

    Aim of this study was to evaluate the possible use of infrared thermography as a supplementary method to the ankle-brachial index used in assessing the treatment effect of percutaneous transluminal angioplasty. The study included 21 patients, mean age was 60.22 years. Healthy control group included 20 persons, mean age was 55.60 years. Patients with symptomatic peripheral arterial disease (Fontaine stages I-III) were admitted for endovascular treatment by percutaneous transluminal angioplasty. Thermal images and ankle-brachial index values were obtained before and after treatment by percutaneous transluminal angioplasty. Median temperature change in the treated limb was 0.4℃, for non-treated limb was -0.5℃. The median value of ankle-brachial index in the treated limb increased by 0.17 from 0.81 after the procedure. The median value of ankle-brachial index in the non-treated limb decreased by 0.03 from the value of 1.01. Significant difference between treated limb and non-treated limb in change of ankle-brachial index was found with p value = .0035. The surface temperature obtained by the infrared thermography correlates with ankle-brachial index. We present data showing that the increase of ankle-brachial index is associated with increase of skin temperature in the case of limbs treated by percutaneous transluminal angioplasty. Our results also suggest potential of the use of infrared thermography for monitoring foot temperature as a means of early detection of onset of foot ischemic disorders.

  11. 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.

  12. 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.

  13. 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.

  14. Finite Element Modeling for Infrared Thermography of Gfrp Bridge Decks

    NASA Astrophysics Data System (ADS)

    Hing, Cheng L.; Halabe, Udaya B.

    2008-02-01

    Glass Fiber Reinforced Polymer (GFRP) composite bridge decks are increasingly being used as replacements for old concrete decks and for new construction. The service performance of the GFRP bridge decks can be adversely affected by the formation of debonds between the wearing surface and the underlying bridge deck. Past experimental studies by the authors have shown the usefulness of the infrared thermography technique in detecting the subsurface debonds prior to maintenance and rehabilitation work. This paper investigates the use of finite element (FE) heat transfer modeling to predict infrared thermography images from GFRP bridge decks with subsurface debonds. The paper includes measurement of thermal properties of the GFRP bridge deck and the wearing surface, and heat transfer FE modeling of decks with debonds of different thicknesses. The results show that FE modeling can be a useful tool for predicting surface temperature profile under different heating conditions and debond sizes. Such predictions can help determine the required heat intensity and detectable debond sizes prior to experimental data acquisition in the field using an infrared camera.

  15. Nde of Frp Wrapped Columns Using Infrared Thermography

    NASA Astrophysics Data System (ADS)

    Halabe, Udaya B.; Dutta, Shasanka Shekhar; GangaRao, Hota V. S.

    2008-02-01

    This paper investigates the feasibility of using Infrared Thermography (IRT) for detecting debonds in Fiber Reinforced Polymer (FRP) wrapped columns. Laboratory tests were conducted on FRP wrapped concrete cylinders of size 6″×12″ (152.4 mm×304.8 mm) in which air-filled and water-filled debonds of various sizes were placed underneath the FRP wraps. Air-filled debonds were made by cutting plastic sheets into the desired sizes whereas water-filled debonds were made by filling water in custom made polyethylene pouches. Both carbon and glass fiber reinforced wraps were considered in this study. Infrared tests were conducted using a fully radiometric digital infrared camera which was successful in detecting air-filled as well as water-filled subsurface debonds. In addition to the laboratory testing, two field trips were made to Moorefield, West Virginia for detecting subsurface debonds in FRP wrapped timber piles of a railroad bridge using infrared testing. The results revealed that infrared thermography can be used as an effective nondestructive evaluation tool for detecting subsurface debonds in structural components wrapped with carbon or glass reinforced composite fabrics.

  16. Automatic Detection of Subsurface Defects Using Infrared Thermography

    NASA Astrophysics Data System (ADS)

    Lonkar, G. M.; Klinkhachorn, P.; Halabe, Udaya B.; GangaRao, H. V. S.

    2005-04-01

    The popularity of FRP bridge decks has increased in recent times because of their high strength to weight ratio, fatigue resistance etc. Defects due to degradation of the bridge deck malign their properties and adversely affect the structural integrity. These defects need to be detected and continuously monitored using field techniques such as infrared thermography. The process of manually analyzing the infrared images is tedious and ambiguous. Instead, using software algorithms on the infrared images of FRP decks can increase the defect detection speed and accuracy. This paper proposes a software automated defect detection technique to detect subsurface anomalies in fiber reinforced polymer (FRP) bridge decks. Thermal images of the FRP decks were captured using a radiometric infrared camera. Software algorithms using morphological image processing and fuzzy clustering techniques were developed to analyze the images for detecting the defects automatically. They were tested on infrared images of FRP bridge decks prepared in the laboratory. In the tests conducted, simulated subsurface defects of varying size, thickness and wearing surfaces were fabricated in the laboratory. The tests include a performance analysis of detecting delaminations and debonds, and the effect of distance on the detecting ability of the algorithm. The algorithms were also tested with FRP deck specimens under solar radiation, to test the response under a passive heat source. The study showed that Infrared Thermography can be effectively used to detect subsurface defects and the process can be automated with substantial accuracy.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. Digital thermography of the fingers and toes in Raynaud's phenomenon.

    PubMed

    Lim, Mie Jin; Kwon, Seong Ryul; Jung, Kyong-Hee; Joo, Kowoon; Park, Shin-Goo; Park, Won

    2014-04-01

    The aim of this study was to determine whether skin temperature measurement by digital thermography on hands and feet is useful for diagnosis of Raynaud's phenomenon (RP). Fifty-seven patients with RP (primary RP, n = 33; secondary RP, n = 24) and 146 healthy volunteers were recruited. After acclimation to room temperature for 30 min, thermal imaging of palmar aspect of hands and dorsal aspect of feet were taken. Temperature differences between palm (center) and the coolest finger and temperature differences between foot dorsum (center) and first toe significantly differed between patients and controls. The area under curve analysis showed that temperature difference of the coolest finger (cutoff value: 2.2℃) differentiated RP patients from controls (sensitivity/specificity: 67/60%, respectively). Temperature differences of first toe (cutoff value: 3.11℃) also discriminated RP patients (sensitivity/specificity: about 73/66%, respectively). A combination of thermographic assessment of the coolest finger and first toe was highly effective in men (sensitivity/specificity : about 88/60%, respectively) while thermographic assessment of first toe was solely sufficient for women (sensitivity/specificity: about 74/68%, respectively). Thermographic assessment of the coolest finger and first toe is useful for diagnosing RP. In women, thermography of first toe is highly recommended.

  2. 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.

  3. 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.

  4. IR Linearity Monitor

    NASA Astrophysics Data System (ADS)

    Hilbert, Bryan

    2012-10-01

    These observations will be used to monitor the signal non-linearity of the IR channel, as well as to update the IR channel non-linearity calibration reference file. The non-linearity behavior of each pixel in the detector will be investigated through the use of full frame and subarray flat fields, while the photometric behavior of point sources will be studied using observations of 47 Tuc. This is a continuation of the Cycle 19 non-linearity monitor, program 12696.

  5. IR linearity monitor

    NASA Astrophysics Data System (ADS)

    Hilbert, Bryan

    2013-10-01

    These observations will be used to monitor the signal non-linearity of the IR channel, as well as to update the IR channel non-linearity calibration reference file. The non-linearity behavior of each pixel in the detector will be investigated through the use of full frame and subarray flat fields, while the photometric behavior of point sources will be studied using observations of 47 Tuc. This is a continuation of the Cycle 20 non-linearity monitor, program 13079.

  6. 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.

  7. PKCdelta-mediated IRS-1 Ser24 phosphorylation negatively regulates IRS-1 function.

    PubMed

    Greene, Michael W; 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 PKCdelta 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. PKCdelta-mediated IRS-1 Ser24 phosphorylation was confirmed in cells with PKCdelta 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.

  8. 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.

  9. Was the Suspect in Contact with the Victim? An Instrumental Methods Experiment for the Analysis of Single Fibers Using FT-IR Microscopy

    NASA Astrophysics Data System (ADS)

    Bender, Sharin; Lillard, Sheri J.

    2003-04-01

    Incorporating experiments with real-world relevance into the instrumental laboratory is accomplished by introducing experiments of a forensic nature. This strategy provides the opportunity for students to perform interesting experiments while they learn proper chemical, analytical, and instrumental techniques. In this laboratory experiment, fibers are (supposedly) collected from a crime scene and from a suspect's personal belongings. These fibers are analyzed and compared by using FT-IR microscopy with a mercury cadmium telluride detector. Physical descriptions, such as color and texture, as well as IR spectra are used for comparison of the fibers. The students identify functional groups that are present in the fiber samples and match them to the functional groups that are present in the fibers of known origin. Based on their experimental data, the students are asked to state the likelihood that the suspect was in contact with the victim.

  10. The super-hydrophobic IR-reflectivity TiO2 coated hollow glass microspheres synthesized by soft-chemistry method

    NASA Astrophysics Data System (ADS)

    Hu, Yan; Wang, Yuanhao; An, Zhenguo; Zhang, Jingjie; Yang, Hongxing

    2016-11-01

    The super-hydrophobic and IR-reflectivity hollow glass microspheres (HGM) was synthesized by being coated with anatase TiO2 and a super-hydrophobic material. The super-hydrophobic self-cleaning property prolong the life time of the IR reflectivity. TBT and PFOTES were firstly applied and hydrolyzed on HGM and then underwent hydrothermal reaction to synthesis anatase TiO2 film. For comparison, the PFOTES/TiO2 mutual-coated HGM (MCHGM), PFOTES single-coated HGM (F-SCHGM) and TiO2 single-coated HGM (Ti-SCHGM) were synthesized as well. The MCHGM had bigger contact angle (153°) but smaller sliding angle (16°) than F-SCHGM (contact angle: 141.2°; sliding angle: 67°). Ti-SCHGM and MCHGM both showed similar IR reflectivity with ca. 5.8% increase compared with original HGM and F-SCHGM. For the thermal conductivity, coefficients of F-SCHGM (0.0479 W/(m K)) was basically equal to that of the original HGM (0.0475 W/(m K)). Negligible difference was found between the thermal conductivity coefficients of MCHGM-coated HGM (0.0543 W/(m K)) and Ti-SCHGM (0.0546 W/(m K)).

  11. 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.

  12. Development of an extra-vehicular (EVA) infrared (IR) camera inspection system

    NASA Astrophysics Data System (ADS)

    Gazarik, Michael; Johnson, Dave; Kist, Ed; Novak, Frank; Antill, Charles; Haakenson, David; Howell, Patricia; Pandolf, John; Jenkins, Rusty; Yates, Rusty; Stephan, Ryan; Hawk, Doug; Amoroso, Michael

    2006-04-01

    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.

  13. 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.

  14. Nondestructive characterization of fatigue damage with thermography

    NASA Astrophysics Data System (ADS)

    Roesner, Henrik; Sathish, Shamachary; Meyendorf, Norbert

    2001-08-01

    A thermal imaging NDE method has been developed for nondestructive characterization of early stages of fatigue damage. The method is based on evaluation of the thermal effects induced in a material by a short-term mechanical loading. The mechanical loading causes in addition to thermoelastic temperature change, an increase due to heat dissipation that depends upon the microstructure of the material in a characteristic manner. The origin of this heat dissipation is the mechanical damping process. Utilizing the initial temperature rise due to a short-term mechanical loading, the dissipated energy per cycle was evaluated as a thermal parameter. This new thermal NDE parameter allows a quantitative characterization of the mechanical hysteresis, without the need for calibration to eliminate influences of thermal boundary conditions. The measurement of the thermal NDE parameters has been performed on Ti-6Al-4V dog-bone specimens, fatigued in low cycle fatigue (LCF) as well as in high cycle fatigue (HCF) experiments. Characteristic dependence of the NDE parameters on the already accumulated fatigue damage has been observed. The advantage of the thermal method is the applicability to components under service conditions because of simplicity, rapid measurements (a few seconds) and the ability of locally resolved evaluations.

  15. 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.

  16. Quantifying Flaw Characteristics from IR NDE Data

    SciTech Connect

    Miller, W; Philips, N R; Burke, M W; Robbins, C L

    2003-02-14

    Work is presented which allows flaw characteristics to be quantified from the transient IR NDE signature. The goal of this effort was to accurately determine the type, size and depth of flaws revealed with IR NDE, using sonic IR as the example IR NDE technique. Typically an IR NDE experiment will result in a positive qualitative indication of a flaw such as a cold or hot spot in the image, but will not provide quantitative data thereby leaving the practitioner to make educated guesses as to the source of the signal. The technique presented here relies on comparing the transient IR signature to exact heat transfer analytical results for prototypical flaws, using the flaw characteristics as unknown fitting parameters. A nonlinear least squares algorithm is used to evaluate the fitting parameters, which then provide a direct measure of the flaw characteristics that can be mapped to the imaged surface for visual reference. The method uses temperature data for the heat transfer analysis, so radiometric calibration of the IR signal is required. The method provides quantitative data with a single thermal event (e.g. acoustic pulse or flash), as compared to phase-lock techniques that require many events. The work has been tested with numerical data but remains to be validated by experimental data, and that effort is underway.

  17. Detecting explosive substances by the IR spectrography

    NASA Astrophysics Data System (ADS)

    Kuula, J.; Rinta, Heikki J.; Pölönen, I.; Puupponen, H.-H.; Haukkamäki, Marko; Teräväinen, T.

    2014-05-01

    Fast and safe detection methods of explosive substances are needed both before and after actualized explosions. This article presents an experiment of the detection of three selected explosives by the ATR FTIR spectrometer and by three different IR hyperspectral imaging devices. The IR spectrometers give accurate analyzing results, whereas hyperspectral imagers can detect and analyze desired samples without touching the unidentified target at all. In the controlled explosion experiment TNT, dynamite and PENO were at first analyzed as pure substances with the ATR FTIR spectrometer and with VNIR, SWIR and MWIR cameras. After three controlled explosions also the residues of TNT, dynamite and PENO were analyzed with the same IR devices. The experiments were performed in arctic outdoor conditions and the residues were collected on ten different surfaces. In the measurements the spectra of all three explosives were received as pure substances with all four IR devices. Also the explosion residues of TNT were found on cotton with the IR spectrometer and with VNIR, SWIR and MWIR hyperspectral imagers. All measurements were made directly on the test materials which had been placed on the explosion site and were collected for the analysis after each blast. Measurements were made with the IR spectrometer also on diluted sample. Although further tests are suggested, the results indicate that the IR spectrography is a potential detection method for explosive subjects, both as pure substances and as post-blast residues.

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

    NASA Astrophysics Data System (ADS)

    Reichle, R.; Brichard, B.; Pocheau, C.; Jouve, M.; van Ierschot, S.; Martinez, S.; Ooms, H.; Berghmans, F.; Decréton, M.

    2008-03-01

    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 Co60 irradiation facilities under γ irradiation. The fibres were ZrF4 (and HfF4) 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.

  19. Application and development of IR techniques for building and construction sector in Denmark

    NASA Astrophysics Data System (ADS)

    Melballe, Jens A.

    1990-03-01

    In Denmark IR-techniques have found a widespend use in the Building and Construction sector. The applications include control of insulation level of buildings, district heating networks, transformer stations, electrical networks and water pipes in buildings, electrically heated floors, etc. In this paper is first described the Danish voluntary system for inspection of building insulation. This work is supervised by a government agency. Some examples are given on how these activities are carried out in practice. An important question is how to develop IR-techniques for new applications and how to transfer this knowledge for practical use. In this paper we describe how activities of this kind are carried out in cooperation with government bodies, research organizations and users of thermography. Important aspects discussed include the initialization of development projects, the financial aspects, the organization of projects of this kind and the technology transfer. Some examples are given from work of this kind.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Moisture evaluation by dynamic thermography data modeling

    NASA Astrophysics Data System (ADS)

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

    1994-03-01

    This paper discusses the design of a nondestructive method for in situ detection of moistened areas in buildings and the evaluation of the water content in porous materials by thermographic analysis. The use of heat transfer model to interpret data allows to improve the measurement accuracy taking into account the actual boundary conditions. The relative increase of computation time is balanced by the additional advantage to optimize the testing procedure of different objects simulating the heat transfer. Experimental results on bricks used in building for restoration activities, are discussed. The water content measured in different hygrometric conditions is compared with known values. A correction on the absorptivity coefficient dependent on water content is introduced.

  5. 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.

  6. 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

    SciTech Connect

    Makarov, G N; Petin, A N

    2016-03-31

    We report the results of studies on the isotope-selective infrared multiphoton dissociation (IR MFD) of SF{sub 6} and CF{sub 3}I 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 SF{sub 6} 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. (laser separation of isotopes)

  7. 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.

  8. 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.

  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. Characterization of Periodic Cylindrical Subsurface Defects by Pulsed Flash Thermography

    NASA Astrophysics Data System (ADS)

    Dikić, Goran; Tomić, Ljubiša; Damnjanović, Vesna; Milanović, Bojan

    2015-03-01

    A characterization of cylindrical periodic subsurface defects of different sizes by means of pulsed thermography is presented in the paper. To ensure a uniform thermal flux distribution, the test samples were heated in lab conditions using two photographic flashes. Surface temperature was intentionally recorded at an angle to the normal of the sample surface. Recorded temperatures were compared with simulated temperatures and the differences in temperature peak values and temperature peak positions were noted. The thermal image was transformed based on known positions of four noncollinear points, in order to cancel out errors resulting from image recording at an angle. The uniformity of surface heating and the effect of the positions of the defects on the results were tested by means of a simulation model. The positions did not affect defect characterization. It was also found that in spite of nonuniform heating, if the reference points were selected properly, the difference in temperature contrast was negligible.

  11. 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.

  12. 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.

  13. The mental and subjective skin: Emotion, empathy, feelings and thermography.

    PubMed

    Salazar-López, E; Domínguez, E; Juárez Ramos, V; de la Fuente, J; Meins, A; Iborra, O; Gálvez, G; Rodríguez-Artacho, M A; Gómez-Milán, E

    2015-07-01

    We applied thermography to investigate the cognitive neuropsychology of emotions, using it as a somatic marker of subjective experience during emotional tasks. We obtained results that showed significant correlations between changes in facial temperature and mental set. The main result was the change in the temperature of the nose, which tended to decrease with negative valence stimuli but to increase with positive emotions and arousal patterns. However, temperature change was identified not only in the nose, but also in the forehead, the oro-facial area, the cheeks and in the face taken as a whole. Nevertheless, thermic facial changes, mostly nasal temperature changes, correlated positively with participants' empathy scores and their performance. We found that temperature changes in the face may reveal maps of bodily sensations associated with different emotions and feelings like love.

  14. Land drainage system detection using IR and visual imagery taken from autonomous mapping airship and evaluation of physical and spatial parameters of suggested method

    NASA Astrophysics Data System (ADS)

    Koska, Bronislav; Křemen, Tomáš; Štroner, Martin; Pospíšil, Jiří; Jirka, Vladimír.

    2014-10-01

    An experimental approach to the land drainage system detection and its physical and spatial parameters evaluation by the form of pilot project is presented in this paper. The novelty of the approach is partly based on using of unique unmanned aerial vehicle - airship with some specific properties. The most important parameters are carrying capacity (15 kg) and long flight time (3 hours). A special instrumentation was installed for physical characteristic testing in the locality too. The most important is 30 meter high mast with 3 meter length bracket at the top with sensors recording absolute and comparative temperature, humidity and wind speed and direction in several heights of the mast. There were also installed several measuring units recording local condition in the area. Recorded data were compared with IR images taken from airship platform. The locality is situated around village Domanín in the Czech Republic and has size about 1.8 x 1.5 km. There was build a land drainage system during the 70-ties of the last century which is made from burnt ceramic blocks placed about 70 cm below surface. The project documentation of the land drainage system exists but real state surveying haveńt been never realized. The aim of the project was land surveying of land drainage system based on infrared, visual and its combination high resolution orthophotos (10 cm for VIS and 30 cm for IR) and spatial and physical parameters evaluation of the presented procedure. The orthophoto in VIS and IR spectrum and its combination seems to be suitable for the task.

  15. 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.

  16. 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.

  17. Determination of Structural and Vibrational Properties of 5-QUINOLINECARBOXALDEHYDE Using Experimental Ft-Ir Ft-Raman Techniques and Theoretical HF and DFT Methods

    NASA Astrophysics Data System (ADS)

    Kumru, Mustafa; Kocademir, Mustafa; Bardakci, Tayyibe

    2013-06-01

    Quinoline derivatives have been used in several pharmaceuticals. They have vital roles in regulating the functions of DNA and cancerous cells. It's necessary to determine the structures and spectroscopic properties of quinoline derivates. In this study, the FT-IR (including mid and far regions) and FT-Raman spectra of 5-quinolinecarboxaldehyde have been investigated. Hartree-Fock (HF) and density functional B3LYP calculations have also been employed with the 6-311++G(d,p) basis set for investigating the structural and spectroscopic properties of the cis and trans conformers of 5-quinolinecarboxaldehyde. Experimental and theoretical results have been compared and the results are in good agreement with each other. Keywords: 5-quinolinecarboxaldehyde; Vibrational Spectroscopy; FT-IR spectra; FT-Raman spectra; Vibrational Modes; HF; DFT [1] V. Kucuk, A. Altun, M. Kumru, Spectrochim. Acta Part A 85(2012)92-98 [2] M. Kumru, V. Kucuk, T. Bardakci, Spectrochim. Acta Part A 90(2012)28-34 [3] M. Kumru, V. Kucuk, M. Kocademir, Spectrochim. Acta Part A, 96 (2012) 242-251 We thank the Turkish Scientific and Technical Research Council (TUBITAK) for their financial support through National Postdoctoral Research Scholarship Programme and Scientific Research Fund of Fatih University under the project number P50011001 G (1457).

  18. IR Gain Monitor

    NASA Astrophysics Data System (ADS)

    Hilbert, Bryan

    2012-10-01

    The gain of the IR channel of WFC3 will be measured using a series of internal flat fields. Using knowledge gained from ground testing and previous cycles, we propose to collect flat field ramps which will be used to create photon transfer curves and give a measure of the gain.

  19. IR gain monitor

    NASA Astrophysics Data System (ADS)

    Hilbert, Bryan

    2013-10-01

    The gain of the IR channel of WFC3 will be measured using a series of internal flat fields. Using knowledge gained from ground testing and previous cycles, we propose to collect flat field ramps which will be used to create photon transfer curves and give a measure of the gain. This continues the strategy of last cycle's gain monitor, in proposal 13080.

  20. APPLICATION OF LASERS AND LASER-OPTICAL METHODS IN LIFE SCIENCES Non-invasive, MRI-compatible fibreoptic device for functional near-IR reflectometry of human brain

    NASA Astrophysics Data System (ADS)

    Sorvoja H. S., S.; Myllylä, T. S.; Kirillin, M. Yu; Sergeeva, Ekaterina A.; Myllylä, Risto A.; Elseoud, A. A.; Nikkinen, J.; Tervonen, O.; Kiviniemi, V.

    2011-01-01

    A non-invasive device for measuring blood oxygen variations in human brain is designed, implemented, and tested for MRI compatibility. The device is based on principles of near-IR reflectometry; power LEDs serve as sources of probing radiation delivered to patient skin surface through optical fibres. Numerical Monte Carlo simulations of probing radiation propagation in a multilayer brain model are performed to evaluate signal levels at different source — detector separations at three operation wavelengths and an additional wavelength of 915 nm. It is shown that the device can be applied for brain activity studies using power LEDs operating at 830 and 915 nm, while employment of wavelength of 660 nm requires an increased probing power. Employment of the wavelength of 592 nm in the current configuration is unreasonable.