Le but de cette étude est de proposer un modèle combiné au transfert de chaleur dans la veine et des tissus de la peau humaine. Il permet de mieux comprendre le comportement thermomécanique de la peau et de son environnement direct lorsqu'ils sont exposés à de fortes variations thermiques. Le travail est basé sur des études expérimentales et numériques. La première étape expérimentale consiste à placer une barre d'acier cylindrique refroidie ou réchauffée sur la peau d'un avant-bras humain et en mesurant l'évolution de température en utilisant une caméra infrarouge. L'influence de la circulation sanguine dans les veines sur la diffusion de la chaleur est très nettement.La deuxième étape expérimentale consiste à mesurer les propriétés géométriques des veines et la vitesse du sang en utilisant une sonde d'écho-Doppler. Ces mesures expérimentales fournissent un modèle numérique de la peau et de son environnement direct. Le modèle tridimensionnel multicouche utilise l'équation biothermique de Pennes pour modéliser les tissus et celle de la chaleur dans un fluide pour modéliser le sang. Les propriétés des matériaux sont tirées de la littérature et validées par notre expérimentation. Le modèle numérique permet de retrouver les mesures expérimentales, mais aussi d'accéder à la température et à la vitesse du sang dans les veines. Enfin, un modèle numérique d'endommagement thermique, couplé au modèle multicouche de la peau, a été développé dans cette étude. Il permet de simuler l'endommagement suite à une brûlure de la peau et de tester l'efficacité de différents traitements visant à limiter les lésions. / The aim of this study is to propose a combined model of heat transfer in the vein and tissue of human skin. It allows to better understand the thermomechanical behavior of the skin and its direct environment when exposed to strong thermal variations. The work is based on experimental and numerical investigations. The first experimental step consists in placing a cooled or a heated cylindrical steel bar on the skin of a human forearm and measuring the temperature change using an infrared camera. Blood circulation in the veins was seen to clearly influence heat diffusion. The second experimental step consists in measuring geometrical properties of the veins and blood velocity using an echo-Doppler probe. These experimental measurements provide a numerical model of the skin and its direct vicinity. The three-dimensional multilayer model uses Pennes equation to model biological tissue and the convective heat transport equation, to model blood. The properties of the biological materials obtained from the literature are validated by our experimentation. The numerical model is able to simulate the experimental observations, but also to estimate blood temperature and velocity in the veins. Finally, a numerical model of thermal damage, coupled with the multilayer model of skin, was developed in this study. It simulates the damage due to burning of the skin and to test the efficacy of different treatments to limit the damage.

Submitted by Adriana Martinez (amartinez@unoeste.br) on 2017-09-05T12:53:44Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Luci.pdf: 503217 bytes, checksum: bcb750cc3835332fed12d8730ecb4254 (MD5) / Made available in DSpace on 2017-09-05T12:53:44Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Luci.pdf: 503217 bytes, checksum: bcb750cc3835332fed12d8730ecb4254 (MD5) Previous issue date: 2017-06-22 / This work aims to study the effects of omega 3 and / or vitamin B12 administration on sperm and histomorphometric parameters of the reproductive organs of Wistar rats and their correlation with the temperature of these regions. Sixteen rats were divided into four groups (n = 4 per group) who received daily injections for 30 days, being: Control Group - saline solution; Group Omega three- fish oil (Equaliv®) 1g / kg; Group B12 - vitamin B12 (Monovin B12 ®) 3μg; And Group Omega + B12 - fish oil 1g / kg and vitamin B12 3μg. Analyzed sperm morphology and the histomorphometries were evaluated by the Motic Images Plus® version 2.0 program. On a daily basis, thermographic images of areas of the body (FLIR E40®, Sweden) were analyzed and analyzed by the Flir Tools 2.1® program. Data were submitted to analysis of variance and Tukey test at 5%. Omega 3 reduced the seminiferous epithelium and B12 minimized this deleterious effect (P ≤ 0.05). The surface temperature of the scrotum was higher in group B12 (P ≤0.05). There was a high positive correlation between scrotum surface temperature and distal cytoplasmic droplet percentage (P = 0.678). / Este trabalho tem como objetivo estudar os efeitos da administração do ômega três e/ou vitamina B12 sobre parâmetros espermáticos e histomorfométricos dos órgãos reprodutivos de ratos Wistar e sua correlação com a temperatura dessas regiões. Utilizou-se 16 ratos, divididos em quatro grupos (n=4 por grupo) que receberam injeções diárias por 30 dias, sendo: Grupo Controle – solução salina; Grupo Ômega três– óleo de peixe (Equaliv®) 1g/kg; Grupo B12 – vitamina B12 (Monovin B12®) 3µg; e Grupo Ômega + B12 – óleo de peixe 1g/kg e vitamina B12 3µg. Analisados morfologia espermática e as histomorfometrias foram avaliados pelo programa Motic Images Plus® versão 2.0. Diariamente, foram obtidas imagens termográficas de áreas do corpo (FLIR E40®, Suécia) e analisadas pelo programa Flir Tools 2.1®. Os dados foram submetidos à análise de variância e teste de Tukey a 5%. O ômega 3 reduziu o epitélio seminífero e a B12 minimizou esse efeito deletério (P ≤ 0,05). A temperatura da superfície do escroto foi superior no grupo B12 (P ≤0,05). Houve alta correlação positiva entre temperatura da superfície do escroto e porcentagem de gota citoplasmática distal (P = 0,678).

Submitted by Michele Mologni (mologni@unoeste.br) on 2018-11-22T11:15:18Z No. of bitstreams: 1 Camila Dutra de Souza Francisquini.pdf: 2946141 bytes, checksum: d4a8301da20ac5338becde2b5af3e95b (MD5) / Made available in DSpace on 2018-11-22T11:15:18Z (GMT). No. of bitstreams: 1 Camila Dutra de Souza Francisquini.pdf: 2946141 bytes, checksum: d4a8301da20ac5338becde2b5af3e95b (MD5) Previous issue date: 2018-10-10 / In regions of tropical climate, mating occurs during warmer months, bulls are subject to environmental variations that interfere with their fertility and reproductive efficacy of the herd. The use of some biotechnologies contributes to the efficiency of the production system and to evaluate the fertilization potential of a semen sample, be it fresh, chilled or frozen. A combination of several analyzes and seminal assay methods offers greater accuracy to define a complex functionality. For Chapter 1, the objectives of the study were: (1) to evaluate the effect of the seasons on the surface temperature of the scrotum and ocular globe, the semen quality and plasma concentration of testosterone from Nellore bulls raised extensively, (2) to verify the plasma protein composition (3) investigate the relationships of these proteins with seminal parameters, surface temperatures of the scrotum and THI. Nellore bulls (n = 20) were evaluated with two data collections with a 30-day interval within each season of the year. Infrared thermography (FLIR E40®) with image analysis (FLIR tools software) for spermatic cord (SCT), proximal pole of the testis (PPT), distal pole of the testis (DPT), tail of the epididymis (TeT) and scrotal temperature gradient (TG), and semen collected and analyzed for quantitative and qualitative characteristics. Blood samples were collected by venipuncture of the jugular to obtain the plasma concentration of testosterone by radioimmunoassay (RIA). The seminal plasma proteins were identified by electrophoresis on SDS-PAGE. The temperature-humidity index (THI) calculated per season. The TG was higher (P <0.05) in autumn (5ºC) and winter (4.4ºC) compared to spring (3.4ºC) and summer (3.7ºC). The THI of spring (73.5) and summer (72) differed (P <0.05) from autumn (64.5) and winter (59.6) and there were correlations (P <0.01) with SCT (0.54), TeT (0.74), PPT (0.71), DPT (0.72) and TG (-0.35). Similarly, MOT (61.5%) and VIG (2.7) in spring were lower in relation to autumn and winter (P <0.05). The plasma concentration of testosterone was higher (P <0.05) in the autumn, in relation to the other seasons of the year. Seminal plasma proteins of 20, 55 and 66KDa contributed positively to seminal quality. The concentration of the protein with 50KDa was high in all seasons, being considered indispensable for the fertility of the bulls. In the spring and summer seasons, in which the THI exceeded the value of 72, there was a decrease in progressive motility and spermatic vigor. The summer and fall, the seasons that presented greater percentages of major and total sperm defects. Ocular globe and scrotal surface temperatures increased in spring and summer and the thermal gradient and testosterone plasma concentration decreased in the same seasons, concluding that the thermal stress with THI above 72 in the spring and summer seasons was sufficient for negatively affect the reproduction of Nelore bulls raised in pasture in the tropics. The chapter 2, the objectives of the study were: (1) assess the quality of refrigerated beef semen transported by 3 hours, passive systems of transport of semen BotuBOX® and BotuFLEX®, diluted in TRIS and BotuBOV®; and (2) evaluate the spermatic kinetics, oxidative stress, mitochondrial potential and cell membrane integrity and acrossomal bovine semen after thawing, diluted in TRIS and BotuBOV® and transported in passive systems semen transport BotuBOX® and BotuFLEX®. The six bulls semen of Nellore breed (Bos taurus indicus), cooled and frozen in 2 extenders TRIS and BotuBOV® and transported in 2 cooling systems BotuBOX® and BotuFLEX®. In a semen sample refrigerated was made a subjective analysis of motility (MOT) and sperm vigor (VIG) and in the sample frozen-thawed, computer-assisted sperm analysis (CASA) and flow cytometry, evaluation of integrity of plasma membrane and acrossomal (IPAM), production of superoxide (O2-) and integrity of cells (IC). On after cooled analysis, the MOT of semen in the BotuBOV® and BotuFLEX® (69.4%) and TRIS and BotuFLEX® (62.9%), were higher (P < 0.05) when compared to the TRIS and BotuBOX®. The largest (P < 0.05) MOT (45.9%) observed in subjective analysis, TM (47.3%) and PM (37%) in the CASA, IPAM (29%), IC (19.8%) and lower production of the O2- (82%) found in the samples frozen-thawed diluted in BotuBOV® extender and transported in the BotuFLEX® system. We conclude that the diluted semen in the BotuBOV® and transported on BotuBOX® or BotuFLEX®, and diluted TRIS extender and transported on BotuFLEX® maintained the viability for using the cooled semen, as well as employment for freezing. The association between the BotuBOV® diluent and refrigerated transport of semen BotuFLEX® presented best effect on the frozen semen in regard to kinetics parameters, integrity of plasma and acrossomal membranes and oxidative stress reduction. / Em regiões de clima tropical, o acasalamento ocorre durante os meses mais quentes, os touros estão sujeitos às variações ambientais que interferem com a sua fertilidade e eficácia reprodutiva do rebanho. A utilização de algumas biotecnologias colabora para a eficiência do sistema de produção e avaliar o potencial de fertilização de uma amostra de sêmen, seja ela fresca, refrigerada ou congelada e Uma combinação de várias análises e métodos de avalição seminal oferece maior acurácia para definir uma complexa funcionalidade. Para o capítulo 1, os objetivos do estudo foram (1) avaliar o efeito das estações do ano na temperatura da superfície do escroto e do globo ocular, na qualidade do sêmen e concentração plasmática de testosterona de touros Nelore criados extensivamente, (2) verificar a composição proteica do plasma seminal em cada estação do ano e as proteínas com maior frequência e (3) investigar as relações dessas proteínas com parâmetros seminais, temperaturas da superfície do escroto e ITU. Touros Nelore (n=20) foram avaliados com duas coletas de dados com intervalo de 30 dias dentro de cada estação do ano, sendo realizados: termografia infravermelha (FLIR E40®) com análise de imagens (software FLIR tools) para cordão espermático (TCE), polo proximal do testículo (PPT), polo distal do testículo (PDT, cauda do epidídimo (TCEp) e gradiente de temperatura escrotal (GT). O sêmen foi coletado e analisado quanto às características quantitativas e qualitativas. Amostras de sangue foram coletadas por venopunção da jugular para obter a concentração plasmática de testosterona por radioimunoensaio (RIA). As proteínas do plasma seminal foram identificadas por eletroforese em SDS-PAGE. O índice de temperatura-umidade (ITU) por estação do ano. O GT foi maior (P<0.05) no outono (5ºC) e inverno (4.4ºC) comparado a primavera (3.4ºC) e verão (3.7ºC). O ITU da primavera (73.5) e verão (72) diferiram (P<0,05) do outono (64.5) e inverno (59.6) e houveram correlações (P<0,01) com TCE (0.54), TCEp (0.74), PPT (0.71), PDT (0.72) e GT (-0.35). Assim como, motilidade espermática (61.5%) e vigor (2.7) na primavera foram inferiores, em relação ao outono e inverno (P<0.05). A concentração plasmática de testosterona foi superior (P<0,05) no outono, em relação às demais estações do ano. As bandas proteicas do plasma seminal de 20, 55 e 66KDa contribuíram de forma positiva para a qualidade seminal. A concentração da banda com 50KDa foi elevada em todas as estações, sendo considerada indispensável para a fertilidade dos touros. Nas estações primavera e verão, nas quais o ITU excedeu o valor de 72, observou-se decréscimo na motilidade progressiva e vigor espermático. O verão e outono, as estações que apresentaram maiores porcentagens de defeitos espermáticos maiores e totais. As temperaturas do globo ocular e da superfície do escroto aumentaram na primavera e verão e o gradiente térmico e a concentração plasmática de testosterona diminuiu nas mesmas estações, concluindo que o estresse térmico com ITU acima de 72, nas estações primavera e verão, foi suficiente para afetar negativamente a reprodução de touros Nelore criados a pasto nos trópicos. Para o capítulo 2, Os objetivos do estudo foram: (1) avaliar a qualidade do sêmen bovino refrigerado transportado por 3 horas, nos sistemas passivos de transporte de sêmen BotuBOX® e BotuFLEX®, diluídos nos meios TRIS e BotuBOV®; e (2) avaliar a cinética espermática, estresse oxidativo, potencial mitocondrial e integridade de membrana plasmática e acrossomal do sêmen bovino pós-descongelação, diluídos nos meios TRIS e BotuBOV® e transportados nos sistemas passivos de transporte de sêmen BotuBOX® e BotuFLEX®. O sêmen de seis touros da raça Nelore (Bos taurus indicus), refrigeradas e congeladas em 2 meios diluentes TRIS e BotuBOV® e transportados em 2 sistemas de refrigeração BotuBOX® e BotuFLEX®. Em uma amostra de sêmen refrigerado foi realizada a análise subjetiva de motilidade (MOT) e vigor (VIG) e na amostra pós-descongelação, realizada a análise computadorizada da motilidade espermática (CASA) e por citometria de fluxo, avaliação de integridade de membrana plasmática e acrossomal (MPA), produção de superóxido (O2) e células íntegras (CI). Na análise pós-refrigeração, a MOT do sêmen na associação BotuBOV® e BotuFLEX® (69.4%) e TRIS e BotuFLEX® (62.9%), foram maiores (P<0.05) quando comparado à TRIS e BotuBOX®. A maior (P<0.05) MOT (45.9%) observada na análise subjetiva, MT (47.3%) e MP (37%) no CASA, MPAI (29%), CI (19.8%) e menor produção de O2- (82%) encontrados nas amostras pós-descongelação diluídas em meio BotuBOV® e transportados no sistema BotuFLEX®. Concluímos que o sêmen diluído no meio BotuBOV® e transportado na BotuBOX® ou BotuFLEX®, e diluído em meio TRIS e transportado na BotuFLEX® mantiveram a viabilidade seminal para uso do sêmen refrigerado, bem como o emprego para a congelação. A associação entre o meio diluente BotuBOV® e o sistema de transporte refrigerado de sêmen BotuFLEX® apresentou melhor efeito sobre o sêmen congelado em relação aos parâmetros de cinética espermática, integridade de membrana plasmática e acrossomal e redução do estresse oxidativo.

Plasma Heat Flux to Solid Structures in Tokamaks Petr Vondráček Energy and particle exhaust is the key issue for future fusion reactors based on magnetic plasma confinement, namely for tokamaks. Good understanding of processes controlling plasma heat fluxes impinging the first wall of tokamaks is of a main concern for fusion research. This doctoral thesis is focused on experimental investigation of plasma heat fluxes in different locations of the COMPASS tokamak. A new infrared thermography system was built for this purpose as a part of this PhD research. There are four main topics studied using the system. First of all, a narrow near-SOL heat flux channel with a very steep radial profile is characterised in HFS limited discharges. It is shown that the near-SOL heat flux decay length is consistent with the drift-based model of the SOL heat transport. Secondly, heat loading of leading edges of misaligned limiters is broadly studied. The optical approximation of the heat flux distribution around a poloidal leading edge is confirmed as a valid approach. Heat loading of a magnetically shadowed side of a toroidal limiter gap is observed experimentally for the first time confirming predictions of particle-in-cell code simulations. Thirdly, localised hot-spots caused by the impact of runaway electrons as well as...

Lorsqu'une structure est soumise à un chargement thermique hétérogène, des dilatations empêchées génératrices de contraintes surviennent. Lorsque ces sollicitations sont répétées un grand nombre de fois, un endommagement puis une fissuration du matériau peuvent apparaître. On parle alors de fatigue thermique du matériau. Ce phénomène, jugé responsable de différents incidents rencontrés dans les zones de mélange entre fluides chaud et froid des centrales nucléaires a fait l'objet de nombreuses études lancées au sein de projets successifs pilotés par EDF. Ces études portaient sur la détermination des chargements thermo-hydrauliques dans les zones de mélange, le transfert de chaleur à la structure, la résolution du problème thermomécanique permettant de connaître les champs de contrainte et de déformation en tout point de la structure et enfin la résistance du matériau (un acier inoxydable austénitique AISI 304L)soumis à de telles sollicitations. Concernant ce dernier aspect, plusieurs types d'essais ont été réalisés : d'une part, des essais de fatigue uniaxiaux et isothermes pour construire une courbe de fatigue mécanique du matériau et, d'autre part, des essais sur plusieurs dispositifs expérimentaux de fatigue thermique développés au sein d'organismes de recherche (CEA, EDF, JRC, JAEA,…) pour s'approcher des conditions de service. L'interprétation de ces derniers essais passe par l'estimation des champs de température et de déplacement dans la structure à partir de quelques mesures ponctuelles de température par thermocouples. On constate alors que les premières fissures s'amorcent en fatigue thermique pour un nombre de cycles sensiblement inférieur à celui estimé à partir des courbes de fatigue mécanique du matériau et de l'amplitude maximale de déformation équivalente estimée dans les essais de fatigue thermique. L'objet de ce travail de thèse consiste donc à concevoir et à réaliser des chocs thermiques sur un matériau de structure couplés à des mesures synchrones et sans contact de champs de température et de déplacement au niveau de la surface endommagée. Les chocs thermiques seront réalisés à l'aide d'un laser de puissance dont la longueur d'onde sort du spectre utilisé par la caméra infrarouge qui mesure le champ de température de surface de telle manière que le dépôt d'énergie n'affecte pas les mesures de température. Plusieurs pistes sont envisagées selon que les champs sont mesurés uniquement avec la caméra infrarouge ou en utilisant deux caméras, l'une travaillant dans l'infrarouge et l'autre dans le visible. Dans les deux cas de figure, l'absorptivité et l'émissivité de la surface soumise au choc thermique doivent être optimisées pour permettre d'avoir à la fois un dépôt d'énergie homogène par laser et une mesure précise des champs thermomécaniques. Une difficulté qu'il conviendra de surmonter est d'obtenir un champ d'émissivité de surface représentant un compromis acceptable entre une émissivité forte et homogène dans l'infrarouge pour des mesures de température et une émissivité hétérogène (dans l'infrarouge ou le visible selon la caméra utilisée) pour créer un contraste de niveau de gris indispensable aux mesures de déplacement par corrélation d'images. Parallèlement aux essais,des simulations numériques thermomécaniques seront également réalisées pour compléter ces champs en volume et tester l'influence des conditions aux limites. L'objectif final de la thèse est d'obtenir pour la première fois une mesure fiable des quantités d'intérêt dans une zone d'amorçage en fatigue thermique et ainsi pouvoir quantifier convenablement un éventuel effet aggravant des sollicitations de fatigue thermique. / Thermal fatigue occurs in nuclear power plant pipes. The temperature variations are due to the turbulent mixing of fluids that have different temperatures. Many experimental setups have been designed but the measured temperatures have only been punctual and out of the zone of interest (e.g., via thermocouples). The equivalent strain variation in the crack initiation region is calculated with numerical thermomechanical simulations. In many cases, the comparisons between numerical and experimental results have shown that the crack initiation predictions in thermal fatigue are non-conservative. A new testing setup is proposed where thermal shocks are applied with a pulsed laser beam while the thermal and kinematic fields on the specimen surface are measured with infrared (IR) and visible cameras, respectively. Experimental testings are performed and different measurement techniques for temperature and kinematic fields are used. IR camera and pyrometers allow to measure the temperature variations in the zone impacted by the laser beam. To estimate the absolute temperature, the surface emissivities at the respective wavelengths are determined by different methods. The absolute temperature field is then used to apply the actual thermal loading in a decoupled FE model after an identification process of the parameters of the laser beam. Once the thermal loading is generated based upon the experimental data, the stress and strain fields can be computed in the region of interest with an elastoplastic law.The experimental strain variations calculated from the DIC measurements are compared with the predictions obtained with the FE simulation.

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[pt] A termografia infravermelha tem sido usada como uma técnica de avaliação não destrutiva para detectar falhas nos componentes estruturais, desempenhando um papel importante nos programas de inspeção de fabricação, inspeção em serviço e manutenção. Um programa de investigação foi lançado com o objetivo de apresentar combinações de métodos analíticos, experimentais e numéricos para prever e monitorar o início da fadiga e a progressão dos danos à fadiga em equipamentos como vasos de pressão, tanques, tubulações e dutos com mossas ou anomalias complexas. O monitoramento do início e propagação da fadiga nas amostras reais utilizou técnicas de inspeção por infravermelho não destrutivo. Análise termoelástica de tensão (TSA), correlação tridimensional de imagem digital (3D-DIC) e strain gages de fibra óptica Bragg (FBSG) foram utilizados para determinar deformações em locais de fadiga em pontos críticos. Os campos de deformação determinados a partir das medições experimentais e do método de elementos finitos (MEF) foram combinados com a equação de vida-de-fadiga de Coffin-Manson e a regra de dano por fadiga de Miner para prever a vida de fadiga (N). Os resultados das amostras tubulares testadas de 3 m de comprimento contendo mossas de formato complexo foram relatados e analisados completamente. Este trabalho confirmou que os métodos infravermelhos de avaliação rápida de fadiga são ferramentas práticas e eficientes que podem fornecer resultados confiáveis, não destrutivos e rápidos acerca do comportamento à fadiga dos materiais. Uma boa concordância entre as estimativas de vida em fadiga e a vida real de mossas com geometria complexas em dutos só pode ser atingida se medições precisas ou determinações numéricas das deformações circunferenciais que atuam nos pontos de interesse forem acopladas a curvas de fadiga deformação-vida adequadas. Acoplando uma técnica experimental para determinar com precisão a geometria das mossas com uma técnica de análise numérica de deformações fará com que sejam obtidas boas estimativas de deformação das posições críticas que serão combinadas com as curvas de fadiga baseadas na relação deformação-vida. As presentes conclusões podem ser aplicadas a outras estruturas que podem apresentar mossas, como tanques e vasos de pressão. / [en] Infrared thermography has been used as a nondestructive evaluation (NDE) technique to detect flaws in structural components, playing an important role in manufacturing inspection, in-service inspection and maintenance programs. An investigation program was launched with the objective of presenting combinations of analytical, experimental and numerical methods to predict and monitor fatigue initiation and fatigue damage progression in equipment such as pressure vessels, tanks, piping and pipelines with dents or complex-shaped anomalies. The monitoring of fatigue initiation and propagation in the actual specimens used nondestructive inspection techniques such as thermoelastic stress analysis (TSA), three-dimensional digital image correlation (3D-DIC) and fiber optic Bragg strain gages (FBSG) to determine strains at fatigue hot spots locations. Strain fields determined from the experimental measurements and from the finite element method (FEM) were combined with the fatigue Coffin-Manson strain-life equation and the Miner s fatigue damage rule to predict fatigue life (N). Results from tested 3m long tubular (with nominal dimensions: 324mm external diameter and 6.35mm wall thickness) specimens containing complex-shaped dents were reported and fully analyzed. This work confirmed that infrared rapid fatigue assessment methods are practical and efficient tools that can provide a reliable, non-destructive and faster results about the fatigue behavior of materials. Good agreement among fatigue life estimations and actual fatigue lives of complex dent shapes in pipeline specimens can only be achieved if accurate measurements or numerical eterminations of the circumferential strains actuating at the dent hot-spots were coupled with suitable fatigue strain-life curves. Coupling an experimental technique for accurately determining dent shapes to a numerical strain analysis technique will lead to good hot-spot strain estimations to be combined with the strain-life fatigue curves. The present conclusions can be applied to other structures that may present dents such as tanks and pressure vessels.

The use of infrared thermography for boundary layer detection was evaluated for use in the Cal Poly Low Speed Wind Tunnel (LSWT) and recommendations for the successful use of this technique were developed. In cooperation with Joby Aviation, an infinite wing model was designed, manufactured and tested for use in the LSWT. The wing was designed around a custom airfoil profile specific for this project, where the nearly-flat pressure gradient at a zero pitch angle would delay the chordwise onset of boundary layer transition. Steady-state, RANS numerical simulations predicted the onset of transition to occur at 0.75 x/c for the design Reynolds Number condition of 6.25x105. The wing was manufactured from 3D printed aluminum, with a wall thickness of 0.125 inches and a chord length of 13.78 inches. Two central rows of static pressure taps were used, each with 12 functional chordwise locations. The taps were able to generate strong correlation to the numerically predicted pressure coefficient distribution. The use of an infrared camera visualized and confirmed the presence of boundary layer transition at the chordline location anticipated by the early simulations. To do so, the model was pre-heated such that the differential cooling properties of laminar and turbulent flow would generate a clear temperature gradient on the surface correlating to boundary layer transition. Adjustment of the model’s pitch angle demonstrated a change in the onset location of boundary layer transition during the infrared testing. The change of onset location was seen to move forward along the chordline as the aerodynamic angle of attack was increased. Testing with a Preston Tube system allowed for the interpolation of local skin friction coefficient values at each static tap location. Application of both laminar and turbulent empirical assumptions, when compared to numerical expectations, allowed for the qualitative assessment of boundary layer transition onset. Overall, the wing model developed for this research proved capable of producing quality and repetitive results for the experimental goals it was designed to meet. The model will next be used in continued tests which will further explore the use of infrared thermography.

The railroad industry is pivotal in the United States to ensure that the supply chain does not shut down for the American people. Non-Destruction Evaluation (NDE) approaches are preferred and performed on the railways to ensure the safety of the population that is exposed to the railway industry. When damage occurs on the rail base, there is an increased risk derailment of the train cars. Due to the nature of the railroad industry, there are challenges with developing a quick and reliable inspection method, along with the improvement of current NDE methods. The load, speed, and cycles of trains have increased the load that track sections endure over time. Some railways that were originally built in the early 20th century are still utilized today, designed for trains that are not nearly as heavy or fast as used today. Defects and damage on the railways lead to the need of development of an NDE approach utilizing Line Scan Thermography approaches. One of the most common defects that are formed are on the rail base is known as “base nicks” and “half-moon cracks”, these types of defects can occur over time. This research aims to study the feasibility of applying this NDE technique to detect defects that can occur on a rail base, both internal and external. For this research, a heat source up to 6000 W and tested velocities up to 447.1 mm/s (1.0 mph) are used to study the effects of line scanning thermography on various samples. In total, 10 samples are employed to test for feasibility: each one having a unique set of defects. Some defects fabricated on these samples are internal, such as bottom drilled holes (BDH) and side drilled holes (SDH); some of these samples are fabricated from actual rail samples. From tests conducted for internal defects, it can be concluded that defects with diameters of 6.35 mm (0.25”) can be detected at a remaining thickness from the observation surface of 6.35 mm. Along with internal defects, there are also external defects employed on the samples; these defects include simulated base nicks, fractures, and half-moon cracks. For surface defects tests from this research, it is found that the anomalies can be detected visually. The results from the experimental studies provide insight and limitations of LST for the possibility of a future commercial application.