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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

An in-scene parameter estimation method for quantitative image analysis /

Snyder, William C. January 1994 (has links)
Thesis (Ph. D.)--Rochester Institute of Technology, 1994. / Typescript. Includes bibliographical references (leaves 93-96).
22

OPTIMIZATION OF TRANSIENT THERMOGRAPHY INSPECTION OF CARBON FIBER REINFORED PLASTICS

Bainbridge, Bradley Glenn 01 December 2010 (has links)
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.
23

Aspects of thermography for non-destructive testing in mechanical maintenance

Jama, Bandile, Gryzagoridis, Jasson, Wilson, Graham January 2017 (has links)
Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2017. / Infrared thermography (IRT) is a non-contacting, non-destructive testing (NDT) technique that provides relatively fast results from inspections; for example, in the detection of defects in engineering components and in systems' condition monitoring. This study examines the use and possible effectiveness of infrared thermography for the detection of faults and defects in just a few aspects that one encounters in the vast mechanical maintenance arena. The study discusses three aspects of infrared thermography, namely internal leaks inspections using passive infrared thermography, pulse thermography and induction thermography both active IRT NDT techniques for the detection of subsurface and surface defects. The promising results that were obtained by performing an experiment in the laboratory using a model fluid handling pipe network, with three isolation valves connected in parallel, encouraged performing inspections in an operating power plant, where it was suspected that there were leaks from safety and drain isolation valves. In both situations, the results were obtained in a short period of time and indicated that passive infrared thermography can detect internal leaks in pipe networks. Pulsed thermography is an active non-contacting non-destructive testing technique used to detect subsurface defects in monolithic materials and delamination's in composites. In the particular experiment that was performed pulse thermography was benchmarked with the conventional technique of ultrasound testing. PVC, stainless steel and mild steel specimens manufactured with flat bottom holes (as models of subsurface defects) were subjected to pulse thermography. The time duration to detect the presence of a defect represented by a temperature contrast or a hot spot on the specimen's surface was approximately a couple of seconds following the thermal excitation. No further characterization of the defect was possible with the technique. In contrast when using the ultrasound testing technique to test the specimens, it took considerable time to detect the defects, however, data in terms of size and depth beneath the surface became available thus enabling their full characterization.
24

The Integration of sUAS into a Diverse Agricultural Operation

Newsum, Andrew January 1900 (has links)
Master of Science / Department of Agronomy / Antonio R. Asebedo / Current population trends project that current agricultural production will need to increase by 110% by the year 2050 to support the growing worldwide population. Many agriculturalists are looking at precision agriculture technology to help achieve this production increase. One technology that is being heavily researched is the integration of small unmanned aerial systems (sUAS) and their sensors into the agricultural sector. Much research has already been conducted in the agronomic sector utilizing sUAS. However, relatively few advancements involving sUAS have been made in the animal science industry. This thesis focuses on how sUAS can be incorporated into a diverse cropping and livestock operation. Chapter 1 - Evaluating Current Capabilities of sUAS and sUAS Mounted Sensors in Diverse Agricultural Operation: A Literature Review, focuses on the current capabilities of sUAS and explains how they are incorporated into cropping systems and livestock production. Chapter 2 - Wheat Variety Interaction on Multispectral Based Vegetative Indices, focuses on wheat variety interaction with yield, grain protein content, NDVI, NDRE and CCCI. Ten wheat varieties were tested in large plot studies; yield, protein and multispectral data were collected for Feekes 4, 7, 10 and 10.5. Wheat variety was statically significant across all vegetative indices, protein and yield during less than favorable growing conditions. Chapter 3 - Estimating Cattle Rectal Temperature Using Thermography, focuses on determining the ideal location for thermographic readings to be taken to predict rectal temperature of beef cattle. To establish if sUAS-based thermography could be utilized for cattle rectal temperature estimation, 35 crossbreed steers were selected and thermographic readings and rectal temperature data were collected and analyzed for correlation. This study found stronger relation in the animal’s eye than other facial features.
25

Optimizing the Methodology for Measuring Supraclavicular Skin Temperature for the Detection of Brown Adipose Tissue in Adult Humans using Infrared Thermography

Haq, Tahniyah January 2016 (has links)
Abstract Background: The discovery of brown adipose tissue (BAT) in adults has sparked interest in its role as a therapeutic target in metabolic disorders. Preliminary studies have indicated that infrared thermography may be a promising way to quantify this thermogenic organ, which in humans is located primarily in the supraclavicular area and is activated by cold. However, ways to standardize infrared thermography methodology and to ensure measurements are reproducible have not been established. Objective: This study aims to establish a standardized and reproducible protocol to measure a thermal response to cold in the supraclavicular area. Method: In phase 1 of the study, thermal images of the supraclavicular area were taken on 3 occasions in 28 healthy adult males with mean age 23.95 ±5.87 years and mean BMI 25.20 ±3.93 kg/m2 who demonstrated a 100kcal/d increase in energy expenditure when exposed to 12ºC; a temperature known to increase BAT activity without shivering. During the first and second visits, participants were acclimated for 1 hour at 32ºC and room temperature (20-23ºC) respectively, followed by a 1 hour period of torso cold exposure at 12ºC using a cooling blanket. The third visit consisted of taking thermal images at room temperature over two hours. Body composition was measured with DEXA scanner. In phase 2, 3 trials of 32ºC acclimation followed by 12ºC cold exposure (32ºC-cold) were studied in 14 healthy adult males (mean age 20.93 ±2.4 years and mean BMI 23.55 ±3.15 kg/m2) for repeatability. The outdoor temperature on the morning of each visit was recorded from the website http://climate.weather.gc.ca in both phases. Results: In phase 1 the supraclavicular temperature stabilized after 45 minutes of acclimation at 32ºC and then rose abruptly with cooling, plateauing at 10 minutes. The change in supraclavicular temperature in response to cooling was greater after 32ºC compared to room temperature acclimation (0.22 ±0.19 vs 0.13±0.17ºC, p=0.053). There was no relation between outdoor temperature on the morning of the visit and the 32°C-cold thermal response (r=-0.18, p=0.14). The 32ºC-cold thermal response did not correlate with cervical and supraclavicular fat in 25 young males with BMI between 19.3-32.3 kg/m2 (r=-0.26, p=0.21). In phase 2, the thermal response after 32ºC acclimation was reproducible [intraclass correlation coefficient of 0.69 (0.14-0.72)]. Conclusion: Acclimation at 32ºC produces a greater and earlier response to cold in the supraclavicular area than room temperature acclimation. The thermal response after 32ºC acclimation is reproducible and unlikely to be affected by outdoor temperature and subcutaneous fat in the neck. These data suggest that the use of infrared thermography using the 32ºC-cold protocol may be effective for detecting the metabolic activity of brown adipose tissue. / Thesis / Master of Science (MSc)
26

Induction Infrared Thermography for Non-Destructive Evaluation of Alloy Sensitization

Roberts, Matthew Thomas 26 June 2019 (has links)
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.
27

A Feasibility Study on Using Infrared- transmitting Fiber-optics for Thermal Imaging

Manning, Bryan James 16 March 2017 (has links)
The objective of this thesis was to evaluate the feasibility of three approaches to thermal imaging that used fiber-optics to decouple the imaging optic from a detector in order to form images without a direct line of sight. All images were formed using 2 m-long fibers, at a working distance of 19 cm, and the ability to detect temperatures between 100 °C to 200 °C. The three approaches were designated active, hybrid, and passive. The active approach involved scanning a single fiber in the image plane to formulate thermal images. Although images had sufficient field of view and spatial resolution, they were not formulated at a frequency of at least 1 Hz using either linear stages or a piezoelectric actuator for scanning. The hybrid approach involved scanning a bundle of fibers in the image plane to formulate a thermal image. Although it was possible to form individual images from fibers within a simple bundle and a seven-fiber bundle with sufficient field of view and spatial resolution, an image formulation frequency of at least 1 Hz was not achieved. While considered feasible, future work is required to identify a suitable motion platform, design a new bundle, and develop a method for stitching images from individual fibers into a single spatially-coherent image in order to achieve an image formulation frequency of at least 1 Hz. Lastly, the passive approach was evaluated in which images were formed using a fixed seven-fiber bundle for direct thermal imaging. The seven-fiber bundle produced images with sufficient field of view and an image formulation frequency on the order of kHz, but without sufficient spatial resolution. Additional work is required to determine the feasibility of designing a passive bundle for a specific spatial resolution, as well as, if overall costs are prohibitive. While no approach satisfied all functional requirements specified herein, evaluation of each approach and a potential solution are provided.
28

Ensaio sobre o uso da termografia infravermelha na avaliação da vitalidade pulpar in vivo / The use of infrared thermographic imaging for pulp vitality evaluation in vivo

Elias, Isabelle 08 October 2008 (has links)
Atualmente, sabe-se que determinar a vitalidade pulpar testando apenas a sua resposta sensorial nervosa, através de testes térmicos ou elétricos, é discutível, pois tais procedimentos não são suficientemente sensíveis para determinar, em definitivo, o real grau de envolvimento pulpar. Além disso, a vitalidade da polpa não depende apenas de seu suprimento nervoso, mas de seu suprimento sanguíneo. Outro fator a considerar com relação ao diagnóstico pulpar, deve-se à possibilidade da ocorrência de respostas pouco confiáveis em pacientes excessivamente ansiosos ao tratamento odontológico, independente do estímulo empregado e da intensidade do teste. O diagnóstico da vitalidade pulpar através de meios de mensuração da temperatura da coroa do dente, como a termografia infravermelha, que avalia a distribuição de temperatura num corpo através da radiação emitida pela sua superfície, surge como possibilidade para superar as desvantagens dos testes de sensibilidade, como a necessidade da estimulação, as variáveis decorrentes da espessura de dentinaesmalte dos dentes, a idade dos pacientes, a condição da estrutura dentária, entre outras. Esta pesquisa verificou a aplicabilidade da imagem infravermelha na análise da queda de temperatura produzida pelo teste térmico com gás refrigerante e a viabilidade como recurso semiotécnico para diagnóstico endodôntico. Para tal, foram analisados quatro dentes portadores de polpa vital e dois dentes tratados endodonticamente. A metodologia utilizada avaliou, através da imagem térmica, a temperatura da superfície coronária submetidos à queda de temperatura, com e sem a utilização do isolamento absoluto. Os resultados não mostraram diferença significante entre os dentes estudados, no que diz respeito à temperatura da superfície coronária e que a utilização do isolamento absoluto também não alterou os resultados. A metodologia proposta neste estudo mostrou-se altamente eficaz para a análise de mudanças térmicas na superfície dentária. No entanto, novos estudos devem ser realizados para que a termografia infravermelha possa se tornar um recurso viável para utilização em Endodontia. / Nowadays, it is known that the determination of the pulp vitality testing only its nerve sensorial response through thermal or electrical tests is discussable because those procedures are not sufficiently sensitive to determine the degree of pulp involvement. Besides the vitality of the pulp does not only depend on its nerve condition, but on its blood supply too. Another factor to consider during the pulp diagnostic, independently of the nature of stimulus or their intensity, is the possibility to occur non reliable responses in excessively anxious patients face to the dentistry treatment. The diagnosis of the pulp vitality by the measurement of the dental crown temperature such as the infrared thermography (which evaluates the temperature distribution in a body through the radiation emitted by its surface) arises as a possibility to overcome the sensitivity tests disadvantages, for example: the stimulation necessity, the variants due to the thickness of the dentin and enamel, the age, the condition of the dental structure and etc. This study evaluated the applicability of the infrared thermography test in the analysis of temperatures decline produced by thermal test using cold spray, and its viability as an aid for the endodontic diagnostic. Using thermal imaging, this methodology analyzed the temperature of the crowns surface of four teeth with vitality and two endodontically treated teeth when submitted to the cold test with and without the use of rubber dam. The results did not show a significant difference between teeth conditions with regard to the crowns surface temperature and the use of rubber dam did not affect these results. The proposed methodology used in this study showed to be highly efficient to analyzing the thermal changes on the dental surface; however new studies must be performed to turn infrared thermography a practicable aid into the endodontic practice.
29

Liquid crystal thermography of torso skin temperatures for dry-ice cooling

Deshpande, Prakash Bapurao January 2011 (has links)
Digitized by Kansas Correctional Industries
30

Termografia e ultrassonografia Doppler do plexo pampiniforme e termografia do escroto de touros : correlação com a qualidade do sêmen /

Portugal, Elói dos Santos. January 2014 (has links)
Orientador: Luiz Carlos Marques / Banca: Lindsay Unno Gimenez / Banca: Cezinande Meira / Banca: Gilson Hélio Toniollo / Banca: Lúcia Helena Rodrigues / Resumo: O Brasil possui o maior rebanho bovino comercial do mundo e chegou a 212,8 milhões de cabeças em 2011. Foram comercializadas 12,3 milhões de doses de sêmen bovino em 2012. O efetivo de fêmeas bovinas em idade reprodutiva é 61,4 milhões e a utilização de duas doses de sêmen por vaca estima-se que 10% do rebanho nacional está sendo inseminado. A fertilidade é uma importante característica nos sistemas produtivos e o macho de grande importância. Utilizando a termografia infravermelha (TIV) e ultrassonografia Doppler a termorregulação e o fluxo sanguíneo foram avaliados em touros. Dois grupos de seis touros foram avaliados por um ano e os dados obtidos da termografia - temperatura global do plexo (TGP), temperatura global do escroto (TGE), temperatura do plexo esquerdo (TPE), temperatura do plexo direito (TPD), temperatura do escroto esquerdo (TEE), temperatura do escroto direito (TED) e da ultrassonografia Doppler - velocidade sistólica máxima (VSM), velocidade diastólica final (VDF), índice de pulsatilidade (IP), índice de resistência (IR) e a temperatura ambiental (TA) foram correlacionados com os espermogramas. Foram observadas correlações positivas e negativas entre as variáveis da TIV e US Doppler com as variáveis dos espermogramas e conclui-se que a TIV permite a observação de alterações precoces da temperatura do plexo e escroto; a US Doppler demonstrou correlações entre a VDF, IR e IP com qualidade do sêmen; de acordo com este estudo touros com qualidade de sêmen superior apresentaram menor impedância vascular das artérias testiculares / Abstract: Brazil has the largest commercial cattle herd in the world and reached 212,8 million head in 2011. 12,3 million doses of bovine semen were sold in 2012. Effective from cows of reproductive age is 61,4 million and the use of two doses of semen per cow is estimated that 10 % of the national herd is being inseminated. Fertility is an important feature in production systems and the bull has great importance. Using infrared thermography (IRT) and Doppler ultrasonography thermoregulation and blood flow were evaluated in bulls. Two groups of six bulls were evaluated for a year and the data of thermography - global temperature plexus (GTP), global temperature of the scrotum (GTE), temperature of the left plexus (TLP), temperature of the right plexus (TRP), temperature the left scrotum (TLE), temperature of the right scrotum (TRE) and Doppler ultrasonography - peak systolic velocity (PSV ), end diastolic velocity (EDV), pulsatility index (PI), resistance index (RI) and room temperature (RT) were correlated with semen analyzes. Positive and negative correlations were found between the variables of IRT and US Doppler variables of semen analyzes and concludes that IRT allows observation of early changes of the plexus and scrotal temperature; Doppler US demonstrated correlations between EDV, RI and IP with semen quality; according to this study bulls with superior quality of semen showed lower vascular impedance of the testicular arteries / Doutor

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