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1

Gaidos, Eric J. (Eric James). "Remote infrared thermography for boundary layer measurements." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/43129.

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2

Monchau, Jean-Pierre. "Mesure d'émissivité pour la thermographie infrarouge appliquée au diagnostic quantitatif des structures." Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1128/document.

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La thermographie infrarouge constitue un outil de diagnostic très utile dans le domaine du bâtiment et du génie civil. Cependant un diagnostic quantitatif reste difficile, et l'émissivité des surfaces étudiées joue un rôle important. Le présent travail est une étude sur la mesure d'émissivité pour le diagnostic quantitatif des structures par thermographie. Un des enjeux est de compléter une base de données d'émissivité pour des matériaux du bâtiment et du génie civil ; pour cela il a été nécessaire de développer des appareils de mesure portables. Deux appareils ont été développés au CERTES, utilisant des méthodes indirectes. Ces méthodes consistent à mesurer la réflexion d'un flux infrarouge modulé et nécessite une référence de réflectance connue. Le premier appareil module le flux par modulation lente de température (mesure en 16mn) ; il est adapté aux surfaces diffusantes et hétérogènes comme les bétons bitumineux et les matériaux de construction du bâtiment. L'autre appareil utilise un système d'écran permettant une modulation plus rapide (mesure en quelques secondes). Il est plus polyvalent. Il est aussi plus facilement transportable et permet également d'obtenir une évaluation du caractère plus ou moins spéculaire de la surface. Ces deux appareils couvrent au choix une bande spectrale large (1 à 40µm) pour évaluer les propriétés radiatives des surfaces et une bande étroite (8 à 14µm) adaptée à la sensibilité des caméras infrarouges. Une étude comparative sur les mesures d'émissivité a été entreprise avec le LNE (Laboratoire National de Métrologie et d'Essais). Les échantillons utilisés pour cette étude comparative ont permis de tester les différents dispositifs pour des matériaux ayant des propriétés radiatives très variées. Des mesures ont été effectuées au laboratoire et sur site sur une large gamme de matériaux usuels du bâtiment et du génie civil
Thermography is a very useful diagnosis tool in buildings and civil engineering structures. However quantitative diagnosis remains difficult, and having accurate values of surface emissivity is an important factor. The present work is a study about emissivity measurement for quantitative diagnosis with thermography. We needed accurate measurement of the emissivity of a number of civil engineering materials, in order to create a database. Thus, it was necessary to develop new portable measurement devices. Two devices using an indirect measurement method were developed at CERTES laboratory. The method uses the measurement of the reflectivity from a modulated IR source and requires calibration with a highly reflective surface. The first device uses a low-frequency, thermal modulation well-adapted to laboratory measurements, whereas the second one is a portable system using a mechanical modulation at a faster frequency, more appropriate to outdoor measurements. Both devices allow measurements in the broad (1—50µm) and narrow (8—14µm) bands. Experiments were performed on a large number of materials commonly used in buildings and civil engineering structures. The final objective of this work is to build a database of emissivity for these materials. A comparison of laboratory and on-site measurements of emissivity values obtained in both spectral bands is presented along with an estimation and an analysis of measurement uncertainties. A comparative study with measurement obtained at LNE (Laboratoire National de Métrologie et d'Essais, French laboratory of metrology) was performed, using a range of materials with widely different radiative properties. An analysis of discrepancies and their possible causes is presented
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3

Richenderfer, Andrew Jonathan. "Development of MiST-IR : multi-spectral infrared thermography." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/103700.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 91-92).
In this thesis, I present a new diagnostic technique for interrogating boiling heat transfer phenomena. The technique, called Multi-Spectral Infrared Thermography or MiST, builds on previous diagnostic techniques for measuring the 2-D wall temperature distribution or the 2-D phase distribution of the fluid above the surface. These methods make use of infrared thermography, a well developed practice involving the use of a high-speed infrared camera to collect visual data. By analyzing the data with both qualitative and quantitative tools, insights into boiling heat transfer mechanisms can be gained. In addition to the MiST technique, a refined infrared camera calibration model is presented for accurately determining the wall temperature. MiST is a new technique that allows for the simultaneous measurement of both the temperature distribution and the phase distribution. This is in sharp contrast to previous techniques which have only allowed the measurement of one or the other. MiST uses a highly engineered, semi-transparent, thin-film heater to enable the simultaneous measurement of the two properties. The heater separates the two signals, one from the temperature and one from the phase, by taking advantage of two regions of the electromagnetic spectrum. By spectrally separating the two signals, no limitation in resolution or field of view is made. The refined camera calibration model presented builds on previous work, which quantified the radiation captured by the camera and used a coupled radiation and conduction model to back out the complete axial temperature distribution within the heater. The new model refines the older version by taking into account spectrally varying optical properties within the heater. The spectral data is easily acquired with a Fourier transform infrared spectrometer, and fed into the radiation model for enhanced accuracy. The development of MiST presents new opportunities in boiling heat transfer for insight into a complex phenomena. The use of MiST in boiling and condensation experiments will lead to the development of new heat transfer models, and can provide high-resolution data for computational fluid dynamics models. MiST presents the logical progression forward in boiling diagnostic tools as it provides enhanced data acquisition opportunities when compared to it's legacy versions.
by Andrew Jonathan Richenderfer.
S.M.
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4

Cuibus, Lucian <1982&gt. "Applications of infrared thermography in the food industry." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5559/1/Cuibus_Lucian_Tesi.pdf.

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In the last 20-30 years, the implementation of new technologies from the research centres to the food industry process was very fast. The infrared thermography is a tool used in many fields, including agriculture and food science technology, because of it's important qualities like non-destructive method, it is fast, it is accurate, it is repeatable and economical. Almost all the industrial food processors have to use the thermal process to obtain an optimal product respecting the quality and safety standards. The control of temperature of food products during the production, transportation, storage and sales is an essential process in the food industry network. This tool can minimize the human error during the control of heat operation, and reduce the costs with personal. In this thesis the application of infrared thermography (IRT) was studies for different products that need a thermal process during the food processing. The background of thermography was presented, and also some of its applications in food industry, with the benefits and limits of applicability. The measurement of the temperature of the egg shell during the heat treatment in natural convection and with hot-air treatment was compared with the calculated temperatures obtained by a simplified finite element model made in the past. The complete process shown a good results between calculated and observed temperatures and we can say that this technique can be useful to control the heat treatments for decontamination of egg using the infrared thermography. Other important application of IRT was to determine the evolution of emissivity of potato raw during the freezing process and the control non-destructive control of this process. We can conclude that the IRT can represent a real option for the control of thermal process from the food industry, but more researches on various products are necessary.
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5

Cuibus, Lucian <1982&gt. "Applications of infrared thermography in the food industry." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5559/.

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In the last 20-30 years, the implementation of new technologies from the research centres to the food industry process was very fast. The infrared thermography is a tool used in many fields, including agriculture and food science technology, because of it's important qualities like non-destructive method, it is fast, it is accurate, it is repeatable and economical. Almost all the industrial food processors have to use the thermal process to obtain an optimal product respecting the quality and safety standards. The control of temperature of food products during the production, transportation, storage and sales is an essential process in the food industry network. This tool can minimize the human error during the control of heat operation, and reduce the costs with personal. In this thesis the application of infrared thermography (IRT) was studies for different products that need a thermal process during the food processing. The background of thermography was presented, and also some of its applications in food industry, with the benefits and limits of applicability. The measurement of the temperature of the egg shell during the heat treatment in natural convection and with hot-air treatment was compared with the calculated temperatures obtained by a simplified finite element model made in the past. The complete process shown a good results between calculated and observed temperatures and we can say that this technique can be useful to control the heat treatments for decontamination of egg using the infrared thermography. Other important application of IRT was to determine the evolution of emissivity of potato raw during the freezing process and the control non-destructive control of this process. We can conclude that the IRT can represent a real option for the control of thermal process from the food industry, but more researches on various products are necessary.
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6

Surabhi, Vijaykumar. "Automatic Features Identification with Infrared Thermography in Fever Screening." Thesis, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20558.

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The goal of this thesis is to develop an algorithm to process infrared images and achieve automatic identification of moving subjects with fever. The identification is based on two main features: the distinction between the geometry of a human face and other objects in the field of view of the camera, and the temperature of the radiating object. Infrared thermography is a remote sensing technique used to measure temperatures based on emitted infrared radiation. Applications include fever screening in major public places such as airports and hospitals. Current accepted practice of screening requires people to stay in a line and temperature measurements are carried out for one person at a time. However in the case of mass screening of moving people the accuracy of the measurements is still under investigation. An algorithm constituting of image processing to threshold objects based on the temperature, template matching and hypothesis testing is proposed to achieve automatic identification of fever subjects. The algorithm was first tested on training data to obtain a threshold value (used to discriminate between face and non face shapes) corresponding to a false detection rate of 5%, which in turn corresponds to 85% probability of detection using Neyman-Pearson criterion. By testing the algorithm on several simulated and experimental images (which reflect relevant scenarios characterizing crowded places) it is observed that it can be beneficially implemented to introduce automation in the process of detecting moving subjects with fever.
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7

Harik, Marc Anthony. "CHARACTERIZATION OF DEFECTS IN METAL SHEETS VIA INFRARED THERMOGRAPHY." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/32.

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Defects in Aluminum, Stainless steel and galvanized steel sheets are studied in reflection mode infrared thermography. The effect of material properties, surface finish, heating intensity, heater emission spectra, pixel size and defect size are studied. Contrast is governed by heat quality, emissivity and defect geometry—which follows a logarithmic trend. The diameter detected via infrared thermography is found to be at least 30% larger than the measured diameter and sub-pixel defects can be detected. The use of gradient and Laplacian of temperature is introduced as a means of increasing defect contrast and mitigating heater variation.
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8

Hu, Ching Wen. "Fabric integrity evaluation of structural materials using infrared thermography." Thesis, University of South Wales, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395349.

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9

Yu, Jimmy Kalok. "Using infrared thermography to measure the maturity of concrete." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14321.

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10

Shrestha, Survesh Bahadur. "Defect Detection on Rail Base Area Using Infrared Thermography." OpenSIUC, 2020. https://opensiuc.lib.siu.edu/theses/2758.

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This research aims to investigate the application of infrared thermography (IRT) as a method of nondestructive evaluation (NDE) for the detection of defects in the rail base area. Rails have to withstand harsh conditions during their application. Therefore, defects can develop in the base area of rails due to stresses such as bending, shear, contact, and thermal stresses, fatigue, and corrosion. Such defects can cause catastrophic failures in the rails, ultimately leading to train derailments. Rail base defects due to fatigue and corrosion are difficult to detect and currently there are no reliable or practical non-destructive evaluation (NDE) methods for finding these types of defects in the revenue service. Transportation Technology Center, Inc. (TTCI) had previously conducted a research on the capability of flash IRT to detect defects in rail base area based on simulation approach. The research covered in this thesis is the continuation of the same project.In this research, three rail samples were prepared with each containing a notched-edge, side-drilled holes (SDHs), and bottom-drilled holes (BDHs). Two steel sample blocks containing BDHs and SDHs of different sizes and depths were also prepared. Preliminary IRT trials were conducted on the steel samples to obtain an optimal IRT setup configuration. The initial inspections for one of the steel samples were outsourced to Thermal Wave Imaging (TWI) where they employed Thermographic Signal Reconstruction (TSR) technique to enhance the resulting images. Additional inspections of the steel samples were performed in the Southern Illinois University-Carbondale (SIUC) facility. In case of the rail samples, the SDHs and the notched-edge reflectors could not be detected in any of the experimental trials performed in this research. In addition, two more rail samples containing BDHs were prepared to investigate the detection capabilities for three different surface conditions: painted, unpainted, and rusted. The painted surface provided a best-case scenario for inspections while the other conditions offered further insight on correlating the application to industry-like cases.A 1300 W halogen lamp was employed as the heat source for providing continuous thermal excitation for various durations. Post-processing and analysis of the resulting thermal images was performed within the acquisition software using built-in analysis tools such as temperature probes, Region of Interest (ROI) based intensity profiles, and smoothing filters. The minimum defect diameter to depth (aspect) ratio detected in preliminary trials for the steel sample blocks were 1.0 at a diameter of 4.7625 mm (0.1875 in) and 1.5 at a diameter of 3.175 mm (0.125 in). For the inspection of painted rail sample, the longest exposure times (10 sec) provided the best detection capabilities in all sets of trials. The three holes having aspect ratio greater or equal to 1.0 were indicated in the thermal response of the painted and rusted samples while only the two holes having aspect ratio greater or equal to 1.5 were indicated in the unaltered sample. Indications of reflectors were identified through qualitative graphical analysis of pixel intensity distributions obtained along a bending line profile. The results obtained from the painted sample provided a baseline for analyzing the results from the unpainted and rusted rail samples. This provided an insight on the limitations and requirements for future development. The primary takeaway is the need for an optimized heat source. Poor contrast in the resulting image for the unpainted and rusted rail samples is experienced due to both noise and lack of penetration of the heat energy. This could have been due to decreased emissivity values. Moreover, the excitation method employed in this research does not comply with current industry standards for track clearances. Therefore, exploration of alternative excitation methods is recommended.
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11

Bangalore, Gurudutt S. "Nondestructive evaluation of FRP composite members using infrared thermography." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2419.

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Thesis (M.S.)--West Virginia University, 2002.
Title from document title page. Document formatted into pages; contains viii, 101 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 98-101).
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12

Bhaskar, Ranjit. "A study of techniques to improve the effective resolution of thematic mapper thermal infrared imagery /." Online version of thesis, 1993. http://hdl.handle.net/1850/11353.

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13

Fike, Gregory Michael. "Using Infrared Thermography to Image the Drying of Polymer Surfaces." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4808.

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During the drying of a surface, the liquid evaporation acts to keep the temperature relatively constant, due to evaporative cooling. As the drying nears completion the liquid film begins to break, exposing areas that are no longer cooled through evaporation, which begin to heat. Although this heating can be measured with an Infrared (IR) camera, the sensitivity is often not sufficient to recognize the point at which the film breaks. Complicating the measurement is the changing emissivity that commonly occurs as objects dry. The sensitivity and emissivity issues can be addressed by analyzing the temperature in the area of interest and computing the coefficient of variance (COV) of the temperature. This technique is compared to temperature and standard deviation measurements made with an IR camera and the COV technique is shown to be superior for determining when the liquid film breaks. The film breakage point is found to vary with temperature and material roughness in two industrially significant applications: the drying of wood flakes and the drying of polymer films. Film breakage in wood flakes is related to detrimental finished quality problems and also to emission problems. The rate at which an adhesive dries affects the roughness of the polymer film and subsequently, the bond strength. The COV technique is used to predict the roughness of the finished polymer film. Use of the COV technique allows the drying of a liquid film to be visualized in a way that has been previously unreported.
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14

Poey, S. M. "Infrared thermography of the anterior eye during contact lens wear." Thesis, University of Manchester, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494480.

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15

Grimler, Henrik. "Investigating Urea Vaporization in a Controlled Environment Using Infrared Thermography." Thesis, KTH, Skolan för kemivetenskap (CHE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174360.

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As the emission legislation becomes more stringent, higher demands are put on the aftertreatment system in trucks. For dealing with nitrous oxides, AdBlue® (urea–water solution) is injected into the exhausts which evaporates and reduces nitrous oxides to nitrogen. At low exhaust temperatures, it is more difficult to evaporate the injected AdBlue® as the exhausts contain less energy. The injected solution may instead form a wall film. In this wall film, side reactions can occur which leads to the formation of deposits. This thesis aims at understanding how and when wall films and deposits are formed. To achieve this, a test rig that allowed visual and infrared observations of the process and variation of governing properties was designed and built. The results show that thicker plates can sustain higher dosages than thinner plates since the temperature drop and film area are smaller for the thicker plate. It was also observed that at plate temperatures >340 °C, the water in the impacting spray evaporated, leaving a urea dust in the gas phase. It is also clear that deposits form faster at higher gas temperatures (> 350 °C) compared to at lower temperatures (200–250 °C). The deposits form at the edge of the wall film in a region with a temperature higher than in the middle of the wall film. At lower temperatures, a wall film that spreads out over a very large area is formed and after a longer time period, deposits form at obstacles and at the wall film edge. Experiments for 2 h at lower temperatures left approximately the same amount of deposits as experiments for 30 min at higher temperatures.
När lagkraven blir strängare sätts högre krav på efterbehandlingssystemet i lastbilar. För att få bort nitrösa gaser injiceras AdBlue® (urea–vattenlösning) in i avgaserna vilken förångas och reducerar de nitrösa gaserna till ofarligt kväve. Vid låga avgastemperaturer är det svårare att förånga den injicerade AdBlue®–lösningen då avgaserna innehåller mindre energi. Den injicerade lösningen kan istället bilda en väggfilm. I denna väggfilm kan sidoreaktioner ske vilket leder till bildning av utfällningar. Detta examensarbete syftar till att öka förståelsen för hur och när väggfilmer och utfällningar bildas. För att uppnå detta designades och byggdes en testrigg i vilken visuella och infraröda observationer kan göras och influerande parametrar varieras. Resultaten visar att tjockare plåtar kan utstå högre doseringar jämfört med tunnare plåtar, eftersom lägre temperaturminskning och film area uppmätts för den tjockare plåten. Det sågs också att vid plåttemperaturer >340 °C så förångades vattnet i AdBlue®-lösningen först och efterlämnade ett ureadamm i gasfasen. Det konstaterades också att utfällningar bildas snabbare vid högre gastemperaturer (> 350 °C) jämfört med vid lägre temperaturer (200–250 °C). Utfällningarna bildas vid kanten av väggfilmen i en region som har en temperatur som är högre än den i mitten av väggfilmen. Vid lägre temperaturer bildas en väggfilm som sprider ut sig över en stor area och med tiden bildas utfällningar vid hinder och vid filmkanten. Experiment under 2 h vid låg gastemperatur gav jämförbara mängder utfällningar som experiment under 30 min vid högre temperatur.
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16

Roberts, Matthew Thomas. "Induction Infrared Thermography for Non-Destructive Evaluation of Alloy Sensitization." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/90668.

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The sensitization of stainless steel describes the process by which a high-carbon steel alloy is heated above a certain threshold (either naturally or artificially) followed by a cooling period during which chromium (one of the elements most responsible for providing stainless steel with its corrosion-inhibiting properties) forms new compounds with the carbon present in the steel. With the chromium being taken from the parent material to form these compounds, the corrosion-resistant properties are compromised, which can lead to corrosion, cracking, and broader failure. Currently, the accepted techniques used to test for the presence of sensitization are qualitative and/or destructive in nature. Attempts have been made to non-destructively detect and characterize sensitization through various means, but all with mixed results. With the use of these high-carbon alloys in a range of industries, a comprehensive, in-place process is desirable. This thesis will focus specifically on non-destructive evaluation of sensitization seen as a result of welding steel plates using induction infrared thermography (IIRT). This process uses an induction coil to generate heat within a sample whose resulting heat signature can then be detected with an infrared (IR) camera and analyzed. Previous IIRT experimental results have shown higher levels of heating in the HAZ when sensitization is present as it modifies the original microstructure of the material. New IIRT experiments have been conducted on both welded and unwelded 440C alloy samples to establish quantitative data on the heating profiles. These results (in conjunction with the appropriate experimental parameters) were then used to create a numerical model to replicate them. Despite some limitations in populating the model with accurate parameters, the results obtained were in good agreement with the experiments and provide a foundation for future work. Future work will focus on establishing a predictive tool that can detect and quantify the level of sensitization in an arbitrary steel sample in the field.
Master of Science
The sensitization of stainless steel describes the process by which a high-carbon steel alloy is heated above a certain threshold (either naturally or artificially) followed by a cooling period during which chromium (one of the elements most responsible for providing stainless steel with its corrosion-inhibiting properties) forms new compounds with the carbon present in the steel. With the chromium being taken from the parent material to form these compounds, the corrosion-resistant properties are compromised, which can lead to corrosion, cracking, and broader failure. Currently, the accepted techniques used to test for the presence of sensitization are qualitative and/or destructive in nature. Attempts have been made to non-destructively detect and characterize sensitization through various means, but all with mixed results. With the use of these high-carbon alloys in a range of industries, a comprehensive, in-place process is desirable. This thesis will focus specifically on non-destructive evaluation of sensitization seen as a result of welding steel plates using induction infrared thermography (IIRT). This process uses an induction coil to generate heat within a sample whose resulting heat signature can then be detected with an infrared (IR) camera and analyzed. Previous IIRT experimental results have shown higher levels of heating in the HAZ when sensitization is present as it modifies the original microstructure of the material. New IIRT experiments have been conducted on both welded and unwelded 440C alloy samples to establish quantitative data on the heating profiles. These results (in conjunction with the appropriate experimental parameters) were then used to create a numerical model to replicate them. Despite some limitations in populating the model with accurate parameters, the results obtained were in good agreement with the experiments and provide a foundation for future work. Future work will focus on establishing a predictive tool that can detect and quantify the level of sensitization in an arbitrary steel sample in the field.
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17

Miceli, Marybeth. "Assessment of Infrared Thermography for NDE of FRP Bridge Decks." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/36320.

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Statistics released in the fall 1989 showed that 238,357 (41%) of the nation's 577,710 bridges are either structurally deficient or functionally obsolete. New materials, such as fiber reinforced polymeric composites (FRP), are being suggested for use in bridge systems to solve some of the current problems. These materials are thought to be less affected by corrosive environmental conditions than conventional civil engineering materials. Therefore they may require less maintenance and provide longer life spans. More specifically, glass fiber reinforced vinyl ester matrix composites are considered possible replacements for deteriorating conventional bridge decks due to their durability, decreased weight, and relative affordability. In order to facilitate rapid acceptance of FRP structural components into the world of civil structural engineering, effective and efficient NDE techniques must be explored and documented in these situations. This thesis will discuss the use of Infrared Thermography (IRT) as a means of detecting debonds and voids caused by conditions encountered both in fabrication and in the field. As forced convective hot air is applied within the bridge deck, debonds between bridge deck components near the riding surface appear cold while imperfections near the bottom of the deck give rise to concentrations of heat. These variations in thermal propagation patterns are observed by the infrared camera and indicate possible structural deficiencies. Results of experimentation and thermal analyses from laboratory studies of a model bridge deck and some from in situ full-scale investigations are presented.
Master of Science
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18

Agarwal, Kevin. "Infrared Thermography for In-pile Imaging of Nuclear Fuel Cracking." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555343437656063.

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19

Zhang, Ying. "Thermal diffusivity evaluation for carbon-carbon composites using infrared thermography /." Available to subscribers only, 2007. http://proquest.umi.com/pqdweb?did=1456294291&sid=1&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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Thesis (Ph. D.)--Southern Illinois University Carbondale, 2007.
"Department of Mechanical Engineering and Energy Processes." Includes bibliographical references (leaves 95-102). Also available online.
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20

Ferrarini, Giovanni. "Evaluation of Thermal Heat Fluxes in Buildings with Infrared Thermography." Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3422893.

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Buildings are the place where people spend the vast majority of their time and are accounting for the 40% of global energy consumption. The research is therefore constantly trying to improve the thermal comfort for people while decreasing the required energy to obtain it. To succeed in this challenge, it is firstly necessary to have a deep knowledge of the energy transfer mechanisms between the building and the environment. This basic knowledge must be applied to the individual study of each single building, as multiple variables make each edifice unique. The following work, after an introduction part, describes traditional and innovative thermographic methods and procedures aimed to determine the heat exchanges between the building and the surrounding environment. The proposed techniques are then applied to different case studies, both in laboratory and on-site, and also compared and integrated with analytical and numerical modeling. The goal is extending the use of thermographic analysis during building surveys, overcoming practical limitations and improving the completeness and accuracy of building investigations.
Gli edifici sono il luogo in cui le persone trascorrono la maggior parte della giornata e sono responsabili del 40% del consumo energetico globale. La ricerca è quindi costantemente indirizzata al miglioramento delle condizioni di benessere termico per le persone cercando al tempo stesso di diminuire l’energia necessaria per ottenerlo. Per vincere questa sfida, è in primo luogo necessaria una profonda conoscenza dei meccanismi di scambio energetico tra l’edificio e l’ambiente. Questa conoscenza di base deve essere poi applicata allo studio individuale di ogni edificio, poiché molteplici variabili tendono a far diventare ogni edificio unico. Il presente lavoro, dopo una parte introduttiva, descrive procedure e metodi termografici tradizionali ed innovativi mirati a determinare gli scambi termici tra l’edificio e l’ambiente circostante. Le tecniche proposte sono successivamente applicate a diversi casi studio, sia in laboratorio che in situ, e confrontate e integrate con modelli numerici e analitici. L’obiettivo è estendere l’uso del metodo di analisi termografico durante l’ispezione degli edifici, superando limitazioni pratiche e migliorando la completezza e accuratezza delle indagini.
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21

Estrada, Catalina. "Infrared Thermography to Evaluate Guastavino Vaulting at the West Side Market." Kent State University Honors College / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1368186834.

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22

Ziegler, Mathias. "Thermography of semiconductor lasers." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2009. http://dx.doi.org/10.18452/15944.

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Halbleiterlaser stellen mit über 70% Wirkungsgrad einzigartig effiziente Lichtquellen dar. Dennoch ist ihre zuverlässige Nutzung, insbesondere im Bereich hoher Leistungsdichten, von thermischen Limitierungen geprägt. Einen grundlegenden Beitrag zu deren physikalischen Verständnis leistet die Analyse der thermischen Eigenschaften und Degradationsprozesse solcher Bauelemente. In dieser Arbeit wird hierzu die Thermographie als innovative Analysemethode untersucht. Das Plancksche Strahlungsgesetz erlaubt die radiometrische Ermittlung der Temperatur. Die wichtige physikalische Kenngröße Emissivität wird in dieser Arbeit für Halbleiter und Halbleiterlaserstrukturen spektral gemessen und auf fundamentale physikalische Eigenschaften zurückgeführt. Auf dieser Grundlage werden methodische Aspekte der Thermographie diskutiert, welche durch den thermischen Hintergrund und die teilweise Transparenz der Halbleitermaterialien geprägt sind. Die daraus folgenden analytischen Fähigkeiten erlauben unter anderem die orts- und zeitaufgelöste Bestimmung der thermischen Eigenschaften von komplexen Hochleistungslasern unterschiedlichster Bauart. Darüber hinaus ermöglicht die Kenntnis der beteiligten thermischen Zeitkonstanten die Extraktion von lokalen Überhöhungen in der Infrarotemission, deren Zusammenhang zur Degradation der Bauelemente untersucht wird. Eine grundsätzliche Begrenzung der Ausgangsleistung ist durch einen abrupten Degradationsprozess gegeben, welcher maßgeblich durch eine Reabsorption der Laserstrahlung an der Frontfacette verursacht wird. Mithilfe einer kombinierten Thermographie-Nahfeld-Messung wird dieser Prozess orts- und zeitaufgelöst analysiert. Die Erweiterung des Messfensters zu kürzeren Wellenlängen hin erlaubt die Detektion strahlender Übergänge unter Einbeziehung von Defektzentren welche als strahlende Signaturen von graduellen Degradationsprozessen aufzufassen sind.
Semiconductor lasers are unequaled efficient light sources, reaching efficiencies of more than 70%. Nevertheless, thermal limits govern their reliable application, in particular in the field of high power densities. The analysis of thermal properties and degradation processes in such devices contributes essentially to the understanding of these limits. This work exploits thermography as an innovative analytical technique for such purpose. Planck''s law allows for a radiometric detection of temperatures. In this work, the important physical parameter emissivity is measured spectrally resolved for both semiconductors and semiconductor laser structures and is related to fundamental physical properties. Based on that, methodological aspects are discussed, which are affected on the one hand by the omnipresent thermal radiation and on the other hand by the partial transparency of the semiconductor materials. The resulting analytical capacities allow, for instance, for the determination of the thermal properties of complex high-power lasers of a wide range of different designs in a spatio-temporally resolved fashion. Furthermore, does the knowledge of the involved thermal time constants allow for an extraction of localized peaks of the infrared emission that is analyzed for its relationship with device degradation. The output power of high-power devices is fundamentally limited by the catastrophic optical damage, an abrupt degradation process that is induced significantly by reabsorption of laser radiation at the front facet. This process is analyzed spatio-temporally resolved with help of a combined thermography and optical near-field technique. Extending the detection range down to shorter wavelengths allows for imaging of radiative transitions that are related to defect centers, which are interpreted as radiative signatures of gradual device degradation processes.
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23

Abdel-Monem, Tarek M. "INFRARED THERMOGRAPHY AND HIGH ACCURACY GPS FOR AUTOMATED ASPHALT CRACK DETECTION." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3264.

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Roads are major public assets. The USA spends billions of dollars each year on road construction and maintenance. To keep these roads in a healthy condition and for better planning and allocation of maintenance budgets, knowledge of distressed locations is needed. Roads develop cracks when they are subjected to stresses that exceed their designed criteria or their materials properties. Early detection and repair of cracks has proven to be the most cost-effective strategy in limiting the damage to roads and reducing expenditures. Various methodologies of crack detection were developed and significant techniques were made in the last few years. One of the most important recent technologies is the infrared thermography, which allows the use of infrared waves for crack detection. Another important technology is the global navigation satellite system (GNSS) which currently includes the GPS and GLONASS constellations. With the help of these systems, accurate location coordinates (longitude, latitude and altitude) up to a few centimeters were located. The objective of this research is to test the combined use of GNSS and infrared thermography in an automated system for the detection of asphalt cracks and their locations. To achieve this goal, two tests have been conducted. The first one, regarding the location tagging, was done using two pairs of GPS receivers which can detect signals from both GPS and GLONASS navigation systems in single and dual frequencies (L1 and L2). Different modes have been set to the receiver and comparison graphs were developed to compare accuracies against modes. The second test involves an infrared camera mounted on a car and moving in speeds approaching highway speed limit. The images obtained from the camera were processed using cracks detection software to analyze cracks properties (length, width, density and severity). It was found that the images that were taken by a moving infrared camera were recognized by crack detection software for moving speeds up to 50 mph. At speeds higher than 50 mph, images were blurred. As for location test, The GLONASS combined by GPS receivers got slightly better results than GPS only in both dual and single frequencies. The GLONASS satellites are not always available in view and when they are there, the number of satellites that can be detected by receiver range from one to three satellites at the most and for only a short period of time. It is recommended that future research be conducted to investigate the effect of using different camera lenses on the clarity of the images obtained as well as the effect of raising the camera level above the pavement surface in such a way that the whole lane width (12 ft.) would be covered in one image. Also the total reliance on GPS only receivers in determining cracks location has proven to be enough for this application.
M.S.C.E.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering
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24

Bainbridge, Bradley Glenn. "OPTIMIZATION OF TRANSIENT THERMOGRAPHY INSPECTION OF CARBON FIBER REINFORED PLASTICS." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/theses/300.

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Infrared thermography was used to evaluate Carbon Fiber Reinforced Panels (CFRP) and optimize the inspection process so that a set of guidelines can be established in order to be efficient and effective. It has been shown in previous work that when a material is heated up the heat will diffuse through the material at a constant rate. However, if there is a defect in the material, such as a delamination, this defect will act like an insulator. When this happens the heat cannot penetrate as quickly as the rest of the material so the surface above the defect shows up hotter than the rest of the material. An operator looks for inconsistent temperatures in the sample to determine the quality of the piece. Samples with simulated defects were made and modeled using a finite element program. Heat will be applied to the models and the temperature profiles analyzed. Along with changing the heat and time, different post-processing techniques were used to improve the method in determining defects in the sample. Once this has been optimized, actual CFRP with the same simulated defects was experimentally tested using the conditions from the analytical model. The analytical and experimental data was compared to insure that the testing process has been optimized. A standardized process was developed for evaluating the CFRPs using infrared thermography.
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25

Musio, Antonio. "Modelling and experimental implementation of infrared thermography on concrete masonry structures." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.

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Industrialized countries have and are based on a network infrastructure is becoming increasingly complex and difficult to manage these systems, mainly due to a lack of financial resources. Asset management is a paradigm that is adopted to properly manage the infrastructure, ensuring that the available resources are properly utilized to ensure the necessary level of service to users of the infrastructure. It includes managing the entire life cycle, including design, construction, commissioning, operation, maintenance, modification, replacement or cancellation of physical infrastructure assets. In this context, there is a big contribution by use of technology, and then using the methods that this thesis will aim to provide a quantitative assessment of structural systems and provide sufficient assistance to any strategy of asset management. Non-destructive tests are types of test required by biggest companies around the world. These types of investigations are also mentioned in technical specifications of products, by norms and administrative orders. Adaptability of non-destructive techniques related to the ability to detect defects, without harming sample, puts these techniques high in context of component reliability check. About the subject of structural diagnostics, plays an important role the use of technology, which if properly exploited can provide a quantitative assessment of infrastructure systems. For example the feedback non-destructive as infrared (IR) and ultrasound (UT ) and others, are becoming more and more accessible and have the ability to assess damage to structures and materials at an early stage
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26

Brown, Jeff Robert. "Infrared thermography inspection of fiber-reinforced polymer composites bonded to concrete." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0011621.

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27

Chowdhuri, Shubham. "A Method to Characterize Gas Turbine Vane Performance Using Infrared Thermography." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/82492.

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Gas turbine vanes find themselves in very hostile environments – extremely high temperature combustion gases, much exceeding material melting temperatures, flowing over them at enormous pressures. It is necessitated due to the increased efficiency and power output at these conditions. However, this also means that, in spite of the technological advancements made, these parts need frequent repairing compared to parts placed in milder environments. Primarily due to economic reasons, gas turbine parts are repaired by companies other than the original equipment manufacturer (OEM). While multitude of condition monitoring techniques have been developed and are used in the industry for regular maintenance checks, there is no easy way to characterize the impact on thermal performance of the repairing processes involved. This thesis reports the development of a technique to address this issue. It also chronicles the test rig design, experiments conducted, development and significance of the thermal performance metric. Heated air (250 ̊C – 300 ̊C) is flown through the internal cooling passages of 8 samples each of OEM and repaired parts at two different pressure ratios (vane inlet over ambient pressure), 1.1 and 1.3. First, steady state mass flow rates through each airfoil (one part is a cluster of 4 airfoils) is experimentally determined and compared among the OEM and repaired sample sets. Second, a transient experiment is run and the surface temperatures of the airfoils are measured using multiple infrared cameras viewing both the pressure and suction side of the airfoils. A parameter involving localized vane surface temperature, airfoil inlet temperature and ambient temperature is formulated to characterize the vane thermal performance. Using statistical analysis, it is found that there is no significant difference between the OEM and repaired samples tested. The development of the discussed technique, it is expected, will help companies in the gas turbine vane repairing business to qualify their parts in a robust and efficient manner without the need to invest a lot of money in buying precision equipment, or, control chambers. Finally, a couple of further studies are recommended to further improve the qualifying procedure and thereby increase the efficiency of the technique.
Master of Science
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28

Lee, Jeffrey Allen. "Nondestructive evaluation of reinforced concrete via infrared thermography: a feasibility study." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/41987.

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An experimental investigation was conducted to develop a laboratory technique for the nondestructive evaluation of reinforced concrete. The methodologies were developed with the intent of eventual field implementation to determine the feasibility of utilizing infrared thermography to inspect substructural elements of concrete bridges.

Several specimen configurations were fabricated for thermographic inspection. A number of tests were performed on a variety of concrete specimens to determine the implementation parameters of the technique. The necessity of utilizing artificial heating methods for thermal input prior to inspection was evaluated.

The present study suggests that infrared thermography cannot be applied to substructural elements of bridges in a noncontact fashion. Internal thermal gradients produced by diurnal temperature fluctuation generally are not sufficient to produce the variations in surface temperature patterns necessary for thermographically detecting nonvisual subsurface defects. Rather, both the envelopment and artificial heating of the substructural element is required prior to thermographic inspection.


Master of Science
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29

Fernandes, Henrique. "Fiber orientation analysis of carbon fiber-reinforced polymers by infrared thermography." Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/27294.

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L’utilisation de Matériaux Composites est de plus en plus courante dans plusieurs applications, notamment dans les structures aéronautiques où des pièces de forme complexe sont fort demandées. Dans ces matériaux, la disposition ou l’orientation des fibres l’une par rapport à l’autre, la concentration de celles-ci, et leur distribution sont des facteurs qui ont une influence notable sur la résistance et d’autres propriétés des composites renforcés de fibres. Ainsi, on a besoin de développer des techniques d’essai pour évaluer la teneur en fibres. Des méthodes destructrices peuvent être utilisées pour évaluer les fibres dans un échantillon composite par exemple, en évaluant une section de coupe du matériau après polissage de la surface par microscopie. Cependant, l’approche destructrice n’est pas toujours une option puisque l’échantillon est endommagé après l’inspection et probablement impropre à l’utilisation. Ainsi, les techniques de Contrôle non-destructif (CND) doivent être utilisées dans certains cas pour évaluer le contenu de la matière fibreuse. Dans cette thèse, la thermographie infrarouge, une technique de CND bien connue, est utilisé afin d’évaluer l’orientation des fibres de matériaux composites, à la surface et sous la surface de pièces plates ainsi que de pièces de forme complexes. Plus précisément, l’ellipsométrie thermique utilisant une source de point laser de chauffage (statique) et une source de chauffage en ligne produit par balayage en vol du point laser (dynamique) sont employés. L’évaluation de l’orientation de la fibre sur des pièces de forme complexe est accomplie avec succès en raison de la fusion d’un modèle en trois dimensions de la surface de l’échantillon avec les données infrarouge obtenues par l’inspection d’ellipsométrie thermique. Le matériau qui va être inspecté dans ce projet est le Carbone/Polyether-Ether-Ketone (PEEK) réalisé par disposition de flocons de fibres appelée Randomly-Oriented Unidirectional Strand (ROS).
The use of Composite Materials (CM) is growing more and more every day in several applications, especially in aeronautic structures where complex shaped parts are highly demanded. The arrangement or orientation of the fibers relative to one another, the fiber concentration, and the distribution all have a significant influence on the strength and other properties of fiber reinforced composites. Thus, one needs to develop testing techniques to assess fiber content. Destructive methods can be employed to evaluate the fiber on a composite, e.g. cutting a section of the material, polishing the area and evaluating it by microscopy. However, the destructive approach is not always an option since the sample will be ‘damaged’ after the inspection and probably unfit for use. Therefore, Non-Destructive Testing and Evaluation (NDT& E) techniques must be employed in some cases to assess the material’s fiber content. In this thesis, InfraRed Thermography (IRT), a well-known NDT& E technique, is used in order to assess fiber orientation of composite materials on the surface and beneath the surface of booth flat and complex shaped parts. More specifically, Thermal Ellipsometry (TE) using a laser spot heating source (static) and a line heating source produced by a flying laser spot inspection (dynamic) are employed. Fiber orientation assessment on complex shaped parts is successfully accomplished due to the merge of a Three-Dimensional (3D) model of the part’s surface with the InfraRed (IR) data obtained by the TE inspection. The specimens that are going to be inspected in this project are Carbon/Polyether-Ether-Ketone (PEEK) plates reinforced by Randomly-Oriented Unidirectional Strand (ROS) of unidirectional slit tape.
O uso de Materiais Compósitos tem crescido mais e mais a cada dia em várias aplicações, especialmente em estruturas aeronáuticas onde peças em forma de complexos sõ extremamente procurados. O arranjo ou orientação das fibras com relação umas às outras, a concentração de fibra, e sua distribuição tem todos um grande impacto na força, rigidez e outras propriedades de materiais compósitos reforçados com fibras. Assim, se faz necessário o desenvolvimento de técnicas capazes de avaliar o conteúdo fibroso destes materiais. Métodos destrutivos podem ser empregados para avaliar as fibras em um material compósito, por exemplo cortando-se uma secção do material, polindo a área e avaliado a região com um microscópio. Entretanto, a abordagem destrutiva nõ é sempre uma opção uma vez que após o ensaio a peça ficará danificada e provavelmente imprópria para uso. Deste modo, ensaios não-destrutivos devem ser empregados em certos casos para avaliar o conteúdo fibroso do material. Nesta tese, termografia infravermelha, uma conhecida técnica de ensaios não-destrutivo, é usada para acessar a orientação das fibras de materiais compósitos na superfície e sub-superfície de amostras planas bem como de amostras com formas complexas. Mais especificamente, elipsometria térmica usando fonte de aquecimento ponto de laser (estático) e uma fonte de aquecimento em linha produzida por uma inspeção de ponto voador (dinâmico) são empregadas. Avaliação de orientação de fibra em amostras de formas complexas é realizada com sucesso graças a fusão de um modelo tridimensional da superfície da amostra e os dados infravermelhos obtidos com o ensaio de elipsometria térmica. As amostras inspecionadas durante este projeto são feitas Carbono/Polyether-Ether-Ketone (PEEK) reforçadas com Randomly-Oriented Unidirectional Strand (ROS).
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30

Joseph, Liselle AnnMarie. "Transition Detection for Low Speed Wind Tunnel Testing Using Infrared Thermography." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/78145.

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Transition is an important phenomenon in large scale, commercial, wind tunnel testing at low speeds because it is an excellent indicator of an airfoil performance. It is difficult to estimate transition through numerical techniques because of the complex nature of viscous flow. Therefore experimental techniques can be essential. Over the transition region the rate of heat transfer shows significant increases which can be detected using infrared thermography. This technique has been used predominantly at high speeds, on small models made of insulated materials, and for short test runs. Large scale testing has not been widely undertaken because the high sensitivity of transition to external factors makes it difficult to detect. The present study records the process undertaken to develop, implement and validate a transition detection system for continual use in the Virginia Tech Stability Wind Tunnel: a low speed, commercial wind tunnel where large, aluminium models are tested. The final system developed comprises of two high resolution FLIR A655sc infrared cameras; four 63.5-mm diameter circular windows; aluminium models covered in 0.8-mm silicone rubber insulation and a top layer of ConTact© paper; and a series of 25.4-mm wide rubber silicone fiberglass insulated heaters mounted inside the model and controlled externally by experimenters. This system produces images or videos of the model and the associated transition location, which is later extracted through image processing methods to give a final transition location in percentage chord. The system was validated using two DU96-W-180 airfoils of different chord lengths in the Virginia Tech Stability Wind Tunnel, each tested two months apart. The system proved to be robust and efficient, while not affecting the airfoil performance or any other system in use in the wind tunnel. Transition results produced by the system were compared to measurements obtained from pressure data and stethoscope tests as well as the numerical predictions of XFOIL. The transition results from all four methods showed excellent agreement with each other for the two models, for at least two Reynolds numbers and for several angles of attack on both suction and pressure side of the model. The agreement of data obtained under such different conditions and at different times suggests that the infrared thermography system efficiently and accurately detects transition for large aluminium models at low speeds.
Master of Science
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31

Miller, Richard A. "NDE method for carbon-carbon composite disk brakes using infrared thermography /." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1650510601&sid=2&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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32

Alqennah, Hasan. "Detection of subsurface anomalies in composite bridge decks using infrared thermography." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1467.

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Thesis (M.S.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains x, 85 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 83-85).
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33

Formenti, D. "EXERCISE-ASSOCIATED SKIN TEMPERATURE DYNAMICS BY INFRARED THERMOGRAPHY. METHODS AND APPLICATIONS." Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/257335.

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Heat dissipation during sport exercise is an important physiological mechanism that may influence athletic performance. Therefore, monitoring skin temperature during exercise provides important physiological information about thermoregulatory processes. Skin temperature measurements through infrared thermography have the advantages to be non-invasive and to record temperature data simultaneously from different points on a wide area of the body. The aim of the present investigation were: first, to compare three methods of thermal images analysis in skin temperature evaluation, and second to study the skin temperature dynamics during two types of physical exercise. In the present thesis three studies will be presented and discussed. The analysis of thermographic images, with the goal of obtaining a temperature value representative of a specific area, is usually performed by different methods of averaging temperature values inside a selected Region of Interest (Troi and Tot). A comparison between the methods mainly used in literature in the specific case of a muscular group of calves on a population of 33 healthy subjects is presented. Here, it is presented an alternative method (Tmax) to obtain a temperature value of a specific area based on maximal temperature detection instead of considering the average temperature on the selected area. No meaningful difference in mean temperature between Troi and Ttot was found (p = 0.9), while temperature values calculated using Tmax were higher than the above methods (p < 0.001). The high correlation among the compared methods prove that they can equally represent temperature trends in cutaneous thermographic analyses. The second and the third study presented here are applicative study investigating the skin temperature response during physical exercise. The aim of the second study was to test the hypothesis that differences exist in the dynamics of exercise-associated skin temperature changes between trained and untrained subjects. Thermoregulation of a local muscle area (muscle–tendon unit) involved in a localized steady-load exercise (standing heels raise) using infrared thermography was investigated. Seven trained female subjects and seven untrained female controls were studied. Each subject performed standing heels raise exercise for 2 min. Thermal images were recorded prior to exercise (1 min), during exercise (2 min), and after exercise (7 min). The analysis of thermal images provided the skin temperature time course, which was characterized by a set of descriptive parameters. Two-way ANOVA for repeated measures detected a significant interaction (p = 0.03) between group and time, thus indicating that athletic subjects increased their skin temperature differently with respect to untrained subjects. This was confirmed by comparing the parameters describing the speed of rise of skin temperature. It was found that trained subjects responded to exercise more quickly than untrained controls (p<0.05). In conclusion, physical training improves the ability to rapidly elevate skin temperature in response to a localized exercise in female subjects. The third study presented here is a preliminary report, since the data analysis is still in progress. It aimed to investigate the skin temperature response by using infrared thermography during slow speed low intensity exercise as compared to normal speed low intensity exercise in squat trial. We hypothesized that low intensity resistance exercise with slow movement would result in a skin temperature response slower than the one of the normal speed exercise with the same intensity. 13 active males performed 2 sessions of deep squat exercise until exhaustion, with 50% of 1 RM. The pace of movement was set in 1s eccentric / 1s concentric and 5s eccentric / 5s concentric phase in the 1st and in the 2nd session respectively. Thermal images were recorded every 20s before exercise (2min), during exercise (until exhaustion), and after exercise (10min). Surprisingly, a different behaviour of skin temperature during and after exercise was observed among subjects: a decrease in skin temperature in 9 subjects (down group) and an increase in the other 4 (up group). Thus, statistics will be performed in each group separately. It was shown that the response of cutaneous circulation to dynamic exercise is characterized by a initial vasoconstriction to dissipate heat from the core through the skin followed by vasodilation driving the blood flow from inactive tissue (including the skin) to active muscles involved in exercise. We speculate that the unexpected different behaviour of the skin temperature response in the 2 sub-groups was probably due to a time-dependent predominance of vasoconstriction over vasodilation or viceversa.
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34

Toullier, Thibaud. "Simultaneous characterization of objects temperature and radiative properties through multispectral infrared thermography." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S038/document.

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L'utilisation de caméras infrarouges bas coûts pour la surveillance long-terme d'infrastructures est prometteuse grâce aux dernières avancées technologiques du domaine. Une mesure précise de la température des surfaces observées in-situ se heurte au manque de connaissance des propriétés radiatives de la scène. L'utilisation d'une instrumentation multi-capteurs permet d'affiner le modèle de mesure afin d'obtenir une estimation plus précise de la température. A contrario, il est montré qu'il est toujours possible d'exploiter des données climatiques en ligne pour pallier un manque de capteur. Des méthodes bayésiennes d'estimation conjointe d'émissivité et de température sont ensuite développées et comparées aux méthodes de la littérature. Un simulateur d'échanges radiatifs diffus de scènes 3D a été implémenté afin de tester ces différentes méthodes. Ce logiciel utilise l'accélération matérielle de la machine pour réduire les temps de calcul. Les résultats numériques obtenus mettent en perspective une utilisation avancée de la thermographie infrarouge multi-spectrale pour la surveillance de structures. Cette estimation conjointe permet alors d'obtenir un estimé de la température par thermographie infrarouge avec une incertitude connue
The latest technological improvements in low-cost infrared cameras have brought new opportunities for long-term infrastructures monitoring. The accurate measurement of surfaces' temperatures is facing the lack of knowledge of radiatives properties of the scene. By using multi-sensors instrumentation, the measurement model can be refined to get a better estimate of the temperature. To overcome a lack of sensors instrumentation, it is shown that online and free available climatic data can be used. Then, Bayesian methods to estimate simultaneously the emissivity and temperature have been developed and compared to literature's methods. A radiative exchange simulator of 3D scenes have been developed to compare those different methods on numerical data. This software uses the hardware acceleration as well as a GPGPU approach to reduce the computation time. As a consequence, obtained numerical results emphasized an advanced use of multi-spectral infrared thermography for the monitoring of structures. This simultaneous estimation enables to have an estimate of the temperature by infrared thermography with a known uncertainty
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35

Lonkar, Gajanan M. "Computer aided detection of defects in FRP bridge decks using infrared thermography." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4368.

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Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains xii, 129 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 120-123).
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36

Johnson, Shane Miguel. "Infrared thermography and thermoelastic stress analysis of composite materials and structural systems." Thesis, Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-07072006-161614/.

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37

Chen, Liang. "Infrared Thermography Technique for Measuring Heat Transfer to a Film Cooled Object." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461231944.

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38

Weekes, Benjamin David. "Investigation of infrared thermography NDE techniques for use in power station environments." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/6930.

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Three active thermal methods capable of detecting surface breaking cracks in metals are considered in this Thesis. The three thermal methods exploit different means of excitation, each with practical advantages and varying abilities to detect specific types of crack morphology. Thermosonics uses a broadband, high power ultrasonic input to vibrate the test-piece. Defects damp the vibrational energy into heat which is imaged by a thermal camera. Laser-spot thermography uses a short laser pulse to spot heat the surface of the test-piece, and the subsequent radial heat diffusion is then observed. Defects can cause both increased emission of infrared and localised increases in thermal impedance, both effects causing distortion of the radial heat diffusion. Eddy-current induced thermography uses a high power magnetic field to induce a flow of current inside the test-piece. Defects create a localised increase in electrical impedance, diverting the electric field around the defect. This diversion of current flow causes neighbouring regions of high and low current density, the corresponding Joule heating imaged by a thermal camera. In this Thesis the three methods are explored experimentally. For laser-spot thermography and eddy-current induced thermography the physical phenomena are characterised and experimental best-practice for short pulse excitation determined. The effect of crack opening on each of the three methods is found to give insight into which applications the methods are most suited. It was found that the relationship between crack opening and detectability was complex for thermosonics, relatively linear for laser-spot thermography, and that eddy-current induced thermography is largely insensitive to crack opening. The methods are tested for the feasibility of detecting cracks in Inconel buried beneath metallic and ceramic coatings typical of gas turbine blades, with thermosonics and eddy-current induced thermography found to be viable methods. A study of the detectability of a large number of cracks in steel, titanium and Waspaloy by eddy-current induced thermography is detailed, and from this data the probability of detection is established. Eddy-current thermography is shown to be an extremely sensitive method capable of detecting fatigue cracks of approximately 0.25 mm in steel and 0.50-0.75 mm in titanium and Waspaloy. The practicality of the thermal methods is discussed, and the methods put into the context of the wider field of NDE. Based on the works in this Thesis it was found that for most applications eddy-current induced thermography is the most appealing thermal method since it is highly sensitive, rapid, non-contacting and relatively easy to validate. However, both thermosonics and laser-spot thermography remain useful alternative inspections for more niche applications.
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39

Vasudevan, Archana. "Application of digital infrared thermography for nondestructive evaluation of composite bridge components." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3347.

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Thesis (M.S.)--West Virginia University, 2004.
Title from document title page. Document formatted into pages; contains ix, 217 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 213-217).
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40

Visentini, Roberta. "Étude expérimentale des transferts thermiques en ébullition transitoire." Thesis, Toulouse, INPT, 2012. http://www.theses.fr/2012INPT0106/document.

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L'ébullition est présente dans la vie de tous les jours et elle a été par conséquent le sujet de beaucoup d'études, mais pour la plupart en régimes stationnaires. Néanmoins, l'intérêt de connaître les caractéristiques de l'ébullition transitoire est aussi important notamment pour la prévention des accidents nucléaires majeurs. C'est justement dans l'optique de mieux comprendre les phénomènes d'ébullition qui se produisent lors d'un RIA (Accident d'Insertion de Réactivité) que cette thèse a été financée par l'IRSN. Le RIA est un accident qui peut résulter d'une défaillance du mécanisme de la grappe contrôlant la réaction nucléaire. La réaction s'emballe pendant quelques dizaines de millisecondes (pulse de puissance) provoquant une augmentation rapide de la température du crayon de combustible et donc l'évaporation du liquide qui l'entoure. Des tests ont été faits par le passé soit sur des crayons de combustibles, soit sur des tubes chauffés ayant les mêmes dimensions qu'un crayon, afin d'améliorer la connaissance de ce phénomène. Par contre, les mesures étaient entachées d'incertitudes importantes, dues à des techniques de mesure non appropriées à des phénomènes si rapides. L'objectif de ce travail a été de concevoir et mettre en place une expérience capable de simuler un RIA à petite échelle, pour mieux comprendre les caractéristiques de l'ébullition lorsque la paroi monte en température très rapidement. De plus, ce dispositif expérimental devait être apte à étudier des montées en température moins violentes pour améliorer la connaissance de l'ébullition transitoire en général. Cette expérience a été conçue à l'Institut de Mécanique des Fluides de Toulouse. Elle est constituée d'une feuille métallique d'acier de 50µm d'épaisseur, formée en demi cylindre (8mm de diamètre et 200mm de longueur) et chauffée par effet Joule. Elle est entourée par du fluide réfrigérant HFE7000, qui permet de travailler en similitude par rapport au cas réel en eau. Le fluide est confiné par un deuxième demi cylindre en verre, ayant 34mm de diamètre. Les expériences peuvent être en vase ou avec écoulement, écoulement qui a été caractérisé par des mesures PIV. Plusieurs débits peuvent donc être employés et le sous-refroidissement du liquide est aussi ajustable. L'emploi d'une alimentation pilotable et très flexible permet d'obtenir des chauffages du métal jusqu'à 2500K/s, mais aussi des montées en température plus faibles, pour tracer des courbes d'ébullition stationnaires ou faiblement transitoires. La température de la paroi est mesurée grâce à une caméra infrarouge, couplée à des visualisations rapides et à des mesures de pression et température dans le liquide
Boiling phenomena can be found in the everyday life, thus a lot of studies are devoted to them, especially in steady state conditions. Transient boiling is less known but still interesting as it is involved in the nuclear safety prevention. In this context, the present work was supported by the French Institute of Nuclear Safety (IRSN). In fact, the IRSN wanted to clarify what happens during a Reactivity-initiated Accident (RIA). This accident occurs when the bars that control the nuclear reactions break down and a high power peak is passed from the nuclear fuel bar to the surrounding fluid. The temperature of the nuclear fuel bar wall increases and the fluid vaporises instantaneously. Previous studies on a fuel bar or on a metal tube heated by Joule effect were done in the past in order to understand the rapid boiling phenomena during a RIA. However, the measurements were not really accurate because the measurement techniques were not able to follow rapid phenomena. The main goal of this work was to create an experimental facility able to simulate the RIA boiling conditions but at small scale in order to better understand the boiling characteristics when the heated-wall temperature increases rapidly. Moreover, the experimental set-up was meant to be able to produce less-rapid transients as well, in order to give information on transient boiling in general. The facility was built at the Fluid-Mechanics Institute of Toulouse. The core consists of a metal half-cylinder heated by Joule effect, placed in a half-annulus section. The inner half cylinder is made of a 50 microns thick stainless steel foil. Its diameter is 8mm, and its length 200mm. The outer part is a 34mm internal diameter glass half cylinder. The semi-annular section is filled with a coolant, named HFE7000. The configuration allows to work in similarity conditions. The heated part can be place inside a loop in order to study the flow effect. The fluid temperature influence is taken into account as well. A flexible power supply that can generate a free-shape signal, allows to get to a wall-temperature increase rate up to 2500 K/s but also to obtain lower rates, which permits to study weaker transients and steady state conditions. The thermal measurements are realised by means of an infra-red camera and a high-speed camera is employed in order to see the boiling phenomena at the same time. From the voltage and current measurements the heat flux that is passed to the fluid is known
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41

Pierce, James. "Defect Detection in Additive Manufacturing Utilizing Long Pulse Thermography." Scholar Commons, 2018. http://scholarcommons.usf.edu/etd/7219.

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Additive Manufacturing (AM), over the years, has seen a tremendous amount of research for improving the manufacturability of materials into final products. The main advantages of additive manufacturing are the minimizing of waste material as it is an additive process. As well as the ability to create custom low-volume products without the need for creation of expensive tooling or programming before manufacturing begins. Because of these advantages, however, AM is susceptible to unique challenges in the quality side of manufacturing. These challenges include minimizing and detecting defects during the build. The focus of this research looks at the capability of using Pulse Thermography (PT), a nondestructive testing method, with longer than typical pulse length on additively manufactured parts for surface and sub-surface defect detection as well as thermal property determination based on a known void depth. The first and second part of this research will look at a range of pulse lengths greater than 100ms to determine if the previously defined assumption is necessary for accurate defect detection. The significance of increasing the pulse length is to have the ability to increase the overall energy input into the part without having to increase the power. Allowing for the capability of defect detection for both shallow and deeper defects with the same overall setup. One-dimensional simulations r using Forward Time Center Space (FTCS) approximation, show that the assumption of an instantaneous pulse is relative, and defects can be accurately calculated within a range of pulse lengths. Based on the simulations, experimentation was conducted to determine the capability of calculating sub-surface defect depths with a longer pulse on a FDM printed ABS part with 100% in fill. The defect depths will range from 0.3mm to 1.8mm and the widths of the defects used for depth calculation will be 8x8mm. Results of the experiments show that even with FDM printed parts defect depths were accurately calculated up to a depth of 1.2mm. The third aspect of this research looks at the infrared reflections emitting off the surface during the longer pulse. With a longer pulse length, there is more time for the infrared camera to collect thermograms of the surface during the pulse. It was noticed during sub-surface defect detection that the infrared reflections paint a picture of the surface characteristics of the part. Characteristics that include surface imperfections not intended in the original build parameters such as under extrusions and cracks. Defects as small as 150μm with a thermal pixel resolution 75μm are detected. The third and final aspect of this research looks at the ability to use PT with a longer pulse to determine thermal properties of a binder jetted additively manufactured part as well as packing factors that may be otherwise be unknown. When a product is binder jetted a chemical binder is added to the powder layer by layer until a product is formed.
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42

Berg, Amanda. "Classification of leakage detections acquired by airborne thermography of district heating networks." Thesis, Linköpings universitet, Datorseende, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-96001.

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In Sweden and many other northern countries, it is common for heat to be distributed to homes and industries through district heating networks. Such networks consist of pipes buried underground carrying hot water or steam with temperatures in the range of 90-150 C. Due to bad insulation or cracks, heat or water leakages might appear. A system for large-scale monitoring of district heating networks through remote thermography has been developed and is in use at the company Termisk Systemteknik AB. Infrared images are captured from an aircraft and analysed, finding and indicating the areas for which the ground temperature is higher than normal. During the analysis there are, however, many other warm areas than true water or energy leakages that are marked as detections. Objects or phenomena that can cause false alarms are those who, for some reason, are warmer than their surroundings, for example, chimneys, cars and heat leakages from buildings. During the last couple of years, the system has been used in a number of cities. Therefore, there exists a fair amount of examples of different types of detections. The purpose of the present master’s thesis is to evaluate the reduction of false alarms of the existing analysis that can be achieved with the use of a learning system, i.e. a system which can learn how to recognize different types of detections.  A labelled data set for training and testing was acquired by contact with customers. Furthermore, a number of features describing the intensity difference within the detection, its shape and propagation as well as proximity information were found, implemented and evaluated. Finally, four different classifiers and other methods for classification were evaluated. The method that obtained the best results consists of two steps. In the initial step, all detections which lie on top of a building are removed from the data set of labelled detections. The second step consists of classification using a Random forest classifier. Using this two-step method, the number of false alarms is reduced by 43% while the percentage of water and energy detections correctly classified is 99%.
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43

Berg, Elliott Philip. "High-speed focal plane array camera for mid-infrared impulse photothermal radiometry." Thesis, London South Bank University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367903.

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44

Mericsko, Robert J. "Enhancements to atmospheric-correction techniques for multiple thermal images." Online version of thesis, 1992. http://hdl.handle.net/1850/10933.

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45

Snyder, William C. "An in-scene parameter estimation method for quantitative image analysis /." Online version of thesis, 1994. http://hdl.handle.net/1850/11061.

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46

Hinnerichs, Christopher M. "Efficacy of Fixed Infrared Thermography for Identification of Subjects with Influenza-like Illness." ScholarWorks, 2011. http://scholarworks.waldenu.edu/hodgkinson/17.

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Due to pandemic threats and the occurrence of biological terrorism, technological advancements are being vetted, developed, and implemented as part of surveillance systems and tools. A potential surveillance tool is infrared thermography (IRT), and its efficacy for screening was the focus of this dissertation. IRT-screened participants' temperatures were compared to laboratory diagnostics to confirm the presence or absence of influenza-like illness (ILI). An archival dataset of personnel on United States Navy and Marine vessels that were identified as exceeding an ILI threshold limit provided the data for the 320 study participants. Using a guiding thermo-science framework, derived from past IRT studies, the primary research question concerned whether IRT could statistically differentiate between afebrile participants (without ILI) and febrile participants (with ILI) using receiver operating characteristics (ROC). Results showed that IRT could differentiate between febrile and afebrile participants 91% of the time (ROC = 0.91; χ 2 = 230.71, p = < 0.01), indicating excellent efficacy in this study setting. In addition, the correlation between oral temperatures and IRT surface temperatures was analyzed by gender. A strong correlation between the two variables for males (r = 0.90, n = 226, p < 0.01) and females (r = 0.87, n = 94, p < 0.01) was shown with little variance between the genders (observed z = 1.12, SE= 0.26). These findings have significant positive social change implications as they could provide senior public health decision makers with informed knowledge of IRTs benefits and limitations for rapid screening of febrile individuals in public settings to impede the transmission of ILI.
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47

Leijon, Sundqvist Katarina. "Evaluation of hand skin temperature -Infrared thermography in combination with cold stress tests." Doctoral thesis, Luleå tekniska universitet, Medicinsk vetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-63216.

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Abstract Since ancient times, warm or cold skin on the human body has been used as a parameter in evaluating health. Changes in body temperature are attributed to diseases or disorders. The assessment of body temperature is often performed to measure fever by detecting an elevated core temperature. With techniques such as infrared thermography, it is possible to perform a non-contact temperature measurement on a large surface area. The overall aim of this thesis was to contribute to a better understanding of the hand skin temperature variability in healthy persons and in persons experiencing whitening fingers (WF). The enclosed four papers discuss issues such as thermal variability response to cold stress test (CST) in repeated investigations; the specific rewarming pattern after CST; the difference between the hand’s palmar and dorsal temperatures; and evaluating skin temperatures and response to CST in participants with WF and healthy participants. All four papers used an experimental approach involving healthy males (I-III) and females (III) as well as individuals with (IV) and without WF (I-IV). Data were generated using dynamic infrared imaging before and after a CST. The radiometric images were analyzed using image analysis and statistics. The study showed that: (I) there is variability in hand skin temperature; (II) there are cold and warm hand skin temperature response patterns; (III) the skin temperatures on the palmar and dorsal sides of the hand are closely related; and (IV) a baseline hand skin temperature measurement can distinguish between whitening fingers and controls. The conclusion of this thesis is that it is necessary to engage in thorough planning before an investigation in order to choose the most adequate method for evaluating peripheral skin temperature response depending on the question asked.
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48

Hilsberg, Sabine. "Aspekte zur klinischen Anwendung der Infrarot-Thermographie in der Zoo- und Wildtiermedizin." Doctoral thesis, Universitätsbibliothek Leipzig, 2004. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-37148.

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Aspekte zur klinischen Anwendung der Infrarot-Thermographie in der Zoo- und Wildtiermedizin. Die Infrarot-Thermographie ist eine nichtinvasive Methode. Mit einer Infrarot-Kamera wird eine Messung der Körperoberflächen-Temperatur aus der Distanz durchgeführt und das Thermoprofil des Tieres als Thermogramm dargestellt. Es bedarf keines direkten Tierkontaktes und keiner Immobilisation. Viele Fallbeispiele belegen, dass die Infrarot-Thermographie eine erfolgversprechende neue Methode in der Zoo- und Wildtiermedizin ist. Schwerpunkte der Arbeit waren: - Erforschung artspezifischer Thermoregulation, besonders im Hinblick auf Tierhaltung und krankheitsauslösende Faktprem bei Zoo- und Wildtieren, - Reproduktionsforschung mittels Infrarot-Thermographie und - Entzündungsdiagnostik mittels Infrarot-Thermographie. Die meisten hier vorgestellten Ergebnisse sind Erstuntersuchungen weltweit
Aspects of the clinical application of Infrared-Thermography in Zoo- and Wildlife Medicine Infrared-thermography is a non-invasive method. With an infrared-camera, the body surface temperature of an animal is measured from a distance and the thermoprofile of this animal is then displayed as a therogram. No direct animal contact or immobilization is necessary. Many case reports show that infrared-thermography is a promising new method in zoo and wildlife medicine. In this thesis threee topics are emphasized: - research in species-specific thermoregulation with regard to animal keeping and disease predisposing factors, - research in reproduction using infrared-thermography, and - inflammation diagnosis using infrared-thermography. Most of the presented results are from primary investigations worldwide
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Lei, Lei. "Cold food chain : infrared thermography applied to the evaluation of insulation anomalies in refrigerated vehicles for the transport of food & exploration of cold approach in infrared thermography for non-destructive testing." Doctoral thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/31430.

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Le coût croissant de l’énergie a fait de l’économie d’énergie une nécessité vitale dans le monde actuel. Un des exemples consiste à “maintenir la chaîne du froid”, c’est-à-dire le transport correct des aliments périssables dans les véhicules réfrigérés, en particulier pour les produits laitiers, la viande et les aliments congelés. Tout en conservant une conservation appropriée des denrées alimentaires, l’ATP (Agreement on Transport of Perishable Foodstuffs) est l’un des accords concernant les essais d’isolation thermique qui déterminent l’adéquation du transport. Le test standard ATP est une procédure pour mesurer l’état isolant des équipements avec une approche globale. Néanmoins, certains défauts locaux dans la structure de l’équipement ne peuvent pas être visualisés dans cette procédure. Dans ce contexte, la technique de thermographie pourrait être particulièrement utile à ces problèmes. Deux exemples de cette application sont présentés dans cette thèse, l’un d’eux se concentre sur la cartographie du flux de chaleur sur la surface externe d’un rouleau-conteneur isolé par la technique de thermographie infrarouge. La seconde tente d’établir une vue panoramique du flux de chaleur sur la surface interne d’un véhicule isolé. Encouragé par les résultats favorables précédents, une exploration de l’approche à froid dans la thermographie infrarouge pour les Tests Non-Destructifs et l’Évaluation est introduite et réalisée dans ce qui suit. Une approche se concentre sur la détection des défauts isolés et des ponts thermiques dans les panneaux de caisses de camions isolés par chauffage à lampe et refroidissement par air, deux moyens d’excitation opposés. L’autre examine un refroidissement à l’azote liquide appliqué à un échantillon d’acier avec des trous à fond plat de différentes profondeurs et tailles. Différentes méthodes de traitement des données et de modélisation et de simulation sont effectuées dans des chapitres connexes.
The increasing cost of energy has made energy saving a vital necessity in the current world. One of the examples involves, “Maintaining the cold chain”, which is the correct transport of perishable foodstuffs in refrigerated vehicles, especially for dairy products, meat and frozen foods. In this respect a suitable thermal insulation implemented in refrigerated vehicles is essential for saving energy while maintaining an appropriate conservation of the foodstuffs. ATP (Agreement on Transport of Perishable Foodstuffs) is one of the agreements concerning thermal insulation tests ensuing the suitability of the transport. The ATP standard test is a procedure to measure the insulating status of equipment with a global approach. Nonetheless, some local defects in the structure of equipment cannot be visualized in this procedure. The thermography technique could be particularly helpful for these issues. Two examples of this application are presented in this thesis, one focuses on mapping the heat flux on the external surface of an insulated rollcontainer by infrared thermography technique. The second one attempts to establish a panoramic view of the heat flux on the internal surface of an insulated vehicle. Encouraged by previous favorable results, an exploration of the cold approach in infrared thermography for Non-Destructive Testing & Evaluation is introduced and performed herein. One approach focuses on the detection of insulated flaws and thermal bridges in insulated truck box panels by lamp heating and air cooling, two opposite means of excitation. The other approach investigates the application of liquid nitrogen cooling to a steel specimen with flat-bottom holes of different depths and sizes. Different data processing methods and modeling and simulation are also carried out.
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50

Dutta, Shasanka Shekhar. "Nondestructive evaluation of FRP wrapped concrete cylinders using infrared thermography and ground penetrating radar." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4837.

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Thesis (M.S.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains xi, 117 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 115-117).
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